Digital computer control systems-an annotated bibliography

Digital Computer Control Systems-An Annotated Bibliography E. M. GRABBE Introduction

Automatic control always involves computing. Even the earliest and simplest analogue controlling devices involved computing functions. With the development of complex highspeed control systems there has been a parallel growth in the computing aspects of control. As controls have grown in complexity there has been a tendency to separate the computing from the process and carry it on as a separate and independent function. Analogue computers have been built which carried out control operations for devices ranging from steel mills to fire control systems; their computing elements are frequently tied together quite closely with the measuring and controlling elements. With the advent of general-purpose analogue computers and digital devices it has been desirable in many systems to separate the computing from the control aspect completely. One of the first papers which shows a computer as a separate part of an industrial control process is by Brown, Campbell and Marcy 1; it is interesting that the paper states: 'Naturally, a computer will be used to control the process .. .'. Figure I,

A number of airborne digital computer developments have continued in the United States and elsewhere. It has been largely these groups with experience in automatic control problems that have generated the enthusiasm and effort which has led to the development of the first computers for industrial process control. The first digital computer for industrial process control was the RW-300 computer, manufactured by Thompson Ramo Wooldridge55 ; it was also the first to be used in completely closed loop control of a large-scale industrial application125 ,127. Since then a large number of process control computers have appeared122 ,130,132,157 ,164,175. The main characteristics of the digital process control computer over its predecessors-the engineering, scientific and business computers-are (a) extremely high reliability, (b) self-checking features, (c) ease of repair and maintenance, (d) multi-channel input and output, which includes analogue-digital conversion capabilities, (e) data-logging ability, and (f) sufficient storage to accommodate a variety of problems. Most of the computers under design today are general-purpose serial magnetic drum machines, although some use cores for storage. Typical process control applications require 30 to 150 inputs and 15 to 50 outputs. Table I lists the various computer units being manufactured for sale as process control computers. The prime benefits of digital computer control, according to the first published reports, come from: (1) increased throughput for a process, (2) improved quality of product, and (3) lower operating costs1 27 ,129,133,l5l. The general-purpose programmed computer can readily handle optimizing techniques for obtaining these benefits. The experiences now being gained will lead to the development of new processes designed especially for computer control, which would not be feasible without computer technology. Literature

j:;EFEI=lENCE

Figure 1. Block diagram typical of explicit control of quality l

taken from this paper, shows the computer in both feedforward and feedback loops and differs little from those of recent papers on computer control. While analogue computers were considered to be the most likely control elements, digital computers were not ruled out. Later papers discuss the application of computers in various industrial processes 6 ,189. The first digital control computers were developed for airborne applications3 ,4,8,13. The performance of the first digital computer system, called Digitac, to be designed and operated for control of a process 8 ,10,12,16 demonstrated that a digital computer could automatically control an aircraft in flight. The system was reliable in operation, could be programmed to reject spurious data and to check itself, and many unexpected benefits accrued from its flexibility. For airborne applications involving complexity, accuracy, and multiple modes of operation the digital computer is superior to analogue equipment.

This bibliography is divided into four parts: Digital computers for process control; Exploratory control employing simple digital computers; Bibliographies on related subjects; and subject classification. The first part is restricted to: (I) systems in which a digital computer is used in either or both feedforward and feedback loops, (2) systems in which the inputs, outputs, or the process or products change with time so that the continuous control operation of the computer is required, and (3) control may be automatic, or operating guides may be calculated for manual control. In the English literature, computer control of a process is often referred to as 'real time', 'on-line' and 'in-line' control. Digital control of machine tools and other types of programmed control, which generally produce products of known but fixed characteristics, are thus not included, nor are systems used as data loggers exclusively, nor else the use of computers to simulate and design processes, unless the intent is to develop models for computer control. The papers in the first part may be subdivided into four groups: general discussion, equipment, theory and applications.

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DIGITAL COMPUTER CONTROL SYSTEMS-AN ANNOTATED BIBLIOGRAPHY Table 1 Characteristics of process control computers Thompson Ramo Wooldridge··

Daystrom systems

General precision equip. cont.'3.

General Electric'··

Computer model

RW-300

Daystrom

Libratrol-500

GE-312

Panellit-609

Genesys

Storage system Capacity (words) Word Length (bits)

drum 7,936 17 + sign

mag. core 1,024-16,384 20 + sign

drum 4,096 30 + sign

drum 2,048-16,384 20 -;- sign

mag. core 4,096 38 T sign T parity bit

mag. disc 10,000-30,000 19 -;- sign

Company

Components: Transistors Diodes Cores Tubes Introduction: Addresses Per word Number Speed clock (kc) addition (ms) multiplication (ms) Max. Input Switching Speed (pts./sec.) Input Signals Olltpllt Signals Weight Obs) Power (kw)

580 4,000

1,800 5,000

250 1,850

153-6 0·78 2·99 3,840 0-10·23 V 0-15 V or 0- 5 ma 600 0·5

2,400 1,000 800

Genesys Corp.

212-280 85-125 157-350

171

13

I + I 1/2 20

1,600 2,000

Panellit Inc.'"

I 1 46

I I 16

50 0·44 9·24 284 0-50 mV

2,000 <2

I, I + 1 I 60

I I 64

136 0·25 15·0

250 0·096 0·29- 2·02

167

200 0-10 V std

300 0-10 mV 0-20 V

1,000 1·5

3,000 4

I I 20

o·no

50-500

2-80

5- 350 0-60 mV

<2

300 0-8 V

200 0·35

Other companies said to have process control computers under design or construction are: Philco, Radio Corp. of Amer., Sylvania, Minneapolis-Honeywell, Westinghouse, Inter. Bus. Machines, Bendix, Elliott (Elliott 802 = Panellit 609), Control Data Corp., Standard Lorentz (Germany), Hokuskin Denki (Japan), Skrzat I (Poland), Ferranti Argus (England). Manufacturers of airborne digital computers are not included in this list. Note: All machines are binary. serial general-purpose computers except the Genesys machine which also has a parallel incremental mode of operation.

References, number of figures and a short abstract are given for each paper. It is certain at this time in history that the weight of the papers published on computing control far exceeds the weight of computer control equipment produced. Many of the general discussion papers cover again and again the same ground as earlier ones-Equipment papers are limited to descriptions of computers. The theory of sampled data systems is a fast-growing field. Only papers on this subject that specifically mention digital computers in the control loop are included in this bibliography. There appears to be a considerable gap between theory and practice. Papers on applications cover planning, systems design and implementation. The people carrying out applications appear to have made little use of theory. In abstracting papers on applications, the greatest space is given to those which are concerned with actual applications or to installations proposed indicating considerable study of the problem. The second part covers literature on control systems employing simple type digital devices which carry out 'l. stepwise search on one or two variables for one optimum parameter. There has been considerable interest in this class of specialpurpose digital computers which may fill the gap between

conventional and general-purpose digital computer control systems. Papers on methods of search are not covered. The Subject Classification is only partial, as papers of a general nature in the first part are not included; a paper is classified by specialized subject only if a major part of it is devoted to that subject. The author recognizes that this bibliography is not complete, especially in references other than from the United States, and would appreciate additions or corrections for a later publication .

Digital Computer Control 1 BROWN, G. S., CAMPBELL, D. P. and MARCY, H. T. Instrument engineering, its growth and its promise. Proc. Ann. Meeting, Engng Calf. Res. Council (1949). In a discussion of factors leading to the rapid expansion of the control field and application to industrial problems which include advanced instrumentation, the authors state: 'Naturally, computers may be needed in the loop to interpret the kinematics of the chemical reaction, and in turn alter the values of temperature, pressure, or flow of the plant operation.' A figure (see Figure 1) shows a computer in both feed forward and feedback control loops used to control a plant. 4 figs.

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E. M. GRABBE 2 BROWN, G . S. and CAMPRELL, D. P. Instrument engineering, its growth and promise in process-control problems. Meclt . Engllg 72 No. 2 (1950) 124

Discussion as

1.

5 figs., 4 refs.

NELSON, E . A digital computer for airborne control systems.

3

/lIst. Radio Ef{firs Trans. Electron . Campllfers PGEC-I, December (1952) 2 Description of general-purpose serial magnetic drum digital computer for airborne control systems. It is miniaturized, contains 250 tubes and 2,000 diodes and its volume is 4 cu. ft. 3 figs., 1 ref. ~ CONN, R. B .

Digital computers for linear real-time control systems. Proc. East. Comp. Cant: 2 (1953) 33 The basic equations for discrete, linear. real-time control systems are given . the operations to be performed are enumerated and described, and several methods for accomplishing each operation are discussed. A weighting-function digital computer is compared with the specialpurpose computer and the digital differential analyser. Table, 3 refs . LINVILL, W. K. and SALZER, J. M. Analysis of control systems involving digital computers. Proc. Inst. Radio Engrs 41 No. 7 (1953) 901 On digital computers used as elements in control systems employing otherwise conventional elements: sampling is shown to be analogous to amplitude modulation by the continuous data of a carrier of unit impulses, de-sampling as analogous to ripple filtering. Linear operations of the digital computer on sampled data are described by transfer functions. An example of computer programme design in the frequency domain is given and the applicability of these methods indicated. 6 figs.

5

6 LONG , M. V. and HOLZMAl',rN. E. G . Approaching the control problem of the automatic chemical or petroleum plant. TraIlS. Amer. Soc. mech. EI{fJrs 73 No. 10, Oct. (1953) 1373 Design of process control systems in the chemical and petroleum industries including field tests and analytical studies, exemplified on a continuous catalytic reaction and a turbine speed control. Benefits to be expected from computer control are discussed. The computer controller in the future chemical and petroleum plant will be an aid to, rather than a substitute for, the human operator. 11 figs., 3 refs.

10

The Digitac, a small. compact general-purpose digital computer used as the computational and control element of an airborne system. demonstrated for the first time the capability of digital computers for actual flight control. The flight test programme since June. 1952, included a number of completely automatic flights navigated by the system. 5 figs., 3 refs. BURNS, T. J., CLOUD, J. D. and SALZER, J . M. Experiments with a digital computer in a simple control system . Proc. Joint

11

West . Comp. Conf, Amer. Inst. elect. Engrs , Inst. Radio and Ass. Compl/t. Mchy. (1954) 60

BOLLES, E. E.

The Digitac Airborne

Ef{~rs

By inserting a sampler and a digital computer with time delay in the forward loop of an experimental control system containing a simple lag. the authors demonstrated that delay and sampling cause deterioration of the system performance as predicted by theory. Within limits the performance can be restored by the proper anticipatory computer programme. Coefficients of the difference equation for anticipation were computed theoretically and adjusted experimentally so as to produce optimum step function response. 14 figs., 7 refs. EXNER, W . L. and SCARBROUGH, A. D . A digital autopilot coupler. Inst. Radio Ef{~rs Conc, Rec. 5 (1954) 174 A system for automatic digital computer control of the heading of an aircraft; it involves the use of a coupler unit which converts the binary steering signal supplied by the computer to a form acceptable to a conventional autopilot. Factors to be considered in the coupler design include the operational features of computer and autopilot and the potential instability due to the finite computer iteration time. A successful coupler and its performance are described. 6 figs., 3 refs.

12

FELKER, J . H. Performance of TRADIC transistor digital computer. Proc. East. Joint Comp . COIlt: (1954) 46 Test performance of a digital computer for airborne control , with 700 point contact transistors in eight types of circuit packages and 11,000 germanium diodes. 4 transistors failed in 5,000 h of testing. 4 figs., 5 refs.

13

GORDON, B. M . Adapting digital techniques for automatic controls. Elect. M{I,' 54 (1954) No. 11, 136,332, No. 12, 120,298 Techniques for using digital techniques as functional units in an analogue fashion. Such operational digital techniques may have many applications in control systems; four are described. 18 figs.

H

7 SPERO, R. E. Effectiveness of two-step smoothing in digital control computers. Proc. Inst. Radio Engrs 41, Oct. (1953) 1465 Analysis of the effect, in smoothing observational data with a digital computer, of using two smoothing steps , the first having a high data handling rate and a short smoothing time, the second the opposite characteristics. 8

BURBECK, D. W., BOLLES, E. E. , FRADY, W. E and GRABBE

E. M. The Digitac Airborne Control System. Proc . West. Comp: COIlt:, Amer. /l15t. elect. Ellgrs (1954) 38

GRABBE, E. M . The use of digital computers in air navigation. Nar{l,'ation 4, June (1954) 67

15

A discussion of new developments in airborne digital computers. Results of flight tests, advantages and potential applications to air navigation. 5 figs., 2 refs.

Digital Computer.

GRARBE, E. M ., BURBECK, D . W. and NElsTER , S. B. Flight testing of an airborne digital computer. Inst. Radio EI(l,'rs Conc. Rec. 5 (1954) 66 A general-purpose digital computer, part of the Digitac System, was flight-tested in a C-47 aircraft. The computer automatically controlled the aircraft through a series of four-way points, and automatic control was smoother and more accurate than manual control from computer steering signals. Details of the flight test are given; these tests demonstrated that airborne digital computers are practical and add versatility and flexibility to an automatic control system. 6 figs., 6 refs.

Inst. Radio Engrs Cont'. Rec. 5 (1954) 72

16

Description of the first airborne digital computer to be employed in an automatic flight control system, a serial general-purpose type with magnetic drum memory and floating address reference for minimum access time programming. Programming and coding of system equations are outlined, including accurate position determination, data smoothing, weapons control and automatic flight control. The operational advantages of using an airborne digital computer to solve these problems are discussed. 6 figs., 2 refs. 9 BRAVl', E. L. Design features of current digital differential analyzers. inst. Radio Engrs Nat . Conc. Rec . Pt 4 (1954) 87 General characteristics of differential analysers, their logical organization, mode of computation and limits of possible complexity. Modifications, extensions and potential applications of machines of this type in solving scientific and engineering problems and for use in control systems are briefly discussed in terms of computer system requirements and economic considerations. 18 figs.

JACOBS, D. H . Design features of the JAINCOMP-C and JAINCOMP-D electronic digital computers. /1151. Radio Engrs Nat. ConL'. Rec. Pt 4 (1954) 98 Description of a digital computer designed for a specific real-time application involving nine variable inputs and three controlled output devices. 12 refs.

17

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1086

DIGITAL COMPUTER CONTROL SYSTEMS-AN ANNOTATED BIBLIOGRAPHY MARGOLIS, M. and WEISS, E. An experimental digital flight control system. Proc. West. Joint Comp. Con{, Amer. Inst. elect. Engrs (1954) 23 Investigating the necessary and desirable characteristics of a digital flight controller to pilot a highly manreuverable aircraft under constantly changing flight conditions. The paper describes the resulting control equations and the special-purpose breadboard model computer used, a fixed-programme magnetic drum type. II figs.

18

SALZER, J. M. System compensation with a digital computer. Inst. Radio Engrs Conv. Rec. 5 (1954) 179 A report on theoretical and experimental studies of compensating a simple closed loop system by appropriate programmes in the digital computer, one of the elements in the system. Analyses of the systems and their compensations were tested experimentally on an analogue computer connected with a general-purpose digital control computer; both narrow-band and wide-band systems were studied. Performance of particular systems was improved by suitable digital computer programmes. 12 figs., 7 refs. 19

SALZER, J. M. Frequency analysis of digital computers operating in real time. Proc. Inst. Radio Engrs 42 No. 2 (1954) 457 Assuming that data inputs to a control system computer are sampled at a constant rate, negligible time delay in computation and that the computer relates a single output quantity to a single input quantity and performs only certain 'linear operations' in real time, analysis reveals the amplitude and phase characteristics that the computer may exhibit with various programmes and the conditions for stability and realization of the programmes. The computer is treated as a filter on lines familiar in network theory and servo design. I3 figs.

20

DUNN, W. H., ELDERT, C. and LEVONIAN, P. V. A digital computer for use in an operational flight trainer. Inst. Radio Engrs Trans. EC-4, June (1955) 55 Programming of the flight equations for use in an operational flight trainer showed that none of the available general-purpose digital computers could perform the required calculation fast enough. A special-purpose digital computer with an instruction code designed to meet the special requirements of real-time flight simulation isdescribed. I3 figs., 6 refs.

21

GRABBE, E. M. Flight control and the digital computer. Control Engng 2 No. 10 (1955) 64 System and flight test results of the first successful airborne digital computer for automatic navigation and flight control. IO figs., 3 refs.

22

GRABBE, E. M. Data-processing systems: how they are used. Control Engng 2 No. 12 (1955) 40 Discussing requirements for digital computer process control. Application of know-how from military to industrial systems is predicted in four to five years. 3 figs., 2 refs. 23

21 KARUSH, W. Stability of a method of smoothing in a digital control computer. Inst. Radio Engrs Trans. EC-4 (1955) 26 In a certain operation a digital computer was used as an element of a control system to smooth consecutive observational data by predicting from past smoothed values and then combining the prediction .vith the next observation. The stability of this useful method is analysed, an explicit formula is derived of the parameter range for which the method is stable and the statistical variance of the smoothed variable is calculated. 2 refs.

SILVERTOOTH, E. W. Optimized plant process control nears reality. Control Engng 2 No. 9 Sept. (1955) 123 Techniques and tools needed for optimizing control using computers. 4 figs. 25

Concepts of delay and distortion in feedback loops, with special reference to some of the special features incurred by digital control and simple examples. Various approximations are presented for the 'starred' transfer function in terms of the original analogue transfer function to facilitate stability computations for digitally controlled loops and to illustrate the dependence of their properties on the analogue and digital parameters. IO figs, I3 refs. 2i YOUNG, A. J. An introduction to process control systems design. 1955. Pittsburgh; Instruments Publ. Co. A computer control plant is discussed (p. 341); elsewhere the author states that the use of computers for process control will require information about plant dynamics more precise than for the design of single loop systems and a completely new range of control equipment.

BROWN, J. J. and LEAVER, E. W. Caveat on computers. Automation 3 No. 2 (1956) 38 The authors hold that the future evolution of automation will be along practical lines and conclude that in the foreseeable future digital computers are never likely to play a very important part in the production of goods, and are not needed. 3 figs., 4 refs. 28

Process Automation Rep. I, 1954-1956, Sept. 1956. Cleveland, Ohio; Case Inst. Technol. Summary in ".

29

DOERSAM, C. H. The 'reasonableness' check in automation. Inst. Radio Engrs Conv. Rec. Pt 4 (1956) 67 A general discussion of reasonableness checks applied to digital computers in control systems, incorporated in the computer routine to limit control information flow to values considered reasonable in the light of all physical limitations of equipment under control. 9 figs.

30

ELLIOTT, W. S. and BRAY, H. S. The use of a small computer in industrial process monitoring and control. Proc. Internal. Autom. Congr., Paris, June (1956) 382 While there is considerable scope for small digital computers in industrial monitoring and control the two main obstacles to their immediate introduction are alleged insufficient reliability and supposed high cost. Four basic types of application are outlined, with a design philosophy based on standardization and 'packaged' construction, which will improve reliability and reduce cost. Examples studied include steel ingot and billet production control, chemical plant data reduction, engine test-bed control and control of an oil refinery. 7 figs., 9 refs.

31

FAULKNER, I. J. Application of digital computers in industrial control. Proc. Instn elect. Engrs 103 (1956) 98, 108 Introductory remarks pointing out that computers for process control require high reliability and should be easy to maintain. Applications to data handling, control and new processes.

32

FELDBAUM, A. A. The application of computers in automatic systems. Automat. Telemech. Moscow I I, Nov. (1956) 1046 (Engl. transl. p. I 177) A survey and classification of the trends prevailing in applying computers in automatic systems, with an examination of tendencies in the development of control systems and their bearing on theory and design principles. 13 figs., 26 refs. 33

GRABBE, E. M. Computers and automation. Proc. Internat. Autom. Congr. Paris, June (1956) 397 A new airborne transistorized digital control computer is described and use of computers for control of machines and processes in industrial and military systems is referred to, but broad applications will require better understanding of processes, new measuring techniques, and in some cases new equipment design. 5 figs., 9 refs.

34

JAMES, E. W., JOHNSON, J., YETTER, E. W. and MARTIN, M. A. How a systems team engineered a plant computer test. Control Engng 3 No. 11 (1956) 83

35

TEICHMANN, T. Closed-loop control systems containing a digital computer. Inst. Radio Engrs Trans. EC-4 Sept. (1955) 106

26

1077

1087

E. M. GRAB BE Equations are developed for the fractionation process which when solved repeatedly yield an appropriate feed tray, an economical reflux rate and the amount of heat input for a column-top product of specified composition . The digital computer programme for carrying out the calculations and indicating the results on a display board is described. 5 figs .

Engineering solutions for computer tests: standard and developed equipment was used for measuring plant variables of a du Pont plant at Niagara Falls and for transmitting them to a general-purpose digital computer at Philadelphia forevaluation of production and yield rates which were then transmitted to Wilmington. 4 figs. KLEIN, M. L., WILLlAMS, F. K. and MORGAN, H. C. Digital process control. Instr. Autom. 29 (1956) 1979 As an example of constructing a digital control system the system design of a simple chemical process control is described, for temperature control at one point and pressure regulation at two points. The solution is a fixed programme machine; stored programme machines for digital control applications are not mentioned. 10 figs.

36

37

FREEMAN, H. Cycle and delay time considerations in a realtime digital computer. Amer. Inst . elect. Engrs Trans . 76 Pt. 1 (1957) 586 Sampling action and computation delay of digital computers in control systems are defined and their relationship to the programme established, showing how they may be selected for programme optimization. 3 figs ., 4 refs.

44

NETfELL, D. F. Digital methods in control systems. Electron.

FREILlCH, A. Computers in process control. Chem. Engng 64, June (1957) 280 A general discussion of the use of computers for data logging, calculation of operating guides, process supervision a~d dynamics control. The author predicts that dynamic control by computers is 10 years away. 4 figs ., 3 refs.

Engng 28, March (1956) 108 This article briefly describes and classifies required in a digital control scheme and various applications. Digital methods are in control where a manufacturing process accuracy or consists of a large number 11 figs., 21 refs.

45

some of the mechanisms discusses their merits for being used to good effect involves a high degree of of repetitive operations.

GRABBE, E. M. (Ed.) Automation in Business and Industry . 1957. New York; Wiley Based on lectures at the University of California covering feedback control theory, instrumentation, analogue and digital computation and data processing, this book provides a background for computer control systems. Over 200 figures, numerous refs.

46

TSYPKIN, J. Z. Automatic control systems containing digital computers. Automat. Telemech., Moscow 17, Aug. (1956) 665 (in Russian) Characteristics and classification of automatic control systems containing digital computers, with analysis of their dynamic properties; an example illustrates improvements due to use of computers. 13 figs., 10 refs. . 38

GRABBE, E. M. Some recent developments in digital control systems, Proc. Con! Instr. and Control in the Process Industries. Feb. (1957) 109 A review of digital computer control systems in military and industrial processes. Four applications are exemplified and two process control computers described briefly. 14 figs., 8 refs. 47

WEDEL, J. J., HUNTINGTON, A. and BAIN, M . B. Automatic data-accumulation system for wind tunnels. Inst. Radio Engrs Trans. EC-5 No. 1, March (1956) 7 In a new high-speed data-accumulation system designed for a supersonic wind tunnel the data are recorded on punched paper tape for direct input into an Electrodata digital computer; extensive presentation of computed data is available to the operators. The system increases testing speed, eliminates intermediate data handling before computation and lowers cost of data reduction. 7 figs., 6 refs.

39

GRABBE, E. M. Computers in the control loop. Fact or Fancy. Proc. ISA 12th Ann. Con!, Cleveland, Ohio (1957) 143 Discussing prospects and advantages of digital computer control for industrial processes the a uthor predicts that lOO such systems will be in use in the U.S.A. by the end of 1961. 7 figs ., 4 refs.

48

BENNETT, C. A. Some experimentation on the tie-in of the human operator to the control loop of an airborne navigational digital computer system. Proc. East. Joint Comp . Con[ (1957) 68 Experiments on operator error correction on tracking in conjunction with a digital computer control system and methods of improving the reduced tracking performance that results from sampling. 6 figs.

40

CLOSE, G. C. Computer control closes the loop. Automation Dec. (1957) 57 A discussion of the capabilities and uses of digital control computers dealing with process optimization, self-checking and economics; the RW-300 is described briefly. 3 figs .

41

ECKMAN, D. P. and LEFKOWITZ, I. Report on optimizing control of a chemical process . Control Engng 4 No. 9 Sept. (1957) 197 In a research project in optimizing control using an analogue computer on batch hydrogenation of cottonseed oil , a saving in batch reaction time of 23 per cent was attained . Though the kinetics of the batch process are known only approximately, it can be controlled to yield a product of specified composition . Processing follows an optimum path, defined by the differential equations of the process kinetics in terms of initial and final composition values, which means minimum processing time for the conditions specified. The benefits of a digital computer control system are discussed briefly. 12 figs ., 1 ref.

42

ENGEL, H . L. Computing control applied to fractionating column . Control Engng 4 No . 9 (1957) 144

43

JAMES, E. W. and BOKSENBOM, A. S. How to establish the control problem for an on-line computer. Control Engng 4 No. 9 (1957) 148 Four ways are devised to attain process models: analysis using the basic laws of nature ; statistical correlation of operating records ; exploring response surfaces from process tests ; and a matrix description of interaction between variables in multi-loop systems. The general control problem is discussed; examples cover analysis of a pipe-line reaction, exploring responses surfaces, multivariable systems and correlation functions . 20 ·figs ., 2 refs.

49

50

LASPE, C. G . Digital computers in refinery process control.

Reftn. Engr 29 No. 10, Sept. (1957) C30 Potential benefits of digital computer control of refinery processes are graphically illustrated and computer application to a hypothetical example of typical refining of asphaltic or naphthalenic base crude oil to produce the highest gasoline yield is described . 8 figs., 19 refs. 51

MAZE, R . O. Converting process data into controller inputs.

Control Engng 4, No. 9, Sept. (1957) 176 In joining a process to the computing controller attention has to be pa id to digital representation and to the more accurate measurement of process variables necessary for a computing control system . Advice is given on how to obtain a signal from a typical transducer and how to convert it into a form acceptable to a computing controller. 8 figs ., 16 refs. 52

OTIS, E. J.

Optimized control through digital equipment.

Proc. East. Joint Comp. Con! (1957) 45

1078

1088

DIGITAL COMPUTER CONTROL SYSTEMS-AN ANNOTATED BIBLIOGRAPHY Application of general-purpose digital computers to process control, with some details of a process control computer. 4 figs.

SLATER, L. E. Chemical process instrumentation in transition, Chem. Engng 64, June (\ 957) 251 Industrial optimization techniques and computer control. 3 figs.

62

53 PELEGRIN, M. and RAYMOND, F. H. Digital computers in automatic control, Proc. Con{ Computers in Control Systems, Amer. Inst. elect. Engrs (\ 958) 5 Analogue techniques in automatic control are inadequate in performing integrations (or differentiations) with variables other than time, and expensive for non-linear operations. Analogue and digital computers are compared as applied to an aircraft pursuit problem, the analogue approach being regarded as the only one economically operational by 1960. Digital computer control of a contouring machine is described; while analogue computers have reached their peak in development, digital are developing rapidly and will more and more come to be used in feedforward (open loop) automatic control systems. 8 figs., 2 refs.

STOUT, T. M. and LAsPE, C. G. Digital computers for process control, Industr. Engng Chem. 49, July (1957) 38A Typical process control equations are given. Computers may be used for calculating optimum operating conditions or minimizing costs; determining composition from analytical instrument measurement; and diagnosing trouble in plant and control system. Economic benefits are indicated. 4 figs., 4 refs.

63

64 STOUT, T. M. Analog or digital computer for process control? Inst. Radio Engrs Trans. PGAC-3, Nov. (1957) 3 Tasks that will probably be assigned to a process control computer; questions prior to computer selection; characteristics of analogue and digital computers in view of process control requirements; computer systems installed or about to be installed. Analogue computers are fast, simple and inexpensive for relatively small jobs while accuracy, versatility and flexibility of digital computers renders them suitable for more complex controls. 3 figs., 8 refs.

PHISTER, M. JR. Use of digital control systems in the process industries, Proc. Eighth Nat. Con{ Standards (1957) Ge~eral discussion of the problems of process control and function and advantages of digital computer control systems.

51

PHISTER, M. JR. and FRADY, W. E. System characteristics of a computer controller for use in the process industries, Proc. East. Joint Comp. Conf (1957) 40 Characteristics and construction of the RW-300 process control computer and its development. 6 figs.

55

PHISTER, M. JR. and GRABBE, E. M. Fitting the computer into a system, Control Engng 4 No. 6 (1957) 129 Design case history of a chemical process including a reactor, a heat exchanger, a catalyst separator and a fractionating tower, with details of how the operational system can be synthesized, optimized, programmed and instrumented. 8 figs.

56

57

RAGAZZINI, J. F.

Digital compuiers in feedback systems,

Inst. Radio En/{rs Conv. Rec. 5 Pt 4 (1957) 33 Various methods of synthesis of digital computer control systems, design procedures and possible results being illustrated by examples. 11 figs., 12 refs. RALSTON, A. Error detection and error correction in realtime digital computers, Proc. West. Joint Comp. Con{ (1957) 179 Programming techniques, some known, some new, for detection and correction of performance errors in real-time digital computers, with several examples. 6 refs.

58

59 ROBINSON, A. S. Synthesis of computer-limited sampleddata simulation and filtering systems, Proc. East. Joint Comp. Con{ (\ 957) 139 Synthesis of systems using a digital computer combined with output 'holds' or filters, either to simulate dynamic transfer characteristics of linear continuous systems or to filter random messages from continuous inputs consisting of a mixture of random message plus random noise. 14 tables, 9 figs. 4 refs.

60

SALZER, J. M. From controller output to process actuation,

Control Engng 4 No. 9 (1957) 183 The techniques of joining a computing controller to a process include transmitting the controller output command to the vicinity of the process, convening it to another form, amplifying it and applying it to an actuator effecting process changes. 11 figs., 10 refs. SEAMONS, M., BAIN, M. and HOOVER, W. Real-time presentation of reduced wind tunnel data, Proc. East. Joint Computer Conf, Dec. (1957) 50 Proposed data handling and computer system for real-time presentation of wind tunnel data are described. The operator uses the computed test results as guide to control the test programme. 2 figs., 2 refs. 61

SUSSKIND, A. K. Notes on Analog-Digital Conversion Techniques, 1957. Cambridge, Mass., New York and London; M.LT.

65

Technology Press, John Wiley, Chapman and Hall Analogue-digital conversion methods are discussed, with a few examples of control systems. TIERNEY, J. W. et al. The digital computer as a process controller, Control Engng 4 No. 9 (1957) 166 For applying a digital computing controller to a continuous chemical process three types of systems were studied by stimulation on a general-purpose computer. In a digital equivalent of the conventional analogue feedback control system the effects of decreasing sampling rates were investigated. In the second system, a second computer provides feed-forward control to re-s:t the conventional. contr?ller while the third incorporates the functIOns of the former m a smgle digital computing controller. The Incremental Computer, a specialpurpose type, was set up in dual simulation with the process dynamics. 9 figs., 6 refs.

66

67

Tou, J.

Digital compensation for control and simulation,

Proc. Inst. Radio Engrs 45, Sept. (1957) 1243 A technique is described for improving the performance of digital

feedback control systems using the computer to programme inputs and outputs, with improved system stability. An example is given. 8 figs., 10 refs. TSYPKIN, J. Z. Correction of control and regulation pulse systems, Automat. Telemech., Moscow 18, Feb. (1957) (in Russian) Continuous and pulse methods of correcting sampled-data systems; techniques for calculating compensating elements; the possibility of using digital computers for compensation is considered. 21 figs., 12 refs.

68

WEIKE, V. L Airborne computers will reduce cockpit work load. Aero. Engng Rev. 16, May (1957) 75, 102 A central digital computer system for transport aircraft which can measure up to the exacting requirements of scheduled aeronauttcal operations is now feasible. 4 figs., 6 refs.

69

70 ZADOFF, S. and RATTNER, J. Use of a digital computer for airborne guidance and navigation. Proc. East. Joint Comp. Cmf (1957) 64 Describes the Cytac navigation system, with a digital computer in the control loop; details of computer and flight control programme are included. 4 figs., 4 refs.

AIKEN, W. S. Programming a digital process control computer for system reliability. Trans. Short Course andCon{ Autom. and Comp. Engr ColI., Univ. of Texas I, June (1958) 4

7l

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E. M. GRABBE Successful inclusion of a digital computer in the real-time control loop of an industrial fluid process plant depends on formulation of adequate mathematical models, development of satisfactory data acquisition techniques and proof of sufficient reliability. The petroleum and chemical industries have used computers as aids in designing new plants and operating existing ones; work on a multiple-tray distillation tower is briefly reviewed. 5 refs.

Reliability of a digital computer control system may be improved by programming (a) tests, (b) reasonableness checks, (c) redundancy features and (d) detection of instrumentation failures, as demonstrated on a hypothetical two-component blending process. 2 figs. 72 AIKEN, W. S. Building reliability into digital process control systems. Control Engng 5, Oct. (1958) 76 Discussion of computer reliability and its effect on overall system reliability, with tabulated methods for keeping computer failures to a minimum: fail-safe circuits, output-range limits and automatic transfer to manual control are necessary. 3 figs.

HELM, H. A. Analysis of digital control systems. Proc. Con[ Computers in Control Systems, Amer. Inst. elect. Engrs, May

83

AMBER, G. H. and AMBER, P. S. Special-purpose computers in the control of continuous processes. Autom. Control May (1958) 43 Need for computers, chiefly analogue, in process control; digital computers are discussed briefly. 9 figs., 1 ref. 73

74 BRAUN, E. L. and POST, G. Systems considerations for computers in proo:ess control. Inst. Radio Engrs Nat. Conv. Rec. 4 (1958) 168 Functional requirements of a computer for process control are outlined and a representative application to a distillation column described, comparing analogue and digital computers. The authors favour a special-purpose system of the incremental type and discuss its capabilities. 6 figs. 75 BRAUN, E. L. Digital computers in continuous control systems. Inst. Radio Engrs Trans. EC-7 No. 2, June (1958) 123 In discussing digital computers in continuous control systems characteristics, advantages and limitations of the general-purpose computer and the digital differential analyser are compared, indicating areas of application. 12 figs.

CHESTNUT, H. Objectives and trends in feedback control systems progress. Electron. Engng 77 Jan. (1958) 58 Report on a panel discussion including digital computer control hardware and trends in applications.

76

(1958) 67 Examining fundamental assumptions in the z transform analysis of digital control systems a more rigorous definition is suggested. Two effects, the increase in effective time constant of a simple lag circuit by the manner in which the sampling switch is implemented and the way in which resonances of greater than half the sampling frequency 'fold down' into the pass band of the computer, can cause violent instability in a sampled-data control system; once the designer is aware of such effects, corrective measures can be applied. 12 figs. 84 HINES, C. K. and WALKER, J. K. Computer-controlled pilot plant. Instrum. Autom. 31 No. 10, Oct. (1958) 1688 An automatic pilot plant is programmed for continuous composition analysis, data logging, scanning, computing and scheduling changes in the operating variables. The plant, small and of modular design, consists of three separate units: utility, reactor and product stabilizer (distillation). The computer has no direct control function but produces operating guides. For process design studies the system can be operated manually, with internal time programming, on the basis of equilibrium conditions, or for optimum composition analysis. A Royal McBee LGP-30 computer is used. 1 fig. 85 HOLLANDER, G. L. Transistorized computers for airborne and mobile systems. Inst. Radio Engrs Trans. ANE-5, 3, Sept. (1958) 159 Description of the Transac airborne computer, with details of operation and programming of a typical problem. 4 tables, 9 figs" 14 refs.

Inst. Radio Engrs Trans. AC-5, July (1958) 59

HOLLANDER G. L. Real-time airborne digital computers. I.S.A. J. 5 No. 12 (1958) 26

Panel discussion on the use of analogue and digital computers for non-linear process control.

The Transac airborne control Computer is described, with tables of operating characteristics. 3 tables, 6 figs., 6 refs.

77

CHESTNUT, H. Obstacles to progress in nonlinear control.

DELOUX, G. KLEINPETER, M. and LAURENT, L. Etude de la regulation de la centre nucleaire EDFI au moyen d'un ca\culateur analogique ou analyseur differentiel. Call. Illt. Electra. Nucl. Paris, Sept. (1958)

78

ECKMAN, D. P. Automatic Process Control. 1958. New York; Wiley: London; Chapman & Hall Optimizing or computing machine control is discussed on p. 264- 267. The two general methods of optimizing by computer control are (a) perturbation with incremental changes and (b) continuous computing. With continuous computing the process equation coefficients can be adjusted periodically with process changes. 2 figs., 2 refs. 79

80 GRABBE, E. M. A review of automation. TrallS. Short Course and Con{ Autom. and Camp. Engr College, Univ. of

Texas 2, June (1958) 2 Review of automation developments, in particular the use of digital control computers. 6 figs ., 4 refs. GRABBE, E. M. Computers in process control. Operat. Res. 1I, IP-309 Michigan Univ., Aug. (1958) 75 A general discussion of digital computers in industrial processes for control and management information. 1 fig., 4 refs. 81

82

GUNNING, W. F.

Computers in process industry control.

Inst. Radio Engrs Trans. EC-7 No. 2, June (1958) 129

86

87 JURY, E. J. Sampled-Data Control Systems. 1958. New York; Wiley A comprehensive review, including digital computers in control systems; evaluation is left to the reader. 88 KALMAN, R. E. and BERTRAM, J. E. General synthesis procedure for computer control of single and multiloop linear systems (An optimal sampled-data system). Proc.

Con! Computers in Control Systems, Amer. Inst. elect. Engrs, May (1958) 130 On the problem of designing optimal systems for the control of a plant governed by a linear differential equation with constant coefficients: when the plant includes time delays (and in some types of follow-up systems), physical realization of optimal control requires real-time analogue or digital computation. Requirements of machine computation for control purposes are derived in a general way; theory presented includes as special cases many commonly used methods for control system synthesis. 9 figs., 13 refs. 89 KAZDA, L. F. Control system optimization using computers as control system elements. Proc. Con! Computers in Control Systems, Amer. Inst. elect. Engrs, May (\ 958) 154 Critical survey of computer control systems for optimizing responses, i.e. reducing the error and its time derivatives to zero in minimum time; most are non-linear or piece-wise linear. Both theoretical and experimental systems are discussed and evaluated as to the optimizing techniques employed. 18 figs., 31 refs.

1080

1090

DIGITAL COMPUTER CONTROL SYSTEMS-AN ANNOTATED BIBLIOGRAPHY 90

Excellent textbook treatment of the subject, including use of digital computers in control systems.

KEIT, H. A. Computers for real-time control. Instrum. Soc.

Amer. Sympos., May (1958) Problems and solutions of real-time computer control discussed include flexibility, reliability and programming for optimum utilization of storage and computation time. 2 figs., 5 refs. 91 LANDY A. JR. Minimum transistor logic modules for airborne control applications. Proc. West. Joint Comp. Cont: May (1958) 141 Logic modules designed for maximum flexibility to allow versatility of a variety of airborne computing systems. 9 figs., 2 refs. 92 LEONDES, C. T. and NOTHMAN, M. Real-time hybrid computers for control systems. Proc. Conf Computers in Control Systems Amer Inst. elect. Engrs May (1958) 88 'Hybrid' systems combining analogue and digital components are illustrated by a proposed air navigation computer to derive latitude and longitude coordinates for up to 200 aircraft in a given coordinate sector. 10 figs., 3 refs. 94

MANILDI, J. F.

Automatic digital process control. World

Petrol. Ann. Refin. Rev. (1958) Engineering preparations for installing an R W-300 control computer at the Port Arthur, Texas, refinery, to be used for catalytic polymerization. 2 figs. MAYO, J. S. Analysis of an on-off control system. Proc. Conf. Computers in Control Systems, Amer. Inst. elect. Engrs May (1958) 98

94

Performance analysis of a second-order ono-off digital computer control system, with the complication of complete error signal quantization. 8 figs. 95 PHISTER, M. JR. Application of digital control systems in the process industries. Comp. Autom. 7, No. 8 (1958) 14 Short discussion of functions and advantages of digital computer process control.

PHISTER, M. JR. Digital computers in process control. Proc. 13th Ann. Instrum. Conf Sept. (1958) Difficulties in planning and installing digital computer control systems: suitable equations, measuring instruments, process dynamics and fail-safe controls. 18 reI's.

96

!J7 PHISTER, M. JR. Application of digital systems to process control. Chem. Engng Progr. 54 No. 9 (1958) 53 Economics, planning, control mathematics and installation of digital chemical process control systems are illustrated on a hypothetical system, including optimizing techniques and possible payoff. 5 figs., 3 refs.

PHISTER, M. JR. How computers will help steelmakers. Steel 143, No. 19 (1958) 126 Possible uses of digital computers for process control in the steel industry include production scheduling, control of coking ovens, blast and open-hearth furnaces, of by-products plant, soaking pit and mill control. 98

99

PHISTER, M. JR.

Controlling a process with a computer.

Indust. Engng Chem. 50 No. 11 (1958) 1624 POST, G. Digital computers in automatic control systems.

Autom. Control, Sept. (1958) 27, Oct. (1958) 48 A general discussion; high performance is based on clever application of memory as a mechanism. 8 figs. RAGAZZlNI, J. R. and FRANKLIN, G. F. Sampled-Data Control Systems. 1958. New York, Toronto, London; McGraw-

101

Hill

SCHUBERT, E. J. Function tables in digital control computers. Trans. Amer. Inst. elect. Engrs (Commun. and Electron.) No. 37, July (1958) 116 Function tables of limited size combined with appropriate interpolation techniques offer advantages in digital control computers of servo systems; pertinent applications are treated in detail, design equations for specifying function tables given and bilog functions, scaling, sine-cosine and arc tan tables and functions of two variables are discussed. 3 tables, 2 figs., 4 refs.

103

SLOANE, G. E. Digital computer control systems for chemical processes. Univ. of Michigan Aero. Engng Dept. Rep. No. 182, Aug. (1958). p. 96. From an outline of the problems of setting up a computer control system-process analysis, mathematical model and control programme-possible applications to raw cane sugar processing and refining are derived, with a hypothetical sugar syrup blending control programme for the RW-300 computer. 10 figs., 18 refs.

104

105 SOLLECITO, W. E. Fitting computers into control systems. Proc. Con! Computers in Control Systems, Amer. Inst. elect. Engrs May (1958) 148

Panel discussion of theory, applications and benefits of computer control. 106

STEVENS, F. Aiding the inertial navigation system. Navi-

gation 6, No. 3 (1958) 166 The function of computers in navigation systems, especially the Nortronics system. 10 figs. 107

STEWARD, M. H. Rate limiting in incremental computers.

Proc. Cont: Computers in Control Systems, Amer. Inst. elect. Engrs May (1958) 87 Analysing the interaction of noise and incremental digital computer if one or more computer inputs are real-time outputs of a physical process, equations for the 1st and 2nd differences are developed. STOUT, T. M. System considerations in computer control of a semicontinuous chemical process. Proc. Con! Computers in Control Systems, Amer. Inst. elect. Engrs May (1958) III Considerations prior to installing digital computer process control include a detailed study of system functions such as process boundaries, objectives and economics, quantitative relationships between process variables, etc., illustrated on the isomerization process for converting normal butane to isobutane. 13 figs., 12 refs. 108

SUMMERS, W. A. Central station control-today and tomorrow. I.S.A. J. 5 No. 7 (1958) 32 For future use of digital computers in automatic power plants large-scale application for starting, stopping and operating a unit and auxiliaries, foreseeing and counteracting interactions of equipment is predicted; magnetic components and transistors should provide reliability. 9 figs., 14 refs.

109

Short report on planning and installing a computer-controlled process. 100

ROBINSON, A. S. The synthesis of computer-limited sampled data control systems. Proc. Con! Computers in Control Systems Amer. Inst. elect. Engrs May (1958) 77 On the synthesis of multi-channel control systems with continuous inputs and outputs, in which a digital computer, moving sequentially from channel to channel, performs the control computations, the sampling rate being limited by the computer speed. The author concludes that linear theory can provide basic insights into the fundamental system problems. 2 tables, 12 figs., 5 refs.

102

T AYLOR, C. F. An approach to non-linear adaptive control. I.S.A. Paper FCS 1-58 presented at Amer. Soc. lIIech. Engrs Con! Instrum. Regulators April (1958)

110

1081

•

1091

E. M. GRABBE Optimum non-linear process control by digital computer with multiple-mode behaviour is illustrated for a second-order instrument servo. III TAYLOR, D. F. Solid-sta te computer automates power station operation, I.S .A . J . 5 No. IO (1958) 32 Specification requirements and functional description of a solid-state, general-purpose digital computer used in the data-handling and computing system for a steam-electric generating station of Louisiana Power and Light Co.; it is a 50 kc single-address general-purpose computer with random access magnetic core storage, no control function is planned. 7 figs.

TRAPP, J. A . Extra building blocks fit check-out computer to many missiles. AL·iat. Age 8 (1958-59) L5 General-purpose digital computers may be used for missile check-out if additional functions (building blocks) are added for adaptation to different missiles, i.e. generation of command signals, programmed measurement of variables and diagnostic routines. Characteristics of a typical digital control computer are given. 3 figs .

112

TRUXAL, J. G. (Ed.) Control Engineers Handbook . 1958 . New York and London; McGraw-Hill While the handbook deals chiefly with components in feedback control systems one chapter is devoted to computers. Engineering applications are in the foreground but real-time computer control is discussed.

113

TSYPKIN, J . Z. Some problems on the theory of discrete automatic systems. Proc. Con! Computers in Control Systems, Amer. Inst . elect. Engrs May (1958) 11 Classification and specific characteristics of discrete automatic systems. For impulse systems and digital automatic systems (under the assumption that in the latter amplitude sampling can be neglected) equations containing extrapolators are derived which describe this state of the system at any chosen instant of time. A method of synthesis for the two types of systems which is set out ensures optimization of minimum regulation time and minimum mean square error. Examples for analysis and synthesis of impulse automatic systems are given. 4 tables, 15 figs. , 46 refs.

114

115

WEBER, N. E.

Computer control or control computers?

13th 1.S.A. Ann. 1nstrum. Conf. Sept. (1958) paper PFT 6-58 U6

GRABBE, E. M., RAMO, S. and WOOLDRIDGE, D. E.

BRANDON, D. B.

Digital control of an alkylation plant.

121 BRANDON, D. B. Developing mathematical models for computer control. I.S.A. J . 6 No. 7 (1959) 70 To interrelate important process variables and provide the means for optimizing plant performance, a non-linear, steady-state mathematical model is developed . Control equations may express (I) the process objective, (2) material (and heat) balance relationships, (3) transformation relationships, (4) operational constraints and limitations, and (5) a suitable optimizing scheme. Theoretical or graphical means may be used for obtaining an approximate model, the latter is illustrated by developing a yield function of four independent variables. 3 tables, I fig., 8 refs.

BRA UN, E. L. A digital computer for industrial process analysis and control. Proc. West. Joint Camp. Con! (1959) 207 The design philosophy of a computer for industrial process control is discussed. Methods of programming incremental changes in process variables to seek optimum operation condition are outlined ; they may be used for experimentation or process control. A functional diagram of the process analyser and control computer proposed is given, said to minimize the number of active storage and switching elements by incremental computation and stored logic. The functions of a magnetic disc storage combined with a small magnetic core transistor sequential network are described . 2 figs. 122

Computer control installations, I.s.A. J. 6 No. 7 (1959) 66 31 computer installations are listed, 23 operating, 8 proposed (10 analogue, 21 digital), indicating type and uses. Abouthalfthesystemshave closed loop control, others calculate operating guides. They are used for engineering tests (3), petroleum and chemical (10), utilities (12), steel (2) and miscella neous (4).

123

Computer-logger eases gas dispatching job. Control Engng 6, No. 6 (1959) 23 A computer logger to be used in the distribution of natural gas by the Public Service Co. of Colorado (Libratrol 5(0) will compute gas demand at 15 metering stations and report to the despatcher for manual control. 2 figs .

124

Computer runs refinery unit for Texaco. Busin. Week, April 4 (1959) 44 Details of a RW-3oo control computer installation at Texaco Port Arthur refinery ; estimates of benefits. 5 figs.

125

(Ed),

Handbook of Automation, Computation and Control Vol. 1. 1958. New York ; Wiley Contains a chapter on sampled-data systems including digital computers in the control loop, and chapters on information theory and data transmission. 117 ATOR, J. T. Concepts of digital process control. Paper 27-59, 14th Ann . Instrum. I.S.A. Conf, Sept. (1959) Possible applications to an alkylation plant, open hearth steel furnaces and a cement plant are sketched. 3 figs. , 4 refs.

AURICOSTE, J. and GAU, G . Commande centralisee de processus industriels it I'aide de calculateurs numeriques . Automatisme No. 5 Mai (1959) 2 (in French) Use and benefits ofa digital computer as control centre, instrumentation, dynamics and reliability are discussed in terms of the R W-3OO computer, exemplified by the process equations for hydrogenation of vegetable oils. 6 figs. , 21 refs. U8

AURICQSTE, J . and PANIS, Y . Utilisation d'une calculatrice numerique universe lie dans une centrale nucIeaire it reacteur it gaz. Tech . mod. 51 No. 1 (1959) 62 (in French) In calculating detection of rupture of tube walls in a nuclear reactor, with 1148 tubes in groups of 4, 12 groups are measured at a time and results calculated in one min so that 24 min are required to examine the pile. The RW-3oo computer capable of handling the problem is described . 4 figs ., 4 refs. U9

120

Prince ton Unit'. Con( Camp . Control Indust. Proc. Feb. (1959)

Computer test dynamics of missile controls. Control Engng 6 No. 10 (1959) 25 An RW-3oo computer test system will automatically programme, calibrate, generate driving signals, and analyse frequency-response test for missile servo systems. 2 figs. 126

Computing control- a commercial reality. Control Engng 9 No. 5 (1959) 40 Being the first closed loop control system using a digital computer for industrial process control, an RW-3oo computer at Texaco's Port Arthur refinery controls 16 variables of a polymerization unit. The plant handles 15 million cu. ft. of propylene, ethylene and propane per day. Computer control is said to raise efficiency from 86 to 93 per cent; prolonged catalyst life saves S75 ,000 per year.

127

128 Data handler monitors plant variables. Automation 6 No. 4 (1959) 60 Details of a Daystrom computer at the 210,000 kW Sterlington Steam Station of Louisiana Power and Light Co. The system performs mathematical functions, logging and trouble annunciation; the pilot installation will provide experience of equipment eventually to be used to operate the entire power plant automatically. 1 fig.

Daystrom computer to control powerplant. Autom. Control 10 No. 4, April (1959) 12DC

129

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1092

DIGITAL COMPUTER CONTROL SYSTEMS-AN ANNOTATED BIBLIOGRAPHY A Daystrom computer to control the Little Gypsy Station of Louisiana Power and Light Co. will initially compute operating guides, with closed loop control to follow. Estimated saving per year will be $148,000. 1 fig. 130

Digital computers-key to tomorrow's push button refinery.

Oil Gas J. 57 No. 41 (1959) 140 Tabulated characteristics of 8 digital process control computers: RW-300, GE 312, Libratrol-500, Daystrom, Panellit 609, Genesys, Recomp 2 and G-15. 1 fig., 8 refs. FRElLICH, A. Process computer control concepts. I.S.A. J. 6 No. 7 (1959) 47 The state of the computer control art described includes off-line and on-line operating guides, automatic optimization by mathematical mode!s or by. direct experimentation, closed loop digital control and expenmentatlOn by computer control. Experiences of various companies with different types illustrate current trends.

131

Available computers and what they do. . !'unctions an? .operation of general-purpose digital, analogue and Incremental digital computers, with tabular comparison of the digital c
132

FRElLICH, A.

I.S.A. J. 6 No. 7 (1959) 55

13~ ~eneral Precision Equipment Controls, Inc., Applying the

digital computer to open-hearth operations. Control Engnlf 6 No. 8 (1959) 94 ( This article, based on a detailed engineering proposal on how to apply a digital computer (Libratrol-500) and electronic automatic co~tr~1 instru:ments to open-hearth furnace operations, the main objectives beIng to Increase efficiency and yield, envisages two separate but related computer functions: (I) to scan, compute and log furnace data, and (2) to provide scheduling guides to operators. The study shows that shorter heat time, increased furnace life, improved product quality and consistency and reduced accounting and fuel costs would result. Computer programmes are diagrammed. 7 figs., 1 ref. 134 GRABBE, E. M. Digital computers for automatic control in medical. applications. Proc. Sec. Ann. Concept. Symposium, Atomedlc Research Center, Inc., Air University, Maxwell A. F. B., Alabama, March (1959) Poten.tial use~ of digital computers in the medical field, especially in expenmentatlon, operatIng room aids and space travel. 3 figs., 4 refs.

KALMAN, R. E. Principles and potentialities of digital control. Princeton Univ. Conf Computer Control Indust. Proc. Feb. (1959) 135

KALMAN, R. E. and KOEPCKE, R. W. The role of digital computers in dynamic optimization of chemical reactions. Proc. West. Joint Comp. Con! March (1959) A ne-:v general approach to the static and dynamic optimization of chemlc~1 proce~ses th:ough efficient utilization of high-speed digital computIng deVices, with a numencal example. 5 figs., 16 refs. 136

137 KALMAN, R ..E., LAPIDUS, L. and SHAPIRO, E. Optimal control of chemical and petroleum processes. Joint Symposium

Instrum. Comput. in Process Development and Plant Design, London, May (1959); also IBM Res. Rep. RE-76, Jan (1959)(to he published in Chem. Engng Progr.). Basic optimization concepts of chemical reactions by digital computer ~ontrol; a control technique for continual real-time optimization of a Simulated chemical reactor is described. 5 figs., 24 refs.

138 KARCHER, B. and JACOBSON, H. Natural gas dispatching computer system. p'aper 139-59, 14th I.S.A. Ann. Instrum. Conf Sept. (1959) A gas dispatching computer system consisting of a Libratrol-500 general-pu.rpose digi~al comput.er with appropriate input equipment is descnbed In detail; It IS to be Installed at the Public Service of Colorado, 55 telemetered signals being read by the computer and hourly tabulated for the gas dispatcher, as well as available on demand. Equations used in the. computation are developed. 1 fig., 1 ref. 139

KOGEN, J. H.

Flow measurement for computer control.

Paper 3-59, 14th Ann. I.S.A. Instrum. Conf., Sept. (1959) Computers. in automatic control systems present a problem of compatlblhty to flow measurement, as Li. with computers solving the mass flow equatIOn for gas, blending several constituents to achieve some desired mixture, and in feed forward control systems. For analogue. computation, present flow measuring accuracy is satisfactory, but In digital computers where extreme accuracy can be utilized it Will have to be Improved. Also discussed are effect of flow pulsation on accuracy, dynamic response, range of measurement and linear flow measurements. 8 figs., 8 refs. 140 LANDES, R. Optimizing refinery operations with a digital computer. I.S.A. J. 6 No. I (1959) 66 The major part of the article is concerned with linear programming, not of real-time control but of operating adjustments to changing economic conditions. 3 figs., 2 refs.

LAPIDUS, L. Problems associated with the computer representation of a real process. Paper 86-59, 14th Ann. I.S.A. lnstrum. Con! Sept. (1959)

141

LARSEN, R. C. Application of a control computer in the closed loop temperature control of an annealing furnace. Paper 141-59, 14th Ann. I.S.A. lnstrum Conf. Sept. (1959) Analyt.ical studies on applying closed loop computer control to an ann~~hng furnace; . the furnace transfer functions are developed and stablhty and samplIng rate considered. 5 figs., 3 refs. 142

LAWS, C. A., SUTHERBY, P. F. and HOBBs, D. W. Developments in automatic data handling. Paper 78-59, 14th Ann. I.S.A. Instrum. Conf., Sept. (1959) Levels of automatic data handling are classified as exemplified on a docksid~ crane installation, an oil gasification plane and a steel billet cut-up hne. In the latter, an Elliot 609 computer is used to obtain minimum wasta~e in cutting hot steel billets; it does not at present ~ontrol the cutt~ng but provides digital display for bringing billets Into proper pOSitIOn under manual control. Computer control is planned after experience. 6 figs.

143

144LEFKOWITZ,. 10 '" ptlmlzmg

controI0f a c hemical process.

Princeton Unil;ersity ConI Comp. Control Indust. Proc. Feb. (1959) LEFKOWITZ, I. and ECKMAN, D. P. A review of optimizing computer control. Adaptive Flight Control Systems Symposium, Wright Air Development Center, Ohio Jan. (1959) In optimizing process control, performance criteria must be defined; 0l?ti~ization c~n be ?chieved by (I) comparing output performance with Input mampulatlOn, (2) a model allowing analytical definition of optimal control conditions. 7 figs., 8 refs.

145

LEFKOWITZ, I. and ECKMAN, D. P. Optimizing control by model methods. I.S.A. J. 6 No. 7 (1959) 74 Optimum control performance by direct experimenting with the process or by an analytical model using a digital computer, exemplified on control equations for a batch process. 5 figs., 8 refs.

146

MANILDI, J. F. Modern developments in control. Automation 6 No. 7 (1959) 70

147

1083

1093

E. M. GRABBE A process computer controller is to be manufactured by Hokushin Denki, Japan, a transistorized magnetic drum machine for calculating operating process guides. 4 figs.

During 1959, a substantial number of completely automatic control systems for large-scale process units employing a general-purpose computer will become operative. Economic systems, engineering and computer problems are discussed. 6 figs.

158

MERZ, D. M. GEVIC-A real-time variable increment digital computer. Autom. Control 10 No. 9 Sept. (1959) 18DC The variable increment computer combines features of generalpurpose and incremental computers for real-time process control; operation, mechanization and uses are discussed. 8 figs. 148

REINE, J., JR. Solid state computer control-Case history.

I.S.A. S)'mp. Solid State Techniques in Mod. Instrum. Nov. (1959) Performance of a solid-state data-handling system, especially component performance, reliability, maintenance training and trouble shooting. ROBERTS, S. M. and LASPE, C. G. Development of on-line computer control equations for a thermal cracking reaction. Process Dynamics and Control Symposium If, Amer. Inst. Chem. Engrs 41st Ann. Meeting Sept. (1959) A thermal cracking reaction in a tubular reactor was simulated on a digital computer to develop control equations for an on-line computer control system. Two relations, one empirical, one theoretical, gave conversion as a function of quantities that can be readily determined in plant operation. 6 figs., 8 refs.

159

MrCHELS, L. S. On-line computation with general purpose computers. Autom. Control 10 No.4 April (1959) 2DC Desired characteristics of low-cost digital computers for on-line use in data and process control. 7 figs.

149

MILAN-KAMSKI, W. J. A high-accuracy. real-time digital computer for use in continuous control systems. Proc. West. Joint Comp. Conf (1959) 197 Relative merits of incremental computers, digital differential analyzers and arithmetic computers for control are discussed. A control computer is described which combines arithmetic techniques with elements of variable incremental computers, so attaining very high accuracy, broad frequency response and freedom from long memory; short computer memory can render errors self-correcting. 6 figs. 150

151 NALLE, P. B. and SAVER, J. M. Applications of a digital computer to cement manufacture. Paper 41-59, 14th Ann. 1.S.A. Instrum. Conf Sept. (1959) An RW-300 computer is used by the Riverside Cement Company for blending raw materials; most of the seven oxides are controlled and bedded in piles to make a uniform product and to improve quarry efficiency. The computer prints out tonnage, per cent and chemical compound analysis. Computer control of kiln operation is estimated to increase capacity by 6-8 per cent.

NESENOFF, N. Airborne digital computer for missile guidance. 3rd Nat. Conv. Inst. Radio Engrs Prof Group Mil. Electronics, Washington June (1959)

152

PHISTER, M. JR. How to plant computer control. I.S.A. J. 6 No. I (1959) 51 To evaluate, develop and instal closed loop .computer control systems in industrial processes extensions of present-day process theory, process data and instrumentation are required. 3 figs., 17 refs.

153

PHISTER, M., JR. Digital systems-present and future. Proc. Conf Indust. Instrum. Armour Research Foundation, Chicago, April (1959) Three philosophies of digital computer process control discussed are predictive, evolutionary and peak-searching control; effects on plant design and operation are outlined.

154

155

PINK, J. F. Three ways to use computers in process control.

I.S.A. J. 6 No. 4 (1959) 56 Analogue computer use for performance guides, feedforward predicting control and feedback closed loop control is discussed. Cost of a 20-variable analogue computer is estimated at about S37,OOO. For over 50 variables, digital computers are cheaper. Feedforward optimizing control is illustrated by a distillation column, feedback optimizing control by a catalytic reactor. 7 figs., 5 refs. POST, G. Practical philosophical considerations in data handling systems. Paper 136-59, 14th Ann. Instrull/. Conf Sept. (1959) Data handling is regarded as the broadest forms of communication, manipulation, digestion, computation and information control. 2 figs.

156

157

Process computer controller pioneered

Monthly (1 p.), February (1959)

III

Japan. Japan Trade

Ross, D. C. A digital system for position determination. Inst. Radio Engrs Trans. Space Electron. Telemetry 5 No. I

160

March (1959) 42 An aircraft position reporting system, part of an air traffic control system projected, includes a coordinate conversion computer. Table, 4 figs. SAGE, M. W. A digital computer for multiple shaft speed regulation. Sympos. Instrum. Comput. in Process Development and Plant Design, London May (1959) A special-purpose digital computer has been designed for accurate control of the rotation of shafts; reasons for adopting this speed control method are set out, with possible alternatives. 15 figs., 7 refs. 161

SCHILLER, H. H. Systems organization of a special purpose airborne digital computer. 3rd Nat. Conv. Inst. Radio Engrs Prof Group Mil. Electronics, Washington June (1959) 162

SCHNEIDER, F. C. Computers as a means toward improving open hearth efficiency. 1.S.A. Proc. 9, March (1959) 35 Improving open hearth efficiency requires continuous analysis of furnace variables and its presentation to the supervisor. A 'computerized' Libratrol 500 data processing system is described. 7 figs., 9 refs.

163

SPIELBERG, A. M. The General Electric 312 Digital Control Computer. Proc. All/er. Inst. elect. Engrs Conf Analog and Digitallnstrum. April (1959) The GE 312 computer, described in detail of design, is a generalpurpose serial magnetic drum machine. Applications to an iron ore sintering plant and a continuous annealing process are discussed. 8 figs.

164

STEIN, 1. M. The outlook for computer control in the process industries. Comput. Autom. 8 No. 5 (1959) 9 General discussion of analogue and digital control.

165

166

STOUT, T. M. Computer control of butane isomerization.

I.s.A. J. 6 No. 9 (1959) 98 A vapour-phase process for converting normal butane to isobutane is used for illustrating two techniques of process optimization by computer control: systematic search applied to a mathematical model of the process, and explicit rules developed from the model by ordinary calculus. Optimizing schemes are presented for computer information from process instruments, the output actuating conventional controllers. Production rates given for equal and optimum feed rates to parallel reactors containing catalysts of different activities, though referring to a simplified system and using artificial data, indicate benefits estimated in studies of real processes. 7 tables, 14 figs., 4 refs.

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DIGITAL COMPUTER CONTROL SYSTEMS-AN ANNOTATED BIBLIOGRAPHY STOUT, T. M. Computer control in the pulp and paper industry. Tech. Assoc. Paper and Pulp Indust. Pittsburgh Oct. (1959) How difficulties in instrumentation and mathematical relationships have been met in other industries. Possible application of digital computer control systems in the paper and pulp industries is discussed in some detail. 6 figs., 9 refs.

167

STOUT, T. M. Application of computer control in pulp and paper manufacture. Amer. Inst. elect. Engrs, Summer Gen. Meeting June (1959) Criteria to be satisfied by prospective computer control installations; ways in which control computers can be used; possible applications in pulp and paper manufacture. 6 figs., 14 refs.

168

31 chapters are on design and use of digital and analogue computers; that on transistor circuits describes two airborne digital computers, and one on input-output equipment, analogue-digital conversion equipment.

Exploratory control employing simple digital computers BURT, D. A. and VAN NICE, R. 1. Optimizing control systems for the process industries. Westinghouse Engr 19 No. 2, March (1959) 39 (Sull1mary: Automat. Progr. Aug. (1959) 268). 4 figs. A description of the Opcon control system. 10 figs.

178

179

BYRON, W.

The Quarie optimal controllers. Instrum.

Autom. 29, Nov. (1956) 2212

T ANAKA, R. I. The ACRE computer-A digital computer for a missile checkout system. Proc. West. Joint Compllt. Conf. (1959) 217 The paper describes in considerable detail a general-purpose magnetic drum digital computer used as central controller in an automatic checkout system. 3 figs.

An optimizing controller with one input and one output is described that (1) makes an incremental change in the input, (2) waits until system is stabilized, (3) compares result of change with instructions, and (4) bases further action on the comparison. 9 figs.

THOMAS, R. J., GUSTAFSON, J. O. and FOSTER, G. E. A solid state digital computing system for electrical load monitoring. 3rd Nat. Conf Analog. and Digital Instrument. Amer. Inst. elect. Engrs Apr. (1959)

Logic circuits for maximizing temperature by air flow control to a gas burner. 6 figs.

169

170

Tou, J. T. Digital and sampled-data control systems. 1959. New York; McGraw-Hill A reference book for the practising engineer offering principles and techniques for analysis and design of digital and sampled-data control systems.

171

COSGRIFF, R. L. Servos that use logic can optimize. Control Engng 2, Sept. (1955) 133

180

DRAPER, C. S. and LI, J. T. Principles of optimalizing control systems and an application to internal combustion engine. Amer. Soc. mech. Engrs Publ., 1951. Original use of the optimizing principle in a control device for an internal combustion engine designed for searching automatically the optimum state of operation and keeping operation close to it.

181

182

USHAKOV, V. B. Soviet trends in computers for control of manufacturing processes. lnstrum. Autom. 31 No. 11 (1958) 1810, No. 12 (1958) 1960, 32 No. 1 (1959) 102 General and special-purpose analogue computers for machining and trainers are described. Digital or analogue computers, or combined analogue-digital circuits, considered for a wide range of industrial controls, have not yet found wide application. A number of programmed control devices are characterized. 4 figs.

172

WILLIAMS, T. J. Systems engineering. Oil Gas J. 57 No. 33, Aug. (1959) 93 The author predicts that during the next 10 years most problems of systems engineering and computer application will be solved. Industrial uses of instrumentation and automatic control will depend on economic justification. 3 figs., 8 refs. 173

m ZIMMERMAN, C. T. Productivity improvement through automatic control techniques. Joint Conf. Autom. Techniques, Chicago May (1959) How digital computer controllers will fit into both feedforward and feedback loops of future steel mill control systems. 8 figs. 175

BENGHIAT, R. Core-transistor computer control-Reliability.

I.S.A. Sympos. Solid State Techniques in Mod. Instrum. Nov. (1959) Description of a solid-state computer system for process control; details of building blocks, logic and reliability of the Panellit 609. On-line computer scores high in big test: control of refinery unit. Chem. Engng 66 No. 21, Oct. 19 (1959) 102 After 6 months' operation Texaco's RW-300 computer for control of a polymerization plant is said to be highly reliable; no data are given. Texaco is evaluating the benefits of computer control. 3 figs. 176

177

GRABBE, E. M., RAMO, S. and WOOLDRIDGE, D. E. (Ed.)

Handbook of Automation, COlllputation and Control Vol. 2, 1959. New York;

Wiley

FARBER, B.

Computer circuit finds peak automatically.

Control Engng I, Oct. (1954) 70 Peak-holding analogue computer circuit used in a system which automatically searches in B and adjusts for the peak value of A; A and B may be input-output relationship or similar system variables. 4 figs. 183

HOOKE, R. Control by automatic experimentation. Chem.

Engng 64 No. 6, June (1957) 284 A computer controller for experimenting with various process variables to optimize operations; it has one input and two outputs and appears to be an early version of Opcon. 2 figs. HOOKE, R. and VAN NICE, R. I. Optimizing control by automatic experimentation. I.S.A. J. 6 No. 7 (1959) 78 Description of the Westinghouse Opcon control system with one input and two outputs; an analogue computer may be used to compute the quantity to be optimized. 3 figs. 184

185

LI, Y. T. Optimalizing system for process control. Instrum.

Autom. 25, Jan. (1952) 324 Forcing function or test variation imposed on a process controller results in automatic adjustment of the controller through output variations, exemplified on an internal-combustion engine control system with optimum output by control of one or two variables. MOROSANOV, I. S. Methods of extremum control. Automat. Telemech., Moscow 18, Nov. (1957) 1029 (Engl. Transl. 1077)

186

Extremum control systems are classified according to methods of seeking the extremum, calculations on self-oscillation modes being demonstrated on relay systems. Very simple digital computers are used in the control units of extremum control predicting systems. 10 figs., 17 refs. VAN NICE, R. I. and BURT D. A. Application of an automatic optimizing control to continuous processes. Paper 26-59, 14th I.S.A. Ann. InstrulII. Conf 1959

187

1085

1095

.

E. M. GRABBE In applying a sequential search type of optlm1zmg control, as represented by the Westinghouse Opcon, to continuous processes the device searches for an optimum by making discrete changes or moves in the variables controlled, the change of magnitude optimized being compared with previous values until the optimum is found. A small analogue computer is required to accept measurements and set-in economic data to provide a single signal for the optimizing control equipment. Topics covered include determining applicability for a given process, preliminary process information needed, choices for quantity to be optimized, interconnection with instrumentation and analogue computation of performance criteria. An Opcon control at Dow Chemical Co., Midland, Michigan, is used to maximize the production rate of styrene in catalytic dehydrogenation of ethylbenzene. A proposed installation at the Sun Oil Company involves control of a distillation tower. 1 fig., 6 refs. 188 WHITE, B. The Quarie Optimal Controller. Instrum. Autom. 29 No. 11, Nov. (1956) 2212 The Quarie Optimal Controller may be termed a non-linear control, a simplified computer control or a logical control. Several examples are given. 9 figs.

Possibilities of a twotime scale computing system for control and simulation of dynamic systems. Askania Regulator Co. Oct. (1953)

189 ZIEBOLZ, H. W. and PAYNTER, H.

In this two-time scale method a computer simulates the dynamic behaviour of a plant at a high rate, the optimum being sought and control action carried out accordingly; the search for an optimum probably proceeds in a step-wise fashion. 190 GROSHKO, N. C. An extremum controller with extremum tracking. Automat. Telemech., Moscow 20 No.4, April (1959) 521 Principle of an extremum controller consisting of two basic sections, measurement of deviation and sampled-data tracking. Results of experimental studies are given. 191 Opcon fills a gap. Control Engng 6 No. 2 (1959) 27 News report on the status of the Opcon controller and installations proposed. 2 figs. 192 Progress report on Opcon: Dow evaluates optimizing control. Control Engng 6 No. II (1959) 124 Eval\lation of the first Opcon controller installation at Dow Chemical Co. Input was production (per cent conversion); outputs two of the three primary variables (ethylbenzene flow, water flow and temperature). Typical operating records are shown and difficulties discussed; waiting times were 45-150 min between moves. An analogue computer is being built to provide a more realistic optimum. 5 figs., 2 refs.

Bibliographies on Related Subjects 193 ASELTINE, 1. A., MANCINI, A. R. and SARTURE, C. W. A . survey of adaptive control systems. Inst. Radio Engrs Trans. PGAC-6, Dec. (1958) 102 Criteria upon which self-optimizing systems have been based, and operation of each type of system. A new system, self-optimizing with respect to impulse response, is described, with experimental results. The adaptive classifications proposed are: passive, input signal, extremum, system variable, and system characteristic. A computer is required for system characteristic adaptive systems. Table, 10 figs., 36 refs. 194 Bibliography of computer control, I.S.A. J. 6 No. 7 (1959) 81 Lists 84 papers on computer control published in the U.S.A.

=

exclusively with transform are included. The bibliography is limited to material which in the authors' opinion represents either a significant contribution or has tutorial value. An introduction indicates the content of 26 important references. Subject index crossreferenced to author list. 97 refs. 196 HIGGINS, T. 1. Classified bibliography on control systems.

Amer. Inst. elect. Engrs 1958-59 An extensive bibliography in 15 parts. systems, has 312 references. 197 HOWELL, 1. V.

Part I, on sampled-data

Survey of sampled-data systems analysis.

Amer. Inst. elect. Engrs, Winter Gen. Meeting Feb. (1959) 198 loHNsON, R. C. et al. Computers, mathematics, statistics and Operations Research. Indust. Engng Chem. 51, March (1959) 422 Covers papers of 1958 on engineering, etc., applications of automatic computers, statistical methods, operations research and mathematics; tables list applications and indicate contents. 4 tables, 262 refs. 199 KHRAMOI, A. V. Bibliography of works on automatic control and some associated problems. 1955. Moscow; Acad. Sci. Press (in Russian) 90 pages of USSR references on automatic control, 1823-1953; 40 pages of international references, 1830-1953. Papers are listed by date; an author index is provided. 200 MURPHY, G. 1. and ORMSBY, R. D. A survey of techniques for the analysis of sampled-data control systems. Inst. Radio Engrs Trans. PGAC-2 (1957) 79 The use of pulsed-data links, track-while-scan radar, digital computers and other intermittently operative devices has stimulated interest in the analysis of sampled-data control systems; several methods have been proposed. The state of the art and techniques of analysis proposed are discussed with explanations of their applications and limitations. 8 figs., 43 refs. 201 NETHERWOOD, D. B. Logical machine design: A selected bibliography. Inst. Radio Engrs Trans. PGEC-7 No. 2, June (1958) 155 References on logical design of machines selected as useful and stimulating to the variety of scientists interested in the subject, with an extensive index of significant title words. 484 refs. 202 STROMER, P. R. A selective bibliography on sampled data systems. Inst. Radio Engrs Trans. PGAC-6 Dec. (1958) 112 References listed alphabetically by author on synthesis and analysis of sampling, as distinct from continuous, servo systems, excluding material prior to 1955 except 'classical' references in this comparatively new area of feedback control system literature. 53 refs. 203 STROMER, P. R. Adaptive or self-optimizing control systems -A bibliography. Inst. Radio Engrs PGAC-4 No. I, May (1959) 65 Adaptive, self-adjusting or self-optimizing servos are designed for operation in slowly changing environment as opposed to those for fixed environment. Optimalizer controls, etc. searching for and adjusting to a pre-set optimum condition are termed 'adaptive' servos. The annotated references are selective samples of recent literature and technical reports, indexed according to subject. 47 refs.

195 FREEMAN, H. and LowENscHuss, O. Bibliography on sampled-data control systems and z transform applications. Inst. Radio Engrs Trans. PGAC-4, March (1958) 28

204 STUMPERS, F. L. H. M. A bibliography of information theory (communication theory, cybernetics). Inst. Radio Engrs Trans. Inform. Theory PGIT-2, Nov. (1953); First Supplement, Sept. (1955); Second, 3 No. 2, June (1957) 150 A comprehensive bibliography with 11 subject classifications.

To simplify literature searching for sampled-data controls or information on certain specific aspects, a number of papers dealing

205 WEISS, R. Transportation lag-An annotated bibliography. Inst. Radio Engrs Trans. PGAC-4 No. 1, May (1959) 56

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DIGITAL COMPUTER CONTROL SYSTEMS-AN ANNOTATED BIBLIOGRAPHY

An attempt to survey papers in various fields of study dealing with functions with retarded argument, characterized by a stimulus response differing from a normal response only by time delay. Situations in which this transportation lag occurs include process control (distance-velocity lag), control of thermal systems (including nuclear reactors), rocket motor combustion (ignition and combustion lags), travelling waves, magnetic amplifiers, human links in control systems (reaction time), high-speed aerodynamic control and economic systems (period of gestation or production lag). A number of the references dealing with this problem are listed and abstracted, crossreferenced by field of application and methods of solution. 139 refs. 206 WILLlAMS,

T. J.

Chemical and Petroleum Steel Utilities Computers Airborne

Process Control

Process control and automation. Indust.

Special Purpose

Engng Chem. 50, March (1958) 520 A review of literature for 1957, with 21 references to digital computers.

3 (1952); 8, 13 (1954); 34 (1956); 70 (1957); 85,86 (1958); 152, 162 (1959) 55 (1957); 122, 130, 132, 138, 157, 164, 175 (1959) 4 (1953); 9, 14, 17, 18 (1954); 21 (1955); 36 (1956); 66 (1957); 73,74,92,107 (1958); 148, 150,161-2 (1959)

Reliability

30 (1956); 40,58 (1957); 71-2 (1958)

Theory

5, 7 (1953); 11, 19, 20 (1954); 24, 26 (1955); 38 (1956); 44,49,57,59,62,67-8 (1957); 83,87-9, 94,101-2,114(1958); 121,136-7,141,143(1959)

Subject Classification Applications Aircraft

6 (1953); 29,35 (1956); 42,43,50,57 (1957); 84,97, 104, 108 (1958); 120, 123, 125, 127, 140, 151,155,159,166--8,176 (1959) 133,142,163,174 (1959) 78,109,111 (1958); 118,119,123,124,128,129, 138,144,158, 170 (1959)

10,12,15,16,18 (1954); 22 (1955); 39 (1956); 40,53,61,69,70 (]957); 86,91,106,112 (1958); 126,160,170 (1959)

Summary subject covers work from 1948 to the present, in particular on systems in which the computer is involved in the control loop. A list of bibliographies on related subjects is included.

The history of the development of digital computer control systems is briefly reviewed and the present status of applications outlined. A bibliography giving abstracts of most of the published papers on the

Sommaire On passe brievement en revue I'histoire du developpement des systemes de commande iI calculatrices numeriques et on souligne le stade actuel des applications. On ajoute une bibliographie donnant des resumes de la pIu part des articles pub lies sur le sujet depuis 1948,

en particulier sur les systemes dans lesquels la calculatrice est incorporee dans la chaine de commande. On trouvera aussi une liste de bibliographie sur des sujets connexes.

Zusammenfassung Es wird ein geschichtlicher Oberblick iiber die Entwicklung von Regelungsanordnungen mit Digitalrechnern gegeben und ihr gegenwartiger Stand beschrieben. Die Literaturzusammenstellung mit Zusammenfassungen iiber die meisten veroffentlichten Arbeiten zum

Thema reicht von 1948 bis heute und behandelt vorwiegend Anordnungen, bei denen der Digitalrechner einen Teil des geschlossenen Kreises bildet. Der Beitrag enthalt auch ein Literaturverzeichnis iiber verwandte Gebiete.

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