105 Continuous-time modelling by multirate processing of sampled data

715 elgenvalue msensmvlty with respect to perturbeuons m the nominal system dynanucs Mulurate samphng provrdes extra deslgrl fre~Iom for assigning the desired eigenstmcture An optimal elgenstnicmre assignment ts used to adneve an acceptable compronuse between control effort mmmusation and assignment of a prescnbed modal structure An example Is used to dlustrate the approach 095 Two-Degree-el-Freedom Design Method el I,QI Servo Systems. Part I Disturbance Rejection by Constant Feedback T. Hagiwara, T Yamasaki, M. Araki, pp 423.426 This paper proposes a new design method of robust servo systems for step references and step &smrbances In the method, trackn~ characteristics for step references md feedback chamctemtics for step thsmrbences can be determined opUmaIly, usmg mdependent quadrauc-mtegral performance mthces Thus, it provides a basis for two-degree-of-freedom design of control systems m the semng

of LQ opumal conu~ 096 Two.Degree-el.Freedom Design Method of LQI Servo Systems. Port II Disturbance ReJectioa by Dynamk Feedback T Hngiwara, T Yamasaki, M. Araki, pp 427-430 Recently, a new design method of robust servo systems for step references and step thsturbances was proposed, m whtch twodegrees-of-freedom design can be camed out m the setUng of lmear-quadrauc opumal oontroL Tlus paper extends these results by introducing frequency-dependent weighting matnces mto the performance index wluch detemunes feedback charactensucs By employing appropriate frequency-dependent we~ghung matnces, some sort of loop-sbapmg can be achieved, and thus more design freedom is provtded 097 The Disturbmsce Decoupling Problem with Stability for a Class of Liaear Delay Systems M Velasco, J A. Alvarez, R Castro, pp 431-434 In flus paper, the dtsturbance decouplm8 problem for a class of smgle-mput single-output (SISO) linear systems wtth delays on the state and the mpat xs stuthed Necessary and suffictent con&UOm for the solvabshty of this problem are given m terms of the relative degrees assoctated with the input md the disturbance of the delay system when considenng a cauud smuc state feedback The stainhty of the resultant closed-lonp system is also mvesUgated 098 Design of Feedback Controllers for Discrete.Time Position Control Systems Via V.Transformatioa T Kangsanont, B.D. Raman, pp 435-440

soluuon to a certain optimal control problem and the existence of a Lyapunov funcuon for the underlying system are related t o a conthtion on the corresponchng Hanuhoman system Tlus conthtion is, m ram, related to the extstmce of a soluuon to the correslxmdmg Harndton-Jacobl parual dffferenual equauon

101 Unified Output Feedback Design and Loop Transfer Recovery Chia-Chi Tsui, pp 449-456 This paper presents a systematic, general, and snnple destgn prot~ure for a dynarmc output feedback (DOF) compensator whose internal state converges to a hnear transformauon of epenloop system states, vahd for all observable systems {A, B, C} wlth more c~tputs than inputs, and for arbttrasy (but stable) compensator poles The compensator I) nnplements a perfectly eqmvalent yet more-powerful static output feedback (SOF), eqmval,~nt to a constrau~ state feedback (S~, 2) guarantees exact and fimte gain LTR for tlus constrained SF, 3) perfectly undies SOF and arbltrary SF wlth exact LTR observer unplementauon, and 4) guarantees the cnucal separauon principle of the correspondmg closed-loop system 102 On the Sampling-Time Effects of High-Order Digitizatious and Their Applications in Digital Redesign

Chi.Hsu Wang, Wei-Yen Wang, Tsu-Tian Lee, pp 457-464 Tlus paper stuches the samphng-ume effects of lugher-order d~grttzauous to convert a contmuons-time system into a (hs~rctetune one A genera] expression for the denominator and numerator of the d ~ u z e d system can pre~sely predict the o~mputauonal stablhty and samphng-ume effects of these kinds of dtgmzations The new "polynonual root-locus" descnbes the pole-vanauons of the &Brazed system when the samplmg-ume Is vaned from zero to mfimty The maxunum san~.hng-mne of a pamcular thgmzauon can also be found During digtud-redesign, these t~m:epts c~m be used to fred a statable samplmg-th-ne to guarantee the stal~mas of open- and closed-loop conf~gurauons of a thgmd oontrol system, and to select sampling-runes for real-world problems Examples are fJven 103 Sampling Period Selection for Digital Variable Structure Control X.H Yu, pp 465-468 The selecuon of sampling panods for the ¢hgtud varmble-structure control of hnear systems is thscussed m flus paper An algonflun ts gtven to esUmate the upper bound of a samphng panod that guarantees the pseudo-shdmg along a prescribed shdmg hyperplane As demonstrated m the computer snnulauous, the aigonthm gives a smasfactory approxunauon of the upper bound of the sarnplmg penod.

A snnple algebnuc method for designing the feedback coutroller

H(z) of SISO systems produces controllers m the form of fimte-

unpulse-respouse (FIR) filters A power-series tnmsformauon based on the method of approxtmauon operates on z-tnmsfer functions In ad&tion to producing dosed-loop systems wnh good mmsient belmvlour, flus ulgonthm enables the designer to obmm the ccefficlmts of the controllor threctly from the transfer funcuon of the plant, and match the dynanuc bchav~onr of systems wah different tune constants Trus property is vesy nnportam m the contouring accuracy of mulu-ams met~on-comroi systems By havmg the coutroller m the feedback path rather than the forward path, the system is less sensmve to parameter v s n m o n 099 Robust Pole Assignment Revisited W.X Zheag, K.L Ten, A. Cantoni, pp 441.444 In flus paper a newly developed method Is used to solve nonsmooth opurmsation problems anmn8 m robust pole placement. It/s shown that the method as veTy effictent, owmg to Its desuable numencal propemes such as guaranteed fast rate of convergence and ease of nnplementauon

100 Generalizatious of the Kalman-Yakubovkh L ~ n m a and Their Applications A.V. Savkin, pp 445-448 This paper presents a number of ganerahzations of the KalmanYakubovlch I.emma to nonlinear and tnne-varymg systems The

104 Sampling of State Space Systems with Several Time Delays B. Bernhardssou, pp 469.472 TIus paper solves the problem of how to olmun a zero-order holdsampled version ul'a state-space system contmnmg lane delays at arbltrasy posiuons No assumpuon ts made about the cornmensuralxhty of the ume delays It ts shown that the condmon for obtammg a fimte-dlmensional sampled system for all sarnplmg penods is that there are "no signal loops" around any of the ume delays A sho~t and constmc~ve algonflun ts presented for samphng such systems All calculauons can be performed using standard programs for semplmg systems

105 Continuous-Tim Mod:;ling by Multirate Processing of Stapled Data P. Albertes, pp 473-476 In most control deslgn methodolog3es a mode] of the plant ts assumed to be known This Is commonly obtamed by processm8 data obtmned by samphng the input and output of the plant and then using data-~denuficauon techmques Severe resmctions m flus type of model preclude chrectthgltalcentrollerdesg~n based on the thscrete identifiedmodel Tim paper presmts a new algornhrn that allows extracuon of the conunuous-tnne model of a plant from sampled I/O data TIus model can be used for sampled-data control design where the samphng rate can chfferfrom that apphed

7 16

Abslracts

dunng the ldentfficauon expenmenL The snnphc~ty of the algorithm allows xt to be used for on-line medelimg

106 Robustness Study Using a Distance Function E.M. Nebot, A. Desages, pp 477-482 Assuming f(s) be a Hurwtz chamaerumc polynonual, ~t ts mteresung to know the maxtmum vanauon that ~ts c~effic~antcan afford m order to remain smctly stable. This paper considers the problem of finding the maxmmm plato parameter vanauon that makes a gaven controller v~olate a performance criterion Tins criterion ~s based on the prenuse that no clmed-loop pole has to be outsad~ a given reglort. Some regtons of mterest are also presented The method comtders mdepandent confficm~ vanauon Exact and approxnnanon soluuons are presented to de~emuue the worst possible parameter combmauon

107 Parametrization of all Liaear Compmmtors for Discrete. Time Stochastic BiliMar Systems

of mteroonuect~ons among subsystems A decentralLZed control for quadraue stabilization is also given to demonstrate the feas~bdxtyof the dengn

112 Considering Social EHects in Control System Design - A Summary T. Martin, pp 503.508 Apl~ropnate automauon for apphcauon m reahsucany complex soactechmcal dornams should be based on an mtegrated undermmdmg of the techmcal, human, orgamzauonal, ecologacal, econonuc and even culmnd atmbutes It Is the engmeer's responmbthty to amslder the dtrect and md~ect dfects of the automauon technology used Intograt, on as, therefore, a question of balancing different values The ke~, quesuon for man-maclune mtarface, control room and team destsn ts. then, how to support operators so that they can be "m charge" suceassfttUy Innovauve destgn concepts, prmmples and methods are summarized Enonuragmg expanencus show how such approaches lead to better ovend] system performance. Much research remains to be done,

though

Eagin Yaz, R.E. Skeltoa, pp 483.486 For chsorete-ume stochasuc bdmear systems, thus paper presents a charactenzauon of all state ~ovanances assq~nable by linear controller schemes and a pamnemzauon of all controlIen that adueve a desued covananee These resultsmthrealy pmvule the paramemzaUon of all hnear fixed-order compensators wInch are mean-square stabdmng for flus class of systems The paper also includes robumficauen of the derived compensators

108 MultiobJective Control Design Via Linear Matrix Equations E. Yaz, K. Grigorladis, R. Skeiton, pp 487490 Vanous methods are ~pven wInch saudy muluple cnterm for control desagn These methods reduce to linear alsclxmc problems and reqmre the rattsfacuon of certain eTastence con&uons All ccetrollers that wall acineve the desired obFAmves are derived The sets of muhxple objectlvus that are allowed include pole re~on asstsmnent, stmctun~l parameter robustness, H2/I-I~ constramu, and Frobemus Hankel norm constmmu

113 Operator Roles in Advanced Manufacturing Systems L.K. Mtrtenesen, pp 509-512 Handhng unexpected events Is the key funcuon m machine-tool operauon Due to the complexay of the task, flus is a job for the hunum operator, gaven proper training Muslow's theory of human needs formed the bans for a Swe&sh study on the job content of fle~ble manufactunn 8 systems, F M S The superv~tory control model, desagned by Sheridan of MIT, used for automated produeum w~h the five operator roles of planmn~g, programming, momtormg, mtervenmg and learnm 8, Is dealt with m the paper, winch concludes that at ts essenual for the operator to be able to use Ins creauwty m tasks hke planning, programming and dtstmbance bandhn8 114 Automation Without Organizational Development Won't Do. Employee Partidpation in Small to Medium-Sized Eaterprbes Assists in Finding the Successful Derision for the Appropriate Proportion of Automation G. Strina, M. Siithoff, S. Grinda, D. Brandt, pp 513-516 The paper shows some typical pt'oblcms m the atstomm~on approach of small to mechm'n-sszedentclpnses (SMEs) Fonowmg

109 Nonlinear Estlmatloa by Covariance Assignment E Yaz, W. Na Naeara, pp 491494 The onvanance ass~nment methed ~s extended to upper-bonnd assagmnem of eatnnauon error onvanances for nonhnear stoch~uc systems. The charactenzmon of asmgnable bounds, together wgh falter gains that adueve a pamcular assignment, as presented. Exmence condmons and a ~¢urs~ve method of soinuon are 8~ven for the roam destsn equauon 110 Opthnality of Direct Velocity sad Dbplaesment Feedback for Large Spaee Structures with Collocated Semo~ am/ Actuators

M Ikeda, K. KouJitanl, T. Kida, pp 495.498 I)tw~ feedback of veluetty and chsplacement (DVDFB) ts conndered for large space structures (LSS) with collocated sensors and a~_~,~_n It as known that d the n81d modes d LSS are controllable and observable, and the feedback 8ants are nogauve defimte, then the clmed-loop system ~ stable under any permrbauons m mass. damping, and mffness Thus. DVDFB u a robust stab~h~n8 control law The objecuve of tha paper is to show that ff the gains are smtably chosen, then DVDFB ts also oixtmal m the sense of the LQ regulator theory 111 Decontralized Quadratic Stabilization of Intorconnected Systems

K. Yasuda, pp 499-502 In thts paper, the problam of quadraucally stabdszmg a hnear mtercormected system wsth p a r a m e t e r uncenamUeS by decentrahzed control is ccumdered The obtained smbthmbthty condmon Is lpven m terms of quadrauc stainhzablhty with chsturbance attonuauon for each subsystan, and the attenuation values are determmed usmg only the upper bounds of the smmgth

an m~od-,=on to the.pu~dy

f,m,~..t,,oj~ "~,~et Ruhr'. ,t

describes two case stumes xrcm me am ~Jerman moustsy regaon oI the "Ruhregebmt" These examples show how employees can be mtegrated m the design process and how they help to fmd apprcpnate soluuom for antcmauon m SMEs T h e paper ends wlth some concinslom that are to be drawn from these two examples and from smnlar ones

115 Human-Cmtorod Design of Human.Machine Systems and Examples from Air Transport T. Hancke, RJ. Braune, pp 517-$20 Tins paper ¢hscusses the nnportance of apFvopnate deslsn of automation technology. Such deugn is not onented at technology and the vmon of full automauon, winch appears less and less achievable for envLronmonts with a Ingh de~ree of uncertainty Instead, tt puts the empham on the human m the system The paper proposes the human-centered deugn phdmophy as an appropriate apprcech and as ~ of a new parad~n It outhnes t~ origins and development of tlns des~n phdol~phy and Its core prmmples Followmg tlns, the human-centered pinlosophy xs apphed to commercud air transpoa, and Is describedin more detad for flight-deckdeign

116 Automation and Development. The Need of Counting on a New ProJect of Humanity A. Pacheco.EspeJel, J. Arce.Arnez, pp 521-524 The objecuve of tins work ts to Identdy the role that automauon plays m hmnan development Tins objecuve will be accomplished atartm~ from a concept of that development, winch ts based on the defimdon of a human being as a three-pole net of needs and capamues The above leads on to the formulation of the need for a "Humamty ProJect", ooncmved on the basls of a pamcular vlew of automation