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Technical Paper Discussions
TECHNICAL PAPER DISCUSSIONS
PLENARY SESSION
and different types of CAMAC systems nowadays used in USA? Author's Reply:
REMOVING BARRIERS TO THE APPLICATION OF AUTOMATION IN DISCRETE PART BATCH MANUFACTURI NG Author:
Before this year, practically no one used the HP Standard except Hewlett Packard. As of this year, several other scientific instrument manufacturers have adopted this standard. CAMAC has been used in nuclear instrumentation and discussed for process control applications; I see little additional application beyond what now exists. I expect ADCCP (ISO HLDC) to become the most attractive interface standard because of its low cost and wide support.
J. M. Evans
Discusser: Affiliation:
Y. Morita Tokyo Institute of Technology, JAPAN
Discussion:
1.
2.
Affiliation:
You mentioned the correction of inherent errors of a measuring machine by measuring them and storing them to be made use of in a dynamic operation. This is understandable. But you also added that the same technique can be applied to a machine tool. I think this is not so simple because a machine tool consumes far greater power than a measuring machine, and eventually ejects heat. Could you explain a bit further on this point? "The mirror surface has a flatness two orders of magnitude better than you are able to measure," you said in your lecture. How do you know it if you are not able to measure?
Author's Reply: 1.
2.
Yes, you must compensate for the thermal error also. In general, the correction will be a function of position, temperature, and applied forces.
Affiliation:
Tokyo Agricultural and Technological University, JAPAN
Discussion: You have figured out the increase of productivity due to NC to be about 300% or a factor of three. Let me ask if this is normally accepted measure in industry. Author's Reply: Productivity is something that is often argued about. This is data reported in many studies and confirmed in our own experience. This is factor for both labor productivity (output per man hour) and total factor productivity (cost reduction). For integrated systems, labor productivity may be thousands of percents, while cost reduction is only 50-70%, quite a different figure.
AUTOMATION RESEARCH IN GERMANY AND ITS ROLE REGARDING NATIONAL PRODUCTIVITY Authors:
You can measure the optical quality of the surface with optical techniques. This is beyond the mechanical measurement capability of stylus instruments. So there really is a measurement made.
Discusser:
A. Nomoto
Discusser:
I congratulate you on your good summary. Two points I want you to make clear.
U. Rembold and I. Bey
Discusser: Affiliation:
A. Kuisma
H. Sato University of Tokyo, JAPAN
Discussion:
Innotec Ltd, FINLAND
It is very interesting to know how the national projects in Germany is carried on. I would like to know the situation of the evaluation for these projects.
Di scuss ion: How widely are HP-Bus Standard (IEEE488) 373
374
Tec hni cal Pa pe r Di sc ussion s
This might not be directly related with your presentation, however, it seems to me that we are facing with some conflicts as for the international trade problems as the results that we have made an effort to increase the productivity and Germany is doing good in this feature. I would like to learn your comments if you have any on these problems Authors' Reply:
D. E. Whitney
Discusser: Affiliation:
C. S. Draper Lab., USA
Discussion: What are the plans of the GDR for building more ROTA or PRISMA Systems? I was interested especially in machine systems for domestic use within GDR. Author's Reply:
In general, it is very difficult to get quantitative figures. In addition, the economical situation in the country will change during a funding program is executed by mea ns of 0 ther, "fund i ng i ndependen t" influences. But there are some figures which will be an answer to your question, e. g. the number of process control computers in the F. R. of Germany increased substantially in the year and surpassed 17,000 installations in 1977. In small business computers and process control computers German manufacturers also get a greater market there within Germany. Projects are evaluated by an advisory board consisting of industry, government and research people who are experts in the field. The results are evaluated in a similar manner. However, this usually is a very difficult job. We look at computer sales figures, computer usage, number of similar installations installed etc. Such figures are very readily available in Germany. Also the word usually gets very quickly around on good computer installations. It thus can be noticed that competitive companies are doing the same thing. The Federal Republic of Germany has a similar problem with trade imbalance as Japan. The frequent re-evaluation of the German Mark had to be done due to this problem. The German government is watching this problem very carefully. With a positive trade balance export will be falling off. I also would like to add that automation may increase unemployment. However, economists say that it will not. In any case, we do have to watch this problem very carefully.
In these days, we are mounting a second machining system similar to the first, but with 50% higher capacity. For another system like FZ200, we have finished the whole project and there is no problem for building up others. Activities in this direction are planned. J. Chiba
Discusser: Affiliation:
R & D Div., Komatsu Ltd., JAPAN
Discussion: I think that the most important thing in such as no man controlled manufacturing system is to minimize down times or to shorten the time of repairing system. Please let me know how to monitor the system activity on an actual line, and how to keep and educate the machines. Author's Reply: The weekly maintenance is 8 hours for the FMS in GDR. The repairing of the System-Elements (machines, measurement-machines) goes on each time with a service-team. In the FMS are Diagnostic-Elements.
MODELING AND SIMULATION OF AUTOMATED MANUFACTURING PROCESSES Authors:
H. J. Warnecke and E. Gericke
Discusser: Affiliation:
D. Whitney C. S. Draper Lab., USA
Discussion: SESSION 1: RESEARCH PROJECTS SPONSORED BY GOVERNMENTS
Have you made direct mathematical models of FMS behavior to supplement your simulation models? Authors' Reply:
NEW FLEXIBLE MANUFACTURING SYSTEMS FROM THE G. D. R. Author:
G. Kleditzsch
No, we think that mathematical models are too sophisticated and expensive when the structure of the FMS is getting more complex, for
375
Tech ni cal paper disc uss i ons
instance having 6 working stations as in our simulation case study. We are going to summarize the results in rules of thumb for the designer.
precisely, but according to a rough estimation it is more than three times of the hardware cost. Discusser:
Discusser:
H. J . Warnecke
T. Sata
Affiliation:
University of Tokyo, JAPAN
Affiliation:
University of Stuttgart, FRG
Discussion: Discussion: What is the purpose of building the physical model of a flexible manufacturing system?
The project "Unmanned Factory", how is it going on here in Japan and by how much money is it sponsored by government?
Authors I Reply:
Authors I Reply:
There are several purposes. One is for teaching students, the others are for supporting design and selling such systems. It is good to simulate and see the performance not only on paper but to see it really before implementation the original sys tern.
The project of a so-called "Unmanned Factory" has been modified into "Integrated Production Center" which is of smaller scale compared to a "Factory" mainly because of the limited funds. The budget is approximately 12 billion yens (= 46 million dollars) for seven years and the project is planned to be sponsored by the Government. Discusser:
CONCEPTUAL DESIGN OF INTEGRATED PRODUCTION CENTER Authors:
Affiliation:
H. J. Warnecke University of Stuttgart, FRG
Discussion:
F. Honda and H. Takeyama
Discusser: Affiliation:
J. M. Evans National Bureau of Standards, USA
In merging processes and designing high integrated manufacturing center, is there not the risk of losing flexibility and bad use of all the investment when there are changes in the design of work pieces and products?
Di scuss i on:
Authors I Reply:
In your figures, robots are shown in several places. Are the parts always free, and located and handled by robots, or are they moved on pallets to maintain part orientation?
Flexibility of the system and effectiveness of machines or unit utilization depend upon the ir.dustrial structure to a large extent, but this is not a matter to discuss here. Apart from this, the pattern of products to be manufactured by a definite factory is usually fixed. If so, limited types and number of modular units can manage the required activities although special operations inherent in the specific products should be trusted to the special purpose equipments.
Authors
I
Reply:
Parts come to the assembling machine on pallets properly oriented, and the robot depalletizes the parts to execute programmed activities while maintaining or identifying the coordinates of the parts. Discusser: Affiliation:
U. Rembold UniversiUit Karlsruhe, FRG
Discusser:
D. Whitney
Affiliation:
C. S. Draper Lab., USA
Discussion:
Discussion:
Please 1 ist all the National Big Projects.
How high is the software cost on this project as percentage of the total cost?
Authors
Authors I Reply:
The National Big Projects range to a wide variety, and at the moment no big project is gOlng on except for this Project "High Quality, Laser-Applied Integrated Manufactur-
We have not figured out the software cost
I
Reply
Tec hni ca l Pap e r Discus s ions
376
ing System", as far as the fiel d of production engineering is concerned.
MAJOR PROJECTS ON CONTROL SYSTEMS FOR DISCRETE PARTS MANUFACTURING IN THE FEDERAL REPUBLIC OF GERMANY Author:
Discussion: l.
Does robot shown in Fig. 1 do tool changing and part loading?
2.
What is the accuracy of parts on pallets?
3.
Does this require sensors?
4.
Are there any sensors in the system?
I. Bey Author's Reply:
Discusser: Affiliation:
T. Sata
1.
The final version most probably will contain two independent handling devices for tool changing and part loading.
2.
I can't tell you this exactly, there is no experience with the system. I think, positioning accuracy will be something 1i ke 1 mm.
3.
This will require some kind of gripping force sensors.
4.
Yes, i.e. for the quality control measurement . The specification is not yet finished.
University of Tokyo, JAPAN
Discussion : 1.
Are the last three flexible manufacturing systems listed in Table 1 of your paper going to be developed on the commercial base?
2.
What is the relation between the development of the flexible manufacturing systems and that of the PEARL programming language?
Author's Reply: 1.
Yes, that's right. They are planned to operate economically at normal industrial conditions.
2.
PEARL will be applied to program the real time operation of FMS, i.e. the system listed in Table 1, column 4 is developed for an AEG - Telefunken plant, where an AEG process control computer with PEARL compiler implemented by AEG will be used. On the INTERKAMA Exhibition October 77 at Duesseldorf a Fischer-Technik-Model of a FMS was shown running with a PEARL program.
Discusser: Affiliation:
D. E. Whitney C. S. Draper Lab., USA
Discussion: When will PE ARL be available for US Compu ters? Author's Reply: This is no my competence. All that I can say is that German software houses are developing PEARL compilers for US computers, too. Discusse r : Affiliation:
J. M. Evans National Bureau of Standards, USA
Technical pa pe r discus s i ons
SESSION 2: AUTOMATIC ASSEMBLY AND INSPECTION (I)
ON-LINE SYSTEM FOR MEASURING THICKNESS OF ULTRA-THIN NON-METALLIC LAYER ON STRIP SURFACE Authors: A. Izumidate, H. Yamamoto, S. Shiki, M. Motomura and Y. Nomura Discusser:
J. Aseltine
Affiliation:
United Nuclear Corp., USA
Discussion: What type of computer was used in the on-line computation?
377
I cited only two defects of a ventilator. Well, I'm not sure of the exact answer because I don't know what feature the random noise of the film-projector you gave as an example has. However, I think it is possible to detect the random noise using our system if you try to modify our system for the noise you wish to detect. 2) It is quite difficult to answer your question right now. That is because I don't have enough information to compare the BRUEL & KJAER with our system, unfortunately. Therefore, I promise to write to you in Warsaw on the examination of that BRUEL & KJAER System at our 1abora tory. However, I think our system is superior to the BRUEL & KJAER System, which can find each defect by the noises and give a "GO!" or a "NO GO!" signal.
Authors' Reply: INTEL 8080 was used for computing the quantity of the oil film of ET or the hydrated chromium oxide of TFS.
APPLICATION OF LASER HOLOGRAPHY TECHNIQUE TO MICRO PATTERN POSITIONING IN INTEGRATED CIRCUITS MANUFACTURING Authors:
PRACTICAL APPLICATION OF DIAGNOSTIC SIGNATURE ANALYSIS TO TESTING OF ROTATING MACHINES Authors: E. Ohno
T. Usami, T. Koi zumi, T. Inari and
Discusser: Affiliation:
A. Oledzki Warsaw Tech. University, POLAND
Discussion: 1) In your paper you took into account only basic sources of noise which may cause failure of a simple equipment like a ventilator. Does your system give a proper answer in case, when the source of noise is of random kind? We know, that very often a perfectly good object ( from mechanical point of view) can produce a tremendous amount of noise, and very often of random kind, which source is very difficult to locate ( Example - A film-projector ). 2) In Europe, equipment is used made by BRIUEL & KJAER for similar diagnostic purposes ( But not so sophisticated! ). I could not find any information in references of your paper. If you try it, by the chance, could you kindly express your opinion? ( As far as I know the system of B&K gives no answer in the form: "GOOD" or "BAD".) Authors' Reply: 1) In my lecture, I mentioned the sound noises and to give an example out of numerous cases
Y. Oshima, N. Mohri and Y. Isogai
Discusser: Affiliation:
A. Izumidate Nippon Steel Corp., JAPAN
Discussion : Has this technique any limitation with scanning area? Authors'Reply: In principle there is no limitation with respect to the size of the object, but as a matter of course there occurs the limitation from the viewpoint of the size of the optical system and the intensity of the laser. We are going to apply this technique to positioning of the IC wafer with the size of several ten millimeters. We can not say the limitation quantitatively because we do not have any experience with respect to the objects with bigger size.
PROFILE PATTERN RECOGNITION SYSTEM FOR MACHINE PARTS Author:
H. Kono
Discusser: Affiliation:
A. Niemi Helsinki Univ. of Tech.,FINLAND
Technical Paper Discussions
378
Discussion:
Authors' Reply:
How do you make a distinction between a slightly curved contour and a corner?
Yes, it is a limiting factor to the speed of operation. The scanning speed of the photodiode array depends on the intensity of illumination. In this machine, we use the halogenlamp (150w) for illumination. If we can use the lamp which has higher intensity, we can get higher speed of inspection. But in this case, the shadow-mask master plate is damaged by the heat of the light. So we couldn't use the lamp which has much higher intensity than this one.
Author's Reply: In the developed pattern recognition system, the profile pattern is recognized as a polygon. Therefore, if a slightly curved contour portion is to be recognized, only the corners which change the corner angle extremely are detected. The recognition limit of the corner angle change to be recognized is from greater than 45° to less than 135°.
Discusser: Affiliation:
A. Izumidate Nippon Steel Corp., JAPAN
Discussion: SESSION 3: AUTOMATIC ASSEMBLY AND INSPECTION (11)
STUDY ON AUTOMATIC VISUAL INSPECTION OF SHADOW-MASK MASTER PATTERNS Authors: Y. Nakagawa, H. Makihira, N. Akiyama, T. Numakura and T. Nakagawa Discusser: Affiliation:
A. Kuni Hitachi Ltd. JAPAN
Discussion: Have you ever investigated the use of the laser hologram for the inspection of such repetition patterns? Authors' Reply: We have discussed whether or not we can use the technique of hologram or optical Fourier transformation. But we didn't dare to use this technique. The emulsion thickness on the shadow mask master plate is not constant all over the plate surface. But in an optical Fourier transformation, the variation of the emulsion thickness can detected with high sensitivity. But it doesn't necessarily mean that the variation is a defect. For this reason we could not use this method, Discusser: Affiliation:
A. Niemi Helsinki Univ. of Tech., FINLAND
Discussion: Is the amount of illumination of the plate a limiting factor to the speed of operation?
Does the magnitude of the reflected light vary depending on the flatness of the surface ? It means that threshold level must vary depending on the flatness of the surface. Namely, threshold level must vary depending on both magnitude of the injected light and the flatness of the surface. Don't you think that this may limit the accuracy of this system? Why is not area-array applied tll this system? Authors' Reply: The flatness doesn't influence the magnitude of the transmitted light, but the roughness of the glass plate does. The surface of the glass plate is so smooth that the roughness doesn't influence the magnitude of the transmitted light. When the magnitude of the injected light varies, the threshold level should be varied. This machine has the adaptive thresholding ability in which the thresholding level varies in response to the detected signal level. In an area-array, a certain area is detected. In the case that a large area must be detected, the shadow-mask plate should be driven in a step and repeat motion. During the detection, the shadow-mask plate has to keep the position without any motion. But, in a linear-array sensor, a row of patterns is detected, during the shadow-mask plate is being driven. In this case, the driving control is very easy and speed is very high. Every time after the longitudinal plate driving, the detecting head is driven transverse, step by step, so the sensor can detect a new row . A linear-array sensor has little distortion, high detection speed and small detector size. In these points of view, we used the solid-state linear image sensor as a detecto~!....r!....._ _ _ _ _ _ _ _ __
Te chni ca l pa pe r dis c ussi ons
SESSION 4: ROBOTICS AND MATERIAL HANDLING (I)
A ROBOT HAND WITH ELASTIC FINGERS AND ITS APPLICATION TO ASSEMBLY PROCESSES Authors:
H. Hanafusa and H. Asada
CLASSIFICATION OF GRASPED OBJECT'S SHAPE BY AN ARTIFICIAL HAND WITH MULTI-ELEMENT TACTILE SENSORS
Affiliation:
Author:
Discussion:
G-I Kinoshita
Di scusser:
C. A. Rosen
379
Di scusser:
G. Kinoshita Chuo Univ., JAPAN
Have you considered using lateral inhibition to enhance the contrast of your multiple sensors? This would sharpen up discontinuities.
1) You proposed the rigidity matrix Q. I understand the physical meaning of the diagonal elements in the matrix Q. But the non-diagonal elements are not clear. Would you please explain the meaning? 2) Is your robot's hand able to adjust the handling force arbitrarily for various shapes of objects? 3) How much is the clearance of the parts mated in your experiments?
Author's Reply:
Authors' Reply:
I think it is important that for extracting the feature of objects, enhancing the contrast of multiple sensors should be considered.
1) The handling force can be written as follows:
Affiliation:
SRI, USA
Discussion:
Discusser: Affiliation:
H. Asada Kyoto Univ., JAPAN
Discussion: 1) What sequence do you use to let the robot hand grasp the object? 2) Do you have any experiments to verify the Eq. (2.3) for practical materials? Author's Reply: 1) Thumb is opposed to the index, middle, ring, and little finger. And each finger is controlled sequentially. 2) This problem is now under consideration. Discusser: Affiliation:
:l
Px Py
+
Pe
*
qxy
*
b. Xa
*
*
*
b.Ya
*
*
*
1',8
a
I explain by an example. The element qxy means the ratio between F and b.y . Thus the row diagonal elements x mean a the interactions between the components of the handling force and the object deviation in different directions. 2) The possibility to adjust Band C to construct desired P and Q is determined from det R, and the fact that each finger force has the limit to generate, such as 0 < f. < Max f .. The details are discussed in 1 ChaptJr 4 of the paper. 3) The clearance between the block and the fixture is less than O.lmm.
I. Bey Ges. fUr Kernforschung, FRG
Discussion: Is the system planned to be applied in industry- if yes, where and when will that be?
TASK-ORIENTED VARIABLE CONTROL OF A MANIPULATOR AND ITS SOFTWARE SERVOING SYSTEM Author:
K. Takase
Author's Reply: Discusser: We have no plan, now . We want to apply in industry.
Affiliation: Discussion:
H. Asada Kyoto Univ . , JAPAN
Technical Paper
380
You introduced H-variables. How do you apply H-variables to the task shown in the film? Author's Reply: For example, when the manipulator saws a board, H-variables are determined in the space where the sawing task is carried out, as shown in the Figure.
Discu~sions
build up a calibration-point for all three axis of the machine-tool. The position of the calibration-point is very precise measured while the machine-tool is under good thermal conditions. Before measuring the workpiece geometry with the special probe, the probe has to be checked at the calibration-point, to see if there is any deviation from the given value coming, for instance, from thermal deformation of the machine-tool.
PROPOSAL OF THE MULTILAYERED CONTROL OF MACHINE FOR FULLY AUTOMATED MACHINING OPERATIONS
T~OLS
Authors:
T. Sata and K. Matsushima
Discusser: Board to be cut Saw
H is set to zero by 3-D position feedback c6ntrol. The position of H is decided by the environmental constraint, Z and a downward force is applied. Control of Hl realizes the reciprocating motion for cutt;~g.
Affiliation:
T. Watanabe Kyoto Univ., JAPAN
Discussion: In your system, the identification of the parameters functions well in Fig. 9. There are four parameters in Eq. 9. Therefore, I think these parameters are decided after collecting four measured values. How long does it take to determine these parameters? Authors' Reply:
SESSION 6 : AUTOMATIZATION OF MATERIAL PROCESSING (I)
ADVANTAGES AND CONDITIONS FOR A DIRECT MEASUREMENT OF THE WORKPIECE-GEOMETRY ON NCMACHINE TOOLS Authors:
" T. Pfei Fer and A. Furst
Discusser: Affiliation:
T. Sata Univ. of Tokyo, JAPAN
The control system on the first level starts to control the cutting variables by using the parameters assumed in advance. After getting a simple datum of the tool wear, the system is able to evaluate the parameters by using equation (17). From an economical point of view it is advisable to perform such a computation after getting several data of the tool wear, unless the system recognizes a considerably large error in the predetermined parameters. So I would like to say that the computation is performed every half day, for example. The real computing time by a minicomputer is much shorter than 1 second. Discsser: H. -J. Warnecke
Discussion:
Affiliation:
How do you take into account thermal deformation of the machine-tool?
Discussion:
Authors' Reply: The system I introduced here is not running yet, but in a planning status. We hope to get first experiences at the end of the next year. Coming back to the question, I've plan to
Univ. of Stuttgart, FRG
Much research work has been done world-wide in the adaptive control field, the response in industry and application is in comparison rather poor. Where do you see the reason and have you already done some cost-value-analysis for your system?
38 1
Techn i ca l p a p er di sc u s si o n s
Authors' Reply: The reason why the adaptive control of a machine tool does not attract the interests of the industrial people, lies in the fact that the function of the simple adaptive control system is not enough to take an operator away from the side of the machine tool, resulting in little contribution to cost reduction. Our research on the multilayered control of a machine tool doe s not reach to the level to be able to make exact economical evaluation on the merit brought by the system. Discusser: Affiliation:
M. Soeda
What kind of merit or profit can be expected by using that system? Please list up the items, for example: 1. saving the operator 2. making the cutter life longer 3.
4.
Authers' Reply: If we will be successful to realize a fully automated machining operations, many advantages would be expected . These are: 1) to increase productivity even in batch production, 2) to reduce machining cost due to saving of the labour cost and 3) to give workers better working environment.
Affiliation:
Discusser: Affiliation:
H. J. Warnecke Univ. ef Stuttgart, FRG
Discussion : Especially the NC machine being expensive it seems to me that the number of shifts is of great influence to the machining cost, more for instance than the number of operators per machine. Am I right in this assumption ? Authors' Reply:
Tokai Univ., JAPAN
Discus s ion :
Discusser:
Authors: M. Soeda, H. Yonaiyama and E. Yamaguchi
G. K. Hutchinson Univ. of Wisconsin, USA
Discus s ion: How was the overhead cost (Mc) in eq . 1 determined? Authers ' Reply : The overhead cost in equation (1) is the conventional one which includes depreciation of the machine tool, the labour cost and others.
THE ROLE OF NUMERICAL CONTROL USED FOR THE MANUFACTURING PROCE SS IN MACHINING ON MAIN INDUSTRIES IN JAPAN
The cost of man power will be increased proportionally, or over proportionally, with increasing of number of shift. By this reason, cost/product is not so much changed as we expect, so long as shift is concerned. But depreciation period is largely changed toward advantageous condition. Judging from the above factor, I presume the cost may be decreased in some degree depending on conditions. This condition will be left to study further .
Tec hni ca 1 Pap(! r Di scus s io n s
382
SESSION 7: AUTOMATIZATION OF MATERIAL PROCESSING (11)
A METHOD OF TOOL PATH DISTRIBUTION ON A CNC Author:
M. Kiyokawa
Discusser:
design, is 12 m/min. The sampling speed is in that case 1/200 s. We are controlling the spindle drives in an open loop manner, so we just send a command value to the drive system . The only problem is the command value resolution, which can be fairly high in some cases.
T. Pfeifer
Affiliation : Werkzeugmaschinenlabor, Aachen, FRG Discussion:
AN ADAPTIVE CNC SYSTEM OF A MILLING MACHINE TOOL Author:
How is running your method when there is only a few material to be cut? That means, when the rough-part is very similar to the finishedpart-geometry.
T. Watanabe
Discusser: Affiliation:
Y. Morita Tokyo Institute of Technology, Japan
Author's Reply: Discussion: The method mentioned here is for cutting barstock on a lathe. There is no special consideration on the amount of material to be cut . The cutting area can be calculated by this method according to the information of the shape and allowance to be finished.
Would it be possible to measure the temperature of the tool tip? Some of the radiation sensitive instruments are capable of detecting the temperature of a spot having very small diameter, say 70 fjm. Author's Reply:
MULTIMICROPROCESSOR CONTROL SYSTEM FOR SPECIAL PURPOSE MACHINE TOOLS Author:
A. Kuisma, K.
Discusser: Affiliation:
M~kel~
and E. Rasi
T. Watanabe Kyoto University, Japan
Discussion: 1.
In Fig.5, the microprocessor controls many servo systems . Do you need the priority interrupt system?
2.
How much are the maximum feed rate and spindle speed of the machine controlled by your system?
Author's Reply: 1.
We have only one program that is executed every 1/200 ... 1/50 second. It is doi ng all the control of slide units one after another and it is also checking some limit switches for safety etc. So no interrupt signals from the slide units are used.
2.
The maximum feed rate, we have used in our
Of course, it is possible to measure the tool tip temperature directly. I think that there are three representative methods. The first method is to use a thermocouple consisting of the tool and work. But, the value measured by this method indicates the mean temperature over the total tool-work interface as mentioned in this presentation . The second method is to use a thermocouple constructed by the thin wire set in the tool tip and the work material. But, in the case of using a milling cutter, it is difficult to set the thin wire in the tool tip. The third method is to use radiation sensitive instruments as is advised from you. But, this method has some prob l ems . Fi rst ly , t he temp erature of the tool tip, while contacting with the work, can not be measured. Secondly, the chip and the cutting fluid disturb the measurement. Thirdly, the mutual positions between the tool and the work vary widely in milling, therefore, the instrument must be moved. We think it is practical to compute the temperature at the flank wear of the tool tip theoretically, because it can be done easily by a minicomputer and it is not affected by the chip and the cutting fluid
383
Te chni ca l pap e r di s c uss i ons
CNC APPLICATIONS
Author:
Author:
Discusser :
R. Nozawa
Discusser: Affiliation:
T. Sata University of Tokyo, Japan
Discussion: 1.
2.
I would like to know how the output of the measuring device is connected with CNC to compensate the setting error of a large workpiece. Is the simulater to find the mulfunction of the machine tool the hardwired one or the softwired one?
Author's Reply: 1.
The probe is moved to a workpiece by the jog or manual pulse generator capability of the CNC. The CNC updates the position and store the final position (position of workpiece) in the memory.
2.
The simulater in the check system is realized by a hardware.
N. Nishiwaki M. Kiyokawa
Affiliation: Discussion:
Are there any problems on the optical fiber sensor, which may be influenced by the vibraton of tool? Author's Reply: If there is any vibration of the tool during cutting, it will be recorded by the optical fiber as a noise signal as shown in Fig.6(b). Since the signal obtained through this sensor is used to investigate the surface roughness as well as the chatter behaviour, the vibration of tool is not suppcsed to create any problem.
EXTRA-CYCLIC PASSAGES OF GRAY CODES AND THEIR APPLICATIONS FOR NUMERICAL CONTROL DESIGN Author:
H.J. Leskiewicz
Discusser: CNC APPLICATIONS
Affiliation :
Author:
Discussion:
R. Nozawa
Discusser: Affiliation:
T. Pfeifer
2.
For which part of a NC system, is your Gray code available?
Author' s Reply: 1.
The hazard may take place in going from one state to another when two or more letters are changed simultaneously in the two coding expres s ions of those states. Thi s should be avoided by proper coding, although this is not always possible.
2.
The method presented in the paper explains first if such a proper coding is possible, and where this is so, gives all codes protecting from hazard from which the designer may choose. The application of the method is as wide as the problem of proper coding of any states which do not form a cycle of states which appear only once in this cycle.
Author's Reply: The same probe with tracer control is used for detecting actual work positions.
CONTROL SYSTEM OF NC MACHINE TOOL FOR HIGH WORKING ACCURACY
Kyoto University, Japan
What is the cause of generating the hazard phenomena in the NC system in the case of using the ordinary method?
Discussion :
SESSION 8: AUTOMATIZATION OF MATERIAL PROCESSING (Ill)
T. Watanabe
1.
Werkzeugmaschinenlabor, Aachen, FRG
What type of probe do you use for identifying the actual workpiece po sition on the table of the CNC machine-tool?
Mitsubishi Electric Corp., Japan
Tec hnical Paper Discussio n f
384
SESSION 9: PRODUCTION CONTROL (I)
of the prdctical control s imulati on for determining optimal plannlng.
AN ANALYSIS OF WATER SUPPLY AND STORAGE CAPACITY Author:
SESSION 10: PRODUCTION CONTROL (11)
T. Odanaka
Discusser: Affiliation:
G.K. Hutchir.son The University of Wisconsin, USA
IMPLEMENTING AN INFORMATION CONTROL SYSTEM FOR MANUFACTURING
Discussion:
Author : J.A . Ase ltine
Has the control theory you developed been applied to the original water supply control problem? With what results? (i.e. What would the plot for one week, like figures 2 & 3, look using your optimal control?)
Di scusser :
Author's Reply: Yes, I have applied my control theory to the original water supply control problem, and given the theoretical background. Simulation excersises have been carried out and some numerical results have been obtained.
Affiliation:
J. Talavage Purdue University, USA
Discussion: Did you co nsider, in the design stages, the use of a decentralized network of, say, minicomput · ers? Author's Reply: The state of the art in software requires the use of a central computer for efficient data base handling. However , we do use about 10 minicomputers for automated inspection, the data being sent to the large computer for inclusion i n the Jata b3s e .
INFORMATION STRUCTURES, DYNAMIC TEAM DECISION, AND AN ECONOMIC APPLICATION Author:
H. Myoken
Discusser: Affiliation:
G. Hutchinson The University of Wiscon s in, USA
IMPLEMENTING AN INFORMATION CONTROL SYSTEM FOR MANUFACTURING Author:
J.A. Aseltine
Discussion:
Di sc usser :
Could you tell us where you expect to go with your interesting work from this point in time?
Affiliation:
M. Terao University of Tokyo, Japa n
Discussion : Author's Reply : As mentioned in this paper, most of studies on the decentralized control problems from a team decision approach have been pres criptive and very formal rather than empirical. This paper presents a new practical and empirical method in order to hold an empirical validity of promise for inte0 rating and ext ending our knowledge about information and decision. As an illustrative example, the realistic multi-item firm mouel is considered, and then we explain in details regarding the procedure
Was there a probl em with the time- sharing use of many CRT's on the fac tory floor? Author's Reply : We exp ~ nded core memory as terminals and data ba se expanded to keep respon se time to about 10 seconds in max. Incidentally, we had no difficulty in training manufacturing personnel to use the term inals-d~e, I think, to their interest in obtaining data so efficientl y.
Technica l pape r disc u ssions
"PASS" AN INTERACTIVE ONLINE SIMULATOR FOR PREDICTIVE PRODUCTION CONTROL Author :
K. Tabata
Discusser: Affiliation:
G.K. Hutchinson The Univers ity of Wisconsin, USA
385
Discusser : What resources were required to develop PASS? Author's Reply : 18 months with one and a half persons were required to develop PASS.
PLENARY SESSION
and different types of CAMAC systems nowadays used in USA? Author's Reply:
REMOVING BARRIERS TO THE APPLICATION OF AUTOMATION IN DISCRETE PART BATCH MANUFACTURI NG Author:
Before this year, practically no one used the HP Standard except Hewlett Packard. As of this year, several other scientific instrument manufacturers have adopted this standard. CAMAC has been used in nuclear instrumentation and discussed for process control applications; I see little additional application beyond what now exists. I expect ADCCP (ISO HLDC) to become the most attractive interface standard because of its low cost and wide support.
J. M. Evans
Discusser: Affiliation:
Y. Morita Tokyo Institute of Technology, JAPAN
Discussion:
1.
2.
Affiliation:
You mentioned the correction of inherent errors of a measuring machine by measuring them and storing them to be made use of in a dynamic operation. This is understandable. But you also added that the same technique can be applied to a machine tool. I think this is not so simple because a machine tool consumes far greater power than a measuring machine, and eventually ejects heat. Could you explain a bit further on this point? "The mirror surface has a flatness two orders of magnitude better than you are able to measure," you said in your lecture. How do you know it if you are not able to measure?
Author's Reply: 1.
2.
Yes, you must compensate for the thermal error also. In general, the correction will be a function of position, temperature, and applied forces.
Affiliation:
Tokyo Agricultural and Technological University, JAPAN
Discussion: You have figured out the increase of productivity due to NC to be about 300% or a factor of three. Let me ask if this is normally accepted measure in industry. Author's Reply: Productivity is something that is often argued about. This is data reported in many studies and confirmed in our own experience. This is factor for both labor productivity (output per man hour) and total factor productivity (cost reduction). For integrated systems, labor productivity may be thousands of percents, while cost reduction is only 50-70%, quite a different figure.
AUTOMATION RESEARCH IN GERMANY AND ITS ROLE REGARDING NATIONAL PRODUCTIVITY Authors:
You can measure the optical quality of the surface with optical techniques. This is beyond the mechanical measurement capability of stylus instruments. So there really is a measurement made.
Discusser:
A. Nomoto
Discusser:
I congratulate you on your good summary. Two points I want you to make clear.
U. Rembold and I. Bey
Discusser: Affiliation:
A. Kuisma
H. Sato University of Tokyo, JAPAN
Discussion:
Innotec Ltd, FINLAND
It is very interesting to know how the national projects in Germany is carried on. I would like to know the situation of the evaluation for these projects.
Di scuss ion: How widely are HP-Bus Standard (IEEE488) 373
374
Tec hni cal Pa pe r Di sc ussion s
This might not be directly related with your presentation, however, it seems to me that we are facing with some conflicts as for the international trade problems as the results that we have made an effort to increase the productivity and Germany is doing good in this feature. I would like to learn your comments if you have any on these problems Authors' Reply:
D. E. Whitney
Discusser: Affiliation:
C. S. Draper Lab., USA
Discussion: What are the plans of the GDR for building more ROTA or PRISMA Systems? I was interested especially in machine systems for domestic use within GDR. Author's Reply:
In general, it is very difficult to get quantitative figures. In addition, the economical situation in the country will change during a funding program is executed by mea ns of 0 ther, "fund i ng i ndependen t" influences. But there are some figures which will be an answer to your question, e. g. the number of process control computers in the F. R. of Germany increased substantially in the year and surpassed 17,000 installations in 1977. In small business computers and process control computers German manufacturers also get a greater market there within Germany. Projects are evaluated by an advisory board consisting of industry, government and research people who are experts in the field. The results are evaluated in a similar manner. However, this usually is a very difficult job. We look at computer sales figures, computer usage, number of similar installations installed etc. Such figures are very readily available in Germany. Also the word usually gets very quickly around on good computer installations. It thus can be noticed that competitive companies are doing the same thing. The Federal Republic of Germany has a similar problem with trade imbalance as Japan. The frequent re-evaluation of the German Mark had to be done due to this problem. The German government is watching this problem very carefully. With a positive trade balance export will be falling off. I also would like to add that automation may increase unemployment. However, economists say that it will not. In any case, we do have to watch this problem very carefully.
In these days, we are mounting a second machining system similar to the first, but with 50% higher capacity. For another system like FZ200, we have finished the whole project and there is no problem for building up others. Activities in this direction are planned. J. Chiba
Discusser: Affiliation:
R & D Div., Komatsu Ltd., JAPAN
Discussion: I think that the most important thing in such as no man controlled manufacturing system is to minimize down times or to shorten the time of repairing system. Please let me know how to monitor the system activity on an actual line, and how to keep and educate the machines. Author's Reply: The weekly maintenance is 8 hours for the FMS in GDR. The repairing of the System-Elements (machines, measurement-machines) goes on each time with a service-team. In the FMS are Diagnostic-Elements.
MODELING AND SIMULATION OF AUTOMATED MANUFACTURING PROCESSES Authors:
H. J. Warnecke and E. Gericke
Discusser: Affiliation:
D. Whitney C. S. Draper Lab., USA
Discussion: SESSION 1: RESEARCH PROJECTS SPONSORED BY GOVERNMENTS
Have you made direct mathematical models of FMS behavior to supplement your simulation models? Authors' Reply:
NEW FLEXIBLE MANUFACTURING SYSTEMS FROM THE G. D. R. Author:
G. Kleditzsch
No, we think that mathematical models are too sophisticated and expensive when the structure of the FMS is getting more complex, for
375
Tech ni cal paper disc uss i ons
instance having 6 working stations as in our simulation case study. We are going to summarize the results in rules of thumb for the designer.
precisely, but according to a rough estimation it is more than three times of the hardware cost. Discusser:
Discusser:
H. J . Warnecke
T. Sata
Affiliation:
University of Tokyo, JAPAN
Affiliation:
University of Stuttgart, FRG
Discussion: Discussion: What is the purpose of building the physical model of a flexible manufacturing system?
The project "Unmanned Factory", how is it going on here in Japan and by how much money is it sponsored by government?
Authors I Reply:
Authors I Reply:
There are several purposes. One is for teaching students, the others are for supporting design and selling such systems. It is good to simulate and see the performance not only on paper but to see it really before implementation the original sys tern.
The project of a so-called "Unmanned Factory" has been modified into "Integrated Production Center" which is of smaller scale compared to a "Factory" mainly because of the limited funds. The budget is approximately 12 billion yens (= 46 million dollars) for seven years and the project is planned to be sponsored by the Government. Discusser:
CONCEPTUAL DESIGN OF INTEGRATED PRODUCTION CENTER Authors:
Affiliation:
H. J. Warnecke University of Stuttgart, FRG
Discussion:
F. Honda and H. Takeyama
Discusser: Affiliation:
J. M. Evans National Bureau of Standards, USA
In merging processes and designing high integrated manufacturing center, is there not the risk of losing flexibility and bad use of all the investment when there are changes in the design of work pieces and products?
Di scuss i on:
Authors I Reply:
In your figures, robots are shown in several places. Are the parts always free, and located and handled by robots, or are they moved on pallets to maintain part orientation?
Flexibility of the system and effectiveness of machines or unit utilization depend upon the ir.dustrial structure to a large extent, but this is not a matter to discuss here. Apart from this, the pattern of products to be manufactured by a definite factory is usually fixed. If so, limited types and number of modular units can manage the required activities although special operations inherent in the specific products should be trusted to the special purpose equipments.
Authors
I
Reply:
Parts come to the assembling machine on pallets properly oriented, and the robot depalletizes the parts to execute programmed activities while maintaining or identifying the coordinates of the parts. Discusser: Affiliation:
U. Rembold UniversiUit Karlsruhe, FRG
Discusser:
D. Whitney
Affiliation:
C. S. Draper Lab., USA
Discussion:
Discussion:
Please 1 ist all the National Big Projects.
How high is the software cost on this project as percentage of the total cost?
Authors
Authors I Reply:
The National Big Projects range to a wide variety, and at the moment no big project is gOlng on except for this Project "High Quality, Laser-Applied Integrated Manufactur-
We have not figured out the software cost
I
Reply
Tec hni ca l Pap e r Discus s ions
376
ing System", as far as the fiel d of production engineering is concerned.
MAJOR PROJECTS ON CONTROL SYSTEMS FOR DISCRETE PARTS MANUFACTURING IN THE FEDERAL REPUBLIC OF GERMANY Author:
Discussion: l.
Does robot shown in Fig. 1 do tool changing and part loading?
2.
What is the accuracy of parts on pallets?
3.
Does this require sensors?
4.
Are there any sensors in the system?
I. Bey Author's Reply:
Discusser: Affiliation:
T. Sata
1.
The final version most probably will contain two independent handling devices for tool changing and part loading.
2.
I can't tell you this exactly, there is no experience with the system. I think, positioning accuracy will be something 1i ke 1 mm.
3.
This will require some kind of gripping force sensors.
4.
Yes, i.e. for the quality control measurement . The specification is not yet finished.
University of Tokyo, JAPAN
Discussion : 1.
Are the last three flexible manufacturing systems listed in Table 1 of your paper going to be developed on the commercial base?
2.
What is the relation between the development of the flexible manufacturing systems and that of the PEARL programming language?
Author's Reply: 1.
Yes, that's right. They are planned to operate economically at normal industrial conditions.
2.
PEARL will be applied to program the real time operation of FMS, i.e. the system listed in Table 1, column 4 is developed for an AEG - Telefunken plant, where an AEG process control computer with PEARL compiler implemented by AEG will be used. On the INTERKAMA Exhibition October 77 at Duesseldorf a Fischer-Technik-Model of a FMS was shown running with a PEARL program.
Discusser: Affiliation:
D. E. Whitney C. S. Draper Lab., USA
Discussion: When will PE ARL be available for US Compu ters? Author's Reply: This is no my competence. All that I can say is that German software houses are developing PEARL compilers for US computers, too. Discusse r : Affiliation:
J. M. Evans National Bureau of Standards, USA
Technical pa pe r discus s i ons
SESSION 2: AUTOMATIC ASSEMBLY AND INSPECTION (I)
ON-LINE SYSTEM FOR MEASURING THICKNESS OF ULTRA-THIN NON-METALLIC LAYER ON STRIP SURFACE Authors: A. Izumidate, H. Yamamoto, S. Shiki, M. Motomura and Y. Nomura Discusser:
J. Aseltine
Affiliation:
United Nuclear Corp., USA
Discussion: What type of computer was used in the on-line computation?
377
I cited only two defects of a ventilator. Well, I'm not sure of the exact answer because I don't know what feature the random noise of the film-projector you gave as an example has. However, I think it is possible to detect the random noise using our system if you try to modify our system for the noise you wish to detect. 2) It is quite difficult to answer your question right now. That is because I don't have enough information to compare the BRUEL & KJAER with our system, unfortunately. Therefore, I promise to write to you in Warsaw on the examination of that BRUEL & KJAER System at our 1abora tory. However, I think our system is superior to the BRUEL & KJAER System, which can find each defect by the noises and give a "GO!" or a "NO GO!" signal.
Authors' Reply: INTEL 8080 was used for computing the quantity of the oil film of ET or the hydrated chromium oxide of TFS.
APPLICATION OF LASER HOLOGRAPHY TECHNIQUE TO MICRO PATTERN POSITIONING IN INTEGRATED CIRCUITS MANUFACTURING Authors:
PRACTICAL APPLICATION OF DIAGNOSTIC SIGNATURE ANALYSIS TO TESTING OF ROTATING MACHINES Authors: E. Ohno
T. Usami, T. Koi zumi, T. Inari and
Discusser: Affiliation:
A. Oledzki Warsaw Tech. University, POLAND
Discussion: 1) In your paper you took into account only basic sources of noise which may cause failure of a simple equipment like a ventilator. Does your system give a proper answer in case, when the source of noise is of random kind? We know, that very often a perfectly good object ( from mechanical point of view) can produce a tremendous amount of noise, and very often of random kind, which source is very difficult to locate ( Example - A film-projector ). 2) In Europe, equipment is used made by BRIUEL & KJAER for similar diagnostic purposes ( But not so sophisticated! ). I could not find any information in references of your paper. If you try it, by the chance, could you kindly express your opinion? ( As far as I know the system of B&K gives no answer in the form: "GOOD" or "BAD".) Authors' Reply: 1) In my lecture, I mentioned the sound noises and to give an example out of numerous cases
Y. Oshima, N. Mohri and Y. Isogai
Discusser: Affiliation:
A. Izumidate Nippon Steel Corp., JAPAN
Discussion : Has this technique any limitation with scanning area? Authors'Reply: In principle there is no limitation with respect to the size of the object, but as a matter of course there occurs the limitation from the viewpoint of the size of the optical system and the intensity of the laser. We are going to apply this technique to positioning of the IC wafer with the size of several ten millimeters. We can not say the limitation quantitatively because we do not have any experience with respect to the objects with bigger size.
PROFILE PATTERN RECOGNITION SYSTEM FOR MACHINE PARTS Author:
H. Kono
Discusser: Affiliation:
A. Niemi Helsinki Univ. of Tech.,FINLAND
Technical Paper Discussions
378
Discussion:
Authors' Reply:
How do you make a distinction between a slightly curved contour and a corner?
Yes, it is a limiting factor to the speed of operation. The scanning speed of the photodiode array depends on the intensity of illumination. In this machine, we use the halogenlamp (150w) for illumination. If we can use the lamp which has higher intensity, we can get higher speed of inspection. But in this case, the shadow-mask master plate is damaged by the heat of the light. So we couldn't use the lamp which has much higher intensity than this one.
Author's Reply: In the developed pattern recognition system, the profile pattern is recognized as a polygon. Therefore, if a slightly curved contour portion is to be recognized, only the corners which change the corner angle extremely are detected. The recognition limit of the corner angle change to be recognized is from greater than 45° to less than 135°.
Discusser: Affiliation:
A. Izumidate Nippon Steel Corp., JAPAN
Discussion: SESSION 3: AUTOMATIC ASSEMBLY AND INSPECTION (11)
STUDY ON AUTOMATIC VISUAL INSPECTION OF SHADOW-MASK MASTER PATTERNS Authors: Y. Nakagawa, H. Makihira, N. Akiyama, T. Numakura and T. Nakagawa Discusser: Affiliation:
A. Kuni Hitachi Ltd. JAPAN
Discussion: Have you ever investigated the use of the laser hologram for the inspection of such repetition patterns? Authors' Reply: We have discussed whether or not we can use the technique of hologram or optical Fourier transformation. But we didn't dare to use this technique. The emulsion thickness on the shadow mask master plate is not constant all over the plate surface. But in an optical Fourier transformation, the variation of the emulsion thickness can detected with high sensitivity. But it doesn't necessarily mean that the variation is a defect. For this reason we could not use this method, Discusser: Affiliation:
A. Niemi Helsinki Univ. of Tech., FINLAND
Discussion: Is the amount of illumination of the plate a limiting factor to the speed of operation?
Does the magnitude of the reflected light vary depending on the flatness of the surface ? It means that threshold level must vary depending on the flatness of the surface. Namely, threshold level must vary depending on both magnitude of the injected light and the flatness of the surface. Don't you think that this may limit the accuracy of this system? Why is not area-array applied tll this system? Authors' Reply: The flatness doesn't influence the magnitude of the transmitted light, but the roughness of the glass plate does. The surface of the glass plate is so smooth that the roughness doesn't influence the magnitude of the transmitted light. When the magnitude of the injected light varies, the threshold level should be varied. This machine has the adaptive thresholding ability in which the thresholding level varies in response to the detected signal level. In an area-array, a certain area is detected. In the case that a large area must be detected, the shadow-mask plate should be driven in a step and repeat motion. During the detection, the shadow-mask plate has to keep the position without any motion. But, in a linear-array sensor, a row of patterns is detected, during the shadow-mask plate is being driven. In this case, the driving control is very easy and speed is very high. Every time after the longitudinal plate driving, the detecting head is driven transverse, step by step, so the sensor can detect a new row . A linear-array sensor has little distortion, high detection speed and small detector size. In these points of view, we used the solid-state linear image sensor as a detecto~!....r!....._ _ _ _ _ _ _ _ __
Te chni ca l pa pe r dis c ussi ons
SESSION 4: ROBOTICS AND MATERIAL HANDLING (I)
A ROBOT HAND WITH ELASTIC FINGERS AND ITS APPLICATION TO ASSEMBLY PROCESSES Authors:
H. Hanafusa and H. Asada
CLASSIFICATION OF GRASPED OBJECT'S SHAPE BY AN ARTIFICIAL HAND WITH MULTI-ELEMENT TACTILE SENSORS
Affiliation:
Author:
Discussion:
G-I Kinoshita
Di scusser:
C. A. Rosen
379
Di scusser:
G. Kinoshita Chuo Univ., JAPAN
Have you considered using lateral inhibition to enhance the contrast of your multiple sensors? This would sharpen up discontinuities.
1) You proposed the rigidity matrix Q. I understand the physical meaning of the diagonal elements in the matrix Q. But the non-diagonal elements are not clear. Would you please explain the meaning? 2) Is your robot's hand able to adjust the handling force arbitrarily for various shapes of objects? 3) How much is the clearance of the parts mated in your experiments?
Author's Reply:
Authors' Reply:
I think it is important that for extracting the feature of objects, enhancing the contrast of multiple sensors should be considered.
1) The handling force can be written as follows:
Affiliation:
SRI, USA
Discussion:
Discusser: Affiliation:
H. Asada Kyoto Univ., JAPAN
Discussion: 1) What sequence do you use to let the robot hand grasp the object? 2) Do you have any experiments to verify the Eq. (2.3) for practical materials? Author's Reply: 1) Thumb is opposed to the index, middle, ring, and little finger. And each finger is controlled sequentially. 2) This problem is now under consideration. Discusser: Affiliation:
:l
Px Py
+
Pe
*
qxy
*
b. Xa
*
*
*
b.Ya
*
*
*
1',8
a
I explain by an example. The element qxy means the ratio between F and b.y . Thus the row diagonal elements x mean a the interactions between the components of the handling force and the object deviation in different directions. 2) The possibility to adjust Band C to construct desired P and Q is determined from det R, and the fact that each finger force has the limit to generate, such as 0 < f. < Max f .. The details are discussed in 1 ChaptJr 4 of the paper. 3) The clearance between the block and the fixture is less than O.lmm.
I. Bey Ges. fUr Kernforschung, FRG
Discussion: Is the system planned to be applied in industry- if yes, where and when will that be?
TASK-ORIENTED VARIABLE CONTROL OF A MANIPULATOR AND ITS SOFTWARE SERVOING SYSTEM Author:
K. Takase
Author's Reply: Discusser: We have no plan, now . We want to apply in industry.
Affiliation: Discussion:
H. Asada Kyoto Univ . , JAPAN
Technical Paper
380
You introduced H-variables. How do you apply H-variables to the task shown in the film? Author's Reply: For example, when the manipulator saws a board, H-variables are determined in the space where the sawing task is carried out, as shown in the Figure.
Discu~sions
build up a calibration-point for all three axis of the machine-tool. The position of the calibration-point is very precise measured while the machine-tool is under good thermal conditions. Before measuring the workpiece geometry with the special probe, the probe has to be checked at the calibration-point, to see if there is any deviation from the given value coming, for instance, from thermal deformation of the machine-tool.
PROPOSAL OF THE MULTILAYERED CONTROL OF MACHINE FOR FULLY AUTOMATED MACHINING OPERATIONS
T~OLS
Authors:
T. Sata and K. Matsushima
Discusser: Board to be cut Saw
H is set to zero by 3-D position feedback c6ntrol. The position of H is decided by the environmental constraint, Z and a downward force is applied. Control of Hl realizes the reciprocating motion for cutt;~g.
Affiliation:
T. Watanabe Kyoto Univ., JAPAN
Discussion: In your system, the identification of the parameters functions well in Fig. 9. There are four parameters in Eq. 9. Therefore, I think these parameters are decided after collecting four measured values. How long does it take to determine these parameters? Authors' Reply:
SESSION 6 : AUTOMATIZATION OF MATERIAL PROCESSING (I)
ADVANTAGES AND CONDITIONS FOR A DIRECT MEASUREMENT OF THE WORKPIECE-GEOMETRY ON NCMACHINE TOOLS Authors:
" T. Pfei Fer and A. Furst
Discusser: Affiliation:
T. Sata Univ. of Tokyo, JAPAN
The control system on the first level starts to control the cutting variables by using the parameters assumed in advance. After getting a simple datum of the tool wear, the system is able to evaluate the parameters by using equation (17). From an economical point of view it is advisable to perform such a computation after getting several data of the tool wear, unless the system recognizes a considerably large error in the predetermined parameters. So I would like to say that the computation is performed every half day, for example. The real computing time by a minicomputer is much shorter than 1 second. Discsser: H. -J. Warnecke
Discussion:
Affiliation:
How do you take into account thermal deformation of the machine-tool?
Discussion:
Authors' Reply: The system I introduced here is not running yet, but in a planning status. We hope to get first experiences at the end of the next year. Coming back to the question, I've plan to
Univ. of Stuttgart, FRG
Much research work has been done world-wide in the adaptive control field, the response in industry and application is in comparison rather poor. Where do you see the reason and have you already done some cost-value-analysis for your system?
38 1
Techn i ca l p a p er di sc u s si o n s
Authors' Reply: The reason why the adaptive control of a machine tool does not attract the interests of the industrial people, lies in the fact that the function of the simple adaptive control system is not enough to take an operator away from the side of the machine tool, resulting in little contribution to cost reduction. Our research on the multilayered control of a machine tool doe s not reach to the level to be able to make exact economical evaluation on the merit brought by the system. Discusser: Affiliation:
M. Soeda
What kind of merit or profit can be expected by using that system? Please list up the items, for example: 1. saving the operator 2. making the cutter life longer 3.
4.
Authers' Reply: If we will be successful to realize a fully automated machining operations, many advantages would be expected . These are: 1) to increase productivity even in batch production, 2) to reduce machining cost due to saving of the labour cost and 3) to give workers better working environment.
Affiliation:
Discusser: Affiliation:
H. J. Warnecke Univ. ef Stuttgart, FRG
Discussion : Especially the NC machine being expensive it seems to me that the number of shifts is of great influence to the machining cost, more for instance than the number of operators per machine. Am I right in this assumption ? Authors' Reply:
Tokai Univ., JAPAN
Discus s ion :
Discusser:
Authors: M. Soeda, H. Yonaiyama and E. Yamaguchi
G. K. Hutchinson Univ. of Wisconsin, USA
Discus s ion: How was the overhead cost (Mc) in eq . 1 determined? Authers ' Reply : The overhead cost in equation (1) is the conventional one which includes depreciation of the machine tool, the labour cost and others.
THE ROLE OF NUMERICAL CONTROL USED FOR THE MANUFACTURING PROCE SS IN MACHINING ON MAIN INDUSTRIES IN JAPAN
The cost of man power will be increased proportionally, or over proportionally, with increasing of number of shift. By this reason, cost/product is not so much changed as we expect, so long as shift is concerned. But depreciation period is largely changed toward advantageous condition. Judging from the above factor, I presume the cost may be decreased in some degree depending on conditions. This condition will be left to study further .
Tec hni ca 1 Pap(! r Di scus s io n s
382
SESSION 7: AUTOMATIZATION OF MATERIAL PROCESSING (11)
A METHOD OF TOOL PATH DISTRIBUTION ON A CNC Author:
M. Kiyokawa
Discusser:
design, is 12 m/min. The sampling speed is in that case 1/200 s. We are controlling the spindle drives in an open loop manner, so we just send a command value to the drive system . The only problem is the command value resolution, which can be fairly high in some cases.
T. Pfeifer
Affiliation : Werkzeugmaschinenlabor, Aachen, FRG Discussion:
AN ADAPTIVE CNC SYSTEM OF A MILLING MACHINE TOOL Author:
How is running your method when there is only a few material to be cut? That means, when the rough-part is very similar to the finishedpart-geometry.
T. Watanabe
Discusser: Affiliation:
Y. Morita Tokyo Institute of Technology, Japan
Author's Reply: Discussion: The method mentioned here is for cutting barstock on a lathe. There is no special consideration on the amount of material to be cut . The cutting area can be calculated by this method according to the information of the shape and allowance to be finished.
Would it be possible to measure the temperature of the tool tip? Some of the radiation sensitive instruments are capable of detecting the temperature of a spot having very small diameter, say 70 fjm. Author's Reply:
MULTIMICROPROCESSOR CONTROL SYSTEM FOR SPECIAL PURPOSE MACHINE TOOLS Author:
A. Kuisma, K.
Discusser: Affiliation:
M~kel~
and E. Rasi
T. Watanabe Kyoto University, Japan
Discussion: 1.
In Fig.5, the microprocessor controls many servo systems . Do you need the priority interrupt system?
2.
How much are the maximum feed rate and spindle speed of the machine controlled by your system?
Author's Reply: 1.
We have only one program that is executed every 1/200 ... 1/50 second. It is doi ng all the control of slide units one after another and it is also checking some limit switches for safety etc. So no interrupt signals from the slide units are used.
2.
The maximum feed rate, we have used in our
Of course, it is possible to measure the tool tip temperature directly. I think that there are three representative methods. The first method is to use a thermocouple consisting of the tool and work. But, the value measured by this method indicates the mean temperature over the total tool-work interface as mentioned in this presentation . The second method is to use a thermocouple constructed by the thin wire set in the tool tip and the work material. But, in the case of using a milling cutter, it is difficult to set the thin wire in the tool tip. The third method is to use radiation sensitive instruments as is advised from you. But, this method has some prob l ems . Fi rst ly , t he temp erature of the tool tip, while contacting with the work, can not be measured. Secondly, the chip and the cutting fluid disturb the measurement. Thirdly, the mutual positions between the tool and the work vary widely in milling, therefore, the instrument must be moved. We think it is practical to compute the temperature at the flank wear of the tool tip theoretically, because it can be done easily by a minicomputer and it is not affected by the chip and the cutting fluid
383
Te chni ca l pap e r di s c uss i ons
CNC APPLICATIONS
Author:
Author:
Discusser :
R. Nozawa
Discusser: Affiliation:
T. Sata University of Tokyo, Japan
Discussion: 1.
2.
I would like to know how the output of the measuring device is connected with CNC to compensate the setting error of a large workpiece. Is the simulater to find the mulfunction of the machine tool the hardwired one or the softwired one?
Author's Reply: 1.
The probe is moved to a workpiece by the jog or manual pulse generator capability of the CNC. The CNC updates the position and store the final position (position of workpiece) in the memory.
2.
The simulater in the check system is realized by a hardware.
N. Nishiwaki M. Kiyokawa
Affiliation: Discussion:
Are there any problems on the optical fiber sensor, which may be influenced by the vibraton of tool? Author's Reply: If there is any vibration of the tool during cutting, it will be recorded by the optical fiber as a noise signal as shown in Fig.6(b). Since the signal obtained through this sensor is used to investigate the surface roughness as well as the chatter behaviour, the vibration of tool is not suppcsed to create any problem.
EXTRA-CYCLIC PASSAGES OF GRAY CODES AND THEIR APPLICATIONS FOR NUMERICAL CONTROL DESIGN Author:
H.J. Leskiewicz
Discusser: CNC APPLICATIONS
Affiliation :
Author:
Discussion:
R. Nozawa
Discusser: Affiliation:
T. Pfeifer
2.
For which part of a NC system, is your Gray code available?
Author' s Reply: 1.
The hazard may take place in going from one state to another when two or more letters are changed simultaneously in the two coding expres s ions of those states. Thi s should be avoided by proper coding, although this is not always possible.
2.
The method presented in the paper explains first if such a proper coding is possible, and where this is so, gives all codes protecting from hazard from which the designer may choose. The application of the method is as wide as the problem of proper coding of any states which do not form a cycle of states which appear only once in this cycle.
Author's Reply: The same probe with tracer control is used for detecting actual work positions.
CONTROL SYSTEM OF NC MACHINE TOOL FOR HIGH WORKING ACCURACY
Kyoto University, Japan
What is the cause of generating the hazard phenomena in the NC system in the case of using the ordinary method?
Discussion :
SESSION 8: AUTOMATIZATION OF MATERIAL PROCESSING (Ill)
T. Watanabe
1.
Werkzeugmaschinenlabor, Aachen, FRG
What type of probe do you use for identifying the actual workpiece po sition on the table of the CNC machine-tool?
Mitsubishi Electric Corp., Japan
Tec hnical Paper Discussio n f
384
SESSION 9: PRODUCTION CONTROL (I)
of the prdctical control s imulati on for determining optimal plannlng.
AN ANALYSIS OF WATER SUPPLY AND STORAGE CAPACITY Author:
SESSION 10: PRODUCTION CONTROL (11)
T. Odanaka
Discusser: Affiliation:
G.K. Hutchir.son The University of Wisconsin, USA
IMPLEMENTING AN INFORMATION CONTROL SYSTEM FOR MANUFACTURING
Discussion:
Author : J.A . Ase ltine
Has the control theory you developed been applied to the original water supply control problem? With what results? (i.e. What would the plot for one week, like figures 2 & 3, look using your optimal control?)
Di scusser :
Author's Reply: Yes, I have applied my control theory to the original water supply control problem, and given the theoretical background. Simulation excersises have been carried out and some numerical results have been obtained.
Affiliation:
J. Talavage Purdue University, USA
Discussion: Did you co nsider, in the design stages, the use of a decentralized network of, say, minicomput · ers? Author's Reply: The state of the art in software requires the use of a central computer for efficient data base handling. However , we do use about 10 minicomputers for automated inspection, the data being sent to the large computer for inclusion i n the Jata b3s e .
INFORMATION STRUCTURES, DYNAMIC TEAM DECISION, AND AN ECONOMIC APPLICATION Author:
H. Myoken
Discusser: Affiliation:
G. Hutchinson The University of Wiscon s in, USA
IMPLEMENTING AN INFORMATION CONTROL SYSTEM FOR MANUFACTURING Author:
J.A. Aseltine
Discussion:
Di sc usser :
Could you tell us where you expect to go with your interesting work from this point in time?
Affiliation:
M. Terao University of Tokyo, Japa n
Discussion : Author's Reply : As mentioned in this paper, most of studies on the decentralized control problems from a team decision approach have been pres criptive and very formal rather than empirical. This paper presents a new practical and empirical method in order to hold an empirical validity of promise for inte0 rating and ext ending our knowledge about information and decision. As an illustrative example, the realistic multi-item firm mouel is considered, and then we explain in details regarding the procedure
Was there a probl em with the time- sharing use of many CRT's on the fac tory floor? Author's Reply : We exp ~ nded core memory as terminals and data ba se expanded to keep respon se time to about 10 seconds in max. Incidentally, we had no difficulty in training manufacturing personnel to use the term inals-d~e, I think, to their interest in obtaining data so efficientl y.
Technica l pape r disc u ssions
"PASS" AN INTERACTIVE ONLINE SIMULATOR FOR PREDICTIVE PRODUCTION CONTROL Author :
K. Tabata
Discusser: Affiliation:
G.K. Hutchinson The Univers ity of Wisconsin, USA
385
Discusser : What resources were required to develop PASS? Author's Reply : 18 months with one and a half persons were required to develop PASS.