Apparatus and method for feedback-adjusting working condition for improving dimensional accuracy of processed workpieces

• US 6,415,200 B1
• Filed: 02/12/1993
• Issued: 07/02/2002
• Est. Priority Date: 02/14/1992
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Kobayashi, Takahiro, Kato, Chisato, Kitao, Kazuo
• Primary Examiner(s): Gordon, Paul P.
• Assistant Examiner(s): Rao, Sheela S.
• Application Number:
  US08/016,979
• Time in Patent Office: 3,427 Days
• Field of Search: 364/468, 364/148, 364/149, 364/150, 364/474.21, 364/474.2, 364/474.35, 364/551.01, 364/551.02, 364/552, 700/193, 700/108, 700/78, 702/84
• US Class Current: 700/193
• CPC Class Codes: G05B 19/401 characterised by control arrangements for measuring, e.g. calibration and initialisation, measuring workpiece for machining purposes G05B19/19 takes precedence
• CPC Class Codes: G05B 2219/34065 Fuzzy logic, controller
• CPC Class Codes: G05B 2219/37345 Dimension of workpiece, diameter
• CPC Class Codes: G05B 2219/37525 Mean, average values, statistical derived values
• CPC Class Codes: G05B 2219/37536 Rate of change, derivative
• CPC Class Codes: G05B 2219/37574 In-process, in cycle, machine part, measure part, machine same part
• CPC Class Codes: G05B 2219/37577 In-process and post-process measurement combined
• CPC Class Codes: G05B 2219/45156 Grind on lathe
• CPC Class Codes: G05B 2219/45161 Grinding machine
• CPC Class Codes: G05B 2219/49277 Oscillating, swinging feed drive, for grinding
• CPC Class Codes: G05B 2219/50008 Multiple, multi tool head, parallel machining
• CPC Class Codes: G05B 2219/50063 Probe, measure, verify workpiece, feedback measured values
• CPC Class Codes: G05B 2219/50307 Correction by probing dimension of machined workpiece

Abstract

A feedback compensating apparatus for adjusting the working condition of a working machine of a working system adapted to process working portions of successive workpieces under control of a machine controller, which determines the working condition from an extraneous signal. The apparatus is used with the controller and a measuring device for measuring the dimensions of the processed working portions of the workpieces, and includes a device for obtaining dimensional data based on outputs of the measuring device during and/or after a working operation of the machine on each workpiece. The dimensional data include a dimensional error of the processed working portions, and a variable indicative of a tendency of change in the dimensional error. The apparatus further includes a device for determining the extraneous signal based on the dimensional data, and applying the signal to the machine controller to adjust the working condition of the machine. Also disclosed is a method of processing workpieces using the apparatus.

Claims

1. A feedback compensating apparatus for a working system including a working machine for performing a working operation on at least one working portion of each of a plurality of workpieces, to process said each working portion as desired, such that working operations on said plurality of the workpieces take place successively one after another, and machine control means for determining a working condition of said working machine on the basis of an extraneous signal, and for controlling said working machine according to the determined working condition, the apparatus comprising;

a measuring device for measuring actual dimensions of the working portions of the workpieces processed or under processing by said working machine;

said measuring device including a post-process measuring device for measuring the actual dimensions of the working portions of the workpieces previously processed by said working machine, said post-process measuring device being positioned relative to said working machine such that there exists at least one pre-measured workpiece previously processed by said machine and which has not been measured by said post-process measuring device;

data obtaining means for obtaining dimensional data on the basis of outputs of said Post-Process measuring device said dimensional data including a dimensional error of the working portions of the workpieces, and a derivative of said dimensional error of the workpieces, said derivative representing a gradient of a straight line approximating successive measured values represented by the outputs of said post-process measuring device, said successive measured values including a currently measured value currently obtained by said post-process measuring device and at least one measured value which precedes said currently measured value; and

compensating means for determining a compensating signal as said extraneous signal on the basis of said dimensional data, and for applying said compensating signal to said machine control means, to adjust said working condition of said working machine.

2. A feedback compensating apparatus according to claim 1, wherein said plurality of workpieces consist of a plurality of cylinder blocks for an engine of a motor vehicle, and said at least one working portion consists of at least one cylinder bore formed in each of said cylinder blocks, said working machine consisting of a honing machine for honing an inner cylindrical surface of each of said at least one cylinder bore.

3. A feedback compensating apparatus according to claim 1, wherein said plurality of workpieces consist of a plurality of crankshafts for an engine of a motor vehicle, and said at least one working portion consists of at least one journal formed on each of said crankshafts, said working machine consisting of a cylindrical grinding machine for grinding an outer cylindrical surface of each of said at least one journal.

4. A feedback compensating apparatus according to claim 1, wherein said measuring device further includes an in-process measuring device for measuring the actual dimensions of the working portions during said working operation on each working portion said machine control means performing an in-process control of said working condition on the basis of an output of said in-process measuring device, and wherein said data obtaining means obtains as said dimensional error differences between the actual dimensions of said processed working portions measured by said post-process measuring device and a nominal value of said working portions, said data obtaining means further obtaining, as said derivative representing said gradient, a derivative of said differences, said compensating means determining said compensating signal on the basis of said differences and said derivative of said differences, and applying said compensating signal to said machine control means so as to adjust a reference value which is set in said machine control means as said working condition, said data obtaining means and said compensating means cooperating to perform a post-process control of said working condition, so that said machine control means controls said working condition by comparing an output of said in-process measuring device with said reference value as adjusted according to said compensating signal as determined by said compensating means.

5. A feedback compensating apparatus according to claim 1, wherein said compensating means comprises fuzzy inference means for effecting fuzzy inference to obtain a fuzzy inference value, on the basis of said dimensional data, said fuzzy inference value affecting said compensating signal.

6. A feedback compensating apparatus according to claim 1, wherein said compensating means determines said compensating signal in the form of a compensating value representative of an amount of adjustment of said working condition, such that said compensating value is changed toward zero, when said dimensional error and said derivative obtained by said data obtaining means are larger than respective threshold values.

7. A feedback compensating apparatus according to claim 1, wherein said compensating means determines said compensating signal in the form of successive compensating values representative of respective amounts of adjustment of said working condition, on the basis of said dimensional data on the working portions successively processed by said machine, said compensating means comprising determining means for determining said successive compensating values such that a present one of said successive compensating values is determined on the basis of said dimensional data currently obtained by said data obtaining means, and at least one preceding compensating value of said successive compensating values which precedes said present one compensating value,

and wherein said determining means determines a present provisional compensating value as said present one of said successive compensating values on the basis of said dimensional error and said derivative of said dimensional error, and adjusts said present provisional compensating value into a present final compensating value such that said present final compensating value lies on a line which is determined by said present provisional compensating value and a plurality of preceding provisional compensating values which precede said present provisional compensating value, said line assuring a gradual change in said amounts of adjustment of said working condition.

8. A feedback compensating apparatus according to claim 7, wherein said determining means determines, as said line assuring said gradual change in said amounts of adjustment of said working condition, a first order regression line on the basis of said present provisional compensating value and said preceding provisional compensating values.

9. A feedback compensating apparatus according to claim 1, wherein said data obtaining means obtains on the basis of said outputs of said measuring device, said dimensional error, and as said derivative of said dimensional error a first derivative of said dimensional error, and a derivative of said second derivative of said dimensional error.

10. A feedback compensating apparatus according to claim 1, wherein said data obtaining means includes means for obtaining a present value of an estimated dimension of the working portions of the workpieces on the basis of a predetermined first number of successive measured values represented by outputs of the measuring device, said data obtaining means further obtaining a present dimensional error value which is a difference between said present value of said estimated dimension and a nominal dimension of the working portion of each workpiece, said data obtaining means further obtaining a present value of said derivative, on the basis of a predetermined second number of successive dimensional error values which include said present dimensional error value, and wherein said data obtaining means includes at least one of the dimension estimating means and derivative obtaining means, said dimension estimating means obtaining said present value of said estimated dimension in a first manner when the number of the successive measured values currently available is not smaller than said predetermined first number, and in a second manner different from said first manner, when the number of said successive measured values currently available is smaller than said predetermined first number, and in a second manner different from said first manner, when the number of said successive measured values currently available is smaller than said predetermined first number, said derivative obtaining means including means for obtaining said present value of said derivative in a third manner when the number of the successive dimensional error values currently available is not smaller than said predetermined second number, and in fourth manner different from said third manner, when the number of said successive dimensional error values currently available is smaller than said predetermined second number.

11. A feedback compensating apparatus according to claim 1, wherein said each workpiece has at least three working portions in the form of at least three coaxial outer cylindrical surfaces arranged in an axial direction thereof, said working machine including an array of working tools which correspond to said at least three working portions, respectively, said array of working tools being moved relative to said each workpiece to simultaneously process said working portions, and wherein said measuring device further includes an in-process measuring device and a post-process measuring device, said in-process measuring device having two in-process measuring heads for measuring diameter values of respective two end working portions of said at least three working portions, during a working operation of said machine on said each workpiece, said two end working portions being located near opposite axial ends of said each workpiece, said post-process measuring device measuring diameter values of said at least three working portions, respectively, after said each workpiece is processed by said machine, said machine control means performing an in-process control of an operating angle of said array of working tools relative to said each workpiece and terminating said working operation of the machine on said each workpiece, on the basis of said diameter values of said two end working portions measured by laid in-process measuring heads, in relation to two reference values set for said two end working portions, respectively, said compensating means comprising:

determining means for determining two compensating values for adjusting said two reference values, on the basis of said diameter values of all of said at least three working portions of said each workpiece measured by said post-process measuring device, said determining means including diameter adjusting means for adjusting the diameter values of said two end working portions of the workpiece measured by said post-process measuring device so that the diameter values of said all of said at least three working portions measured by said post-process measuring device lie on a line which assures a gradual chance of said diameter values in said axial direction; and

applying means for applying said two compensating values to said machine control means.

12. A feedback compensating apparatus according to claim 1, wherein the working machine performs the working operations successively on said plurality of workpieces of at least one kind, and wherein said data obtaining means obtains a set of dimensional data for each of said at least one kind of the workpieces, said apparatus further comprising:

number data obtaining means for obtaining the number of said pre-measured workpieces of each of said at least one kind processed by said machine and which have not been measured by said post-process measuring device,

said compensating means including means for determining as said extraneous signal a compensating value for said each said at least one kind of the workpieces, on the basis of said set of dimensional data and said number of said pre-measured workpieces of the corresponding kind which have been obtained by said data obtaining means and said number data obtaining mans, respectively, said compensating means for applying said compensating value to said machine control means.

13. A feedback compensating apparatus according to claim 1, wherein said measuring device successively measured the workpieces processed by said working machine, wherein said compensating means includes:

determining means for determining as said extraneous signal a compensating value for adjusting said working condition of said working machine, on the basis of said dimensional data obtained by said data obtaining means, said determining means updating said compensating value from time to time on an intermittent basis while said workpieces processed by said machine are measured successively by said measuring device, such that said determining means chances said compensating value from a last value to a present value, only after a first one of the workpieces processed by said machine under the working condition adjusted by said last value has been measured by said measuring device, whereby said compensating value is not updated for a period after said last value is determined and before said first one of the workpieces has been measured; and

applying means for applying said compensating value to said machine control means.

14. A feedback compensating apparatus according to claim 1, wherein said compensating means includes:

determining means for determining as said extraneous signal a compensating value for adjusting said working condition of said machine for the workpieces to be processed subsequently by said machine, on the basis of the actual dimensions of the working portion of the workpieces which have been measured by said measuring device, and according to a compensation rule which changes with a change in a variation amount of measured values of said actual dimensions successively obtained by said post-process measuring device; and

applying means for applying said compensating value to said machine control means.

15. A feedback compensating apparatus according to claim 1, where in s aid compensating means applies said compensating value to said machine control means to adjust said working condition of said machine when said compensating value is outside a predetermined tolerable range, and inhibits the application of said compensating value to said machine control means when said compensating value falls within said tolerable range.

16. A feedback compensating apparatus according to claim 1, further comprising manual compensating means for effecting a manual adjustment of said working condition of said machine, said manual compensating means determining also as said extraneous signal a manual compensating value to adjust said working condition of said machine, in response to manual compensating data entered by an operator of said machine, said manual compensating means applying said manual compensating value to said machine control means, and wherein said compensating means functions as automatic compensating means for effecting an automatic adjustment of said working condition, said automatic compensating means determining as said compensating signal an automatic compensating value for adjusting said working condition of said machine for the workpieces to be processed subsequently by said machine, on the basis of said dimensional data obtained by said data obtaining means, said automatic compensating means applying said automatic compensating value to said machine control means,

said automatic compensating means interrupting an operation to effect said automatic adjustment when said manual adjustment by said manual compensating means is started, and resuming said operation to effect said automatic adjustment, at a moment not earlier than a moment when a first one of the workpieces processed by said machine under the working condition adjusted by said manual compensating value has been measured by said post-process measuring device.

17. A feedback compensating apparatus according to claim 1, wherein said data obtaining means obtains, as said straight line approximating said successive measured values represented by the outputs of said post-process measuring device, a first order regression line on the basis of a present one of said successive measured values, and at least one preceding measured value of said successive measured values which precedes said present one measured value.

18. A feedback compensating apparatus according to claim 1, wherein said data obtaining means obtains a moving average of a present one of said successive measured values represented by the outputs of said post-process measuring device, and at least one preceding measured value of said successive measured value which precedes said present one measured value, data obtaining means obtaining said dimensional error on the basis of said moving average.

19. A method of processing at least one working portion provided on each of a plurality of workpieces, such that said workpieces are successively processed one after another by a working machine, comprising the steps of:

operating a post-process measuring device to measure actual dimensions of the working portions of the workpieces which have been processed by said working machine, such that between said machine and said post-process measuring device, there exists at least one pre-measured workpiece previously processed by said machine and which has not been measured by said measuring device;

obtaining dimensional data including a dimensional error of the processed working portions of the workpieces, and a derivative of said dimensional error of the workpieces, said derivative representing a gradient of a straight line approximating successive measured values represented by the outputs of said post-process measuring device, said successive measured values consisting of a currently measured value currently obtained by said post-process measuring device and at least one measured value which precedes said currently measured value; and

feeding back said dimensional data to said working machine, to adjust a working condition of said machine on the basis of said dimensional data, for subsequent working operation on the working portions of the workpieces according to the adjusted working condition.

20. A method according to claim 19, wherein said step of obtaining dimensional data comprises obtaining, as said straight line approximating said successive measured values represented by the outputs of said post-process measuring device, a first order regression line on the basis of a present one of said successive measured values, and at least one preceding measured value of said successive measured values which precedes present one measured value.

21. A method according to claim 19, wherein said step of obtaining dimensional data comprising obtaining a moving average of a present one of said successive measured values represented by the outputs of said post-process measuring device, and at least one preceding measured value of said successive measured value which precedes said present one measured value.

22. A feedback compensating apparatus for a working system including a working machine for successively processing a plurality of workpieces, and machine control means for determining a working condition of said working machine on the basis of an extraneous signal, and controlling said working machine according to the determined working condition, the apparatus comprising;

a measuring device for measuring actual dimensions of working portions of the workpieces processed by said working machine,

said measuring device including a post-process measuring device for measuring the actual dimensions of the working portions of the workpieces previously processed by said working machine, said post-process measuring device being positioned relative to said working machine such that there exists at least one pre-measured workpiece which has been processed by said machine and which has not been measured by said post-process measuring device and further comprising;

data obtaining means for obtaining dimensional data on the basis of outputs of said post-process measuring device, said dimensional data including a dimensional error of the processed workpieces, and a derivative of said dimensional error of the workpieces, said data obtaining mans obtaining a present value of an estimated dimension of the working portions of the workpieces on the basis of a predetermined first number of successive measured values represented by the outputs of said post-process measuring device, said predetermined first number of successive measured values consisting of a currently measured value currently obtained by said post-process measuring device and at least one measured value which precedes said currently measured value;

said data obtaining means for obtaining a present dimensional error value which is a difference between said present value of said estimated dimension and a nominal dimension of the working portion of said each workpiece, said data obtaining means including means for obtaining a present value of said derivative, on the basis of a predetermined second number of successive dimensional error values, when said present dimensional error value is obtained, said predetermined second number of successive dimensional error values including said present dimensional error value and at least one error value which precedes said present dimensional error value, said derivative representing a gradient of a straight line approximating said successive dimensional error values;

said data obtaining means including at least one of the dimension estimating means and the derivative obtaining means, said present value of said estimate dimension in a first manner when the number of the successive measured values currently available is not smaller than said predetermined first number, and in a second manner different from said first manner, when the number of said successive measured values currently available is smaller than said predetermined first number, said derivative obtaining means obtaining said present value of said variable in a third manner when the number of the successive dimensional error value currently available is not smaller than said predetermined second number, and in a fourth manner different from said third manner, when the number of said successive dimensional error values currently available is smaller than said predetermined second number; and

compensating means for determining a compensating signal as said extraneous signal on the basis of said present value of said estimated dimension and said present value of said derivative, and for applying said compensating signal to said machine control means, to adjust said working condition of said working machine.

23. A feedback compensating apparatus according to claim 22, wherein said dimension estimating means obtains said present value of said estimated dimension in said first manner by inserting said predetermined first number of successive measured values into a predetermined equation, when the number of said successive measured values currently available is not smaller than said predetermined first number, said dimension estimating means obtaining said present value of said estimated dimension in said second manner by substituting said currently measured value for said present value of said estimated dimension, when said successive measured values currently available is smaller than said predetermined first number.

24. A feedback compensating apparatus according to claim 22, wherein said dimension estimating means obtains said present value of said estimated dimension in said first manner by inserting said predetermined first number of successive measured values into a predetermined equation, when the number of said successive measured values currently available is not smaller than said predetermined first number, said dimension estimating means obtaining said present value of said estimated dimension in said second manner by inserting successive measured values currently available whose number is smaller than said predetermined number, into an appropriate one of other equations which correspond to respective numbers smaller than said predetermined first number, when the number of said successive measured values currently available is smaller than said predetermined first number.

25. A feedback compensating apparatus according to claim 22, wherein said derivative obtaining means obtains said present value of said variable in said third manner by inserting said predetermined second number of successive dimensional error values into a predetermined equation, when the number of said successive dimensional error values currently available is not smaller than said predetermined second number, said derivative obtaining means obtaining said present value of said variable in said fourth manner by inserting successive dimensional error values currently available whose number is smaller than said predetermined number, into an appropriate one of other equations which correspond to respective numbers smaller than said predetermined second number, when the number of said successive dimensional error values currently available is smaller than said predetermined second number.

26. A method of processing a plurality of workpieces by a working system including a working machine for successively processing said plurality of workpieces, and machine control means for determining a working condition of said working machine on the basis of an extraneous signal, and for controlling said working machine according to the determined working condition, and a post-process measuring device for measuring actual dimensions of working portions of the workpieces processed by said working machine, said method comprising the steps of:

operating said post-process measuring device to measure the actual dimensions of the working portions of the workpieces which have been processed by said machine, such that between said machine and said measuring device, there exists at least one pre-measured workpiece which has been processed by said machine and which has not been measured by said measuring device;

obtaining dimensional data on the basis of outputs of said post-process measuring device, said dimensional data including a dimensional error of the processed workpieces, and a derivative of said dimensional error of the workpieces, said step of obtaining dimensional data including the sub-steps of (a) obtaining a present value of an estimated dimension of the working portions of the workpieces on the basis of a predetermined first number of successive measured values represented by the outputs of said measuring device, when each of the workpieces is measured by the measuring device, said predetermined first number of successive measured values consisting of a currently measured value currently obtained by said measuring device and at least one measured value which precedes said currently measured value, (b) obtaining a present dimensional error value which is a difference between said present value of said estimated dimension and a nominal dimension of the working portion of said each workpiece, and (c) obtaining a present value of said derivative, on the basis of a predetermined second number of successive dimensional error values, when said present dimensional error value is obtained, said predetermined second number of successive dimensional error values including said present dimensional error value and at least one error value which precedes said present dimensional error value;

determining a compensating signal as said extraneous signal on the basis of said present value of said estimated dimension and said present value of said derivative; and

applying said compensating signal to said machine control means, to adjust said working condition of said working machine,

and wherein said step of obtaining dimensional data comprises at least one of two substeps (d) and (e), said substep (d) comprising obtaining said present value of said estimated dimension in a first manner when the number of the successive measured values currently available is not smaller than said predetermined first number, and in a second manner different from said first manner, when the number of said successive measured values currently available is smaller than said predetermined first number, said substep (e) including obtaining said present value of said derivative in a third manner when the number of the successive dimensional error values currently available is not smaller than said predetermined second number, and in a fourth manner different from said third manner, when the number of said successive dimensional error values currently available is smaller than said predetermined second number.

27. A feedback compensating apparatus for a working system including (a) a working machine for successively processing a plurality of workpieces one after another, each of said workpieces having at least three working portions in the form of at least three coaxial outer cylindrical surfaces arranged spaced from one another in an axial direction thereof, said working machine including an array of working tools which correspond to said at least three working portions, respectively, said array of working tools being moved relative to said each workpiece to simultaneously process said working portions, (b) an in-process measuring device having two in-process measuring heads for measuring diameter values of respective two end working portions of said at least three working portions, during a working operation of said machine on said each workpiece, said two end working portions being located near opposite axial ends of said each workpiece, (c) a post-process measuring device for measuring diameter values of said at least three working portions, respectively, after said each workpiece is processed by said machine, (d) and machine control means for performing an in-process control of an operating angle of said array of working tools relative to said each workpiece and terminating said working operation of the machine on said each workpiece, on the basis of said diameter values of said two end working portions measured by said in-process measuring heads, in relation to two reference values set for said two end working portions, respectively, said feedback compensating apparatus being used with said post-process measuring device and said machine control means, said apparatus comprising:

determining means for determining two compensating values for adjusting said two reference values, on the basis of said diameter values of all of said at least three working portions of said each workpiece measured by said post-process measuring device, said determining means including diameter adjusting means for adjusting the diameter values of said two end working portions of the workpiece measured by said post-process measuring device so that the diameter values of all of said at least three working portions measured by said post-process measuring device lie on a line which assures a gradual change in said axial direction; and

applying means for applying said two compensating values to said machine control means.

28. A feedback compensating apparatus for a working system including (a) a working machine for successively processing a plurality of workpieces one after another, each of said workpieces having at least three working portions in the form of at least three coaxial outer cylindrical surfaces arranged in an axial direction thereof, said working machine including an array of working tools which correspond to said at least three working portions, respectively, said array of working tools being moved relative to said each workpiece to simultaneously process said working portions, (b) an in-process measuring device having two in-process measuring heads for measuring diameter values of respective two end working portions of said at least three working portions, during a working operation of said machine on said each workpiece, said two end working portions being located near opposite axial ends of said each workpiece, (c) a post-process measuring device for measuring diameter values of said at least three working portions, respectively, after said each workpiece is processed by said machine, and (d) machine control means for performing an in-process control of an operating angle of said array of working tools relative to said each workpiece and terminating said working operation of the machine on said each workpiece, on the basis of said diameter values of said two end working portions measured by said in-process measuring heads, in relation to two reference values set for said two end working portions, respectively, said feedback compensating apparatus being used with said post-process measuring device and said machine control means said apparatus comprising:

determining means for determining two compensating values for adjusting said two reference values, on the basis of said diameter values of all of said at least three working portions of said each workpiece measured by said post-process measuring device, said determining means including diameter adjusting means for adjusting the diameter values of said two end working portions of the workpiece measured by said post-process measuring device so that the diameter values of said all of said at least three working portions measured by said post-process measuring device lie on a line which assures a gradual change in said axial direction; and

applying means for applying said two compensating values to said machine control means,

wherein said determining means includes;

diameter adjusting means for adjusting the diameter values of said two end working portions of the workpiece measured by said post-process measuring device, so that the diameter values of all of said at least three working portions measured by said post-process measuring device lie on a first order regression line;

data obtaining means for obtaining dimensional error data relating to a dimensional error of each of said two end working portions, on the basis of the diameter values of said two end working portions adjusted by said diameter adjusting means; and

means for determining said two compensating values for adjusting said two reference values, on the basis of said dimensional error data.

29. A method of processing a plurality of workpieces by a working system including (a) a working machine for successively processing said plurality of workpieces one after another, each of said workpieces having at least three working portions in the form of at least three coaxial outer cylindrical surfaces arranged spaced from one another in an axial direction thereof, said working machine including an array of working tools which correspond to said at least three working portions, respectively, said array of working tools being moved relative to said each workpiece to simultaneously process said working portions, (b) an in-process measuring device having two in-process measuring heads for measuring diameter values of respective two end working portions of said at least three working portions, during a working operation of said machine on said each workpiece, said two end working portions being located near opposite axial ends of said each workpiece, (c) a post-process measuring device for measuring diameter values of said plurality of working portions, respectively, after said each workpiece is processed by said machine, and (d) machine control means for performing an in-process control of an operating angle of said array of working tools relative to said each workpiece and terminating said working operation of the machine on said each workpiece, on the basis of said diameter values of said two end working portions measured by said in-process measuring heads, in relation to two reference values set for said two end working portions, respectively, said method comprising the steps of:

determining two compensating values for adjusting said two reference values, on the basis of said diameter values of all of said at least three working portions of said each workpiece measured by said post-process measuring device, said step of determining two compensating values including adjusting the diameter values of said two end working portions of the workpiece measured by said post-process measuring device so that the diameter values of all of said at least three working portions measured by said post-process measuring device lie on a line which assures a gradual change in said axial direction; and

applying said two compensating values to said machine control means.

30. A feedback compensating apparatus for a working system including (a) a working machine for performing a working operation on each of at least one working portion of each of a plurality of workpieces of at least one kind, to process said each working portion as desired, such that working operations on said plurality of workpieces take place successively one after another, (b) machine control means for determining a working condition of said machine on the basis of an extraneous signal, and controlling said machine according to the determined working condition, and (c) a post-process measuring device for measuring actual dimensions of the working portions of the workpieces processed by said machine, said feedback compensating apparatus being used with said machine control means and said post-process measuring machine, said apparatus comprising:

dimensional data obtaining means for obtaining a set of dimensional error data relating to a dimensional error of the processed working portions of the workpieces, for each of said at least one kind of the workpieces, on the basis of outputs of said post-process measuring device;

number data obtaining means for obtaining the number of pre-measured workpieces of each of said at least one kind which have been processed by said machine and which have not been measured by said post-process measuring device; and

compensating means for determining as said extraneous signal a compensating value for said each kind of the workpieces, on the basis of said set of dimensional error data and said number of said pre-measured workpieces of the corresponding kind which have been obtained by said dimensional data obtaining means and said number data obtaining means, respectively, said compensating means applying said compensating value to said machine control means, to adjust said working condition of said machine for the workpieces of said each kind to be subsequently processed.

31. A feedback compensating apparatus according to claim 30, wherein said plurality of workpieces are of a single kind, and said compensating means includes memory means for storing a plurality of control rules which correspond to selected respective values of said number of said pre-measured workpieces and which define respective different relationships between said compensating value and said set of dimensional error data for said single kind of workpieces, said memory means also storing a plurality of data groups which correspond to said plurality of control rules and which define relationships between said number of said pre-measured workpieces to be obtained by said number data obtaining means, and an optimum degree of influence of said control rules to be given on said compensating value to be determined, said compensating means determining the optimum degree of influence of each of said control rules, which optimum degree corresponds to said number of said pre-measured workpieces obtained by said number data obtaining means, said compensating means determining said compensating value based on the determined optimum degree of influence, said plurality of control rules and said dimensional error data.

32. A method of processing a plurality of workpieces by a working system including (a) a working machine for performing a working operation on each of at least one working portion of each of said workpieces of at least one kind, to process said each working portion as desired, such that working operations on said plurality of workpieces take place successively one after another, (b) machine control means for determining a working condition of said machine on the basis of an extraneous signal, and controlling said machine according to the determined working condition, and (c) a post-process measuring device for measuring actual dimensions of the working portions of the workpieces processed by said machine, said method comprising the steps of:

obtaining a set of dimensional error data relating to a dimensional error of the processed working portions of the workpieces, for each of said at least one kind of the workpieces, on the basis of outputs of said post-process measuring device;

obtaining the number of pre-measured workpieces of each of said at least one kind which have been processed by said machine and which have not been measured by said post-process measuring device;

determining as said extraneous signal a compensating value for said each kind of the workpieces, on the basis of said set of dimensional error data and said number of said pre-measured workpieces of the corresponding kind which have been obtained by said dimensional data obtaining means and said number data obtaining means, respectively; and

applying said compensating value to said machine control means, to adjust said working condition of said machine for the workpieces of said each kind to be subsequently processed.

33. A feedback compensating apparatus for a working system including (a) a working machine for successively processing a plurality of workpieces, (b) machine control means for determining a working condition of said working machine on the basis of an extraneous signal, and controlling said working machine according to the determined working condition, and (c) a post-process measuring device for measuring actual dimensions of working portions of the workpieces processed by said working machine, said working system permitting existence between said machine and said measuring device, of at least one pre-measured workpiece which has been processed by said machine and which has not been measured by said measuring device, said feedback compensating apparatus being used with said machine control means and said measuring device, said apparatus comprising:

determining means for determining as said extraneous signal a compensating value for adjusting said working condition of said working machine for the workpieces to be processed subsequently by said machine, on the basis of the actual dimensions of the working portions of the workpieces which have been measured by said measuring device, said determining means updating said compensating value from time to time on an intermittent basis while said workpieces processed by said machine are measured successively by said measuring device, such that said determining means changes said compensating value from a last value to a present value, only after a first one of the workpieces processed by said machine under the working condition adjusted by said last value has been measured by said measuring device, whereby said compensating value is not updated for a period after said last value is determined and before said first one of the workpieces has been measured; and

applying means for applying said compensating value to said machine control means.

34. A feedback compensating apparatus according to claim 33, wherein said determining means includes memory means for storing measured values of said actual dimensions of the processed workpieces obtained by said measuring device, and determines a present value of said compensating value on the basis of a predetermined number of said measured values stored in said memory means, when the number of said measured values stored in said memory means has become equal to or larger than said predetermined number, said determining means clearing said memory means and resuming an operation to store therein said measured values obtained by said measuring device, after completion of determination of said present value.

35. A feedback compensating apparatus according to claim 33, wherein said determining means includes memory means for storing measured values of said actual dimensions of the processed workpieces obtained by said measuring device, and determines a present value of said compensating value on the basis of a predetermined number of said measured values stored in said memory means, when the number of said measured values stored in said memory means has become equal to or larger than said predetermined number, said determining means clearing said memory means and resuming an operation to store therein said measured values obtained by said measuring device, after a moment when said measuring device has measured a first one of the workpieces processed by said machine under the working condition adjusted by said present value.

36. A feedback compensating apparatus for a working system including (a) a working machine for successively processing a plurality of workpieces, (b) machine control means for determining a working condition of said working machine on the basis of an extraneous signal and controlling said working machine according to the determined working condition, and (c) a post-process measuring device for measuring actual dimensions of working portions of the workpieces processed by said working machine, said working system permitting existence between said machine and said measuring device, of at least one pre-measured workpiece which has been processed by said machine and which has not been measured by said measuring device, said feedback compensating apparatus being used with said machine control means and said measuring device, said apparatus comprising:

determining means for determining, as said extraneous signal a compensating value for adjusting said working condition of said working machine for the workpieces to be processed subsequently by said machine, on the basis of the actual dimensions of the working portions of the workpieces which have been measured by said measuring device, said determining means updating said compensating value from time to time on an intermittent basis while said workpieces processed by said machine are measured successively by said measuring device, such that said determining means changes said compensating value from a last value to a present value, only after a first one of the workpieces processed by said machine under the working condition adjusted by said last value has been measured by said measuring device, whereby said compensating value is not updated for a period after said last value is determined and before said first one of the workpieces has been measured; and

applying means for applying said compensating value to said machine control means,

wherein said determining means includes memory means for storing measured values of said actual dimensions of the processed workpieces obtained by said measuring device, said determining means effects primary compensation and auxiliary compensation to update said compensating value,

said primary compensation including determining a primary compensating value on the basis of a predetermined first number of said measured values stored in said memory means, when the number of said measured values stored in said memory means has become equal to said predetermined first number,

said auxiliary compensation including continuing to store said measured values in said memory means even after completion of determination of said primary compensating value, and determining a present provisional compensating value on the basis of a predetermined second number of said measured values stored in said memory means, when each of the processed workpiece is measured by said measuring device, during a time period between a moment of the completion of determination of said primary compensating value and a moment not later than a moment when a workpiece immediately preceding a first one of the workpieces processed by said machine under the working condition adjusted by said primary compensating value has been measured by said measuring device, said determining means determining as a final auxiliary compensating value a difference of said present provisional compensating value from a last provisional compensating value which immediately precedes said present provisional compensating value, said primary compensating value being used as said last provisional compensating values upon determination of said final auxiliary compensating value for the first time,

said determining means clearing said memory means and resuming an operation to store therein said measured values obtained by said measuring device, after a moment when said measuring device has measured said first one of the workpieces,

said applying means applying said primary compensating value and said final auxiliary compensating values to said machine control means.

37. A feedback compensating apparatus according to claim 36, wherein said determining means includes a counter for counting the number of said final auxiliary compensating values successively determined in said auxiliary compensation, said determining means terminating said auxiliary compensation if a sum of at least a predetermined number of said final auxiliary compensating values when the counted number of the determined final auxiliary compensating values has become equal to said predetermined number, is not substantially equal to zero, and continuing said auxiliary compensation with said counter cleared, if said sum is substantially zero.

38. A feedback compensating apparatus for a working system including (a) a working machine for successively processing a plurality of workpieces, (b) machine control means for determining a working condition of said working machine on the basis of an extraneous signal, and controlling said working machine according to the determined working condition, and (c) a post-process measuring device for measuring actual dimensions of working portions of the workpieces processed by said working machine, said working system permitting existence between said machine and said measuring device, of at least one pre-measured workpiece which has been processed by said machine and which has not been measured by said measuring device, said feedback compensating apparatus being used with said machine control means and said measuring device, said apparatus comprising:

determining means for determining, as said extraneous signal, a compensating value for adjusting said working condition of said working machine for the workpieces to be processed subsequently by said machine, on the basis of the actual dimensions of the working portions of the workpieces which have been measured by said measuring device, said determining means updating said compensating value from time to time on an intermittent basis while said workpieces processed by said machine are measured successively by said measuring device, such that said determining means changes said compensating value from a last value to a present value, only after a first one of the workpieces processed by said machine under the working condition adjusted by said last value has been measured by said measuring device, whereby said compensating value is not updated for a period after said last value is determined and before said first one of the workpieces has been measured; and

applying means for applying said compensating, value to said machine control means,

wherein said determining means includes memory means for storing measured values of said actual dimensions of the processed workpieces obtained by said measuring device, and determines a present value of said compensating value on the basis of a predetermined number of said measured values stored in said memory means, when the number of said measured values stored in said memory means has become equal to or larger than said predetermined number, said determining means clearing said memory means after completion of determination of said present value,

said determining means obtaining an estimated value of said actual dimensions of the workpieces, on the basis of said present value of said compensating value and a present one of said measured values, when each of the processed workpieces is measured by said measuring device to obtain said present one of said measured values, during a time period between a moment when said operation to store said measured values in said memory means is resumed and a moment not later than a moment when a workpiece immediately preceding a first one of the workpieces processed by said machine under the working condition adjusted by said present value of said compensating value has been measured by said measuring device, said determining means determining said estimated value as a dimension of the workpiece which would be measured by said measuring device if said workpiece were processed under the working condition of said machine adjusted by said present value of said compensating value, said determining means storing said estimated value in said memory means, as said actual dimension of said workpiece, immediately preceding said first one of the workpieces, each time said estimated value is obtained during said time period.

39. A feedback compensating apparatus for a working system including (a) a working machine for successively processing a plurality of workpieces, (b) machine control means for determining a working condition of said working machine on the basis of an extraneous signal, and controlling said working machine according to the determined working condition, and (c) a post-process measuring device for measuring actual dimensions of working portions of the workpieces processed by said working machine, said working system permitting existence between said machine and said measuring device, of at least one pre-measured workpiece which has been processed by said machine and which has not been measured by said measuring device, said feedback compensating apparatus being used with said machine control means and said measuring device, said apparatus comprising:

determining means for determining, as said extraneous signal, a compensating value for adjusting said working condition of said working machine for the workpieces to be processed subsequently by said machine, on the basis of the actual dimensions of the working portions of the workpieces which have been measured by said measuring device, said determining means updating said compensating value from time to time on an intermittent basis while said workpieces processed by said machine are measured successively by said measuring device, such that said determining means chances said compensating value from a last value to a present value, only after a first one of the workpieces processed by said machine under the working condition adjusted by said last value has been measured by said measuring device, whereby said compensating value is not updated for a period after said last value is determined and before said first one of the workpieces has been measured; and

applying means for applying said compensating value to said machine control means,

wherein said determining means includes memory means for storing measured values of said actual dimensions of the processed workpieces obtained by said measuring device, said determining means effects primary compensation and auxiliary compensation to update said compensating value,

said primary compensation including determining a primary compensating value on the basis of a predetermined first number of said measured values stored in said memory means, when the number of said measured values stored in said memory means has become equal to or larger than said predetermined first number,

said auxiliary compensation including continuing to store said measured values in said memory means even after completion of determination of said primary compensating value, and determining a present provisional compensating value on the basis of a predetermined second number of said measured values stored in said memory means, when each of the processed workpieces is measured by said measuring device, during a time period between a moment of the completion of determination of said primary compensating value and a moment not later than a moment when a workpiece immediately preceding a first one of the workpieces processed by said machine under the working condition adjusted by said primary compensating value has been measured by said measuring device, said determining means determining as a final auxiliary compensating value a difference of said present provisional compensating value from a last provisional compensating value which immediately precedes said present provisional compensating value, said primary compensating value being used as said last provisional compensating values upon determination of said final auxiliary compensating value for the first time,

said determining means clearing said memory means after completion of said auxiliary compensation, and obtaining an estimated value of said actual dimensions of the workpieces, on the basis of said final auxiliary compensating value and a present one of said measured values, when each of the processed workpieces is measured by said measuring device to obtain said present one of said measured values, during a time period between a moment when said operation to store said measured values in said memory means is resumed and a moment not later than a moment when a workpiece immediately preceding a first one of the workpieces processed by said machine under the working condition adjusted by said primary compensating value has been measured by said measuring device, said determining means determining said estimated value as a dimension of the workpiece which would be measured by said measuring device if said workpiece were processed under the working condition of said machine adjusted by said present value of said compensating value, said determining means storing said estimated value in said memory means each time said estimated value is obtained during said time period,

said applying means applying said primary compensating value and said final auxiliary compensating value to said machine control means.

40. A feedback compensating apparatus according to claim 39, wherein said determining means includes a counter for counting the number of said final auxiliary compensating values successively determined in said auxiliary compensation, said determining means terminating said auxiliary compensation if a sum of at least a predetermined number of said final auxiliary compensating values when the counted number of the determined final auxiliary compensating values has become equal to said predetermined number, is not substantially equal to zero, and continuing said auxiliary compensation with said counter cleared, if said sum is substantially zero.

41. A method of processing a plurality of workpieces by a working system including (a) a working machine for successively processing the workpieces, (b) machine control means for determining a working condition of said working machine on the basis of an extraneous signal, and controlling said working machine according to the determined working condition, and (c) a measuring device for measuring actual dimensions of working portions of the workpieces processed by said working machine, said working system being adapted to permit existence between said machine and said measuring device, of at least one pre-measured workpiece which has been processed by said machine and which has not been measured by said measuring device, said method comprising the steps of:

determining as said extraneous signal a compensating value for adjusting said working condition of said working machine for the workpieces to be processed subsequently by said machine, on the basis of the actual dimensions of the working portions of the workpieces which have been measured by said measuring device, said determining means updating said compensating value from time to time on an intermittent basis while said workpieces processed by said machine are measured successively by said measuring device, such that said compensating value is changed from a last value to a present value, only after a first one of the workpieces processed by said machine under the working condition adjusted by said last value has been measured by said measuring device, whereby said compensating value is not updated for a period after said last value is determined and before said first one of the workpieces has been measured; and

applying said compensating value to said machine control means.

42. A feedback compensating apparatus for a working system including a working machine for successively processing the workpieces, and machine control means for determining a working condition of said working machine on the basis of an extraneous signal, and controlling said working machine according to the determined working condition, the apparatus comprising;

a post-process measuring device for measuring actual dimensions of working portions of the workpieces processed by said working machine compensating;

said post-process measuring device being positioned relative to said working machine such that there exists at least one pre-measured workpiece which has been processed by said machine and which has not been measured by said post-process measuring device;

manual compensating means for effecting a manual adjustment of said working condition of said machine, said manual compensating means for determining as said extraneous signal a manual compensating value to adjust said working condition of said machine, in response to manual compensating data entered by an operator of said machine, said manual compensating means for applying said manual compensating value to said machine control means; and

automatic compensating means for effecting an automatic adjustment of said working condition, said automatic compensating means including means for determining also as said extraneous signal an automatic compensating value for adjusting said work condition of said machine for the workpieces to be processed subsequently by said machine, on the basis of the actual dimensions of the working portion of the workpieces which have been measured by said post-process measuring device, said automatic compensating means for applying said automatic compensating value to said machine control means,

said automatic compensating means including means for interrupting an operation to effect said automatic adjustment when said manual adjustment by said manual compensating means is started, and for resuming said operation to effect said automatic adjustment, at a moment not earlier than a moment when a first one of the workpieces processed by said machine under the working condition adjusted by said manual compensating value has been measured by said measuring device.

43. A feedback compensating apparatus according to claim 42, wherein said automatic compensating means includes memory means for storing the dimensions of the processed workpieces which are successively measured by said measuring device, said automatic compensating means determining said automatic compensating value on the basis of the dimension of the workpiece measured last by said measuring device, and at least one dimension previously measured and stored in said memory means, said automatic compensating means resuming the operation to effect said automatic adjustment by storing the dimensions to be subsequently measured with said memory means cleaned, at said moment not earlier than said moment when said first one of the workpiece has been measured.

44. A feedback compensating apparatus for a working system including a working machine for successively processing workpieces, machine control means for determining a working condition of said working machine on the basis of an extraneous signal, and controlling said working machine according to the determined working condition, and a measuring device for measuring actual dimensions of working portions of the workpieces processed by said working machine, said feedback compensating apparatus being used with said machine control means and said measuring device, said apparatus comprising:

determining means for determining as said extraneous signal a compensating value for adjusting said working conditions of said machine for the workpieces to be processed subsequently by said machine, on the basis of the actual dimensions of the working portion of the workpieces which have been measured by said measuring device, and according to a compensation rule which chances with a change in a dynamic variation amount of measured values of said actual dimensions successively obtained by said measuring device; and

applying means for applying said compensating value to said machine control means;

wherein said determining means determines said compensating value such that said dynamic variation amount of said measured values of said actual dimensions successively obtained by said measuring device is represented by a derivative of said dimensional error of the workpieces obtained by said data obtaining means, said derivative representing a gradient of a straight line approximating said measured values of said actual dimensions.

45. A method of processing a plurality of workpieces by a working system including a working machine for successively processing the workpieces, machine control means for determining a working condition of said working machine on the basis of an extraneous signal, and controlling said working machine according to the determined working condition, and a measuring device for measuring actual dimensions of working portions of the workpieces processed by said working machine, said method comprising the steps of:

determining as said extraneous signal a compensating value for adjusting said working condition of said machine for the workpieces to be processed subsequently by said machine, on the basis of the actual dimensions of the working portion of the workpieces which have been measured by said measuring device, and according to a compensation rule which changes with a change in a dynamic variation amount of measured values of said actual dimensions successively obtained by said measuring device; and

applying said compensating value to said machine control means;

wherein said step of determining said compensating value comprises determining said compensating value such that said dynamic variation amount of said measured values of said actual dimensions successively obtained by said measuring device is represented by a derivative of said dimensional error of the workpieces obtained by said data obtaining means, said derivative representing a gradient of a straight line approximating said measured values of said actual dimensions.