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

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 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:

• data obtaining means for obtaining dimensional data on the basis of outputs of said measuring device, said dimensional data including a dimensional error of the processed workpieces, and a variable indicative of a tendency of change in said dimensional error of the workpieces, said data obtaining means 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 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;
• said data obtaining means obtaining a present dimensional error value which is a difference of said present value of said estimated dimension from a nominal dimension of the working portion of said each workpiece, said data obtaining means obtaining a present value of said variable, on the basis of a predetermined second number of successive dimensional error values, when said present dimensional error value is obtained, said predetermined number of successive dimensional error values consisting of said present dimensional error value and at least one error value which precedes said present dimensional error value;
• said data obtaining means including at least one of dimension estimating means and variable obtaining means, said dimension estimating means obtaining said present value of said estimated dimension in a standard manner when the number of the successive measured values currently available is not smaller than said predetermined first number, and in a special manner different from said standard manner, when the number of said successive measured values currently available is smaller than said predetermined first number, said variable obtaining means obtaining said present value of said variable in a standard manner when the number of the successive dimensional error values currently available is not smaller than said predetermined second number, and in a special manner different from said standard manner for said variable, 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 variable, and applying said compensating signal to said machine control means, to adjust said working condition of said working machine.

A method of processing a plurality of workpieces by a working system including (a) a working machine for successively processing said 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 measuring device for measuring actual dimensions of working portions of the workpieces processed by said working machine, said method by comprising:

• a step of obtaining dimensional data on the basis of outputs of said measuring device, said dimensional data including a dimensional error of the processed workpieces, and a variable indicative of a tendency of change in 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 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 of said present value of said estimated dimension from a nominal dimension of the working portion of said each workpiece, and (c) obtaining a present value of said variable, on the basis of a predetermined second number (L) of successive dimensional error values, when said present dimensional error value is obtained, said predetermined number of successive dimensional error value consisting of said present dimensional error value and at least one error value which precedes said present dimensional error value;
• and
• a step of 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 variable, 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 is characterized by comprising at least one of two features (d) and (e), said feature (d) consisting in obtaining said present value of said estimated dimension in a standard manner when the number of the successive measured values currently available is not smaller than said predetermined first number, and in a special manner different from said standard manner, when the number of said successive measured values currently available is smaller than said predetermined first number, said feature (e) consisting in obtaining said present value of said variable in a standard manner when the number of the successive dimensional error values currently available is not smaller than said predetermined second number, and in a special manner different from said standard manner for said variable, when the number of said successive dimensional error values currently available is smaller than said predetermined second number.

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 a plurality of working portions in the form of a plurality of coaxial outer cylindrical surfaces arranged in an axial direction thereof, said working machine including an array of working tools which correspond to said plurality of 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 plurality of 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 (116) 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 controlling said machine such that an operating angle of said array of working tools relative to said each workpiece is adjusted and said working operation of the machine on said each workpiece is terminated, 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 plurality of working portions of said each workpiece measured by said post-process measuring device;
• and
• applying means for applying said two compensating values to said machine control means.

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 a plurality of working portions in the form of a plurality of coaxial outer cylindrical surfaces arranged in an axial direction thereof, said working machine including an array of working tools which correspond to said plurality of 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 plurality of 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 controlling said machine such that an operating angle of said array of working tools relative to said each workpiece is adjusted and said working operation of the machine on said each workpiece is terminated, 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 plurality of working portions of said each workpiece measured by said post-process measuring device and
• applying for applying said two compensating values to said machine control means.

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.

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.

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 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 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;
• and
• applying means for applying said compensating value to said machine control means.

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, to process said each working portion as desired, such that working operations on said plurality of the workpieces take place successively one after another, (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 the working portions of the workpieces processed or under processing by said working machine, said feedback compensating apparatus being used with said machine control means and said measuring device, said apparatus comprising:

• data obtaining means for obtaining dimensional data on the basis of outputs of said measuring device during at least one of a first period and a second period following said first period, said working operation on said each working portion being performed during said first period, said dimensional data including a dimensional error of the working portions of the workpieces;
• and
• compensating means for determining a compensating value as said extraneous signal on the basis of said dimensional data, and effecting the adjustment of said working condition of said machine according to the determined compensating value when said compensating value is outside a predetermined tolerable range, said compensating means inhibiting the adjustment of said working condition according to said compensating value when said compensating value falls within said tolerable range.

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:

• obtaining dimensional data including a dimensional error of the working portions of the workpieces, during at least one of a first period and a second period following said first period, said working operation on said each working portion being performed during said first period;
• determining a compensating value as said extraneous signal on the basis of said dimensional data;
• and
• adjusting said working condition of said working machine according to said compensating value when said compensating value is outside a predetermined tolerable range, and inhibiting the adjustment of said working condition according to said compensating value when said compensating value falls within said tolerable range.

A feedback compensating apparatus for 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 feedback compensating apparatus being used with said machine control means and said measuring device, said apparatus comprising:

• manual compensating means for effecting an manual adjustment of said working condition of said machine (110), said manual compensating means 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 applying said manual compensating value to said machine control means;
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• automatic compensating means for effecting an automatic adjustment of said working condition, said automatic compensating means determining also as said extraneous 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 the actual dimensions of the working portion of the workpieces which have been measured by said measuring device, 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 measuring device.