Numerical fine-coarse positioning control system

Claim 2

A numerical positioning control system for controlling the position of at least one axis of a machine comprising: a. a source of input data for providing a command signal indicative of the desired position of the controlled machine axis; b. means for generating a first relatively high frequency reference signal for synchronizing the operation of the system; c. first and second digital counters operatively connected to said reference signal means to be counted thereby so as to supply first and second time varying digital signals; d. means for feeding said input data to said first and second counters so as to preset said counters to numbers proportional to said input data; e. a single position transducer operatively connected to said reference signal means and mechanically coupled to the controlled machine axis so as to be excited by said reference signal means and operative to generate a phase varying signal indicative of the position of said controlled axis; f. phase varying means operatively connected to said position transducer for generating a second phase varying signal having a scale factor greater than the scale factor of said position transducer; g. a first comparator operatively connected to said first counter and said phase varying means to generate a signal indicative of the phase difference between the outputs of said first counter and said phase varying means; h. a second comparator operatively connected to said second counter and to said position transducer operative to generate a signal indicative of the phase difference between the outputs of said second counter and said position transducer; and, i. driving means operatively connected to said first and second comparators and being operative to move said controlled machine axis in accordance with the outputs of said first and second comparators.

Claim 3

The numerical positioning control system recited in claim 1 further comprising cycle control means operatively connected to said position transducer for generating a digital pulse indicative of a predetermined amount of travel by the controlled machine axis, the output of said cycle control means being operatively connected to said phase varying means so as to advance or retard the phase thereof.

Claim 4

The numerical positioning control system recited in claim 2 wherein said phase varying means comprises a third digital counter operatively connected to said reference signal means and to said cycle control means so as to be counted by said reference signal means and operative to vary in phase in response to output pulses from said cycle control means.

Claim 5

The numerical positioning control system recited in claim 3 wherein said cycle control means comprisEs: a. a reversible counter operatively connected to said position transducer and to said reference signal means, said reversible counter being operative to be counted in a first direction by said reference signal and in the opposite direction by the output of said position transducer; and b. monitoring means operatively connected to said reversible counter for monitoring the count stored in said reversible counter and operative to generate a pulse each time the count in said reversible counter exceeds a predetermined number.

Claim 6

Digital control means for generating a second phase varying digital signal in response to a first phase varying digital signal, said second digital signal having a scale factor greater than the scale factor of said first digital signal comprising: a. means for supplying a reference signal having a frequency proportional to said first digital signal; b. a source of said first digital signal comprising a single position transducer whose output signal varies in phase as a function of position; c. a reversible counter operatively connected to said source of said first digital signal and to said reference signal means, said reversible counter being operative to be counted in a first direction by said reference signal and in the opposite direction by said first digital signal; d. monitoring means operatively connected to said reversible counter for monitoring the count stored in said reversible counter and operative to generate a digital pulse each time the count exceeds a predetermined number; and e. a digital counter operatively connected to said reference signal means and said monitoring means, said digital counter being operative so as to be counted by said reference signal and further operative to be phase varied in response to pulses from said monitoring means.

Claim 7

Digital control means for generating a second phase varying digital signal in response to a first phase varying digital signal, said second digital signal having a scale factor greater than the scale factor of said first digital signal comprising: a. means for supplying a reference signal having a frequency proportional to said first digital signal; b. a source of said first digital signal comprising a single position transducer whose output signal varies in phase as a function of position; c. a reversible counter operatively connected to said source of said first digital signal and to said reference signal means, said reversible counter being operative to be counted in a first direction by said reference signal and in the opposite direction by said first digital signal; d. monitoring means operatively connected to said reversible counter for monitoring the count stored in said reversible counter and operative to generate a digital pulse each time the count exceeds a predetermined number; and e. a digital counter operatively connected to said reference signal means and said monitoring means, said digital counter being operative so as to be counted by said reference signal and further operative to be phase varied in response to pulses from said monitoring means.

Claim 8

The digital control means recited in claim 5 further comprising means for connecting the output of said monitoring means to said reversible counter so as to count said reversible counter.

Claim 11

A phase discriminator for generating output signals indicative of the phase difference between two phase varying signals comprising: a. first means for generating a first phase varying signal having a first basic frequency comprising a single position transducer operatively connected to one axis of a controlled machine tool so as to indicate the position thereof; b. second means for generating a second phase varying signal having the same basic frequency as said first phase varying signal and indicative of the desired position of said cOntrolled machine tool axis; c. a first frequency divider operatively connected to said first means for generating a third phase varying signal proportional to said first phase varying signal; d. a second frequency divider operatively connected to said second means for generating a fourth phase varying signal proportional to said second phase varying signal; e. first phase comparing means operatively connected to said first and second means for generating an output signal proportional to the phase difference between said first and second phase varying signals; and f. second phase comparing means operatively connected to said first and second frequency dividers and to the output of said first phase comparing means for generating an output signal proportional to the phase difference between said third and fourth phase varying signals at the rate determined by the basic frequency of said output signal from said first phase comparing means.

Claim 12

A phase discriminator for generating output signals indicative of the phase difference between two phase varying signals comprising: a. first means for generating a first phase varying signal having a first basic frequency comprising a single position transducer operatively connected to one axis of a controlled machine tool so as to indicate the position thereof; b. second means for generating a second phase varying signal having the same basic frequency as said first phase varying signal and indicative of the desired position of said cOntrolled machine tool axis; c. a first frequency divider operatively connected to said first means for generating a third phase varying signal proportional to said first phase varying signal; d. a second frequency divider operatively connected to said second means for generating a fourth phase varying signal proportional to said second phase varying signal; e. first phase comparing means operatively connected to said first and second means for generating an output signal proportional to the phase difference between said first and second phase varying signals; and f. second phase comparing means operatively connected to said first and second frequency dividers and to the output of said first phase comparing means for generating an output signal proportional to the phase difference between said third and fourth phase varying signals at the rate determined by the basic frequency of said output signal from said first phase comparing means.

Claim 13

The phase discriminator recited in claim 8 further comprising a pulse width-to-current converter operatively connected to the output of said second phase comparing means for generating current pulses proportional to the width of said output signal from said second phase comparing means.

Claim 14

A discriminator system for generating an output signal representative of the position error of at least one axis of a controlled machine tool comprising: a. first and second phase varying means for generating first and second phase varying digital signals having different scale factors and being indicative of the desired position of said controlled machine tool axis; b. a single position transducer operatively connected to said controlled machine tool axis for generating a third phase varying signal having a scale factor corresponding to the scale factor of said first phase varying signal, said third phase varying signal being indicative of the actual position of said controlled machine tool axis; c. means for generating a fourth phase varying digital signal indicative of the actual position of said controlled machine tool axis and having a scale factor corresponding to the scale factor of said second phase varying digital signal; d. first zone detecting means operatively connected to said second phase varying means and to said means for generating said fourth phase varying signal being operative to generate an output signal when said position error exceeds a first predetermined amount; e. a first pulse width-to-current converter operatively connected to said first zone detecting means and to said second phase varying means and said means for generating said fourth phase varying signal and being operative to generate an output current which is a function of the phase difference between said second and fourth phase varying signals in response to said output signal from said first zone detecting means; f. second zone detecting means operatively connected to said second phase varying means and to said means for generating said fourth phase varying signal and being operative to generate an output signal when said position error is less than a second predetermined amount; and g. a second pulse width-to-current converter operatively connected to said second zone detecting means and to said first phase varying means and said position transducer and being operative to generate an output current proportional to the phase difference between said first and third phase varying signals in response to said output from said second zone detecting means.

Claim 15

A discriminator system for generating an output signal representative of the position error of at least one axis of a controlled machine tool comprising: a. first and second phase varying means for generating first and second phase varying digital signals having different scale factors and being indicative of the desired position of said controlled machine tool axis; b. a single position transducer operatively connected to said controlled machine tool axis for generating a third phase varying signal having a scale factor corresponding to the scale factor of said first phase varying signal, said third phase varying signal being indicative of the actual position of said controlled machine tool axis; c. means for generating a fourth phase varying digital signal indicative of the actual position of said controlled machine tool axis and having a scale factor corresponding to the scale factor of said second phase varying digital signal; d. first zone detecting means operatively connected to said second phase varying means and to said means for generating said fourth phase varying signal being operative to generate an output signal when said position error exceeds a first predetermined amount; e. a first pulse width-to-current converter operatively connected to said first zone detecting means and to said second phase varying means and said means for generating said fourth phase varying signal and being operative to generate an output current which is a function of the phase difference between said second and fourth phase varying signals in response to said output signal from said first zone detecting means; f. second zone detecting means operatively connected to said second phase varying means and to said means for generating said fourth phase varying signal and being operative to generate an output signal when said position error is less than a second predetermined amount; and g. a second pulse width-to-current converter operatively connected to said second zone detecting means and to said first phase varying means and said position transducer and being operative to generate an output current proportional to the phase difference between said first and third phase varying signals in response to said output from said second zone detecting means.

Claim 16

The discriminator system recited in claim 10 wherein said means for generating said fourth phase varying digital signal comprises a digital counter operatively connected to said position transducer and being operative to be counted by a reference signal so as to generate a phase varying signal whose phase varies as a function of the movement of said position transducer.

Claim 17

The discriminator system recited in claim 11 further comprising cycle control means operatively connected to said position transducer for generating a digital pulse indicative of a predetermined amount of travel by the controlled machine tool axis, the output of said cycle control means being operatively connected to said digital counter so as to advance or retard the phase thereof.

Claim 18

The discriminator system recited in claim 10 further comprising first and second frequency dividers having their inputs operatively connected to said first phase varying means and said position transducer, respectively, and their outputs operatively connected to said second pulse width-to-current converter.