Interpolator for machine tool control

Claim 2

A control for use in controlling movement of a machine tool comprising: a source of pulses having a first pulse rate, feed rate generator means including first pulse rate multiplying means having a plurality of states for modifying the pulse rate of pulses derived from said pulse source in accordance with a multiplier having a value M/N, where N is of a fixed value corresponding with the maximum number of states of said multiplying means and M is a first modifying signal having a value depending upon a function of the values of first, second, and third signals, means for receiving a said first, second, and third signal and deriving as said functions thereof the normalized value of each of said signals, and means for developing from said normalized first, second, and third signals a said first modifying signal M; and function generator means including second and third pulse rate multiplying means for each receiving the said modified output pulses from said feed rate generator means and multiplying the pulse rate thereof by a multiplier M''/N'' wherein M'' for said second rate multiplier is a second modifying signal having a value corresponding with said first signal and M'' for said third rate multiplier is a third modifying signal having a value corresponding with said second signal, and wherein N'' is variable having a maximum value of the same amount for each of said second and third rate multiplier means corresponding with the maximum number of states of each of said second and third rate multiplier means, said second and third rate multipliers having means for respectively receiving said first signal and said second signal, and means for effectively normalizing said first and second signals by varying the value of N'' by the same extent in each of said second and third multiplier means in dependence upon the value of the larger of said first and second signals.

Claim 3

A control as set forth in claim 1, wherein said feed rate generator means includes means for developing said first modifying signal such that it has a value corresponding with the ratio of the normalized third signal to the square root of the sum of the squares of the normalized first and second signals.

Claim 4

A control as set forth in claim 2 including means for providing said first and second signals with values respectively corresponding with commanded displacements of said tool along first and second mutually perpendicular axes.

Claim 5

A control as set forth in claim 2 including means for effectively denormalizing said normalized third signal.

Claim 6

A control as set forth in claim 4, wherein said denormalizing means includes fourth pulse rate multiplying means for multiplying said pulses derived from said pulse source by a multiplying factor dependent upon the value of the unnormalized said third signal.

Claim 7

A control as set forth in claim 5, wherein said denormalizing means is interposed between said pulse source and said first pulse rate multiplying means.

Claim 8

A control as set forth in claim 1, wherein said first pulse rate multiplying means is a counter rate multiplier having counting means for counting N-1 pulses derived from said pulse source.

Claim 9

A control as set forth in claim 1, wherein at least one of said first, second and third pulse rate multiplying means is an adder rate multiplier having an adder means and an accumulator means, means for presetting said adder means to a summation corresponding with an associated one of said first, second and third signals, means for applying pulses derived from said pulse source to said accumulator means to cause the contents thereof to be supplied to said adder means to be added to said preset summation.

Claim 10

A control as set forth in claim 8, wherein said first rate Multiplying means is a counter rate multiplier having counting means for counting N-1 pulses derived from said pulse source and said second and third pulse rate multiplying means is each a said adder rate multiplier wherein its said adder means has a maximum summation value of N''-1.

Claim 11

A control as set forth in claim 8, including means for parallel shifting the contents of said accumulator means into said adder means in response to each said applied pulse, said adder means having circuit means for parallel adding said parallel shifted contents to said preset summation contents to provide an updated summation and means for parallel shifting said adder updated summation into said accumulator means.

Claim 12

A control for use in controlling movement of a machine tool comprising a source of pulses having a first pulse rate, feed rate generator means having at least a first rate multiplier means for modifying the pulse rate of pulses derived from said pulse source in dependence upon the value of a first modifying signal to provide feed rate pulses, function generator means having second and third pulse rate multipliers for receiving said feed rate pulses and respectively modifying the pulse rate thereof in dependence upon the value of a second modifying signal and a third modifying signal to respectively provide first command pulses and second command pulses for controlling movement of a said tool, at least one of said rate multipliers comprises: accumulator means having a plurality of stages and having parallel output circuit means for providing a pattern of output signals wherein the pattern of output signals has a value in accordance with the contents of said accumulator means and input circuit means for receiving a pattern of input signals for updating the contents of the accumulator means in accordance with the value of said pattern of input signals, adder means for receiving a modifying pattern of signals corresponding with the associated one of said first, second or third modifying signals and said pattern of output signals from said accumulator means for adding said two patterns of signals in parallel and providing a summation pattern of signals having a value in accordance with the summation of said two patterns of signals; means for iteratively applying said summation pattern signals in parallel to said input circuit means of said accumulator means to update the contents thereof in accordance with the value of said summation pattern of signals at a rate corresponding with the pulse rate of pulses derived from said pulse source, and circuit means connected to said adder means for deriving carry output pulses therefrom whereby said output pulses have a pulse rate in dependence upon the pulse rate of said derived pulses and the value of said received modifying pattern of signals.

Claim 13

A control for use in controlling movement of a machine tool comprising a source of pulses having a first pulse rate, feed rate generator means having at least a first rate multiplier means for modifying the pulse rate of pulses derived from said pulse source in dependence upon the value of a first modifying signal to provide feed rate pulses, function generator means having second and third pulse rate multipliers for receiving said feed rate pulses and respectively modifying the pulse rate thereof in dependence upon the value of a second modifying signal and a third modifying signal to respectively provide first command pulses and second command pulses for controlling movement of a said tool, at least one of said rate multipliers comprises: accumulator means having a plurality of stages and having parallel output circuit means for providing a pattern of output signals wherein the pattern of output signals has a value in accordance with the contents of said accumulator means and input circuit means for receiving a pattern of input signals for updating the contents of the accumulator means in accordance with the value of said pattern of input signals, adder means for receiving a modifying pattern of signals corresponding with the associated one of said first, second or third modifying signals and said pattern of output signals from said accumulator means for adding said two patterns of signals in parallel and providing a summation pattern of signals having a value in accordance with the summation of said two patterns of signals; means for iteratively applying said summation pattern signals in parallel to said input circuit means of said accumulator means to update the contents thereof in accordance with the value of said summation pattern of signals at a rate corresponding with the pulse rate of pulses derived from said pulse source, and circuit means connected to said adder means for deriving carry output pulses therefrom whereby said output pulses have a pulse rate in dependence upon the pulse rate of said derived pulses and the value of said received modifying pattern of signals.

Claim 14

A control as set forth in claim 11 wherein said adder means has a plurality of summation output circuits for carrying said pattern of summation signals and a carry output circuit for providing a carry output pulse each time said adder means overflows.

Claim 15

A control as set forth in claim 12 including a plurality of gating means respectively connected to an associated one of said adder summation output circuits, and means for selectively enabling one of said plurality of gating means to pass signals from the selected said summation output circuit to provide said carry output pulses therefrom.

Claim 16

A control as set forth in claim 13 including pulse doubling means for doubling the pulse rate of said signals passed by said enabled gating means.

Claim 17

A control as set forth in claim 11 wherein said circuit means for deriving output pulses from said adder means includes means for varying said pulse rate of said derived pulses by a multiplier of M/N wherein M has a value corresponding with said applied modifying pattern of signals and N has a maximum value corresponding with the maximum number of states of said adder means so thAt the maximum summation of said adder means is N-1.

Claim 18

A control as set forth in claim 15 including means for effectively varying the value of N including means for generating carry pulses for a summation output circuit position of said binary adder means in dependence upon the frequency of signal changes at the next most significant summation output circuit position of said adder means.

Claim 19

A control as set forth in claim 16 including means for doubling the pulse rate of the signal changes at said selected summation position for providing output pulses having a pulse rate in accordance with the carry pulse rate for the next least significant summation position of said adder means.

Claim 20

A control as set forth in claim 17 wherein said at least one of said rate multipliers includes said second and third rate multipliers, means for normalizing said second and third modifying signals comprising: summation output circuit selection means for selecting a corresponding summation output circuit of said adder means in each of said second and third rate multipliers with said selection being dependent upon the larger of said second and third modifying signals.

Claim 21

A control as set forth in claim 18 including: first and second storage means for respectively storing said second and third patterns of modifying signals, and most significant position selection means for detecting the storage position of the most significant signal of the larger of said second and third patterns of modifying signals.

Claim 22

A control as set forth in claim 19, including means for providing a coded signal representative of the said storage position of the most significant signal of the larger of said second and third patterns of modifying signals.

Claim 23

A control as set forth in claim 20, wherein said summation output circuit selection means includes means responsive to said coded signal for selecting said corresponding summation output circuits of said adder means in said second and third rate multipliers.