Trigonometric signal generator and machine control

Claim 5

The apparatus of claim 2 wherein said output error signal is phase-detected to form a first system signal indicative of the direction from null of the displacement of said first and second relatively movable members, wherein said output error signal is rectified to form a second system signal proportional to the magnitude of the displacement from null of said first and second relatively movable members, and wherein said control means further includes, strobe generation means for generating strobe pulses, null crossover detector means connected to receive said first system signal and connected to said strobe generation means, said detector means operative to sample said first system signal, only after receipt of each one of said strobe pulses, so as to generate a first binary level when sampling indicates displacement of said first and second relatively movable members in one direction and to generate a second binary level when the sampling indicates displacement of said relatively movable members in the opposite direction.

Claim 6

The apparatus of claim 3 wherein said control means further includes, pulse rate generator means, connected to receive said second system signal, for generating operating pulses having a frequency related to the magnitude of said second system signal.

Claim 7

The apparatus of claim 4 wherein said strobe generation means includes, inhibit means connected to said pulse rate generator means for inhibiting said strobe generation means from generating said strobe pulses at any time when a pulse from said pulse rate generator means is present.

Claim 8

The apparatus of claim 4 wherein said pulse rate generator means includes, a variable frequency oscillator means for generating oscillator pulses variable over a frequency range, substantially including the range from 500 to 500KHz, as a function of the magnitude of said second system signal, and timing circuitry means connected to said source and connected to said variable frequency oscillator for generating one of said operating pulses for each one of said oscillator pulses such that each one of said operating pulses has a timed relation with a pulse from said source.

Claim 9

The apparatus of claim 4 wherein said pulse rate generator means includes, a variable frequency oscillator, asynchronous with respect to said source, for generating oscillator pulses, variable over a first frequency range, as a function of the magnitude of said second system signal, means for synchronously deriving first pulses having a constant frequency and having a timed relation to said input signals, means for combining said oscillator pulses and said first pulses for generating said operating pulses whereby said operating pulses are substantially said constant frequency when the magnitude of said second system signal indicates that said first and second relatively movable members of said position measuring device are in the vicinity of the null position, and wherein, said strobe generation means generates one of said strobe pulses for each one of said operating pulses.

Claim 10

The apparatus of claim 4 wherein the number of said operating pulses supplied to said generation means equals n whereby said operating pulses generate said digital count difference between the counts in said first and second counter means.

Claim 11

The apparatus of claim 8 wherein said first binary level from said null crossover detector means causes said operating pulses to generate a count difference between the counts in said first and second counter means in one direction and wherein said second binary level from said null crossover detector means causes said operating pulses to generate a count difference between the counts in said first and second counter means in the opposite direction.

Claim 12

The apparatus of claim 9 wherein said null crossover detector includes, a two stage shift register stepped by said strobe pulses for recording the status of said first system signal each time one of said strobe pulses is received, external generator means, connected to said shift register means, for generating an inhibit signal when said shift register stages are not identical, said external generating including means responsive to said inhibit signal for inhibiting transmission of said operating pulses.

Claim 13

A plural axes system responsive to the position indications of first and second position measuring devices, one for each of two axes, said first position measuring device comprising relatively movable first and second members inductively related to form an output first error signal as a function of the relative space position of said first and second members and as a function of first analog input signals to said first position measuring device, said second position measuring device comprising relatively movable third and fourth members inductively related to form an output second error signal as a function of the relative space position of said third and fourth members and as a function of second analog input signals to said second position measuring device, said system comprising, first and second control means responsive to said first and second error signals, respectively, for controlling digital counts which define the digital magnitude of first and second numbers, respectively, representative of the relative space position of said first and second members and of said third and fourth members, respectively, a source of pulses, first and second counter means and third and fourth counter means where each counter means is operative to be stepped, by stepping pulses having a timed relation to the pulses of said source, cyclically through a count range, first and second generation means responsive to said first and second control means, respectively, for generating first and second digital count differences, respectively, between the counts in said first and second counter means and between the counts in said third and fourth counter means, respectively, where said first and second count differences are proportional to the digital magnitude of said first and second numbers, respectively, first and second combining means for logically combining signals from said first and second counter means and from said third and fourth counter means, respectively, so as to generate said first and second input signals, respectively, each of said first input signals having an analog component proportional to a function of said first digital count difference and each of said second input signals having an analog component proportional to a function of said second digital count difference, and a reference counter operative to be stepped by stepping pulses synchronously derived from said source, said reference counter maintaining a count representing a number midway between numbers represented by the counts in said first and second counter means and midway between numbers represented by the counts in said third and fourth counter means.

Claim 14

A plural axes system responsive to the position indications of first and second position measuring devices, one for each of two axes, said first position measuring device comprising relatively movable first and second members inductively related to form an output first error signal as a function of the relative space position of said first and second members and as a function of first analog input signals to said first position measuring device, said second position measuring device comprising relatively movable third and fourth members inductively related to form an output second error signal as a function of the relative space position of said third and fourth members and as a function of second analog input signals to said second position measuring device, said system comprising, first and second control means responsive to said first and second error signals, respectively, for controlling digital counts which define the digital magnitude of first and second numbers, respectively, representative of the relative space position of said first and second members and of said third and fourth members, respectively, a source of pulses, first and second counter means and third and fourth counter means where each counter means is operative to be stepped, by stepping pulses having a timed relation to the pulses of said source, cyclically through a count range, first and second generation means responsive to said first and second control means, respectively, for generating first and second digital count differences, respectively, between the counts in said first and second counter means and between the counts in said third and fourth counter means, respectively, where said first and second count differences are proportional to the digital magnitude of said first and second numbers, respectively, first and second combining means for logically combining signals from said first and second counter means and from said third and fourth counter means, respectively, so as to generate said first and second input signals, respectively, each of said first input signals having an analog component proportional to a function of said first digital count difference and each of said second input signals having an analog component proportional to a function of said second digital count difference, and a reference counter operative to be stepped by stepping pulses synchronously derived from said source, said reference counter maintaining a count representing a number midway between numbers represented by the counts in said first and second counter means and midway between numbers represented by the counts in said third and fourth counter means.

Claim 15

A plural axes system responsive to the position indications of first and second position measuring devices, one for each of two axes, said first position measuring device comprising relatively movable first and second members inductively related to form an output fiRst error signal as a function of the relative space position of said first and second members and as a function of first analog input signals to said first position measuring device, said second position measuring device comprising relatively movable third and fourth members inductively related to form an output second error signal as a function of the relative space position of said third and fourth members and as a function of second analog input signals to said second position measuring device, said system comprising, first and second control means responsive to said first and second error signals, respectively, for controlling digital counts which define the digital magnitude of a first number n1 and of a second number n2, respectively, wherein n1 is representative of the relative space position of said first and second members and wherein n2 is representative of the relative space position of said third and fourth members, respectively, a source of pulses having a frequency NF, first and second counter means and third and fourth counter means where each counter means is operative to be stepped, by stepping pulses having a timed relation to the pulses of said source, cyclically through a count range proportional to N, first and second generation means responsive to said first and second control means, respectively, for generating first and second digital count differences, respectively, between the counts in said first and second counter means and between the counts in said third and fourth counter means, respectively, where said first and second count differences are proportional to n1 and n2, respectively, first and second combining means for logically combining signals from said first and second counter means and from said third and fourth counter means, respectively, so as to generate said first and second input signals, respectively, each of said first input signals having an analog component of frequency F proportional to a sinusoidal function of theta 1 where theta 1 equals 360(n1/N) degrees and each of said second input signals having an analog component of frequency F proportional to a sinusoidal function of theta 2 where theta 2 equals 360(n2/N) degrees, and a reference counter operative to be stepped, by stepping pulses synchronously derived from said source, said reference counter maintaining a count representing a number midway between the numbers represented by the counts in said first and second counter means and midway between the numbers represented by the counts in said third and fourth counter means.

Claim 16

A plural axes system responsive to the position indications of first and second position measuring devices, one for each of two axes, said first position measuring device comprising relatively movable first and second members inductively related to form an output fiRst error signal as a function of the relative space position of said first and second members and as a function of first analog input signals to said first position measuring device, said second position measuring device comprising relatively movable third and fourth members inductively related to form an output second error signal as a function of the relative space position of said third and fourth members and as a function of second analog input signals to said second position measuring device, said system comprising, first and second control means responsive to said first and second error signals, respectively, for controlling digital counts which define the digital magnitude of a first number n1 and of a second number n2, respectively, wherein n1 is representative of the relative space position of said first and second members and wherein n2 is representative of the relative space position of said third and fourth members, respectively, a source of pulses having a frequency NF, first and second counter means and third and fourth counter means where each counter means is operative to be stepped, by stepping pulses having a timed relation to the pulses of said source, cyclically through a count range proportional to N, first and second generation means responsive to said first and second control means, respectively, for generating first and second digital count differences, respectively, between the counts in said first and second counter means and between the counts in said third and fourth counter means, respectively, where said first and second count differences are proportional to n1 and n2, respectively, first and second combining means for logically combining signals from said first and second counter means and from said third and fourth counter means, respectively, so as to generate said first and second input signals, respectively, each of said first input signals having an analog component of frequency F proportional to a sinusoidal function of theta 1 where theta 1 equals 360(n1/N) degrees and each of said second input signals having an analog component of frequency F proportional to a sinusoidal function of theta 2 where theta 2 equals 360(n2/N) degrees, and a reference counter operative to be stepped, by stepping pulses synchronously derived from said source, said reference counter maintaining a count representing a number midway between the numbers represented by the counts in said first and second counter means and midway between the numbers represented by the counts in said third and fourth counter means.