Apparatus measuring relative velocity of movable members including means to detect velocity from the position encoder

Claim 2

signal to provide an error signal. 9. Apparatus as in claim 8 where said plurality of windings consists of second and third windings which are in

Claim 3

space quadrature. 10. Apparatus as in claim 8 together with means for inverting at least a portion of said velocity signals and commutating such signal along with the non-inverted velocity signals. .[.11. Apparatus for the control of relative position and relative velocity between two relatively movable members comprising: transducer means coupled to said movable members producing an electric alternating position signal having periods inversely proportional to the velocity between said members, the peak amplitudes of said position signal being substantially constant with changes in velocity and the slope of said position signal at its zero crossing being proportional to instantaneous relative velocity, means for deriving from said slope information of said position signal a velocity signal said deriving means including means for differentiating said position signal with respect to time to provide said velocity signal whose maximum instantaneous magnitudes are proportional to instantaneous velocity and which provides a continuous indication of velocity, means for deriving a reference signal from said position signal said reference signal having periods proportional to said periods of said position signal and an amplitude proportional to the amplitude of said position signal, means for comparing said reference signal with said velocity signal to provide an error signal, and motor means for providing said relative velocity between said two movable members said motor means being responsive to said error signal to vary said relative velocity in a manner to minimize said error signal said continuous indication of velocity maintaining, in cooperation with said reference signal, said relative

Claim 4

velocity at a desired level..]. 12. Apparatus as in claim 11 including means for adjusting said reference signal for controlling said relative velocity and together with homing switch means for coupling said position signal to said comparing means for causing said relative velocity to be reduced to zero. .[.13. Apparatus as in claim 11 including commutating means for commutating said peak amplitudes of said position signal to provide said reference signal and for commutating the peak amplitudes of the differentiated position signal for providing said velocity signal..].

Claim 5

Apparatus as in claim .[.11.]. .Iadd.21 .Iaddend.where said position .[.signals are.]. .Iadd.signal is .Iaddend.in the form of .[.mudulated.]. .Iadd.a modulated .Iaddend.carrier together with means for demodulating

Claim 6

.[.such signals.]. .Iadd.said position signal.Iaddend. . 15. Apparatus as in claim .[.11.]. .Iadd.21 .Iaddend.where said .[.velocity signal deriving means includes commutating.]. .Iadd.first .Iaddend.means .Iadd.for commutating is .Iaddend.driven by said position signal for selecting segments of said differentiated position signal around the maximum amplitudes of .[.such.]. .Iadd.said .Iaddend.differentiated .Iadd.position .Iaddend.signal said .Iadd.first .Iaddend.commutating means combining such segments in a piecewise continuous velocity signal of constant polarity for each direction of velocity, and .[.together with commutating.]. .Iadd.where said second .Iaddend.means .[.included in said means for deriving said reference signal.]. .Iadd.for commutating includes means .Iaddend.for selecting segments around the maximum amplitude of said position signal to form a piecewise continuous reference signal. .[.16. Apparatus as in claim 2 where said deriving means includes commutating means for selecting segments of said differentiated position signal around the maximum amplitudes of such differentiated signal said commutating means combining such segments in a piecewise continuous velocity signal of constant polarity for a single direction of velocity..]. .[.17. Apparatus for the control of relative position and relative velocity between two relatively movable members comprising: transducer means coupled to said movable members producing an electric alternating position signal in response to said relative movement, said position signal having periods inversely proportional to the velocity between said members, the peak amplitude of said position signal being substantially constant with changes in velocity and the slope of said position signal at its zero crossing being proportional to instantaneous relative velocity, means for deriving from said slope information of said position signal a velocity signal whose maximum instantaneous magnitude are proportional to instantaneous velocity and which provides a continuous indication of velocity, means for deriving a reference signal from said position signal said reference signal having periods proportional to said periods of said position signal and an amplitude proportional to the amplitude of said position signal, and means for comparing said reference signal with said velocity signal to provide an error signal said continuous indication of velocity maintaining, in cooperation with said reference signal, said relative velocity at a desired level..]. .[.18. Apparatus as in claim 17 where said deriving means includes means for differentiating said position signal with respect to time and commutating means for selecting segments of said differentiated position signal around the maximum amplitudes of such differentiated signal said commutating means combining such segments in a piecewise continuous velocity signal of constant polarity for a single direction of velocity..]. .[.19. Apparatus as in claim 17 where said means for deriving said reference signal includes commutating means for selecting segments around the maximum amplitudes of said position signal to form a piecewise continuous reference signal..]. .[.20. Apparatus as in claim 17 where said transducer means produces at least two position signals in space phase and said velocity and reference signals are derived from such position signals..]. .Iadd. 21. Apparatus for the control of relative position and relative velocity between two relatively movable members, comprising: transducer means coupled to said movable members for producing an electric alternating position signal having periods inversely proportional to the velocity between said members, the peak amplitudes of said positional signal being substantially constant with changes in velocity and the slope of said position signal at its zero crossing being proportional to instantaneous relative velocity; means for deriving from said slope information of said position signal a velocity signal, said deriving means including means for differentiating said position signal with respect to time and first means for commutating the peak amplitudes of said differentiated position signal to provide said velocity signal whose instantaneous magnitudes are proportional to instantaneous velocity and which provides a continuous indication of velocity; means for deriving a reference signal from said position signal, said means for deriving including second means for commutating the peak amplitudes of said position signal to provide said reference signal whose periods are proportional to the periods of said position signal and whose amplitude is proportional to the amplitude of said position signal; means for comparing said reference signal with said velocity signal to provide an error signal; and motor means for providing said relative velocity between said two movable members, said motor means being responsive to said error signal to vary said relative velocity in a manner to minimize said error signal.

Claim 7

.Iaddend. .Iadd. 22. Apparatus for the measurement of relative velocity between two relatively movable members, comprising: transducer means coupled to said relatively movable members for producing a plurality of mutually phase-displaced electrical alternating position signals, said position signals being of substantially identical peak amplitude and frequency, said frequency being proportional to the relative velocity between said members and said peak amplitude being substantially constant with changes in velocity, the slope of each position signal at its zero-crossing being proportional to instantaneous relative velocity; means for deriving from the slope information of said position signals a velocity signal that provides a continuous indication of the relative velocity between said members, said means for deriving comprising means for differentiating said position signals with respect to time to provide a plurality of phase-displaced rate signals whose instantaneous magnitudes are proportional to instantaneous velocity, and means for commutating said rate signals around their maximum amplitudes to provide said velocity signal; means for deriving a reference signal from said position signals by commutating said position signals around the maximum amplitudes; and means for comparing said velocity signal with said reference signal to provide an error signal representative of the difference between the actual relative velocity between said members and a desired relative velocity. .Iaddend.