Servo system with feedback signal compensation

Claim 2

A servo system for controlling the energization of an actuator employed to move a movable member in response to a cyclic power signal for positioning the movable member in accordance with a desired position signal, said system comprising: position detecting means for generating a signal responsive to the present position of said movable member; servo control means for comparing the desired and present position signals to generate a position error signal for controlling the magnitude and polarity of said cyclic power signal energizing said actuator to move said member toward the desired position; and attenuation means for reducing the magnitude of a portion of each cycle of said error signal after a predetermined time period and to a predetermined magnitude to attenuate said cyclic signal without causing a substantial phase shift thereof.

Claim 3

A servo system for controlling the energization of an actuator employed to move a movable member in response to a cyclic power signal for positioning the movable member in accordance with a desired position signal, said system comprising: position detecting means for generating a signal responsive to the present position of said movable member; servo control means for comparing the desired and present position signals to generate a position error signal for controlling the magnitude and polarity of said cyclic power signal energizing said actuator to move said member toward the desired position; attenuation means for reducing the magnitude of a portion of said error signal to a predetermined magnitude to attenuate said error signal without causing a substantial phase shift thereof; and said attenuation means including means for sensing and signaling when the error signal passes through a zero crossover point during a signal cycle and attenuating said error signal for a predetermined time period following each zero crossover point in response to the signal indicating a zero crossover point has been detected.

Claim 4

A servo system for controlling the energization of an actuator employed to move a movable member in response to a cyclic power signal for positioning the movable member in accordance with a desired position signal, said system comprising: position detecting means for generating a signal responsive to the present position of said movable member; servo control means for comparing the desired and present position signals to generate a position error signal for controlling the magnitude and polarity of said cyclic power signal energizing said actuator to move said member toward the desired position; attenuation means for reducing the magnitude of a portion of said error signal to a predetermined magnitude to attenuate said error signal without causing a substantial phase shift thereof; and said attenuation means including means for sensing and signaling when the error signal passes through a zero crossover point during a signal cycle and attenuating said error signal for a predetermined time period following each zero crossover point in response to the signal indicating a zero crossover point has been detected.

Claim 5

A servo system as defined in claim 1 wherein the attenuating means reduces the magnitude of said portion of said cyclic power signal to a preselected magnitude other than zero magnitude.

Claim 6

A servo system as defined in claim 1 wherein said attenuation means reduces the magnitude of said cyclic power signal for a portion of each one-half cycle of the signal.

Claim 7

A servo system as defined in claim 1 including means for sensing the magnitude of the position error signal for preventing attenuation of said cyclic power signal when the position error signal is greater in magnitude than a preselected value.

Claim 8

A servo system as defined in claim 1 wherein said attenuation means includes a switching means connected to interrupt the transmission of the cyclic signal to the actuator when it is desired to attenuate said cyclic power signal.

Claim 9

A servo system as defined in claim 6 wherein said switching means includes a single shot switching circuit which opens the cyclic power circuit a predetermined time period to attenuate said cyclic signal.

Claim 10

A servo system for controlling the energization of an actuator employed to move a movable member in response to a cyclic power signal for positioning the movable member in accordance with a desired position signal, said system comprising: position detecting means for generating a signal responsive to the present position of said movable member; servo control means for comparing the desired and present position signals to generate a position error signal for controlling the magnitude and polarity of said cyclic power signal energizing said actuator to move said member toward the desired position; attenuation means for reducing the magnitude of a portion of said error signal to a predetermined magnitude to attenuate said error signal without causing a substantial phase shift thereof; and said attenuation means including means for sensing and signaling each time the error signal passes through a zero crossover point during a signal cycle and said attenuation means being set to attenuate said error signal for a predetermined time period with said time period being measured from a first zero crossover point with the attenuation of the error signal commencing only when the error signal passes through the next zero crossover point.

Claim 11

A servo system for controlling the energization of an actuator employed to move a movable member in response to a cyclic power signal for positioning the movable member in accordance with a desired position signal, said system comprising: position detecting means for generating a signal responsive to the present position of said movable member; servo control means for comparing the desired and present position signals to generate a position error signal for controlling the magnitude and polarity of said cyclic power signal energizing said actuator to move said member toward the desired position; attenuation means for reducing the magnitude of a portion of said error signal to a predetermined magnitude to attenuate said error signal without causing a substantial phase shift thereof; and said attenuation means including means for sensing and signaling each time the error signal passes through a zero crossover point during a signal cycle and said attenuation means being set to attenuate said error signal for a predetermined time period with said time period being measured from a first zero crossover point with the attenuation of the error signal commencing only when the error signal passes through the next zero crossover point.

Claim 12

A servo system for controlling the energization of an actuator employed to move a movable member in response to a cyclic power signal for positioning the movable member in accordance with a desired position signal, said system comprising: position detecting means for generating a signal responsive to the present position of said movable member; servo control means for comparing the desired and present position signals to generate a position error signal for controlling the magnitude and polarity of said cyclic power signal energizing said actuator to move said member toward the desired position; attenuation means for reducing the magnitude of a portion of said error signal to a predetermined magnitude to attenuate said error signal without causing a substantial phase shift thereof; means for sensing whether the error signal passes through a zero crossover point; means to detect the polarity of the slope when the error signal passes through the zero crossover point; means to detect the polarity of the drive signal being supplied to the actuator; and means to inhibit attenuation of the error signal by said attenuation means except during the period when the polarity of the error signal and the drive signal are in a predetermined relationship.

Claim 13

A servo system for controlling the energization of an actuator employed to move a movable member in response to a cyclic power signal for positioning the movable member in accordance with a desired position signal, said system comprising: position detecting means for generating a signal responsive to the present position of said movable member; servo control means for comparing the desired and present position signals to generate a position error signal for controlling the magnitude and polarity of said cyclic power signal energizing said actuator to move said member toward the desired position; attenuation means for reducing the magnitude of a portion of said error signal to a predetermined magnitude to attenuate said error signal without causing a substantial phase shift thereof; means for sensing whether the error signal passes through a zero crossover point; means to detect the polarity of the slope when the error signal passes through the zero crossover point; means to detect the polarity of the drive signal being supplied to the actuator; and means to inhibit attenuation of the error signal by said attenuation means except during the period when the polarity of the error signal and the drive signal are in a predetermined relationship.

Claim 14

A servo system as defined in claim 1 wherein said attenuation means reduces the magnitude of a portion of each cycle of said error signal for a predetermined time period starting when the error signal passes through a zero crossover point.