Adaptive servo control system and method

A servo-motor position control system, comprising:

• a motor configured to be controllably energized;
• a current control coupled to receive at least a current command signal and a current feedback signal and operable, in response thereto, to controllably energize the motor;
• and
• a position control adapted to receive a position command signal and a position feedback signal and operable, in response thereto, to supply the current command signal to the current control, the position control comprising:
• a non-linear lead-lag filter adapted to receive a position error signal and the position feedback signal, the position error signal representative of a difference between the position command signal and the position feedback signal, the non-linear lead-lag filter operable to exhibit a frequency response that varies in response to the position error signal, the non-linear lead lag filter further operable to filter the position feedback signal and supply a compensated position feedback signal;
• a comparator adapted to receive the position command signal and coupled to receive the compensated position feedback signal from the non-linear lead-lag filter, the comparator responsive to the position command signal and the compensated position feedback signal to supply a compensated position error signal;
• and
• a non-linear integral filter coupled to receive the compensated position error signal and operable to exhibit a gain that varies in response to the compensated position error signal, the non-linear integral filter further operable to at least selectively filter the compensated position error signal and supply a filtered position error signal.

A method of controlling servomechanism position, comprising the steps of:

• filtering a position feedback signal using a non-linear lead-lag filter to thereby generate a compensated position feedback signal, the non-linear lead-lag filter having a variable frequency response;
• generating a position error signal from a position command signal and a sensed position signal;
• varying the frequency response of the non-linear lead-lag filter in response to the position error signal;
• generating a compensated position error signal from the commanded position signal and the compensated position feedback signal;
• at least selectively filtering the compensated position error signal using a non-linear integral filter to thereby at least selectively supply a filtered position error signal, the non-linear integral filter having a variable gain;
• and
• varying the gain of the non-linear integral filter in response to the compensated position error signal.