Patent ID: 6546296
Filing Date: 2003-04-08
Classification: G05B,G11B

Abstract:
A calibration method for a feedback control system for a two-stage actuator having a main actuator using a voice coil motor as driving means and a subactuator mounted on said main actuator, comprising the steps of:cutting off a control loop for said subactuator to fix a control input up(k) to said subactuator to 0; inserting a sinusoidal disturbance dv(k) into a control input uv(k) to said main actuator; comparing uv(k) and uv(k)+dv(k) to obtain an open-loop gain; setting the reciprocal of said open-loop gain in a gain compensator for said main actuator; adding a sinusoidal disturbance dp(k) to an input to said subactuator with said control loop for said subactuator being kept cut off; comparing said sinusoidal disturbance dp(k) with an output y(k) from said two-stage actuator to obtain a disturbance input-displacement gain; dividing a design nominal value by said disturbance input-displacement gain to obtain a compensation gain; and setting said compensation gain in a gain compensator for said subactuator.