Active vibration suppression apparatus, control method therefor, and exposure apparatus having active vibration suppression apparatus

摘要

An active vibration suppression apparatus includes an actuator fixed to a vibration suppression target, an inertial load driven relative to the target by the actuator, and a driving system which drives the actuator based on a first signal corresponding to the vibration, generated or to be generated, of the target. The driving system includes a compensation unit which performs a compensation for the first signal. The compensation, separately or as a composite compensation includes (i) a linear compensation for the first signal to obtain a first compensated signal, and (ii) a nonlinear compensation for the first compensated signal to obtain a second compensated signal. A rate of a change in the second compensated signal to a change in an absolute value of the first compensated signal becoming less with an increase of the absolute value.