Linear motor force ripple identification and compensation with iterative learning control

Abstract

Embodiments of the present invention are directed to compensating for force ripple of an apparatus driven by a force produced by a linear motor. In one embodiment, a method of compensating for force ripple comprises generating force commands for a trajectory starting at a plurality of starting positions of the apparatus driven by the linear motor to produce different trajectory motions based on the same trajectory at the plurality of starting positions, the force commands each including peaks of large acceleration/deceleration and valleys of low force levels; calculating an average of the force commands during large acceleration/deceleration generated based on trajectory motions for the plurality of starting positions; calculating a variation ratio of the force command for each trajectory motion to the calculated average of the force commands; and compensating for force ripple in the apparatus based on the calculated variation ratio to control the force applied by the linear motor to the apparatus.

Dependencies are inferred from the claim text.