US Patent 7373836 Velocity feedforward compensation for force control systems

A controlled system (480) for application of force on a test object includes a force actuator (484) that is coupled to and applies a force on the test object. A velocity signal generator (482) is in a feedforward configuration relative to the force actuator (484) and generates a velocity signal (503) that is predictive of the velocity of the test object. A controller (482) is coupled to the force actuator (484) and to the velocity signal generator (482) and generates a desired applied force signal (546) compensated by the velocity signal (503).