Auto-tuning of model-based feedforward controller by feedback control signal in ultraprecision motion systems

摘要

In this paper, an auto-tuning algorithm of model-based feedforward controller by feedback control signal in ultraprecision motion systems is proposed. The algorithm is predicated on the simple fact that for a control system with well-tuned feedback controller, at low frequency range, feedback control signal is a good approximation of the ideal feedforward signal required to achieve perfect tracking control. Based on this mechanism, model-based feedforward such as acceleration, jerk (third derivative of reference trajectory) and snap (fourth derivative of reference trajectory) feedforward can be tuned by least squares algorithm with feedback control signal. Simulation and experiment both well validate the proposed algorithm.