Autonomous Parameter Design for Cascade Structure Feedback Controller Based on Time and Frequency Domain Optimization

This paper presents an autonomous parameter design method for a cascade structure feedback (FB) controller in industrial precision servo systems with resonance modes, considering a time and frequency domain optimization. In conventional autonomous design methods, parameters of a cascade structure FB controller are optimized by solving a frequency domain optimization problem to expand the control bandwidth and satisfy the desired stability margins. Therefore, a desired positioning response that is generally defined in time domain is not necessarily realized by the designed FB controller. The proposed method combines a time domain optimization problem to a conventional frequency domain optimization problem for improving the time domain positioning response. The effectiveness of the proposed method is demonstrated through an example FB controller design for a galvanometer scanner, in comparison with the conventional autonomous design method based on only the frequency domain parameter optimization.