Multirate Sampling Method for Acceleration Control System

This paper focuses on the realization of high-performance motion control based on acceleration control. A disturbance observer is used to construct an acceleration control system. A high sampling frequency is known to be effective for improving the performance. Characteristics of acceleration control are investigated to discuss the relationship between the performance and a sampling frequency of the system. The needs for a high sampling frequency for an output are then described. Based on these considerations, a novel multirate sampling method for the acceleration control system is proposed. An output sampling period is set shorter than an input sampling period, and control calculation is executed at each output sampling period in the method. The disturbance observer is redesigned for application to the multirate system. Stability analysis is performed to verify the validity of the proposal. Feasibility of the proposed method and its influence on the performance are also verified by experimental results