Digital Tracking Control of a Cylindrical Voice-Coil Actuator

Tracking performance of voice coil actuators is often of utmost importance in precision motion control applications. The focus of this paper is the design and implementation of a digital control system capable of tracking pre-specified trajectories with high accuracy. After describing the main components of the actuator system, an empirical model of the open-loop plant is obtained, based on which a PI controller is designed to close the control loop. Then, the closed-loop model is empirically obtained and used for model-based control system design. Two main design approaches are employed to meet tracking requirements: zero-phase error tracking control (ZPETC) and minimum-effort model predictive control (MEMPC). The designed controllers are implemented on an ARM cortex-M4 processor and experimental results show the superior performance of MEMPC in tracking certain position reference trajectories compared to ZPETC.