Robust Repetitive Control of a Cylindrical Voice-Coil Actuator

Cylindrical Voice Coil Actuators (CVCAs) have a wide range of applications in various industries, especially in the field of precision motion applications, due to their simple structure, small size, lack of backlash, and force ripple-free operation. Most often, the actuator is required to track a periodic trajectory accurately. Hence, designing a digital controller to achieve zero tracking error in the presence of plant uncertainties, is of high importance. In this paper, a physics-based model of a previously-designed optimal VCA is developed. This model is then used to design a PI controller which stabilizes the plant. Finally, an empirical model of the stabilized plant is obtained which is used for model-based design of a robust repetitive controller. The designed controller is then implemented on an ARM cortex-M4 processor and experimental results show the high performance of the control system in tracking custom periodic signals.