This paper introduces a novel control scheme aimed at achieving precise repetitive motion within a dual-input-single-output (DISO) system consisting of two actuators. Repetitive motion stands as a crucial operation in various applications, particularly in manufacturing processes. Designing a control system capable of accurately tracking reference signals during repetitive motion is imperative for DISO systems. The proposed method employs adaptive feed-forward cancellation (AFC) to effectively compensate for position error signals related to the reference signal. The previous control scheme implements the AFC to entire control loop. In the control system, the same characteristic of AFC works for both actuators in the DISO control system. The same AFC output is working to both actuators. On the other hand, the proposed control scheme implements AFC to each actuator. The typical control system employs course-actuator and fine-actuator for precise motion control. The suitable AFC output is working to each actuator, namely course actuator and fine actuator. That is, the major contribution of proposed control scheme individually optimizes the AFC in the course-fine control system. This design approach significantly enhances the control performance of DISO systems, taking into account the distinctive characteristics and stroke limitations of the actuators. Experimental implementation of the proposed control system validated its efficacy, affirming its potential for improving control performance in DISO systems.
INDEX TERMSDual-input-single-output (DISO) system, Repetitive Control, Adaptive feedforward cancellation, Loop shaping I. INTRODUCTION Control design methodologies play a pivotal role in achieving desirable dynamics in mechatronic systems [1]. In the pursuit of enhanced control performance, certain mechatronic systems incorporate dual actuator systems, including piezoelectric dual-stage tape [2], head positioning control systems for hard disk drives [3], servo systems for optical mechatronic applications [4], and wafer stage control systems in manufacturing [5]. These systems are characterized as dual-inputsingle-output (DISO) systems. One of the common functionalities in these mechanical systems involves repetitive motion, found in patterned movements, manufacturing processes, and various applications [6], [7]. In such scenarios, precise tracking of a reference signal during repetitive motion is crucial. Given that the reference signal exhibits periodic frequency components, minimizing periodic error signals becomes imperative for enhancing tracking performance. 18 This study centers on adaptive feed-forward cancellation 19 (AFC) to mitigate periodic error signals [8], [9]. Developed 20 to compensate for position error signals induced by periodic 21 disturbances, AFC's efficacy has been validated in previous 22 mechatronic system studies. To optimize its effectiveness, 23 a critical consideration involves the apt design of parame-24 ters within the adaptive algorithm. Various sophisticated de-25 sign methods for...
