Vibration Control of L-Shaped Arm Considering Hysteresis Characteristics of Actuators and Sensors Erika KINOSHITA a and Mingcong DENG a,1 a The Undergraduate School of Engineering Tokyo University of Agriculture and Technology, Tokyo, Japan Abstract. Lightening the weight of the robot arm improves work efficiency, but at the same time increases arm vibration, which has a negative impact on the improvement of work efficiency. The vibration of the arm must be controlled in order to achieve high speed and high precision movement while reducing the weight of the arm. In this study, piezoelectric elements, which are one of the smart materials, are used to control the vibration of the L-shaped arm. However, piezoelectric elements exhibit hysteresis characteristics in both actuators and sensors, necessitating compensation. In this study, control system design based on operator theory is conducted, taking into account the hysteresis characteristics of both actuators and sensors. Central Pattern Generator (CPG) is being used to control vibrations while performing hysteresis compensation. The parameters of the CPG are optimized using Ant Colony Optimization (ACO). Finally, the effectiveness of the control is demonstrated through simulations in MATLAB and experiments. Keywords. Nonlinear vibration control, operator theory, piezoelectric actuator, piezoelectric sensor, right coprime factorization, ant colony optimization, central pattern generator 1. Introduction In recent years, robotic arms have been widely utilized across various industrial sectors. Moreover, the lightweighting of robotic arms has progressed to achieve faster operations. However, the increased flexibility due to lightweighting has led to more oscillations, causing issues in positional accuracy. To achieve both high-speed and high-precision movements, controlling the arm’s vibrations becomes essential. In the field of vibration control for flexible structures, various smart materials are employed as actuators to suppress vibrations [1]. The piezoelectric element used in this study is one such smart material, possessing two characteristics: piezoelectric effect and inverse piezoelectric effect. The piezoelectric effect refers to the phenomenon where voltage is generated when force or pressure is applied to a piezoelectric element. The inverse piezoelectric effect signifies the deformation of the piezoelectric element when voltage is applied. By utilizing these two characteristics, vibrations can be controlled. However, due to the hysteresis characteristics, the piezoelectric element requires 1 Corresponding Author, Mingcong Deng, The Graduate School of Engineering Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei-shi, Tokyo, 184-8588, Japan; E-mail: deng@cc.tuat.ac.jp. Power, Energy and Electrical Engineering M. Deng (Ed.) © 2024 The Authors. This article is published online with Open Access by IOS Press and distributed under the terms of the Creative Commons Attribution Non-Commercial License 4.0 (CC BY-NC 4.0). doi:10.3233/ATDE240362 623