Dynamic Turning Control of a Quadruped Locomotion Robot using Oscillators Katsuyoshi Tsujita Hiroomi Toui and Kazuo Tsuchiya Dept. of Aeronautics and Astronautics, Graduate School of Engineering,Kyoto University, Yoshida Hon-machi, Sakyo, Kyoto 606–8501 E-mail:tsujita@kuaero.kyoto-u.ac.jp Abstract The authors have proposed a dynamic turning control system of a quadruped robot by using nonlinear oscillators. It is composed of a spontaneous locomotion controller and voluntary motion controller. In this article, capability of dynamic turning motion of the proposed control system is verified through numerical simulations and hardware experiments: Various turning speed and orientation make the motion of the robot asymmetry in terms of duty ratio, stride and center of pressure. The proposed controller actively and adaptively controls redundant DOF to cancel the dynamic asymmetry and established stable turning motion at various locomotion speed and turning orientation. keywords: Quadruped locomotion robot, Oscillators, Turning motion 1 INTRODUCTION Locomotion is one of the basic functions of a mobile robot. Using leg is one of the strategies for accomplishing locomotion. It allows the robot to move on rough terrain. Therefore, a considerable amount of research has been done on motion control of legged locomotion robots. This article treats the motion control of a quadruped robot, with emphasis on the dynamic turning control. In the future, a walking robot will be required which can carry out various tasks on unstructured terrain. The walking robot is required to realize the real-time adaptability to a changing environment and maneuverability to generate voluntary motion according to context of changing environment. Biological research of the last years has made great contributions to overcome such difficulties; during a spontaneous motion such as straight walking, a lot of joints and muscles are organized into a collective unit to be controlled as if it had fewer degrees of freedom but to retain the necessary flexibility for a changing environment. On the other hand, during a voluntary motion such as turning walk, another organized collective unit emerges selectively according to the commanded signal[1]. 1