A control strategy of null space motion using passivity of PID controller

In this paper, strategy of design in null space by a PID controller is proposed. There are many studies about asymptotical stabilizing by PID controller about a robot manipulator. Recently, robot works in various situations. It is necessary for the robot manipulator to have many degrees of freedom(DOF). So, we consider a control strategy of manipulator motion using a redundant manipulator. The redundant manipulator can divide into work space and null space. Here, we propose that work space carries out position control and null space uses PID control. Work space sets an observer. It is said to be work space observer. And, in null space, design of parameters of PID controller is used passive theory. In addition when unknown disturbance (interactive null space interference) is operated null space, it is compensated by the PID controller. To compensate null space disturbance, γ-dissipative property is used. Finally, we carry out experiments for 4-link manipulator. In addition, comparing proposed method with PD control using null space observer is introduced. So, feasibility of control design of null space by the PID controller is confirmed.