Joint space torque controller based on time-delay control with collision detection

This paper addresses a control method for friction-existing robot manipulators and safe motion with its environment. In order to control the robot manipulator with unknown effects, a time-delay control(TDC) method that eliminates the nonlinear effects is used to control the joint torque servo. Although the TDC is very adaptive in nonlinear systems, there is limitation of the TDC in a high friction robot manipulator; hence, a friction model is considered. A collision detecting method is proposed to secure safety for human and robot-interacting environment. Using the torque sensor attached at the joints of the robot arm, the collision is detected more effectively. After detecting collision, a safety reaction method is applied. A torque sensor based 3-joints robot arm is used to verify the performance of the proposed methods.