Impedance control system based on contact force distribution for wearable robot with tactile sensors

The authors aim for safe assistance by feedback control of the contact force distribution in wearable robots. Since the wearable robot is in direct contact with the user, safety control is important. In order to improve safety, robot is desirable to be able to be controlled based on contact force: the force applied to the human body by the robot. A control system that feeds back joint torque as contact force has been proposed. However, since the joint torque is the resultant force of the contact force, there is a possibility that the dangerous contact force can not be detected directly. In this paper, the authors propose a new control system based on contact force distribution. The contact force distribution is sensed as pressure distribution by the tactile sensors attached to the robot surface. Impedance control in manipulator was expanded and applied to contact force distribution feedback control. The proposed method is compared with the control based on joint torque and the effectiveness of our method is verified.