Active Compliance Control of the RED Hand: A PID Control Approach

Robot with non-back-drivable actuators will appear stiff when in contact with the environment and human. This scenario is unsafe for the Human-Robot Interaction (HRI). In order to guarantee safety in HRI, the robot will be made “soft” such that a compliant control can be introduced. Apart from utilizing the proper mechanism design, the back drivability actuators can be achieved by a suitable choice of control. In particular, in this paper, a PID control is employed to achieve an active compliance control. The reference impedance model characteristics are exploited for which the system allows us to introduce a virtual mass-spring-damper system to adjust the compliant control level. The performance of the PID control will be tested on the RED Hand in the simulation. The results are recorded and analyzed for the thumb finger. The results show that the PID controller is capable of controlling the motion and position of the RED Hand. In addition, the compliance behavior for the RED Hand can be suitably adjusted based on the required compliant level.