Variable Admittance Control for Human-Robot Collaboration in Robot-Assisted Orthopedic Surgery.

In recent days, orthopedic surgical robots play an increasingly important role in surgeries. Impedance/admittance control is a commonly used method for orthopedic surgical robots. In this paper, we proposed a variable admittance control method for orthopedic surgery. Instead of modifying virtual damping or mass which present in previous variable admittance control works, we present a new method by setting a dynamic reference point for virtual spring to improve operators’ boundary control ability during robot assisted orthopedic surgery. The reference point is the mean point of robot end effector trajectory in the past T period. The performance of the proposed controller was tested by conducting a cooperative experience, where all subjects were asked to finish a reaching task by using a Mini-robot.