Research on controlling network time delay in teleoperation orthopedic restoration surgery

To address the problem of time delay in the teleoperation orthopedic surgery process, in this paper we propose a robustness control design method based on the H_∞ and μ-synthesis methods. Firstly, from an analysis of delay-time data tested under the UDP and TCP/IP protocols, we selected the UDP protocol to transport data. Then, to address the difference between the dynamic and real models of the teleoperation robot, we used a disturbance observer and low-pass filter to modify the robot's dynamic model. Then, using a method based on the H_∞ mixed-sensitivity robustness control theory, we designed master slave controllers. For conditions in which the time delay was no more than 2 seconds, the μ-synthesis method was used for processing. Finally, on the Internet, we conducted a position-tracking experiment for an unconstrained situation and a force-tracking experiment for a constrained situation. Experimental results show that using the designed controller guarantees a more stable master-slave system when a time delay occurs with a maximum value of no more than 2 seconds. These results verify the feasibility of teleoperation orthopedic restoration surgery on the Internet environment.