Shaft Torque Limiting Control Using Shaft Torque Compensator for Two-Inertia Elastic System With Backlash

This paper aims to present a solution for torsional vibration suppression and shaft torque limitation simultaneously in servo system with backlash. The existence of backlash, which would make conventional notch filter invalid, will aggravate the mechanical vibration and bring the risk of unsafety to the system. In order to solve that problem, a novel shaft torque compensator is proposed, which would make the system similar to a rigid system with one inertia. What is more, this compensator can limit shaft torque as expected, making the system relatively safe under any situation with different load inertias and torques. The limiting control is based on the adaptive online identification of load inertia in order to improve robustness of the system and ensure not only the accuracy, but also the arbitrariness of shaft torque limit. Simulation and experimental results are presented to illustrate the favorable behavior of the drive with the robust shaft torque compensator.