Vibration Suppression with Shaft Torque Limitation Using Explicit MPC-PI Switching Control in elastic drive systems

In this paper, the application of model predictive control (MPC) for torsional vibration suppression and shaft torque limitation control in the elastic drive system is demonstrated. Standard MPC is converted to fast explicit MPC (EMPC) to solve its difficult online implementation issues. Constraint condition of shaft torque limitation control is firstly proposed through theoretical derivation, implying that the responses of shaft torque vary with the changed critical value of shaft torque, but the limitation function can still be available. Eventually, the EMPC-PI switching control is used for the application of shaft torque limitation control into the typical drive successfully, which can significantly reduce the amount of data storage, closer to practical industrial applications. Meanwhile, the advantage of eliminating the steady-state error provided from PI controller can further enhance robustness of the system compared with the pure EMPC controller. The switching criterion is based on the speed hysteresis value, which can be properly adjusted under different circumstances. Simulation and experimental results of speed step responses verify the EMPC-PI switching controller a more effective approach compared with the PI controller designed by pole-placement method.