A switching strategy with a sliding mode control based on sub-optimal energy consumption for dual-motor servo systems with backlash

Aiming at a waste of energy resulted from using bias torque method for dual-motor servo systems with backlash, this paper presents a switching strategy with a sliding mode control based on sub-optimal energy consumption. A switching strategy is proposed to guarantee that one motor can contact with the load, and the other motor can go through the backlash quickly when the systems stay in the reversing direction stage. According to the maximum principle of optimal control, the optimal energy control law with an inequality constraint is derived by solving the Hamilton canonical equation. A sliding mode controller is designed based on optimal control and the energy consumption for the systems can be greatly reduced by this design. Meanwhile, the nonlinear influence of the backlash can be effectively eliminated through this switching strategy. Simulation results are conducted to validate the tracking performance and less energy consumption of the proposed method.