Dual-motor Driven Control of Microgravity Simulation System Based on Dynamic Friction Compensation

In this paper, a dual-motor driven control method for active suspension system is proposed to realize microgravity simulation of spacecrafts, in which a separate-complementary control strategy with two controllers is adopted. Controller 1 (for the large motor) is directly designed through the angle difference between two sides of the torsion spring. Meanwhile, to compensate the control error of two motors, the load torque of large motor is used as an input of Controller 2 (for the small motor) and the output of Controller 2 is used as an input of Controller 1. Based on the modified LuGre friction model, an adaptive backstepping non-singular fast terminal sliding mode controller (ABNFTSMC) combined with a dual-state observer is adopted to further improve the control accuracy. Finally, the effectiveness of the control strategy is verified by simulation.