Research on Adaptive Friction Compensation for Electric Linear Load Simulator Based Backstepping controller

The electric linear load simulator (ELLS) is one kind of servo system with uncertainties and disturbances such as friction nonlinear characters. In order to improve the loading accuracy of ELLS system, aiming at the friction torque existing in the system, we present adaptive friction Backstepping controller based on the LuGre friction model. Using Lyapunov stability theorem to prove the global asymptotic stability of the system. Backstepping control theory reorganizes system equations into multiple virtual subsystems. Design virtual control variables for each virtual subsystems, and obtain the system nonlinear controller by Backstepping recursion. Finally, simulation results show that: compared with the traditional force command feedforward compensation + PID controller, the adaptive friction Backstepping controller can better suppress the excess force, ELLS system output can achieve asymptotic tracking of the given force reference signal. The proposed control method can better suppress the effect of friction on ELLS system and improve the loading accuracy.