Backstepping control for nonlinear dual smart drive

Intended for being used in legged robots, a specially designed nonlinear actuator, dual smart drive, which offers continuously changing transmission ratio and dual properties, and that is very suitable for situations where the same drive is required to perform two different types of start-stop motions of the mobile link, is introduced. Then, the associated control problem to this nonlinear actuator is established and a backstepping design strategy is adopted to develop a Lyapunov-based nonlinear controller that ensures asymptotic tracking of the desired laws of motion, which have been properly selected using time optimal control. Finally, experimental results are presented to show the effectiveness and feasibility of the proposed nonlinear control method for the dual smart drive