Nonsmooth backstepping design for motion control of a class of Euler-Lagrange systems

A nonsmooth backstepping design method is proposed to solve motion control problem of a class of Eular-Lagrange systems. Compared with the typical backstepping design method, the virtual control selected in nonsmooth backstepping procedure is designed to be nonsmooth but Lipschitz continuous such that the flexible feedback gain can be abtained according to the error regions. It results that the performance of the motion control can be also regulated according to the regions of the system variables. Simulation results on a 2DOF manipulator system show that the performance of the closed-loop system under the nonsmooth backstepping design is also improved.