Abstract:For the tip position control for two-link flexible manipulators, the dynamic characteristics of joint motor and the uncertainty of model parameters were considered, and a nonlinear sliding mode control method was proposed. The joint model of flexible manipulator and joint motor was established, and the output-redefinition method was used to decouple the system model and solve its nonminimum phase problem. The subsystem and flexible modal subsystem were redefined. For the redefined subsystem, a nonlinear sliding mode controller was designed for the robust control of redefined variables and joint motor dynamics simultaneously. The expression of the decomposed flexible modes in the state space near the equilibrium point was derived, based on the Lyapunov stability theory, the constraint relationship between the output redefinition coefficient and the system stability was deduced, and the error range of the tip position was achieved. The simulation results show that the influence of joint motor dynamics can not be overlooked, and the system response performance can be significantly improved by using the proposed method.