Research on Backstepping control of flexible joint manipulator with state constraint

“Large computation” is a problem of the traditional backstepping method, leading to the poor control effect of the system. To solve this problem, a backstepping controller based on active disturbance rejection control (ADRC) is designed for the nonlinear system of flexible joint manipulator with state constraints. The uncertainties of the model are approximated with the nonlinear extended state observer (ESO) to further improve the control effect of the system. The Lyapunov function is designed to restrict all states of the system. Results show that the designed controller can effectively achieve the state constraint performance and improve the position tracking accuracy of the system significantly.