Predictive disturbance-observer-based controller design for a class of input time-delay mechanical systems with input constraints

A predictive disturbance-observer-based controller (DOBC) is proposed for a class of input time-delay mechanical systems with input constraints. A predictive disturbance observer is developed for external disturbance and proof for exponential convergence of estimation error is provided. In the controller design process, the input integral is fed back into the controller to eliminate the effect of input delay, and the input integral method and hyperbolic tangent function are firstly combined to solve the problem of input delay and limit the control input simultaneously. The optimisation function FMINCON of MATLAB is used to obtain control parameters. Control goal realisation and the exponential stability of the closed-loop system are proven via the Lyapunov direct method. Simulation results verify the effectiveness of the proposed controller.