Sliding Mode Control of Cable Suspended Load with Acceleration Constraint

The paper presents a new method of sliding mode control for cable suspended load with acceleration constraint. The method employs a time-varying switching line which moves with a decreasing velocity and a constant angle of inclination to the origin of the error state space. Then, it stops moving and it remains fixed. Since at the initial time the line consists of these points in the error state space which represent initial conditions of the system, the reaching phase is eliminated. As a consequence the considered system is insensitive with respect to external disturbance and model uncertainty from the very beginning of the control action. Furthermore, the proposed method ensures the monotonic error convergence and it guarantees the minimization of the time multiplied by the absolute error (ITAE) with acceleration constraint.