Finite-time model-free trajectory tracking control for overhead cranes subject to model uncertainties,parameter variations and external disturbances

The payload mass and the cable length are always different/uncertain for various transportation tasks and external disturbances that accompany industrial overhead crane systems. In addition, existing control methods can obtain merely asymptotic results. To solve the aforementioned problems, an accurate model-free trajectory tracking controller subject to finite time convergence for overhead crane systems is proposed based on the suitably defined non-singular terminal sliding vector. Moreover, the proposed controller is absolutely continuous, addressing the limitations and shortcomings of the traditional sliding mode control. Lyapunov techniques are used to prove that the proposed controller guarantees finite-time tracking result and the finite time T is calculated. Simulation and experimental results are included to demonstrate the robustness of the proposed controller with respect to model uncertainties, parameter variations and external disturbances.