A Novel Positioning Control Method for Overhead Cranes With Uncertain System Parameters

Anti-swinging system is meaningful to ensure the safety and efficiency of the overhead crane. This paper treats the positioning control problem of overhead crane as a finite-time LQ optimal control problem with fixed boundary value of the state according to the actual demand. Then the double generating functions method proposed recently is adopted to solve it. In order to eliminate the adverse effect of the system parameter uncertainty, the derivative system is employed by expanding the original system. In the case that the derivative system is uncontrollable, a general restrictive condition is given which guarantees the elimination of the adverse effect of system parameter uncertainty. Furthermore, this uncontrollable derivative system can be reduced to be controllable to be freed from the general restrictive condition. The simulation results show that the optimal control input obtained by the improved derivative system eliminates the adverse effect of system parameter uncertainty on the positioning control accuracy and the sway reduction.