Research On Positioning And Antiswing Of Bridge Cranes With Restricted Control Input

As a cargo transportation machine,overhead cranes have been playing extremely important roles in various fields,such as logistics,construction,metallurgy,and manufacturing,among others.As a typical underactuated system,the degrees of the freedom of the overhead crane are more than its control inputs,which initiates challenges in control design.For these reasons,underactuated systems have become a research focus in the field of control theory and technology.In the process of practical applications,the actuator works in a preset range,the control inputs are usually bounded by a known constant,and it is difficult to achieve large control signals.Besides,the presences of uncertainties and disturbances may cause poor qualities of the controller in operating environment.Therefore,input saturation and robustness of the system are the problems to be solved in this paper.In this paper,an adaptive sliding mode controller is developed for the model of 3D overhead cranes in case of actuator constraint.The proposed controller can simultaneously execute the duties consisted of keeping the payload swings small during the transport process and absolutely suppressing the cargo vibrations at destinations of trolley and bridge even in an extremely complicated operation.Chattering is eliminated because of the substitution of the sign function.The simulation results indicate the effectiveness of the proposed control method.