Study On Anti-swing Control Of Overhead Crane

Overhead cranes are widely used in industry for load transfer. In most of the applications, the transfer has to be performed as fast as possible. Such fast motion would induce undesirable sway, which may cause load damage and other types of hazards, and hence reduces the operation efficiency. Therefore, anti-swing control of crane is the core technology for improving operation efficiency and avoiding accidents. In recent years, intensive research work has focused on developing control techniques towards anti-sway load transfer. This thesis can be divided into three sections as follows:Firstly, the experimental model of crane system is made in order to verify the effectiveness of control strategies. Using PCL-818L card as data channels, the Real-Time Windows Target toolbox of MATLAB and proportional reduced crane model are used to build a hardware-in-loop simulation experiment platform. The platform may be a research environment for SISO, MIMO, nonlinear, time- variant system.Secondly, for the actual crane model, the basic method of theoretic mechanics and Lagrange equation is used to establish three-dimensional dynamics of the system and simplified dynamics of crane system with fixed cable. An internal model controller is proposed to obtain its precise position via inverse system method that can convert the bridge crane system into a pseudo-linear system. At the same time, an angle feedback controller is designed to make the angle damp out. Eventually compared with conventional PID and fuzzy controller respectively, the experiments demonstrate the proposed strategy has better performance because it can guarantee not only no positioning errors and quickly damping-out of angle but also has a good ability of anti-disturbance and robustness.Lastly, an anti-swing control strategy is proposed for the overhead crane system with variable cable based on the linear quadratic regulator (LQR) and variable universe fuzzy method. The crane system is first decomposed into two subsystems, then the optimal feedback gain is found based on LQR. The proposed strategy realizes the nonlinear optimization anti-swing control of the crane system. The simulation result demonstrates the effectiveness of the proposed control strategy. At the same time, many simulations are made under the different situations such as initial angle, undefined cable length and mass of load. The simulation result shows the anti-swing control strategy not only can transfer load fast as well as small swing angle, but also has a good ability of angle disturbance and robustness.