Base On Port-Controlled Hamiltonian Model Of Permanent Magnet Synchronous Linear Motor Passivity-based Control

Permanent magnet synchronous linear motor does not need intermediate transmission device, which is able to directly convert electrical energy into linear motion of mechanical energy. And it has an advantage of high response speed, high efficiency and high precision. So it is widely used in the field of numerical control machine tools, etc. Because permanent magnet synchronous linear motor has the unclosed structure, which causes end effect and others, what increases the difficulty of its control. However, we should seek for more excellent control method to research for it. In recent years, a kind of passivity-based control method based on interconnection and damping assignment is highly recognized and fast developed. Which requires that the system must have the feature of port controlled dissipative Hamiltonian structure. What’s more, the method takes the system’s total energy as the Hamilton function for the controller design. In the while, there are many benefits in the method, such as clearly physical meaning, easy to adjust parameters, stable in balance as the closed-loop, etc. And which will do great help to industrial control in the future.In this thesis, we review the development of linear motor, the research status at home or abroad, control strategy, and introduce the classification of the linear motor. Under the condition of reasonable hypothesis, permanent magnet synchronous linear motor’s electromagnetic and mechanical motion models are established with the method of coordinate transformation. According to port controlled dissipative Hamiltonian system theory, we take permanent magnet synchronous linear motor as a two-port device(electrical port and mechanical port), introducing interconnection and damping assignment. Then we design passivity-based controller of the system. After that, the load resistance observer is constructed, aiming at the condition of the load resistance unknown. In order to achieve better speed control effect, we use hierarchical control strategy. We still use interconnection and damping assignment of passivity-based control in the inner loop, but H￥ robust control method is applied to the outer loop in the permanent magnet synchronous linear motor control system. Based on Lyapunov stability theory, this paper analyzes the stability of the designed controller. Under the MATLAB/Simulink platform, we build modules. Then we simulate the passivity-based controller with observer and passivity-based controller with H∞ robust control method. The simulation results show that passivity-based controller after adding load resistance observer can effectively restrain disturbance caused by the load resistance unknown. In addition, the introduction of H∞ robust control method largely improves the system’s immunity ability and enhances the system’s robustness.