Study On Robust Control For Permanent Magnet Linear Motor Servo System

Study on robust control for permanent magnet linear motor servo system is a comprehensive project, which is on the basis of robust control theory, permanent magnet linear motor as controlled plant, numerical controlled machine tool as a background of application, and the key point of study is control algorithm. The purpose of research is to solve control problem of permanent magnet linear motor servo system with uncertainty. The research of this dissertation is based on two aspects: standard H_∞control and nonlinear L₂ control for permanent magnet linear motor servo system. The research work is as follows:1. Study of H_∞control for permanent magnet linear motor servo system. Synthesize problem of the current controller and the speed controller in permanent magnet linear motor servo system is turned into standard H_∞control by being set up mathematical model of servo system robust control in state space. For standard H_∞control problem, analytic expression of controller is obtained through solving an algebraic matrix Riccati inequality. Like this, the current H_∞controller and the speed H_∞controller are found under the same mathematical model in order that linear servo system is able to restrain uncertainty load disturbance. The performance of permanent magnet linear motor servo system is studied by use of Matlab software simulation.2. Study of nonlinear L₂ robust control for permanent magnet linear motor servo system. On the basis of servo system available mathematical model, the dynamic mathematical model of error system is set up by backstepping, and the track and disturbance restraint are summed up L₂ control problem. Further, requisition of the performance index for linear motor servo system is changed into dissipative problem and stabilization problem in order to find L₂ controller. Nonlinear L₂ robust controllers for permanent magnet linear motor servo system are design by defining proper storage function. And then, the L₂ robust control laws are proved. On the one hand, a difficult work of solving Hamilton-Jacobi-Isaacs inequality is avoided. On the other hand, both the disturbance restraint performance and the tracks performance are solved when dissipative inequality and asymptotical stability conditions are met. Finally, feasibility of the design method is verified by virtue of computer simulation.3. Experiment research of nonlinear L₂ robust controller design method for permanent magnet linear motor servo system. Nonlinear L₂ robust control algorithm is achieved by use of digital signal processors for a practical permanent magnet linear motor servo system.In accordance with the different properties disturbance, experiment research is carried out about the robustness for nonlinear L₂ control algorithm. Feasibility of the design method used for a linear motor servo system is verified.