The Study For Inertia Identification And Self-tuning Of Controller Parameter Of Numerical Control Machine Feeding System

Since numerical control machine has good performance in degree of automation, flexibility and high precision, it has been applied widely and further developed in modern manufacturing, especially, in complex part machining. The machining precision of numerical control machine is important performance index of numerical control machine, represents manufacture ability and developing level of manufacturing and is also one of most important symbol of all nation science and technology and industrialization level. The precision numerical control machine mostly depends on the precision of the servo feeding system. Permanent magnet synchronous motor (PMSM) has been widely used in high performance numerical control machine servo feeding system for its advantages, such as compactness, high efficiency, reliability and suitability to environment.The performance of PMSM servo feeding system is highly influenced by uncertainties of unpredictable variation of mechanical parameters and external load disturbances. In order to enhance the system static and dynamic performances. it is necessary to identify the mechanical parameters and auto-tune the speed controller.The thesis studies PMSM servo feeding system based on computer simulation. First, the mathematical model of PMSM and basic theory of vector control are introduced, the vector control scheme (i_d=0) based on rotor field orientation and current and speed double loops control scheme for PMSM servo system are made certain. Second, current controller and speed controller are designed respectively based on the method of engineering design and the method of part model matching. Then, the inertia of system is identified respectively based on model reference self adapting identification and recursive least square method with oblivious gene. And the scheme for auto-tuning the speed controller based on the identified inertia is presented as well. The simulation results prove that the PMSM servo system has good dynamic and static performance when the inertia varies. The load torque is also difficult to be measured directly, so it needed to be online identified. This dissertation adopt a compensate control algorithm, which could dynamically compensate load torque variation. The simulation results show that, this compensatory control strategy can improve the anti-disturbance and enhance robustness of serve feeding system. A summery of whole thesis is given in the end.