Research On Parameters Self-tuning Controller In PMSM Servo System

Equipment manufacturing industry is the basic department of national economy and national defense construction in China. In the modern equipment manufacturing industry, because of its high automation degree and high process precision, CNC system, which equipped with high performance servo system, obtain the widespread application. With the rapid development of the defense industry, the aviation industry, industrial automation and other industries, more requirements are given for servo system, and the capability to adapt rapidly in a changing environment is needed. Therefore, research and development of the high-performance servo drive system has great economic and social benefits.At present, the servo driver usually applies the controller with fixed parameters, and it can’t change the parameters of the controller when the work environments are changing. Its performances of adaptation and anti-interference ability are not so good. The parameter setting of servo system controller is mainly relied on manual operation, which is slow, laborious and ineffective. So, the controller parameter self-setting technology is quite necessary, and it is one of the most critical technical points to facilitate the development of servo drive technology.PID controller is still mainly used in servo driving system. This article studied the parameters self-tuning PID controller in servo system, including off-line parameters setting and on-line parameter self-setting method, and two auto-tuning PI controllers were designed. Off-line parameters setting is used to setting the initial parameters before the servo drives leave the factory. The on-line parameter self-tuning controller appropriates for the frequently changing environment of the servo system. Parameter self-setting technology makes servo drive system have better control parameters, and make it adapt to the more complex conditions. And user’s high request is very good satisfied.Firstly, the paper introduced the basic structure and the mathematical model of permanent magnet synchronous motor. And the mathematical model of AC servo system, vector control principle and SVPWM are analyzed. The simulation model of the PMSM servo system is established and simulation results proved the above theories and technologies.Secondly, parameter offline self-tuning technology based on the particle swarm optimization algorithm was studied. The suitable control parameters can be directly found, using PSO’s searching capability. This can solve many disadvantages of manual parameters tuning, and the simulation result is satisfied.Thirdly, this paper presents the basic principle of model reference adaptive system. According to the relationship between the value of parameters of PI and the inertia, the appropriate parameters can be got by identifying the real-time inertia of servo system based on MRAS. The parameters on-line self-tuning was realized and the simulation experiment results show that the parameter self-tuning PI controller can improve the performance of servo system.Finally, the servo drive based on STM32F103ZET6processor of ARM Cortex M3series was designed. Both hardware and software design are discussed, and the graphical user application for servo control and debugging was introduced. The PI parameters self-tuning technology based on inertia identification was tested on this servo drive platform. The experiment results indicate that the technology can make the servo system have a good adaptability to terrible environment, and the performance of the servo system can be greatly improved.