| The performance of servo systems plays a decisive role in the realization of precise control of CNC systems and industrial robots, as servo systems make up a core part of them. AC servo system with permanent magnet synchronous motor (PMSM) has been widely used manufacturing and other fields with characters of fast response, high steady precision, strong anti-interference and wide speed range. Along with the development of micro-controller technology, power electronics technology, modern control theory and modern AC servo theory, the servo system has been developed toward the direction of all-digital and intelligent.In this paper, a mathematical model is established based on the characteristics and structure of PMSM. After analysising PMSM vector control theory, the process of how voltage space vector PWM (SVPWM) be implemented on DSP is given. A PMSM can perform as a DC motor after Clark and Park transformation according to vector control theory. Five control methods are given to chose from according to the function of torque current and excitation current of PMSM decoupling and excitation current id=0is chosen in this paper.A control method of combining PID control and fuzzy adaptive PID control is put out based on the analysis of PID control theory and fuzzy adaptive PID control theory. Adjusting the the proportion of the outputs of PID controller and fuzzy adaptive PID controller according to the change of system error, a smooth transition can be achieved between the two controllers without any shocks. So the PMSM control system has better dynamic performance as well as steady precision.The performance of all-digital servo system mostly depends on the performance of it’s DSP controller, since DSP is the most part of it. TI’s floating-point DSP controller TMS32OF28335is a DSP integrated with a floating-point unit and rich peripherals on it. TMS320F28335has a better performance with higher speed and greater stability, compared with fixed-point DSPs. Hardware circuit of PMSM control system including current detection circuit, the IPM module circuit, protection circuit and photoelectric encoder interface circuit are designed based on TMS320F28335.A PMSM control system model is built based on MATLAB/Simulink simulation software and SVPWM control, parameter optimization and overall system control are simulated with it respectively. After the simulation, parameters in the software system programmed based on the hardware system are verified according to the simulation result. The emulation of PMSM hardware system shows the result that the PID and fuzzy adaptive PID control method performs better than that of PI control method. |
