Research And Design On Servo Control System Of Permanent Magnet Synchronous Motor

The permanent magnet brushless DC motor not only owns properties of small volume, lowpower and high efficiency which belongs to the permanent magnet synchronous motor, but alsoowns superiorityes of low value, easy to operate, reliable operation which belongs to itself. So it isdiffusely utilized in the scopes such as servo control, aerospace, industrial control, vehicles, etcnowadays. However, there are a series of problems in the control systems of brushless motor,obsolete control strategies, large torque ripple as well as low reliability with none positiontransducer, for instance. These problems limit their application and promotion in high-performanceoccasions. Therefore, the improvement and optimization against these problems have been a hottopic in the field of automation. It has significant applied worth and theoretical significance todevelopment the control system of the brushless motor with great performance. In this paper, theprinciple of the brushless motor, restrain techniques of torque ripple, intelligent control strategiesand other aspects were researched in-depth. The implementation and design of the brushless motorcontrol system were also completed.Aiming at the characteristic of time variation and strong nonlinear of the brushless motor, themain component, structural features and working principle were elaborated, then the mathematicalmodel of it was established, the drive circuit, control strategy and speed adjustment manner weredissected, the research on theory of the brushless motor was completed at last.Aiming at torque ripple especially the ripple when the brushless motor is in commutating, thedistinct effects on commutation torque ripple of five PWM manners were contrasted and dissectedat first, the advantage of PWM_ON mode was proved in quantitative calculation, then thegenerating process of torque ripple and current waveform during commutation with phase ofbrushless motor were researched and analyzed, the essential origin of commutation torque ripplewere revealed, a “12-step” control strategy that can reduce commutation torque ripple wasproposed after theoretical investigates, the control strategy was simulate and analyzed comparedwith the conventional “6-step” commutation strategy, the results of experiments indicated that thetactics can obviously cut down the commutation torque ripple and enhance the smoothness ofbrushless motor in running.Aiming at the performance of servo control system of the brushless motor, the principle ofconventional PID controller was considered, the defects of brushless motor control system with traditional PID controller were generalized and dissected, an intelligent control strategy ofbrushless motor with Neuron PID was proposed. The advantage and characteristics of Neuron PIDwere expounded, then the algorithms of the Neuron PID control system were implemented anddesigned, the Neuron PID controller was applied in closing-cycle control of permanent magnetbrushless, utilizing the self-training capability of Neuron PID, systematic parameters can beadjusted and trained in real time, simulation of brushless motor control system based on NeuronPID and traditional PID were given with Simulink. The results of experiments indicated that thesystem based on Neuron PID controller can enhance the rotary smoothness and the response ofvelocity of brushless motor.After completion of the theoretical analysis and design of algorithm, the software as well ashardware program of brushless motor control system were proposed. In terms of hardware,NUC130RC1CN is used as master chip, peripheral circuits and each module were designed andillustrated. The control modes of speed and position based on hall closed-loop and no hall closed-loop, the control modes of current based on bus current sampling and phase current sampling, themodes of communication based on RS485and CAN were all integrated in the design. In terms ofsoftware, the programs of control system were developed and implemented, then theimplementation process and key modules were described. In addition, the reliability of designtechniques used in the realization process of the hardware and software were introduced.