Study On Brushless Dc Motor Control System Based On The Real-time Kernel UC/OS-II

Brushless DC motor uses the electronic commutator to replace the mechanical brush and commutator of traditional DC motor,that avoid sparks, noise and other issues caused by the contact of the mechanical brush and commutator.So,Brushless DC motor integrates the advantages of DC motor and AC motor.BLDC has the following characteristics:low noise,high efficiency,good speed performance,simple structure, reliable operation, easy maintenance , etc.At present, the brushless DC motor has been widely applied to various fields of national economy.As the development of the microelectronics, power electronics and computer application technology,digital control system is used to control motor.As the growing complexity of modern control system functions,relying on a single main program loop detection to complete these tasks make application design becomes complex, development efficiency becomes low, not easy to extend system function and maintain system.The introduction of embedded real-time operating system can make a complex application into several independent tasks to complete,improve system development efficiency , reduce development effort, and facilitate application extensions and maintenance.In this paper, BLDC motor control system is designed based on the embedded real time operating system uC/OS-II and MCU dsPIC30F6010A.First, the structure , principle and operation characteristics of the BLDC motor were described in detail;Study the control technology of BLDC motor,determine the speed and current dual-loop control strategy , analysis five methods to control PWM, compare two ways to detect phase current and introduce digital PID algorithm and digital filter algorithms.The hardware of the BLDC controller uses the 16-bit microcontroller dsPIC30F6010A as the processor,which is specifically designed for embedded motor control applications.The BTS7960 is a fully integrated high current half bridge for motor drive applications.The main circuits of BLDC controller are described.Introduce the embedded real time operating system uC / OS-II,analysis system structure, the composition of the task, the task status, task-ready list and task scheduling.Design the processor-related code in uC/OS-II,and port the code on MCU dsPIC30F6010A.Design the program of BLDC motor controller based on uC/OS-II.The application is decomposed into multiple tasks to complete.The design for the tasks are described in detail.Finally,test the processor-related code in uC/OS-II that are ported on MCU dsPIC30F6010A.Experiments show that it is successful. On this basis,complete the open-loop experiment and the speed closed-loop experiment of BLDC motor,good experimental results are obtained for the follow-up study has laid a good foundation.