Research On Brushless DC Motor Servo Control System Based On PID Algorithm

The phenomenon of population aging in China is becoming more and more serious.The nursing problem for the elderly has become an important issue for the society in China.Therefore,medical assistant robots have broad application prospects.Compared with brushed DC motors,brushless DC motors have very good torque characteristics and mechanical characteristics,and there is no carbon brush,which minimizes the degree of wear,long service life and easy maintenance,so in medical walking aids Among them,brushless DC motors have become the best choice in the drive system.Therefore,the servo control problem of the brushless DC motor has become an important issue in the field of medical robots.After reading related thesis and literature books,and on the basis of an in-depth investigation of the current status of research at home and abroad,this thesis briefly describes the research development of brushless DC motor servo control systems in the field of robotics,leading to the current brushless DC motor servo control systems.The three major issues are mainly studied,and the hardware components and software control strategies of the brushless DC motor servo control system are also analyzed.According to the requirements of practical applications,this thesis carried out the hardware and software design and system simulation of the brushless DC motor servo control system.In terms of hardware,all the circuits related to the servo control system and the reliability design of the circuits have been completed.In terms of software,the drive algorithm and closed-loop control algorithm of the brushless motor are studied.By studying the drive control algorithms such as field weakening control and square wave control,the advantages and disadvantages of various drive algorithms are pointed out.Advantages in topic applications.In the design of the torque and speed control algorithm,the shortcomings of the traditional PID control algorithm are analyzed.The PID control strategy based on"Anti-windup" is adopted to effectively solve the problem of integral saturation caused by the system’s limiting link and improve the system stability.Aiming at the problem that the glitch noise of the current feedback signal is very serious,a method for identifying noise by judging the slope is proposed,and the algorithm is improved in combination with the actual problem to further improve the method.The system simulation and actual system debugging prove the method Feasibility.The experimental results show that the proposed method can effectively filter the glitch noise and reduce the jitter of the current response.This thesis takes STM32 as the control core of the system,develops a brushless DC motor servo control system for a medical walking assistance system and builds a walking assistance system platform.At the same time,the walking assistance equipment studied in this thesis replaces the portable walking assistance equipment,which provides stable upper arm support for patients with inconvenience in walking,and also reduces the burden on the patient’s upper arm,which promotes the recovery of the patient’s walking ability.