The Design And Implementation Of Control System Of Brushless DC Motor For Noninvasive Ventilator

Chronic obstructive pulmonary disease is a kind of chronic respiratory diseases characterized by airflow limitation.Because the number of patients,high mortality and significant socio-economic burden,it has become an important public health problem.Currently,using the positive pressure ventilation ventilator is known as one of the effective treatment of COPD.Brushless DC motor control system is non-invasive ventilator power execution units,meanwhile it is core components,whose performance directly determines the non-invasive ventilator dynamics,control precision,comfort,noise as well as other key technical indicators,and has decisive impact on noninvasive ventilator performance,structure layout and manufacturing costs.This thesis is intended to design a high-performance,low-cost brushless DC motor control system for non-invasive ventilation.The control system uses ARM microprocessor as the core,Combined with closed-loop control principle,the motor drives the wind blower output pressure as the system feedback,and design the fuzzy PID switching controller.Meanwhile,based on using the software product line,the thesis designs a motor control system components in order to achieve non-invasive ventilator component-based development.This thesis completed the following tasks:(1)The working principal of brushless DC motor is analyzed,the main formulas are deduced and its mathematical model is built.According to the motor control system requirements,determined to pressure data and current data for the feedback pressure,current and fuzzy double closed loop switching control scheme,proposed system performance,demonstration of the control strategy,describes the control side,and control technologies.(2)It uses ATMEL Corporation’s ARM chip-AT91SAM9G45 to control the core,combined with IR’s IR2181 driver chips,power MOSFET-IRF540N and Honeywell’s precision digital pressure sensor designed the hardware of brushless DC motor control system.(3)Design of the fuzzy controller and dual-loop PID controller.Introduce AT91SAM9G45 chip peripheral module configuration method,and show the software design process flow chart of key algorithms.(4)Design software components and hardware components of the motor control system for ventilator product line development.Introduce the basic elements of the component and study the variability of component in-depth.(5)Brushless DC motor control system has been used in unit testing and integration testing,at last analyzed test data and gave the conclusion.The application results show that the proposed design of the brushless DC motor control system with an output pressure of high precision,small overshoot,fast response and Little impact load effects,and the system has used in the non-invasive ventilator...