The Design And Implementation Of The Deviation Control System Based On Brushless DC Motors

With the rapid development of electronic technology in the last decade, there are many advanced methods and techniques towards the control of BLDC. Its increasingly wide range of applications is due to the improved function of BLDC. In this report, a designed deviation control system for BLDC is designed to achieve an efficient and effective deviation control based on good performance of brushless direct current motor.The whole deviation control system is designed to consist of three ring closings according to Automatic Control Theory:the inner loop as current loop is mainly utilized to limit threshold current, security system and to inhibit voltage disturbance; intermediate loop is considered as speed ring, and its output was inner loop’s input. Its output amplitude limited allowed threshold current. The introduction of speed loop can be used to strengthen the anti-jamming of loadmaster; outer loop is also named position loop. Compared the actual position from sensor with given value, the output signal is transmitted to speed loop, then to control changing position.The first part of report is about deviation control system, its basic principle of operation and current development situation. The designed deviation control system for brushless direct current motor is suggested. In the following part, the structure, operation principle, and control method, and motor’s mathematic model of the system are described in detailed, and then three ring closing systems are analyzed based on the information above. Dynamic structure drawing of each ring will be provided, what is more, Matlab simulation analysis of regulator in each designed ring is used to check the function of designed regulators. In the next part, hardware circuit and software flow will be presented based on theoretical analysis, to implement the designed deviation control system for brushless direct current motor.In theory, the three closed-loop system analysis and mathematical modeling, calculated according to the parameters of the actual BLDC gives the regulator time constant of the feedback scale factor, the simulation analysis of the performance of the regulator. The article according to the parameters given by adjusting the parameters of the performance through simulation analysis, given the implementation of the regulator, current regulator uses the hardware circuit to adjust the speed and position adjustment according to the time domain equations are discredited transform, find the differential equation then be achieved through software programming.STM32single chip in ST Company is taken as key part of this system to control the whole deviation control system. The deviation sensor of this system is ultrasonic sensor, and brushless direct current motor is considered as drive part in operation structure. The software should be designed as modular design, to ensure the clear structure of whole system.