DC motor control system

First prize team member in the semi-finals of the 13th Wuhan University of Technology’s Electrical and Electronic Innovation Design Competition: Guo Zeyu, Wang Chengxiang and Wang Yong. Competition topic: DC motor control system. Instructor: Zhang Jialiang DC motor control system. 1. Task: Make a current feedback DC motor control system And complete the corresponding test device. (Draw the system block diagram) 2. Requirements (1) The system uses +12V power supply, and a boost circuit is made to provide +15V power supply to the motor. The boost circuit requires a maximum error of output voltage of ±3% and a maximum output current of ≥3A under resistive load conditions. Under full load, the efficiency is ≥90%, and the ripple is less than 200mVpp; under inductive load (DC motor no-load movement), the maximum error of the output voltage is ±6%, and the ripple is less than 500mVpp. (15 points) Improvement part: When all the above indicators are met, if you can achieve obvious optimization of at least 3 indicators (accuracy, load capacity, etc. are doubled, the ripple is reduced by half, and the efficiency is increased by 5%), you can get additional Add points. (5 points) (2) Make an auxiliary power supply that meets the normal working requirements of the system to power the microcontroller, measurement system, etc. The system quiescent current is required to be less than 5mA. (That is: the system needs to reduce power consumption as much as possible when there is no test task. During system testing, an ammeter will be connected in series to the input end to monitor the system operating current). (5 points) (3) Make a motor drive circuit that can realize motor polarity switching (forward and reverse switching), output instantaneous maximum current ≥10A, rated current ≥5A, and working voltage 12-24V. (10 points) (4) To make a motor current detection circuit, the system requires a single power supply, the current monitoring accuracy is better than 1%, and when the current changes dynamically, the monitoring bandwidth is >1KHz. The detection results are transmitted to the computer for display through the wireless transmission module. (20 points) (5) Use the encoder speed feedback method to control the movement of the motor and pull the 1KG object vertically to achieve the following movement process: stationary - acceleration - uniform speed (the speed of uniform movement is determined by yourself according to the actual situation). In the process of rising at a constant speed, by increasing the weight of the object, when the motor current reaches or exceeds 150% of the current when a 1KG vertically pulled object rises when the constant speed is restored, the buzzer is controlled to implement an overload alarm. In the process of falling at a constant speed, by increasing the weight of the object, when the motor current reaches 50% of the current when the object of 1KG is vertically pulled down, the buzzer is controlled to implement a stall alarm. (15 points) Note: The total weight of the object does not exceed 2kg, and the added object has no initial velocity. (6) Use the current feedback method to control the movement of the motor and pull the 1KG object vertically to achieve the following movement process: stationary - acceleration - constant speed. When at rest, start by pressing the button to realize the rest-acceleration process. The acceleration movement distance is 0.3 meters (strictly guaranteed), the final speed is 0.3 meters/second, the uniform movement distance is 1 meter, and it will decelerate and stop immediately after exceeding 1 meter (do not do this) requirements), rise and fall independent testing. (15 points) Note: During actual scoring, the encoder in (5) needs to be in a non-working state; if the motor movement is controlled by using encoder feedback to meet the requirements of this question, no points will be awarded. (7) The motor needs to have a speed detection function (absolute encoder, etc.), and a self-made speed and distance measurement display system is required, and the instantaneous measurement results are transmitted to the PC through the wireless module for verification. This part of the circuit system is required to be powered and work independently, and have no electrical connection with the above control system, drive system, etc. (that is, it must not share power or ground with the motion control system). The evaluation process will be compared with standard instruments and equipment. (15 points) 3. Supplementary matters (1) This system involves system design in basic power supply production, motion control and signal detection. Each sub-function is independently evaluated and scored. Students can make comprehensive choices based on their own knowledge reserves and score points. priority! (2) In the system, except for the controller core board (microcontroller, FPGA, DSP, etc.) and the wireless module, which can use finished modules, other components such as auxiliary power supply, motor drive module, signal detection module, etc. must be made in-house (circuit board drawing). (3) It is recommended to use WIFI, BLE and other serial port modules for wireless modules. Uploaded part of the code of the wifi module. This project uses the constantan resistor + differential amplification current detection module and the TB6612 motor drive module. The voltage information read by the AD is collected through the STM32 main control board, and the corresponding parameters are output to the motor drive module to control the motor speed, etc.