Design Of Rain Sensor And Wiper Control System Based On LIN Bus

The automotive wiper is an indispensable safety electronic component of the car.It provides the driver with a clear view by cleaning the windshield of the car when driving in the rain.With the progress of automotive electronic technology,the wipers are also developing towards intellectualization and humanization.This paper proposes a scheme of rain sensor and wiper control system based on LIN bus.This scheme aims to realize the automatic control of wiper.And this scheme can improve the safety of the driving in the rainy day.The main contents of this paper include:1.Design an infrared rain sensor.Firstly,the principle of infrared rain detection method was analyzed,and then the hardware design of rain sensor was completed based on rainfall information interface chip MLX75308,and the hardware circuit diagrams of each module were given.By referring to the datasheet of MLX75308 and a large number of experiments,the rainfall was divided into 4 levels which correspond to the four positions of the wiper controller.The software of the rain sensor was finished and the flow chart of the main program was given;At last,the rain sensor used the LIN bus interact with the MCU.2.Design the wiper controller based on STM32.The rain wiper controller hardware was designed,including power module,motor driver,speed position feedback and communication module.And the circuit diagram of each module was given.The speed of motor was controlled by changing the PWM duty cycle.And the motor was reversal by changing the MOSFET H-bridge conduction sequence.The LIN bus communication method was used to interact with the MCU.3.The research of Motor Control Algorithm Based on Fuzzy PID.In order to realize the precise control of wiper motor speed,a motor control strategy based on fuzzy PID controller was proposed.The fuzzy PID controller was simulated and analyzed by simulation software MATLAB.Then the fuzzy PID controller was compared with the traditional PID control strategy.The simulation results show that the fuzzy PID control system has small overshoot and better stability,which is suitable for the control of the wiper motor.The final simulation experiment shows that the rain sensor of the subject can automatically select the wiper gear and control the wiper motor through the wiper controller.This project achieved the goal of automatic wiper control.