车用红外感雨器的设计

Design of Automotive Infrared Rain Sensor

摘要:

设计了一种车用红外感雨器。该感雨器系统以高亮度红外发光二极管作为光源照射汽车挡风玻璃,以Motorola公司的MC68HC908SR12单片机为控制核心,利用其10位的A/D转换器,完成对挡风玻璃上雨点及水的散射信号的探测采样。通过其PWM端口输出不同占空比的脉冲信号,通过滤波平滑后可转换为相应的直流电平控制雨刮器的转速。

Abstract:

A design of automotive infrared rain sensor is presented in this paper.In the system,the infrared diode of high luminance is used as the lamp-house to irradiate the windshield of automobile and Motorola MC68HC908SR12 is used as MCU.The sensor finishes the detecting and sampling of the rain drops and water on the windshield with a 10-bit A/D converter of MC68HC908SR12.It output impulse signals of different duty cycles,and those signals are then transformed to relevant volts DC through the smoothing of filter.The volts DC is able to control the rotating speed of windshield wiper.