基于CPLD的超声波倒车预警系统的研究

Research of ultrasonic reversing warning system based on CPLD

针对目前市场上很多小型货车不具备倒车预警系统的现状,设计了一种超声波倒车预警装置。该系统以CPLD作为控制核心,采用HC-SR04传感器作为超声波收发模块,系统硬件部分还包括数码管显示、蜂鸣器和LED报警等模块。为了提高测量精度,利用DS18B20芯片对声速进行了温度补偿。软件部分主要在QuartusⅡ集成开发环境中通过Verilog HDL硬件描述语言设计完成。用户可以通过按键启动和停止倒车预警系统,数码管实时显示障碍物距离,并根据距离大小发出相应的声光报警,以提示驾驶员。通过实验将系统测量值和实际值进行对比,实验结果表明,系统的量程为2~450 cm,测量精度可达3 mm,具有一定的实用性和推广价值。

Aiming at the current situation that many minivans in the market do not have a reversing warning system,an ultrasonic reversing warning device was designed.The system uses CPLD as the control core and HC-SR04 sensor as the ultrasonic transceiver module.The hardware part of the system also includes digital tube display,buzzer and LED alarm module.In order to improve the measurement accuracy,DS18 B20 chip was used to compensate the temperature of sound velocity.The software part is mainly designed by Verilog HDL hardware description language in Quartus Ⅱ intergrated development environment.User can start and stop the reversing warning system by pressing button,the digital tube displays the distance of obstacles in real time,and sends out the corresponding sound and light alarm according to the distance to prompt the driver.The experimental results show that the measuring range of the system is 2~450 cm,and the measuring accuracy is up to 3 mm.It has certain practicability and popularization value.