基于AVR单片机的超声波测距系统构建

为了提高超声波测距精度,构建了基于AVR单片机的测距及数据处理系统。分析了超声波测距的原理,以AVR单片机为处理器设计了超声波产生和发射电路、超声波接收和信号处理电路以及温度测量和补偿电路等。针对温度对超声波速度的影响,根据超声波速度与温度的关系,设计了超声波速度补偿算法。为了提高回波时间测量准确性,减小随机噪声及空气中其他杂散播干扰的影响,采用均值数字滤波方法,对计数时间进行处理。实测结果表明,在3cm~400cm范围内,超声波测距系统测量数据准确,最大误差为0.66cm。

System Construction on Ultrasonic Distance Measuring Based on AVR Microcontroller

In order to improve the distance measuring precision, a distance measuring and data processing system based on AVR microcontroller is constructed. The ultrasonic distance measuring principle is analyzed, using AVR microcontroller as processor, some circuits are designed including ultrasonic generating and transmitting circuit, ultrasonic receiver and signal processing circuit, temperature measuring and compensating circuit, and so on. In view of the influence of temperature on ultrasonic velocity, according to the relationship of ultrasonic velocity and temperature, the ultrasonic velocity compensating algorithm is designed. In order to increase the echo time measuring accuracy, and decrease the interference of random noise and the other spurious noise from the air, the mean value digital filter method is put forward to deal with the counting time. The measured results show that within the scope of 3cm to 400cm, the measure data is accuracy using the ultrasonic distance measuring system, the most error is 0.66cm.