自具补偿互相关超声测距系统设计

Design of Ultrasonic Ranging System with Self Compensation and Cross Correlation

结合超声波回波特性和互相关算法原理,设计了一套测距系统以降低超声测距的误差。使用QuartusⅡ软件和FPGA控制2套相同的测距装置,一组测量声速,作为另一组距离测量装置的补偿数据。根据FPGA的特性设计互相关算法模块,完成声波飞行时间的处理,并调整FPGA内部结构简化算法模块。测量结果表明,在不使用补偿传感器的情况下,所设计的测距系统在0~1500 mm的范围内,测距的绝对误差为±4 mm,相对误差低至0.2%。

Based on the characteristics of ultrasonic echo and the principle of cross-correlation algorithm,a ranging system was designed to reduce the error of ultrasonic ranging.The QuartusⅡsoftware and FPGA were used to control two sets of same ranging system,the cross-correlation algorithm module was designed to complete the processing of acoustic flight time,and the internal structure of FPGA was adjusted to simplify the algorithm module.The measurement results show that the absolute error is±4 mm and the relative error is as low as 0.2%in the range of 0~1500 mm without the use of a compensating sensor.