Robust ultrasonic range finder-an FFT analysis

Abstract

An ultrasonic range measurement system has been developed, based on bandpass to lowpass transformation of the impulse response. The impulse response is a sensitive indicator of time delays between signals. In this case the time delay is caused by the propagation of the sound wave between transmitter and receiver. The proposed method features two important advantages, especially usable in robot automation or automated guided vehicle (AGV) application: firstly, it is robust against disturbances with maintenance of high accuracy in the range estimation; secondly, standard signal processor I/O cards can be used due to the reduced analysis frequency interval. Experimental results illustrating the performance of the ultrasonic range system are presented. Some experimental comparisons with the pulse echo method are also made.