The Study Of Ultrasonic Ranging System Based On Beamforming

As ultrasound has characteristics of good directivity,slow attenuation,and strong anti-interference ability,it was widely used in distance measurement,target identification,medical testing and other fields.According to the basic principles of beam forming,we use ten ultrasonic probes to form the transmit and receive arrays.By designing the number and spacing of array elements,we reduced the side lobe interference,and extended the scanning angles.We control the ultrasonic probe to transmit and receive sound waves according to certain time delay by FPGA,forming a directional beam in a predetermined direction.This paper designed and completed the transmitter and receiver circuitry,including the launch drive,preamplifier,bandpass filtering and A/D acquisition.By software programming,the system is capable of emitting a beam which angle within the range of-20? ~ 20?,and has the ability to receive echo and do the beam forming processing.The system designed the SDRAM controller.the FPGA control SDRAM to storage data,and transmit them via the serial port to the PC.In order to get more accurate results,we process echo data by WMT(Weighted Mean Time)and BDI(Bearing Deviation Indicator).At last,by setting different distance,orientation of the obstacle,we compare the measurement results of comparative system under different conditions and analysis the experimental data to get the conclusions.