Three-dimensional Ultrasonic Positioning System Design And Implementation

Ultrasonic infrared positioning technology，which implement location by measuringthe time of flight (TOF), It widely used in electronic whiteboards, virtual reality, smarthome and other fields. In recent years, with multimedia technology, virtual realitytechnology and stereoscopic video technology rapid development, which makes the3D positioning technology attracts more and more researchers’ attention.This topic is platform by ultrasonic infrared electronic whiteboards, which designsignal processing circuit and optimize the receiving circuit and design PC program,realize the3D ultrasonic infrared positioning system principle prototype, overcomegraphic display and bad sinking feeling of the two-dimension interactive electronicwhiteboard.In this paper, which firstly introduce the basic theory and method of ultrasonicranging, design of3D ultrasonic positioning system overall scheme, realized byTMS320VC5502core processor of the ultrasonic signal processing circuit board andPCB board test, by verification, each module of in the circuit board work normal, eachindex can satisfy the system requirements.Three-dimensional ultrasonic positioning system of the overall hardware designinclude analog circuits and digital circuits. analog circuits mainly finished receivingand amplification of ultrasonic signals, the digital circuit is mainly finished ultrasonicsignal acquisition and filtering processing.According to the received ultrasonic signal amplitude is small (mv degree), whichin-depth study the low noise transistor amplifier circuit design principle and method,according to the cascade amplifier of low noise design principles, which introducedwithout noise in the first stage of amplifier circuit, theoretical analysis shows that cangreatly improve the SNR of signal.Based on TMS320VC5502core processor of the ultrasonic signal processing circuit,It mainly completed processing of the ultrasonic signal and the realization of thelocalization algorithm, system application program development and preservation.This part of the circuit mainly includes power circuit, A/D sampling circuit, resetingcircuit and the PC serial port communication circuit, FLASH storage circuit. On thebasis of the hardware circuit design and the modularization program design idea,which introduce C language and assembly language mix programming method anddevelop each module software program of system board, complete the system boardhardware and software of the test. Finally the PC software of system was designed and implemented, includingcommunications programs and display program, communication program uses virtualserial port operation method, display program uses OpenGL program design method,complete the computer3D display function.The main contribution of the paper is as follows:1. According to the requirements of the three-dimensional ultrasonic positioningsystem overall design, design three-dimensional ultrasonic positioning systemhardware implementation scheme, including ultrasonic signal receiving circuit andsignal processing circuit;2. Designed and implemented by TMS320VC5502as the core processor of thesignal processing circuit, including power supply circuit, A/D conversion circuit,crystal vibration circuit, FLASH storage circuit, and the PC serial port communicationcircuit. Through software and hardware joint measurement, achieve the function ofevery module circuit, meet the system requirements, It is the preparation of the systemupgrades and maintenance, and then introduction of no noise in the signal receivingamplifier circuit, which greatly improves signal-to-noise ratio, reduces the time delayerror of the extraction algorithm;3. After the analysis of ultrasonic signal time delay extraction algorithm, whichdesigns the three-dimensional ultrasonic positioning system software, achievecommunication program and display program function of the PC.The above work for three-dimensional ultrasonic positioning system hardwaredevelopment provides reference scheme. It provides reference value forhuman-computer interaction, virtual reality, robot track positioning device productsresearch and development.