Design Of Close Quarters And High Accuracy Ultrasonic Distance Measure System

Technology of ultrasonic range finder has been widely used in ascertain location, medical flaw detection, collision-proof auto in civil area and industrial area. Distance measurement by ultrasonic is an effective and noninvasive method. In recent years, it has been put forward more and higher requirement to the accuracy, range and anti-interference of the range-find system, especially in the small size of work-piece measurement. In this paper, research is based on the principle of high-precision ultrasonic ranging system, designed a high-precision and short distance measure system.First, a particular introduction of the physical characteristic of the ultrasonic and characteristics of T/R40-16 ultrasonic sensors in this paper, in addition, the ultrasonic distance measurement principle characteristics and functions of TDC-GP2 chip, principles of time measurement. Combining with the characteristics of the subject, several schemes of measurement are put forward and fully analyzed in term of error, advantage and disadvantage. The factors and interferences which will make an effect in measurement accuracy are analyzed at large and the solution is put forward. Second, using the principle of Benchmarking Method designs the hardware circuits which are chosen the low power dissipation MSP430 microcontroller as the controller of the system and the TDC-GP2 chip as the core of the time measurement. Some of the programs and some flow charts are given with modular programming idea adopted. To avoid the sensitive time in which ultrasonic transmit from transmitter to receiver directly, the method of receiving lapsed is adopted. Last, experimental results show that the operation of the system is stable. From 1 cm to 1 Ocm, the system measurement error is less then 10μm, the results agree well with our demands.