Based On Msp430-phase-shift Laser Range Finder

The laser ranging is a technology for precision measurement and it is developing along with the development of the laser technology. The laser ranging is extensively used in the military field and the civil field because of its high accuracy.The theory of laser range finder is firstly introduced in this paper. Then based on the laser radar ranging theory, the laser radar ranging equation, the effect of the travel characters of the laser in the air on the measurement and the laser ranging SNR equation are discussed. The scheme is designed based on these researches.For traditional laser rang finders, most of them use heterodyne method as the phase shift measurement. The advantage of heterodyne method is the high measurement accuracy, but its disadvantage is the low measurement velocity. According to the requirement of measurement accuracy and velocity, a novel twofold frequency laser ranging method based on phase ranging technology is proposed. By using MSP430 micro controller unit and CPLD technology, this method realized twofold frequency phase ranging: The rough measurement of the distance is realized by countering high frequency pulses which are filled in discriminating phase pulses; The accurate discriminating phase pulses are converted by using the method of time to voltage conversion, and then the ADC device samples the converted voltage, so the accurate measurement of the distance is obtained by processing the ADC samples through micro controller unit. Various technical measures are adopted to make sure the accuracy of the laser ranging and the requirement of the high velocity of the laser ranging is satisfied. So the real-time measurement of the dynamic target is satisfied by using this method. According to the phase laser rang finder design scheme, the fundamental hardware circuits are designed. The hardware designation uses the MSP430 micro controller unit as the control center. The rough and accurate values of the measurement are obtained by using CPLD and ADC devices. The analog circuits mainly included the modulating and driving circuit of the laser, receiving circuit and APD high-voltage biased circuit. Serial communication circuit and power circuit are designed. The system...