Laser Ranging System Research Based On FPGA

This paper is introduced a laser ranging system based on FPGA. Laser ranging technology is an important branch in the field of laser application. It has the advantages in the measurement of distance because that laser is high monochromaticity, high directionality and good coherence. So it is a laser as a light source ranging technology.The laser range finder is divided into pulse and phase two types at present. Pulse Laser Range Finder has many advantages, such as compactness, facilities of signal process, the real-time measurement and huge development potential. This system is used pulse to make up a laser ranging system. The thesis is introduced the basic principles of the pulse laser ranging system, and analyzes the ranging method. This system consists mainly of three parts of the laser emission, laser receiver and signal processing. The laser emitting part is used special ranging laser to produce a high performance pulse laser. Laser receiving part is selected APD to perform photoelectric conversion. An effective design scheme of the reverse bias voltage and temperature compensating circuit was proposed based on the comprehensive analyses of the performance of APD. The core signal processing module is designed based on FPGA. It achieve laser emission control, the clock divider and internal PLL high-frequency timing clock. The design is improved the accuracy and stability of the system.The main work of this paper is a laser ranging system signal processing system design. The timing clock frequency signal influence on system measurement accuracy, so the system using FPGA internal PLL clock multiplier signal high frequency clock to improve the measurement accuracy. ALTERA Cyclone EP2C8series chip is selected. it will eventually reach an equivalent clock frequency of200MHz. The entire system configuration achieved within FPGA using VHDL language programming. Laser drive signal generation and the generation of high-frequency clock are simulated in the Quartus Ⅱ compiler environment, The entire system functions and measurement error analysis are also finished.