The Design Of Laser Echo Acquisition And Processing Circuit Of Digital Laser Range Finder

Since Dr.T.H.Maiman of U.S.A made the first laser instrument in the world, the laser's excellent monochromatic, directionality and high light characteristic cause the concerns from all walks of life. Technology of the laser range finder is a kind of comparatively extensive laser technology at present. Comparing with general method of range finder, it has a lot of advantages, such as easy to operate, available with the day and night, high precision.Miniaturized, intelligent, high accuracy, safe to the human eye is the developing direction of laser range finder, but the laser range finder mostly uses analog technology at present, and generally has a lot of shortcomings, such as more components and parts, weight is heavier, the consumption is relatively high, flexibility is not enough, weak anti-interference ability, so it is difficult to realizing the integration and miniaturization of the laser range finder. Aiming at the shortcomings of the laser range finder, this thesis puts forward a kind of design of the laser range finding receiver, which could deal with the echo applying digital signal processing technology.According to the principle of range finding and the characteristic of echo, the thesis puts forward the parameter request of the circuit. On account of the characteristics of laser narrow, capturing difficulty and the high real time, a design method is introduced with high-speed ADC+FPGA+DSP for data acquisition and real-time processing. In the design, the main function of the ADC is to convert quickly analog signal to digital signal and the DSP takes charge of processing signals acquired in time. The FPGA concentrates the timing and control circuit, the buffer FIFO and dispersive component into an independent circuit block, which can not only reduce print area, but also advance reliability analysis of the system. With regard to circuit design, this thesis discusses the circuit of analog-to-digital converting, the buffer and control circuit based on FPGA, the DSP circuit in detail. Furthermore, it details the key parts in each circuit module. Because the sampling rate of the circuit is 200MHz, the circuit belongs to high-speed circuit. The thesis details the problem which should pay attention to high-speed PCB(Printed Circuit Board)design, including reflection, crosstalk and ground bounce, then based on it puts forward the PCB design of the circuit. Finally Evaluation of the circuit is given found on the test, and the development of the circuit in the future is suggested.