Study On Laser Range Finder System Based On FPGA And DSP

Since 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. The laser range finder was divided into two kinds of the pulse type and continuous type at present. The continuous type laser range finder arouses the attention from people with the development of technology of the laser instrument in recent years. In the civil field, the continuous type laser range finder is especially expected in some no real-time character systems.Miniaturized, intelligent, high accuracy, safe to the human eye is the developing direction of laser range finder, but present laser range finder generally has a lot of shortcomings, such as more components and parts, the consumption is relatively high, flexibility is not enough, weak anti-interference ability. So it is unfavorable to realizing the integration and miniaturization of the laser range finder.Aiming at the shortcomings above, a kind of new thought , applying digital signal processing technology to the continuous type laser range finder based on phase ranging technology, is proposed in this paper. The detail way is to utilize DDS technology produce sine signal to modulate laser instrument, use FPGA and DSP to implement high-speed digital process to signals. With this method, the laser range finder is not only merely overcoming the shortcoming above, but also holding the following advantages: the frequency of modulating can be changed through the method of software, it simplifies the design greatly and improves the convenience, it solves the problem that frequency is unstably and the phase is shaking by using DDS technology, it improves real-time character with DSP IC to deal with the signal, it has space of promotion on the precision by using FFT technology to detect the phase with the constant development of micro-electronics technique.The feasibility of the laser ranging scheme is proved in the paper. Theoretically, the ranging precision in the order of millimeter is obtained when various technical measures are adopted to minimize the interference from the environment. The method is novelty, and the influence from environment is little. It can be used to measure short distance (usually less than 15 meters) under hostile conditions. The results prove that the scheme is feasible.