Polarization diversity double-channel speed and distance measuring coherent laser radar measurement method and device

Abstract

The invention discloses a polarization diversity double-channel speed and distance measuring coherent laser radar measurement method and device. A laser beam output by a laser source is divided by a first polarization beam splitter into a speed measurement light beam and a distance measurement light beam which are orthogonally polarized; the speed measurement light beam adopts quadrature demodulation coherent homodyne Doppler for laser speed measurement; and the distance measurement light beam uses pseudo-random code high-speed phase modulation for laser distance measurement. The speed and distance of a long-distance target are measured precisely and synchronously by means of polarization diversity, the whole system is small, operation is easy, and the development prospects are good.

Description

technical field [0001] The invention relates to the technical field of laser ranging and speed measurement, in particular to a polarization diversity dual-channel speed measurement and ranging coherent laser radar measurement method and device 。 Background technique [0002] Environmental perception technology is an important part of the autonomous driving platform. It uses sensors such as lidar and millimeter-wave radar to perceive the surrounding environment and provide decision-making basis for the autonomous driving platform. As one of the key core technologies, lidar technology can effectively provide the information required by the autonomous driving platform decision-making and control system, and has become an indispensable sensor for autonomous driving environment perception. The distance and speed of the target are important information for the autonomous driving platform to judge the external environment, and it is an indispensable part to realize intelligent dri...

AI Technical Summary

Problems solved by technology

[0003] The current commercial LiDAR usually uses single-pulse laser time-of-flight method (Time of Flight) for distance measurement. The advantage is that the structure is simple and the technology is mature. The disadvantage is that it can only provide the distance information of the target, and the speed is based on the change of the distance measurement data. Obtained by differential calculation

However, this algorithm requires a high signal-to-noise ratio. It is necessary to determine the head position of the Doppler signal through the distance calculation process to ensure that the sampling sequence is a Doppler signal mixed with noise instead of pure noise. restricted

[0011] To sum up, the existing lidar technology has the problems of low distance resolution and limited speed measurement accuracy, and the overall system is complex and difficult to operate, which limits the application prospects

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