A method and device for laser radar ranging based on spread spectrum technology

Abstract

The invention discloses a method and device for laser radar distance measurement based on spread spectrum technology, which belongs to the field of laser radar distance measurement, and includes the following steps: S1: the bit information of the transmission sequence is compared with the phase difference of a pair of adjacent symbols The light source signal is phase-modulated, S2: the phase-modulated optical signal is transmitted through the transmitting optical antenna into the space to be measured, S3: the reflected optical signal enters the delay interferometer, thereby realizing the demodulation of the optical signal, S4: the demodulated The optical signal is photoelectrically converted by the photoelectric balance detector. S5: The local sequence uses at least one phase comparison method of chip phase comparison and code clock phase comparison to realize distance measurement. The method and device for laser radar ranging of the present invention are based on spread spectrum technology, have strong anti-interference ability, have a longer distance for detection, and are cheap. At the same time, rough measurement or fine measurement can be performed according to actual needs, and the measurement speed can be improved.

Description

technical field [0001] The invention relates to the field of laser radar distance measurement, in particular to a laser radar distance measurement method based on spread spectrum technology. [0002] The invention relates to the field of laser radar distance measurement, in particular to a laser radar distance measurement device based on spread spectrum technology. Background technique [0003] As a sensor that can obtain information about the position and shape of objects, lidar is suitable for terrain mapping. It is often used in indoor modeling, data collection of roads and facilities, mine goaf measurement, or carried on aircraft for large-scale power line inspection, forestry census, water conservancy survey, etc., and has a wide range of applications. At present, the application of lidar measurement technology is showing a diversified trend. In addition to traditional surveying and mapping, it has shown broad market prospects in emerging industries such as unmanned dr...

AI Technical Summary

Problems solved by technology

The main disadvantages of FMCW are: firstly, the FMCW laser source is bulky and expensive, and secondly, it requires more computing power, so it is slower in generating a full 3D surround map, and the measurement accuracy is very critical to the degree of linearity in modulation. sensitive

The difference in beam diameter will lead to completely different phase modulation methods. For example, it is very easy to select a device with a half-wave voltage of a few volts for a fiber phase modulator. If the phase modulation is performed on a beam whose beam diameter reaches centimeters, the half-wave voltage will Dozens of times or even hundreds of thousands of times increase, which will make the modulation method used in the optical fiber phase modulator unchanged, and in some cases it is difficult to use it in the laser radar

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