a laser radar

Abstract

A laser radar, the laser radar comprising: at least one laser adapted to emit a laser pulse; a transmitting light path module which is coupled with the at least one laser, and the laser pulse is transmitted out through the transmitting light path module; a receiving light path module which is suitable for receiving echo pulses; and the at least one single-photon detector which is coupled with thereceiving light path and is suitable for detecting the echo pulse processed by the receiving light path module. Through the technical scheme of the invention, the ranging performance of the laser radar can be improved.

Description

technical field [0001] The invention relates to the field of measurement technology, in particular to a laser radar. Background technique [0002] Lidar generally refers to a scanning ranging device that uses the Direct Time-of-Flight method for distance measurement. Due to the limitation of its measurement principle, the distance measurement range of lidar using triangulation method and indirect time-of-flight method is usually about 10 meters; the measurement distance will be greatly reduced under the condition of strong outdoor ambient light. [0003] In the prior art, for lidar using pulsed time-of-flight methods, such as single-line lidar for robotics, ground mapping and airborne, multi-line lidar for assisted driving and autonomous driving, there is usually a pair of laser and detector Or multiple pairs of lasers and detectors, where the lasers fire pulses of light at very high frequencies. The detector system measures the distance by measuring the time difference be...

AI Technical Summary

Problems solved by technology

However, as a non-solid-state photodetector, its disadvantages include the following points: 1. It is large in size and cannot be used on small lidars; 2. It will be damaged if the incident light is too strong, so when ambient light or laser pulses When the echo is strong, there is a potential risk of damaging the PMT; 3. The production process requires manual steps, and the cost of the device is high

4. The working voltage is usually thousands of volts, which increases the difficulty of system integration

The disadvantages of APD are as follows: 1. The photoelectric gain of APD is usually dozens of times to 100 times, which is far lower than the typical value of PMT photoelectric gain of one million times, so the circuit noise is more likely to "drown" the APD signal and affect the long-distance Detection performance; 2. In the case of low APD photoelectric gain, in order to increase the detection distance, it is usually necessary to increase the aperture of the receiving lens, which increases the volume of the device; 3. Also due to the low photoelectric gain of the APD, there must be a high The bandwidth amplifier circuit amplifies the current pulse signal output by the APD, especially in a multi-channel radar system, usually each channel is required to be equipped with an amplifier circuit, which will increase the volume, power consumption and cost of the system; 4. The gain of the APD device drifts significantly with temperature, which requires adding functions such as temperature monitoring and temperature control in the system to deal with the influence of APD temperature drift on the measurement results, which further increases the complexity and cost of the system

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