Lidar readout circuit based on pulse echo ultra-high speed sampling reconstruction

Abstract

The invention relates to the field of lidars, which aims to obtain reconstructed images by ultra-high speed sampling of pulse echoes while avoiding walking errors and reducing power consumption. The lidar readout circuit based on pulse echo ultra-high speed sampling reconstruction of the invention is composed of a transimpedance amplifier TIA, a comparator COMP, a high speed sampling circuit HSH,a delay circuit Delay, a time-digital converter TDC, and an analog-to-digital converter LADC. The TDC is connected with a laser emitter. The transimpedance amplifier TIA is connected with a linear avalanche photodiode APD. LADC performs output. The transimpedance amplifier TIA is simultaneously connected with the comparator COMP and the high-speed sampling circuit. The delay circuit Delay is connected with the rear of the comparator COMP. The delay circuit Delay is connected with the TDC and the high speed sampling module. The TDC and the high speed sampling module are both connected with theLADC. The invention is mainly applied to the design and the manufacture of lidars.

Description

technical field [0001] The invention is applicable to the field of laser radar, and relates to the high-speed sampling and reconstruction technology of the laser radar echo pulse signal. Background technique [0002] LiDAR technology is crucial to autonomous driving. It can perform 3D imaging and map mapping through accurate detection of distance information, and then realize target recognition, navigation and obstacle avoidance functions. Due to the above functions, lidar is also widely used in drones, robots, terrain mapping, agricultural production and other fields. The principle of vehicle lidar to achieve accurate ranging is time of flight (TOF). The process of TOF is that the laser emits a laser beam and starts timing at the same time. When the laser encounters an obstacle, it will be reflected on the surface of the obstacle. The reflected light is irradiated on the detector after passing through the receiving optics, and the timing is stopped when the detector detect...

AI Technical Summary

Problems solved by technology

[0003] However, there are large errors in the existing technology, which requires high linearity of frequency modulation (chirp), which directly affects the accuracy of ranging; the current integrated frequency modulation method is not very mature (such as Strobe's frequency modulation laser based on WGM mode) , other frequency modulation methods (such as optical fiber, MEMS) have problems such as cost and volume that need to be solved

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