Obstacle information acquisition method, laser pulse transmission method and device

Abstract

The invention discloses an obstacle information acquisition method, a laser pulse transmission method and a laser pulse transmission device. The laser pulse transmission method comprises the steps of:transmitting a first laser pulse at a first moment; and transmitting a second laser pulse at a second moment, wherein peak power of the first laser pulse is less than that of the second laser pulse,a time interval between the second moment and the first moment is longer than T, and the T is a time length from a moment that the laser pulse is transmitted to a moment that a laser pulse echo signalreflected by a near-field obstacle is received. By adopting the obstacle information acquisition method, the laser pulse transmission method and the laser pulse transmission device, since the power of the first laser pulse is small, stray light cannot cause voltage saturation of a detection circuit, thus the first laser pulse reflected by the near-field obstacle can be detected, thereby effectively solving the problem of measurement blind area of the near-field obstacle caused by the stray light inside a laser radar at low cost; and since the signal intensity of the second laser pulse is high, normal detection of a far-field obstacle can be guaranteed.

Description

technical field [0001] The embodiments of the present invention relate to the field of environment perception technologies, and in particular to a method for obtaining obstacle information, a method and a device for emitting laser pulses. Background technique [0002] Since the shape and distance information of all obstacles within 100 meters of the vehicle can be obtained, lidar has become a necessary sensor for automatic driving. In the current laser radar system, the method of pulse ranging is mainly used to obtain obstacle information, that is, by emitting laser pulses with narrow pulse width and high peak power, and then measuring the reflection with an avalanche photodiode detector (Avalanche Photo Diode, APD). The time delay of the pulse, so as to calculate the distance information of the obstacle. [0003] For the lidar system using the pulse ranging method, during the transmission of optical pulses, a small part of the transmitted pulses will be directly received b...

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Problems solved by technology

[0005] The technical problem solved by the embodiments of the present invention is how to solve the problem of the measurement blind area of ​​near-field obstacles caused by stray light inside the lidar at a lower cost

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