Secondary optical path focusing structure in receiving module of laser radar ranging system

Abstract

The invention relates to a secondary optical path focusing structure in a receiving module of a laser radar ranging system, comprising a primary focusing optical module and a photoelectric detection module, further comprising: a primary focusing diaphragm adjustment module and a secondary focusing optical module, wherein the primary focusing diaphragm adjustment module is arranged at a focusing position of the primary focusing optical module and the secondary focusing optical module is arranged between the primary focusing diaphragm adjustment module and the photoelectric detection module; the primary focusing diaphragm adjustment module comprises a diaphragm and a three-dimensional adjusting and fixing mechanism which is used for adjusting the diaphragm at XYZ three-direction positions of a vertical optical axis and a parallel optical axis and fixing the diaphragm on the adjusted position; the secondary focusing optical module comprises a collimation lens group, a converging lens group and a mounting bracket, wherein the collimation lens group is used for collimating the light focused by the primary focusing optical module into parallel light or approximate parallel light; the converging lens group is used for converging the parallel light or approximate parallel light collimated by the collimation lens group to the photoelectric detection module; and the mounting bracket is used for mounting the collimation lens group and the converging lens group. The structure is not only easy for processing, but also simple and convenient for adjusting.

Description

technical field [0001] The invention relates to a laser radar system, in particular to a secondary optical path focusing structure in a receiving module of a laser radar ranging system. Background technique [0002] At present, the working principle of the laser radar ranging system is that the transmitting module transmits a laser signal to the target, and then the receiving module receives the light signal diffusely reflected by the target, and processes the reflected signal to calculate the distance of the target. The receiving module includes a focusing optical module and a photoelectric detection module. The optical signal is focused on the optical sensor of the photoelectric detection module through the focusing optical module. Due to the machining accuracy and assembly error, the optical axis of the transmitting module and the optical axis of the optical system of the receiving module are not coaxial, and the position of the optical focus on the optical sensor changes...

AI Technical Summary

Problems solved by technology

The optical signal is focused on the optical sensor of the photodetection module through the focusing optical module. Due to machining accuracy and assembly errors, the optical axis of the transmitting module and the optical system of the receiving module are not coaxial, and the position of the optical focus on the optical sensor changes. , exceeding its effective sensing area, resulting in the inability to detect light signals and radar ranging failure

This requires changing the position of the sensor, and adding linear adjustments in the X and Y directions (the plane perpendicular to the optical axis) on the basis of the original Z-direction (optical axis) linear adjustment. Although the measurement target can be achieved in theory, in practice In operation, it is very difficult to adjust the assembly

At the same time, there is no aperture in the system, the signal interference is large, and the stability is poor

In addition, in an ordinary system that only focuses once, no filter is used, the signal interference is large, and the measurement is unstable

If you want to add an optical filter, due to the consideration of the incident angle requirements of the optical path on the optical filter, the coating is difficult, the cost is very high, and it is not competitive

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