阅读说明：本技术 检测激光雷达发射光束指向的方法、系统及激光雷达装置 (Method and system for detecting laser radar emission beam direction and laser radar device ) 是由 黄红林 刘慧林 何婕 韩巍 于 2021-07-30 设计创作，主要内容包括：本发明涉及一种检测激光雷达发射光束指向的方法、系统及激光雷达装置,包括：构设反射靶材；激光雷达发射激光束,并沿反射靶材的水平方向扫描,扫描激光束与所述第一参考线、第二参考线和第三参考线的相交的激光点分别为B、C和A；获取A、B和C三个激光点的回波能量值T-(0)、T、和T-(c)；获取第一反射率对应的区域的平均能量阈值T-(1)和第二反射率对应的区域的平均能量阈值T-(2)；根据T-(0)、T、T-(c)、T-(1)和T-(2),计算获得光束指向。其无需占用较大空间和各种昂贵探测器,利用激光雷达回波信号的能量快速检测发射光束指向,速度快,测量精度高。(The invention relates to a method and a system for detecting the direction of a laser radar emission beam and a laser radar device, wherein the method comprises the following steps: constructing a reflective target material; the laser radar emits laser beams and scans along the horizontal direction of the reflective target, and the laser points of the intersection of the scanning laser beams and the first reference line, the second reference line and the third reference line are B, C and A respectively; a, B and C three laser points echo energy value T are obtained 0 T, and T c (ii) a Obtaining the average energy threshold T of the area corresponding to the first reflectivity 1 Average energy threshold T of area corresponding to second reflectivity 2 (ii) a According to T 0 、T、T c 、T 1 And T 2 And calculating to obtain the beam pointing direction. The method does not need to occupy larger space and various expensive detectors, utilizes the energy of the laser radar echo signal to quickly detect the direction of a transmitted light beam, and has high speed and high measurement precision.)

1. A method of detecting the pointing direction of a laser radar transmitted beam, comprising:

the method comprises the following steps of constructing a reflective target, sequentially arranging a reference area, a test area and an identification area on the surface of the reflective target, wherein a square tooth identifier is arranged on the identification area, preset areas are arranged in the test area and the identification area, and the square tooth identifier in the identification area is positioned on the upper side of the preset area and is connected with the preset area; the materials corresponding to the reference area, the preset area and the square tooth mark are all first reflectivity, the materials corresponding to the non-preset area of the test area, the non-preset area of the mark area and the non-square tooth mark are all second reflectivity, and the first reflectivity is not equal to the second reflectivity;

taking a first reference line along the central line of the test area in the vertical direction, taking a second reference line along the central line of the square tooth in the vertical direction, and taking a third reference line in the reference area in the vertical direction, wherein the third reference line and the second reference line are symmetrically arranged relative to the first reference line;

the laser radar emits laser beams and scans along the horizontal direction of the reflective target, and the laser points of the intersection of the scanning laser beams and the first reference line, the second reference line and the third reference line are B, C and A respectively;

a, B and C three laser points echo energy value T are obtained₀T, and T_c；

Obtaining the average energy threshold T of the area corresponding to the first reflectivity₁Average energy threshold T of area corresponding to second reflectivity₂；

According to T₀、T、T_c、T₁And T₂And calculating to obtain the beam pointing direction.

2. The method of claim 1, wherein the second reflectivity is less than the first reflectivity.

3. Method for detecting the pointing of an emission beam of a lidar according to claim 2, characterized in that the method is based on T₀T, and T_cCalculating a beam pointing direction, comprising:

when T is₀＝T＝T_cWhen the laser radar emits light beams, the light beams are in an angle range corresponding to the preset area;

when T is₂/T₁<T/T₀<1,T_C＝T₁When the laser radar emits light beams, the light beams are within an angle range corresponding to a boundary between a preset area and a square tooth mark on the upper side of the preset area;

when T/T₀＝T₂/T₁，T_C＝T₁When the laser radar emits light beams, the light beams are within an angle range corresponding to the square tooth marks on the upper side of the preset area;

when T is₂/T₁<T/T₀<1,T₂<T_C<T₁When the laser radar is used, the emission light beam of the laser radar is in an angle range corresponding to the junction of the preset area and the non-preset area on the lower side of the preset area;

when T/T₀＝T₂/T₁，T_C＝T₂And when the laser radar emits light beams, the light beams are in the angle range corresponding to the non-preset area on the lower side of the preset area.

4. Method for detecting the pointing of a radiation beam from a lidar according to claim 3, characterized in that the maximum angle of the radiation beam from the lidar, substantially within the predetermined area, is ± θ₀The minimum angle of the emitted light beam of the laser radar is shifted upwards/downwards to the preset area completely entering the test area is +/-theta₁And then the angle pointing area of the laser radar emission beam to be detected meets the following requirements:

when T is₀＝T＝T_cWhen, -theta₀<θ<θ₀；

When T is₂/T₁<T/T₀<1,T_C＝T₁When theta is greater than theta₀<θ<θ₁；

When T/T₀＝T₂/T₁，T_C＝T₁When theta is greater than theta>θ₁；

When T is₂/T₁<T/T₀<1,T₂<T_C<T₁When, -theta₁<θ<-θ₀；

When T/T₀＝T₂/T₁，T_C＝T₂When theta is greater than theta<-θ₁。

5. The method of claim 1, wherein the second reflectivity is greater than the first reflectivity.

6. The method of claim 1, wherein said square tooth marks are arranged in a linear array.

7. A system for rapidly detecting the direction of a laser radar transmitted beam, comprising:

the device comprises a reflection target, wherein a reference area, a test area and an identification area are sequentially arranged on the surface of the reflection target, a square tooth identifier is arranged on the identification area, preset areas are arranged in the test area and the identification area, and the square tooth identifier in the identification area is positioned on the upper side of the preset area and is connected with the preset area; the materials corresponding to the reference area, the preset area and the square tooth mark are all first reflectivity, the materials corresponding to the non-preset area of the test area, the non-preset area of the mark area and the non-square tooth mark are all second reflectivity, the first reflectivity is not equal to the second reflectivity, a first reference line is taken along the central line of the test area in the vertical direction, a second reference line is taken along the central line of the square tooth in the vertical direction, a third reference line is taken in the reference area in the vertical direction, and the third reference line and the second reference line are symmetrically arranged relative to the first reference line;

the laser beam emitting module is used for emitting laser beams and scanning along the horizontal direction of the reflective target, and the intersecting laser points of the scanning laser beams and the first reference line, the second reference line and the third reference line are B, C and A respectively;

an energy acquisition module for acquiring A, B echo energy values T of three laser points C₀T, and T_c；

An average threshold energy threshold obtaining module, configured to obtain an average energy threshold T of an area corresponding to the first reflectivity₁Average energy threshold T of area corresponding to second reflectivity₂；

A calculation module according to T₀、T、T_c、T₁And T₂And calculating to obtain the beam pointing direction.

8. The system for rapidly detecting the pointing direction of a laser radar beam as defined by claim 7, wherein said computing module is based on T₀、T、T_c、T₁And T₂And calculating to obtain the beam direction, comprising:

when T is₀＝T＝T_cWhen the laser radar emits light beams, the light beams are in an angle range corresponding to the preset area;

when T is₂/T₁<T/T₀<1,T_C＝T₁When the laser radar emits light beams, the light beams are within an angle range corresponding to a boundary between a preset area and a square tooth mark on the upper side of the preset area;

when T/T₀＝T₂/T₁，T_C＝T₁When the laser radar emits light beams, the light beams are within an angle range corresponding to the square tooth marks on the upper side of the preset area;

when T is₂/T₁<T/T₀<1,T₂<T_C<T₁When the laser radar is used, the emission light beam of the laser radar is in an angle range corresponding to the junction of the preset area and the non-preset area on the lower side of the preset area;

when T/T₀＝T₂/T₁，T_C＝T₂And when the laser radar emits light beams, the light beams are in the angle range corresponding to the non-preset area on the lower side of the preset area.

9. The system for rapidly detecting the pointing direction of a laser radar transmitted beam as claimed in claim 7, wherein said laser beam emission module is configured to emit a pulsed laser beam.

10. Lidar device, comprising a system for fast detection of the direction of a laser beam emitted by a lidar according to any of claims 7 to 9.

Technical Field

The invention relates to the technical field of laser radars, in particular to a method and a system for detecting the direction of a laser beam emitted by a laser radar and a laser radar device.

Background

With the rapid development of various robots, automatic driving and other industries, the application of laser radars is more and more extensive. The laser radar sends out laser beam, and the distance and the position of the object are determined through echo signals reflected by the object. The direction of the emitted light beam determines the detection range and the use scene of the laser radar, and the accurate measurement of the direction of the laser beam has important significance for the use of the laser radar. At present, there are various measurement methods for detecting the laser pointing direction, such as a target plate method and a fold mirror method mentioned in "research on laser emission beam pointing direction detection method" (research on electronic detection and instrumentation 2014) of duckweed, and an angular velocity measurer used in CN 201710402741.

Both the target plate method and the fold mirror method require a probe. The target plate method is characterized in that a detector is used as a target plate and placed at a far position to directly receive collimated light spots, or the target plate is used for receiving irradiation of the collimated light spots, and imaging devices such as a CCD (charge coupled device) record light spot miss distance. Due to the fact that the distance is long, the light energy attenuation is serious, the accuracy of the detector is limited, the measurement accuracy is not high, the light spot divergence is larger when the distance is longer, and the requirement on the size of the target plate is stricter. Although the required detection distance of the fold-back mirror method is short, the detector is extremely easy to damage due to the concentrated energy of the laser beam near the fold-back mirror method, an attenuation sheet is often required to be added for use, laser radar noise is easy to cause, and the detector and the emitted laser are required to be in the same wave band. Sensors such as angular velocity measuring devices and inclination measuring devices are precise in structure, but expensive, and are not cost-effective to manufacture in large quantities.

Disclosure of Invention

Therefore, the technical problem to be solved by the invention is to overcome the technical defects that the target plate method in the prior art has serious light energy attenuation and low measurement precision, and the fold-back mirror method is easy to damage a detector and has high cost.

In order to solve the above technical problem, the present invention provides a method for detecting the direction of a laser beam emitted by a laser radar, comprising:

the method comprises the following steps of constructing a reflective target, sequentially arranging a reference area, a test area and an identification area on the surface of the reflective target, wherein a square tooth identifier is arranged on the identification area, preset areas are arranged in the test area and the identification area, and the square tooth identifier in the identification area is positioned on the upper side of the preset area and is connected with the preset area; the materials corresponding to the reference area, the preset area and the square tooth mark are all first reflectivity, the materials corresponding to the non-preset area of the test area, the non-preset area of the mark area and the non-square tooth mark are all second reflectivity, and the first reflectivity is not equal to the second reflectivity;

taking a first reference line along the central line of the test area in the vertical direction, taking a second reference line along the central line of the square tooth in the vertical direction, and taking a third reference line in the reference area in the vertical direction, wherein the third reference line and the second reference line are symmetrically arranged relative to the first reference line;

the laser radar emits laser beams and scans along the horizontal direction of the reflective target, and the laser points of the intersection of the scanning laser beams and the first reference line, the second reference line and the third reference line are B, C and A respectively;

a, B and C three laser points echo energy value T are obtained₀T, and T_c；

Obtaining the average energy threshold T of the area corresponding to the first reflectivity₁Average energy threshold T of area corresponding to second reflectivity₂；

According to T₀、T、T_c、T₁And T₂And calculating to obtain the beam pointing direction.

Preferably, the second reflectance is smaller than the first reflectance.

Preferably, said is according to T₀T, and T_cCalculating a beam pointing direction, comprising:

when T is₀＝T＝T_cWhen the laser radar emits light beams, the light beams are in an angle range corresponding to the preset area;

when T is₂/T₁<T/T₀<1,T_C＝T₁Square tooth mark of laser radar emitting light beam in preset area and upper side of preset areaIdentifying the angle range corresponding to the boundary;

when T/T₀＝T₂/T₁，T_C＝T₁When the laser radar emits light beams, the light beams are within an angle range corresponding to the square tooth marks on the upper side of the preset area;

when T is₂/T₁<T/T₀<1,T₂<T_C<T₁When the laser radar is used, the emission light beam of the laser radar is in an angle range corresponding to the junction of the preset area and the non-preset area on the lower side of the preset area;

when T/T₀＝T₂/T₁，T_C＝T₂And when the laser radar emits light beams, the light beams are in the angle range corresponding to the non-preset area on the lower side of the preset area.

Preferably, the maximum angle of the emission beam of the laser radar within the preset area is + -theta₀The minimum angle of the emitted light beam of the laser radar is shifted upwards/downwards to the preset area completely entering the test area is +/-theta₁And then the angle pointing area of the laser radar emission beam to be detected meets the following requirements:

when T is₀＝T＝T_cWhen, -theta₀<θ<θ₀；

When T is₂/T₁<T/T₀<1,T_C＝T₁When theta is greater than theta₀<θ<θ₁；

When T/T₀＝T₂/T₁，T_C＝T₁When theta is greater than theta>θ₁；

When T is₂/T₁<T/T₀<1,T₂<T_C<T₁When, -theta₁<θ<-θ₀；

When T/T₀＝T₂/T₁，T_C＝T₂When theta is greater than theta<-θ₁。

Preferably, the second reflectance is greater than the first reflectance.

Preferably, the square tooth marks are multiple, and the square tooth marks are arranged in a linear array.

The invention discloses a system for rapidly detecting the direction of a laser beam emitted by a laser radar, which comprises:

the device comprises a reflection target, wherein a reference area, a test area and an identification area are sequentially arranged on the surface of the reflection target, a square tooth identifier is arranged on the identification area, preset areas are arranged in the test area and the identification area, and the square tooth identifier in the identification area is positioned on the upper side of the preset area and is connected with the preset area; the materials corresponding to the reference area, the preset area and the square tooth mark are all first reflectivity, the materials corresponding to the non-preset area of the test area, the non-preset area of the mark area and the non-square tooth mark are all second reflectivity, the first reflectivity is not equal to the second reflectivity, a first reference line is taken along the central line of the test area in the vertical direction, a second reference line is taken along the central line of the square tooth in the vertical direction, a third reference line is taken in the reference area in the vertical direction, and the third reference line and the second reference line are symmetrically arranged relative to the first reference line;

the laser beam emitting module is used for emitting laser beams and scanning along the horizontal direction of the reflective target, and the intersecting laser points of the scanning laser beams and the first reference line, the second reference line and the third reference line are B, C and A respectively;

an energy acquisition module for acquiring A, B echo energy values T of three laser points C₀T, and T_c；

An average threshold energy threshold obtaining module, configured to obtain an average energy threshold T of an area corresponding to the first reflectivity₁Average energy threshold T of area corresponding to second reflectivity₂；

A calculation module according to T₀、T、T_c、T₁And T₂And calculating to obtain the beam pointing direction.

Preferably, the calculation module is based on T₀、T、T_c、T₁And T₂And calculating to obtain the beam direction, comprising:

when T is₀＝T＝T_cWhen the laser radar emits light beams, the light beams are in an angle range corresponding to the preset area;

when T is₂/T₁<T/T₀<1,T_C＝T₁When the laser radar emits light beams, the light beams are within an angle range corresponding to a boundary between a preset area and a square tooth mark on the upper side of the preset area;

when T/T₀＝T₂/T₁，T_C＝T₁When the laser radar emits light beams, the light beams are within an angle range corresponding to the square tooth marks on the upper side of the preset area;

when T is₂/T₁<T/T₀<1,T₂<T_C<T₁When the laser radar is used, the emission light beam of the laser radar is in an angle range corresponding to the junction of the preset area and the non-preset area on the lower side of the preset area;

when T/T₀＝T₂/T₁，T_C＝T₂And when the laser radar emits light beams, the light beams are in the angle range corresponding to the non-preset area on the lower side of the preset area.

Preferably, the laser beam emitting module is used for emitting a pulse laser beam.

The invention discloses a laser radar device which comprises the system for quickly detecting the direction of a laser beam emitted by the laser radar

Compared with the prior art, the technical scheme of the invention has the following advantages:

1. the invention provides a method for detecting the direction of a laser radar emission beam, which does not need to occupy larger space and various expensive detectors, quickly detects the direction of the emission beam by using the energy of a laser radar echo signal, and has high speed and high measurement precision.

2. The invention compares the echo energy of each region with the reference energy by arranging the reflecting surfaces with different reflectivities on the reflecting target material to determine the direction of the laser emission beam, and has low cost and convenient operation.

Drawings

FIG. 1 is a schematic diagram of an application of a detection method for detecting the direction of a light beam emitted by a laser radar system;

FIG. 2 is a schematic view showing the distribution of regions of the target plate;

FIG. 3 is a schematic diagram of a scanning laser beam moving to different positions of a reflective target;

FIG. 4 is a diagram of laser radar emission beam pointing zones;

FIG. 5 is a flow chart of detection of the laser radar emission beam pointing direction;

fig. 6 is a schematic diagram of a lidar system.

The specification reference numbers indicate: 10. a laser radar; 11. scanning the laser beam; 20. reflecting the target material; 21. presetting an area; 22. marking square teeth; 30. a first reference line; 31. a second reference line; 32. a third reference line.

Detailed Description

The present invention is further described below in conjunction with the following figures and specific examples so that those skilled in the art may better understand the present invention and practice it, but the examples are not intended to limit the present invention.

Referring to fig. 1-6, the method for detecting the pointing direction of a laser radar emission beam according to the present invention includes the following steps:

s1, constructing a reflection target 20, sequentially arranging a reference area, a test area and an identification area on the surface of the reflection target 20, arranging a square tooth mark 22 on the identification area, arranging a preset area 21 in both the test area and the identification area, and arranging the square tooth mark 22 in the identification area on the upper side of the preset area 21 and connecting the preset area 21; the materials corresponding to the reference area, the preset area and the square tooth mark are all first reflectivity, the materials corresponding to the non-preset area of the test area, the non-preset area of the mark area and the non-square tooth mark are all second reflectivity, and the first reflectivity is not equal to the second reflectivity.

And S2, taking a first reference line 30 along the vertical center line of the test area, taking a second reference line 31 along the vertical center line of the square tooth, and taking a third reference line 32 in the vertical direction of the reference area, wherein the third reference line 32 and the second reference line 31 are symmetrically arranged relative to the first reference line 30.

And S3, emitting laser beams by the laser radar, scanning along the horizontal direction of the reflecting target, wherein laser points of the intersection of the scanning laser beams 11 and the first reference line 30, the second reference line 31 and the third reference line 32 are B, C and A respectively.

S4, acquiring echo energy values T of A, B and C three laser points₀T, and T_c。

S5, obtaining the average energy threshold T of the area corresponding to the first reflectivity₁Average energy threshold T of area corresponding to second reflectivity₂。

S6, according to T₀、T、T_c、T₁And T₂And calculating to obtain the beam pointing direction.

In the invention, the first reflectivity and the second reflectivity can be set according to requirements, and the first reflectivity and the second reflectivity can generate obvious echo energy difference. The material corresponding to the first reflectivity may be a single material or a composite optical material. The second reflectivity may be less than the first reflectivity, and the second reflectivity may also be greater than the first reflectivity.

Specifically, when the second reflectivity is smaller than the first reflectivity, the second reflectivity is based on T₀T, and T_cCalculating to obtain the beam direction, including the following cases:

when T is₀＝T＝T_cMeanwhile, the emission beam of the laser radar is within the angle range corresponding to the preset area 21;

when T is₂/T₁<T/T₀<1,T_C＝T₁During the process, the emission light beam of the laser radar is in the angle range corresponding to the junction of the preset area 21 and the square tooth mark 22 on the upper side of the preset area 21;

when T/T₀＝T₂/T₁，T_C＝T₁At the time, the emission beam of the laser radar is corresponding to the square tooth mark 22 on the upper side of the preset area 21Within the range of angles;

when T is₂/T₁<T/T₀<1,T₂<T_C<T₁When the laser radar emits a light beam, the light beam is within an angle range corresponding to a boundary between the preset area 21 and a non-preset area on the lower side of the preset area 21;

when T/T₀＝T₂/T₁，T_C＝T₂Meanwhile, the emission beam of the laser radar is within the angle range corresponding to the non-preset area below the preset area 21.

The maximum angle of the emission beam of the laser radar completely in the preset area is +/-theta₀The minimum angle of the emitted light beam of the laser radar is shifted upwards/downwards to the preset area completely entering the test area is +/-theta₁And then the angle pointing area of the laser radar emission beam to be detected meets the following requirements:

when T is₀＝T＝T_cWhen, -theta₀<θ<θ₀；

When T is₂/T₁<T/T₀<1,T_C＝T₁When theta is greater than theta₀<θ<θ₁；

When T/T₀＝T₂/T₁，T_C＝T₁When theta is greater than theta>θ₁；

When T is₂/T₁<T/T₀<1,T₂<T_C<T₁When, -theta₁<θ<-θ₀；

When T/T₀＝T₂/T₁，T_C＝T₂When theta is greater than theta<-θ₁。

In an alternative embodiment, the square tooth marks may be provided in plurality, and a plurality of the square tooth marks are arranged in a linear array.

The invention also discloses a system for rapidly detecting the direction of the laser radar emission beam, which comprises a reflection target material, a laser beam emission module, an energy acquisition module, an average threshold energy threshold acquisition module and a calculation module.

The surface of the reflection target is sequentially provided with a reference area, a test area and an identification area, wherein the identification area is provided with a square tooth identification, the test area and the identification area are both provided with preset areas, and the square tooth identification in the identification area is positioned on the upper side of the preset area and is connected with the preset area; the materials corresponding to the reference area, the preset area and the square tooth mark are all first reflectivity, the materials corresponding to the non-preset area of the test area, the non-preset area of the mark area and the non-square tooth mark are all second reflectivity, the first reflectivity is not equal to the second reflectivity, a first reference line is taken along the central line of the test area in the vertical direction, a second reference line is taken along the central line of the square tooth in the vertical direction, a third reference line is taken in the vertical direction of the reference area, and the third reference line and the second reference line are symmetrically arranged relative to the first reference line.

The laser beam emitting module is used for emitting laser beams and scanning along the horizontal direction of the reflecting target, and the laser points of the intersection of the laser beams and the first reference line, the second reference line and the third reference line are B, C and A respectively.

The energy acquisition module is used for acquiring A, B echo energy values T of three laser points C₀T, and T_c。

The average threshold energy obtaining module is used for obtaining an average energy threshold T of the area corresponding to the first reflectivity₁Average energy threshold T of area corresponding to second reflectivity₂。

The calculation module is based on T₀、T、T_c、T₁And T₂And calculating to obtain the beam direction, comprising:

when T is₀＝T＝T_cWhen the laser radar emits light beams, the light beams are in an angle range corresponding to the preset area;

when T is₂/T₁<T/T₀<1,T_C＝T₁When the laser radar emits light beams, the light beams are within an angle range corresponding to a boundary between a preset area and a square tooth mark on the upper side of the preset area;

when T/T₀＝T₂/T₁，T_C＝T₁The laser radar has a square emission beam on the upper side of the predetermined regionThe tooth mark is in the corresponding angle range;

when T is₂/T₁<T/T₀<1,T₂<T_C<T₁When the laser radar is used, the emission light beam of the laser radar is in an angle range corresponding to the junction of the preset area and the non-preset area on the lower side of the preset area;

when T/T₀＝T₂/T₁，T_C＝T₂And when the laser radar emits light beams, the light beams are in the angle range corresponding to the non-preset area on the lower side of the preset area.

In one embodiment, the laser beam emitting module is configured to emit a pulsed laser beam.

The invention discloses a laser radar device which comprises the system for quickly detecting the direction of the emitted light beam of the laser radar, namely the system for quickly detecting the direction of the emitted light beam of the laser radar is integrated in the laser radar device. Of course, the invention can also set the modules such as the energy acquisition module, the calculation module and the like as external processing equipment.

The technical solution of the present invention will be further explained with reference to the specific embodiments.

Referring to fig. 1-2, the laser radar emits pulsed laser to scan the reflective target plate at a predetermined angle ± θ in the vertical direction₀The area within the range is made of square dentate high-reflection material, and the up-down direction exceeds the preset angle +/-theta₀The area of the range is a low reflective material. In the horizontal direction, the left side is a reference area, the middle part is a light beam pointing test area, the right side is a direction identification area, and a square tooth identification is arranged on the identification area. The central direction angle of the test area is 0 DEG, and the central direction angle of the square tooth mark of the mark area is alpha₁And then taking the direction angle-alpha on the left reference area₁The size of the three areas is determined by the scanning frequency of the laser radar and the resolution of the echo energy read by the software, and then +/-alpha is determined₁The size of (2). Reading the emitted pulse laser at 0 deg. and +/-alpha respectively₁And determining the direction of the laser radar emission beam according to the echo energy value.

Referring to FIG. 2, a reflective targetThe material may be coated with two reflective materials of different refractive indices: a high reflective material and a low reflective material. The high-reflection material comprises a left reference area, a central test area and a right direction identification area which are all arranged at a preset angle +/-theta₀An in-range region, and a square tooth identification. For the area coated with the high-reflection material, the echo signal received by the laser radar is strong and the energy is high. And other areas of the reflection target material are coated with low-reflection materials, and echo signals received by the laser radars in the areas are weak and low in energy. Emitting laser beams at 0 DEG and + -alpha₁The points in the direction are A, B, C respectively.

Referring to fig. 3, the detailed principle of the detection of the beam orientation of the laser radar of the present invention: scanning the laser beam at 0 and + -alpha directly in front₁The three test points scanned in three directions onto the reflective target are A, B, C. Echo energy T of point A₀The echo energy T at the point B is the reference energy. Echo energy T of point C_CEnergy is identified for the direction. The echo energy value of the area coated with the high-reflection material is a first energy threshold value T₁The value of the local echo energy of the low-reflection material is a second energy threshold value T₂. First energy threshold T₁And a second energy threshold T₂The mean values obtained after extensive testing of the lidar and the selected reflective material.

The maximum angle of the laser beam of the laser radar within the preset area is +/-theta₀The minimum angle of the emitted light beam of the laser radar is shifted upwards/downwards to the preset area completely entering the test area is +/-theta₁。

Referring to FIG. 3(a), the laser emission beam is directed at a predetermined angle + -theta₀When the range is within, A, B, C three points are all on the preset area of the reflection target plate, and echo energy test energy T and reference energy T of the three points are obtained without considering the small distance difference between the points and the laser radar₀And direction marking energy T_CAre all equal to T₁Test energy T and reference energy T₀Ratio of (T)/(T)₀＝1。

Referring to FIG. 3(b), the laser emission beam is directed upwardly at a predetermined angle θ₀In the range ofIn the angle range corresponding to the boundary of the square tooth marks on the upper sides of the preset area and the preset area, the echo energy of the point A is unchanged and is still T₀The echo energy at point B starts to decrease and the echo energy at point C does not change. T is₂/T₁<T/T₀<1,T_C＝T₁。

Referring to fig. 3(C), the laser emission beam points and continues to shift upwards to the angle range corresponding to the square tooth mark on the upper side of the preset area, and the echo energy of the point a and the point C is still T₁Echo energy at point B is equal to T₂，T/T₀＝T₂/T₁，T_C＝T₁。

Referring to FIG. 3(d), the laser emission beam is directed downward at a predetermined angle θ₀The range is that the echo energy of the point A is not changed and is still T within the angle range corresponding to the junction of the preset area and the non-preset area at the lower side of the preset area₀The echo energy at points B and C begins to decrease. T is₂/T₁<T/T₀<1,T₂<T_C<T₁。

Referring to fig. 3(e), the laser emission beam continues to be downwardly deflected to an angle range corresponding to the non-predetermined region at the lower side of the predetermined region, and the echo energy at point a is still T₁Echo energy at points B and C is equal to T₂，T/T₀＝T₂/T₁，T_C＝T₂。

Referring to fig. 4 and table 1, the beam pointing range distribution is as follows:

TABLE 1

T/T0	TC	Pointing interval
			T/T0＝T2/T1	TC＝T1	θ>θ1
T2/T1<T/T0<1	TC＝T1	θ0<θ<θ1
			T/T0＝1	TC＝T1	-θ0<θ<θ0
T2/T1<T/T0<1	T2<TC<T1	-θ1<θ<-θ0
			T/T0＝T2/T1	TC＝T2	θ<-θ1

Referring to fig. 5, the flow of the method for detecting the direction of the emission beam of the laser radar of the present invention includes: after pulse laser emitted by the laser radar is reflected by the target plate, the laser radar receives an echo signal, reads the echo energy of the selected test point, calculates the test energy T and the reference energy T₀Judging the deflection angle of the light beam, and combining the energy T of the mark point_CAnd judging the light beam pointing direction to obtain accurate light beam pointing.

Referring to fig. 6, the lidar system provided by the present invention includes a laser pulse emitting module, an echo signal receiving module, and an emitted light beam pointing processing module.

The laser pulse emitting module is used for driving the light source and emitting laser pulse signals.

The echo signal receiving module is used for converging the echo laser signals and converting the optical signals into electric signals.

The emitted light beam pointing processing module is used for reading the pulse width of the echo laser signal, comparing the test energy T with the reference energy T₀And the energy T of the marking point_CDetermining the emitted beam pointing direction.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.