A surface array laser radar measurement system

Abstract

The embodiment of the present invention discloses a planar array laser radar measurement system. The system includes: a laser light source module, a two-dimensional scanning mechanism, a photoelectric detector, a transmitting lens, a receiving lens, a spectroscope, a two-dimensional position detector, a control module and a computing module; the control module is respectively connected to the laser light source module and the two-dimensional scanning mechanism, and is used to control the laser intensity emitted by the laser light source module and the scanning angle of the two-dimensional scanning mechanism; the spectroscope is used to divide the laser reflected by the two-dimensional scanning mechanism into two beams, and the two-dimensional position detector receives the laser beam reflected by the spectroscope and generates a first electrical signal, which is sent to the computing module; the computing module is respectively connected to the two-dimensional position detector and the photoelectric detector, and is used to calculate the target parameters of the measured object according to the first electrical signal and the second electrical signal generated by the photoelectric detector. The embodiment of the present invention improves the spatial resolution of the planar array scanning laser radar and improves the spatial position accuracy of the measurement.

Description

Technical Field

[0001] The embodiments of the present invention relate to laser radar technology, and in particular to a planar laser radar measurement system. Background Art

[0002] Laser radar is a radar system that transmits a detection signal (laser beam) to the target, then compares the received signal reflected from the target (target echo) with the transmitted signal, and after appropriate processing, it can obtain relevant information about the target, such as the target's distance, direction, altitude, speed, and attitude characteristics.

[0003] In existing laser radar measurement systems, the beam deflection angle is mostly measured indirectly, that is, the beam deflection angle is calculated by measuring the mechanical surface of the scanning mechanism, and the target parameters of the target object are calculated using the indirectly obtained deflection angle. However, the indirect measurement method has insufficient accuracy or resolution, and it is not easy to achieve accurate time synchronization between the laser pulse and position feedback, which leads to large position measurement errors. Summary of the invention

[0004] The embodiment of the present invention provides a planar array laser radar measurement system to directly measure the deflection angle of a laser beam, thereby improving the accuracy of target parameter measurement.

[0005] The embodiment of the present invention provides a planar array laser radar measurement system, which includes: a laser light source module, a two-dimensional scanning mechanism, a photoelectric detector, a transmitting lens and a receiving lens, and also includes: a spectroscope, a two-dimensional position detector, a control module and a computing module; wherein,

[0006] The control module is connected to the laser light source module and the two-dimensional scanning mechanism respectively, and is used to control the laser intensity emitted by the laser light source module and the scanning angle of the two-dimensional scanning mechanism;

[0007] The beam splitter is used to split the laser reflected by the two-dimensional scanning mechanism into two beams, wherein the reflected beam hits the two-dimensional position detector, and the transmitted beam is irradiated onto the object to be measured through the transmitting lens;

[0008] The two-dimensional position detector receives the laser beam reflected by the beam splitter and generates a first electrical signal, and sends the first electrical signal to the operation module;

[0009] The operation module is connected to the two-dimensional position detector and the photoelectric detector respectively, and is used to calculate the target parameter of the object to be measured according to the first electrical signal and the second electrical signal generated by the photoelectric detector.

[0010] Optionally, the operation module is specifically used for:

[0011] determining a reflection angle of the reflected light beam according to the first electrical signal;

[0012] Determining an exit angle of the transmitted light beam according to the reflection angle;

[0013] determining the angle of the light beam reflected from the object to be measured according to the second electrical signal;

[0014] The target parameter of the object to be measured is determined according to the time when the laser light source module emits laser, the time when the photoelectric detector receives the second electrical signal, the emission angle of the transmitted light beam and the angle of the light beam reflected back by the object to be measured.

[0015] Optionally, the target parameters include at least one of the target distance, orientation, height, speed, and posture characteristic quantities of the object being measured.

[0016] The embodiment of the present invention adds a spectroscope and a two-dimensional position detector to the area array laser radar measurement system to directly measure the deflection angle of the laser light beam irradiated to the object to be measured, and then calculates the target parameters of the object to be measured. This solves the problem of insufficient accuracy or resolution of an indirect measurement method of obtaining the deflection angle of the light beam by measuring and calculating the mechanical surface of the scanning mechanism, and inaccurate time synchronization of pulses and position feedback, which leads to target parameter measurement errors. This improves the spatial resolution of the area array scanning laser radar and improves the spatial position accuracy of the measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the area array laser radar measurement system in an embodiment of the present invention.

[0018] Figure 2 Schematic diagram of a photodetector array in an embodiment of the present invention. DETAILED DESCRIPTION

[0019] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0020] Example

[0021] Figure 1 The schematic diagram of the structure of the planar laser radar measurement system provided by the embodiment of the present invention is applicable to laser ranging and the like. Figure 1 As shown, the system specifically includes:

[0022] Laser light source module 1, two-dimensional scanning mechanism 2, photoelectric detector 7, transmitting lens 5 and receiving lens 6, spectroscope 3, two-dimensional position detector 4, control module 8 and operation module 9; wherein,

[0023] The control module is connected to the laser light source module 1 and the two-dimensional scanning mechanism 2 respectively, and is used to control the intensity of the laser emitted by the laser light source module 1 and the scanning angle of the two-dimensional scanning mechanism 2 .

[0024] Specifically, during the operation of the area array laser radar measurement system, the tilt angle of the two-dimensional scanning mechanism 2 will be continuously adjusted so that the laser beam emitted by the laser light source module 1 is reflected by the two-dimensional scanning mechanism 2 and illuminates different positions on the object to be measured, thereby realizing two-dimensional scanning of the measurement scene and obtaining the overall information of the object to be measured. The two-dimensional scanning mechanism 2 can be a micro-electromechanical system galvanometer, a mechanical galvanometer, a rotating prism, etc., and the scanning frequency in each direction can reach more than khz, thereby realizing high-resolution and high-frame-rate three-dimensional measurement of the measurement scene.

[0025] The beam splitter 3 is used to split the laser reflected by the two-dimensional scanning mechanism 2 into two beams, wherein the reflected beam hits the two-dimensional position detector 4, and the transmitted beam (i.e., the main energy beam) is irradiated onto the object to be measured through the transmitting lens 5; thus, accurate measurement of the emission angle of the beam irradiated onto the object to be measured can be achieved.

[0026] The two-dimensional position detector 4 (Position Sentitive Detector, PSD) is used to determine the two-dimensional coordinate position of the light beam. It is a device that can detect the position of the light beam and is often widely used as a position sensor combined with a light source. When the two-dimensional position detector 4 receives the laser beam reflected by the spectroscope, it will generate a first electrical signal, and then send the first electrical signal to the operation module 9. The operation module 9 can calculate the reflection angle of the reflected light beam based on the received first electrical signal, and then calculate the emission angle of the light beam irradiated on the object to be measured. In particular, because the PSD and the object to be measured receive the same laser pulse signal emitted by the light source, it is a direct measurement method, so the measurement of the emission angle of the light beam irradiated on the object to be measured is more accurate.

[0027] In addition, by obtaining the position where the reflected light beam is irradiated through the two-dimensional position detector 4 and accurately measuring the emission angle of the light beam irradiated on the object to be measured, there is no need for the two-dimensional scanning mechanism 2 to perform position feedback. In this way, through a variety of choices, limiting factors such as mirror size and scanning rate can be solved, thereby improving the measurement performance of the radar.

[0028] The calculation module 9 is connected to the two-dimensional position detector 4 and the photoelectric detector 7 respectively, and is used to calculate the target parameter of the object to be measured according to the first electrical signal and the second electrical signal generated by the photoelectric detector 7.

[0029] Furthermore, the target parameter includes at least one of the target distance, orientation, height, speed, and posture characteristic quantities of the measured object.

[0030] The further operation module 9 is specifically used to: determine the reflection angle of the reflected light beam according to the first electrical signal; determine the emission angle of the transmitted light beam according to the reflection angle; determine the angle of the light beam reflected back from the object to be measured according to the second electrical signal; determine the target parameters of the object to be measured according to the time when the laser light source module emits the laser, the time when the photoelectric detector receives the second electrical signal, the emission angle of the transmitted light beam and the angle of the light beam reflected back from the object to be measured.

[0031] Exemplarily, it is assumed that the laser beam emitted by the laser light source module 1 is reflected by the two-dimensional scanning mechanism 2 and irradiated to the beam splitter 3. The beam splitter 3 divides the laser beam into two beams, one of which hits the point P on the two-dimensional position detector 4. An electrical signal is generated at the point P and sent to the operation module 9. The operation module 9 can determine the two-dimensional coordinates of the point P according to the received electrical signal, and then determine the reflection angle of the reflected light beam reflected on the two-dimensional position detector 4, and determine the emission angle of the transmitted light beam according to the reflection angle, that is, the emission angle of the light beam irradiated on the object to be measured. The laser beam irradiated on the object to be measured is reflected by the object to the receiving lens 6 and irradiated to the point P1 in the photoelectric detector array, such as Figure 2 As shown. Then, an electrical signal will be generated at the position of point P1, and the electrical signal will be sent to the operation module 9, which can determine the orientation of the irradiated object based on the electrical signal. Furthermore, according to the time when the laser light source module 1 emits the laser and the time when the photoelectric detector receives the electrical signal generated by the light beam reflected by the object to be measured, the distance of the object to be measured can be calculated, thereby knowing the target parameters of the object to be measured. Furthermore, the phase delay of the laser beam can also be determined based on the phase difference between the emitted light and the received light, thereby calculating the distance of the object to be measured.

[0032] The technical solution of this embodiment directly measures the deflection angle of the laser beam irradiating the object to be measured by adding a spectroscope and a two-dimensional position detector to the area array laser radar measurement system, and then calculates the target parameters of the object to be measured, thereby solving the problem of insufficient accuracy or resolution of the indirect measurement method of calculating the deflection angle of the light beam by measuring the mechanical surface of the scanning mechanism, and inaccurate time synchronization of pulse and position feedback, which leads to target parameter measurement errors, thereby improving the spatial resolution of the area array scanning laser radar and the spatial position accuracy of the measurement; the two-dimensional scanning mechanism does not need to rotate the position feedback structure, simplifies the complexity of the scanning mechanism, reduces the performance requirements for the scanning mechanism, and expands the selection range of the scanning mechanism.

[0033] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A planar laser radar measurement system, comprising: The system comprises a laser light source module, a two-dimensional scanning mechanism, a photoelectric detector, a transmitting lens and a receiving lens. The system further comprises a spectroscope, a two-dimensional position detector, a control module and a computing module. The control module is connected to the laser light source module and the two-dimensional scanning mechanism respectively, and is used to control the laser intensity emitted by the laser light source module and the scanning angle of the two-dimensional scanning mechanism; The beam splitter is used to split the laser reflected by the two-dimensional scanning mechanism into two beams, wherein the reflected beam hits the two-dimensional position detector, and the transmitted beam is irradiated onto the object to be measured through the transmitting lens; The two-dimensional position detector receives the laser beam reflected by the beam splitter and generates a first electrical signal, and sends the first electrical signal to the operation module; The computing module is connected to the two-dimensional position detector and the photoelectric detector respectively, and is used to calculate the target parameter of the measured object according to the first electrical signal and the second electrical signal generated by the photoelectric detector; The computing module is used to determine the reflection angle of the reflected light beam according to the first electrical signal; The emission angle of the transmitted light beam is determined according to the reflection angle.

2. The system according to claim 1, characterized in that The operation module is specifically used for: determining the angle of the light beam reflected from the object to be measured according to the second electrical signal; The target parameter of the object to be measured is determined according to the time when the laser light source module emits laser, the time when the photoelectric detector generates the second electrical signal, the emission angle of the transmitted light beam and the angle of the light beam reflected back by the object to be measured.

3. The system according to claim 1, characterized in that The target parameter includes at least one of the target distance, orientation, height, speed, and posture characteristic quantities of the measured object.

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