Laser radar system and laser radar control method

Abstract

The present invention relates to a laser radar system and a laser radar control method, the system comprising: a laser emitting system for emitting an outgoing laser; an optical component comprising a beam splitter and a reflector, for allowing the outgoing laser to pass through the beam splitter, and also for allowing the beam splitter and the reflector to deflect the received return light signal; the return light signal is a return laser carrying relevant information of the target object after the outgoing laser responds to the target object; an optical scanning device for changing the direction of the outgoing laser passing through the beam splitter so that the outgoing laser is directed toward the target object, and also for changing the direction of the return light signal so that the return light signal is directed toward the optical component; a laser receiving system for receiving the return light signal deflected by the beam splitter and the reflector. In this way, no matter what the surface condition of the target object is, the laser receiving system can have a good response to the return light signal, increase the energy of the return light signal received by the laser receiving system, and improve the precision and accuracy.

Description

Technical Field

[0001] The present invention relates to the field of laser radar, and in particular to a laser radar system and a laser radar control method. Background Technology

[0002] Lidar is a radar system that emits laser beams to detect the position, speed and other characteristic quantities of a target. Its working principle is to emit a detection signal to the target object, and then compare the received signal reflected from the target object with the transmitted signal. After appropriate processing, relevant information about the target object can be obtained.

[0003] Currently, there are two main detection methods for solid-state coaxial solutions of laser radar. The first is to use the polarization characteristics of the laser and the depolarization characteristics of the target object for laser detection, and the second is to use the reflectivity of the target object for laser detection.

[0004] In the first method mentioned above, due to the random depolarization characteristics of the target object, the laser radar using this method for detection is difficult to identify both natural objects and man-made objects. In the second method mentioned above, when detecting smooth target objects with low reflectivity, the laser radar can respond well to the return light signal of the target object. When detecting rough target objects with low reflectivity, the laser radar has difficulty obtaining the return light signal of the target object.

[0005] Therefore, it is necessary to provide a laser radar system that can take into account the above two detection methods. SUMMARY OF THE INVENTION

[0006] Based on this, it is necessary to provide a laser radar system and a laser radar control method, which can better respond to the return light signal for target objects with different surface conditions.

[0007] On the one hand, an embodiment of the present invention provides a laser radar system, including:

[0008] Laser emission system, used for emitting outgoing laser;

[0009] The optical component includes a beam splitter and a reflector, which is used to make the outgoing laser pass through the beam splitter and also to make the beam splitter and the reflector deflect the received return light signal; the return light signal is the return laser carrying the relevant information of the target object after the outgoing laser responds to the target object;

[0010] An optical scanning device, used to change the direction of the outgoing laser transmitted from the beam splitter so that the outgoing laser is directed toward the target object, and also used to change the direction of the return light signal so that the return light signal is directed toward the optical component;

[0011] A laser receiving system is used to receive the returned optical signals deflected by the beam splitter and the mirror.

[0012] In one embodiment, the centers of both the beam splitter and the mirror are located on the optical axis of the emitted laser.

[0013] In one embodiment, the mirror is a mirror with a central opening.

[0014] In one embodiment, the area of the beam splitter is less than or equal to the area of the central opening of the mirror.

[0015] In one embodiment, the beam splitter is located at the central opening of the mirror.

[0016] In one embodiment, the area of the beam splitter is equal to the area of the central opening of the mirror.

[0017] In one embodiment, the beam splitter is a beam splitting prism, a beam splitting flat plate or a semi-transmissive and semi-reflective mirror.

[0018] In one embodiment, the optical scanning device is a one-dimensional MEMS, a two-dimensional MEMS, a mechanical galvanometer or a combination thereof.

[0019] In one embodiment, the system further includes a filter, which is disposed between the optical component and the laser receiving system for filtering out interfering light.

[0020] On the other hand, an embodiment of the present invention provides a method for controlling a lidar. The method is applied to the lidar system as described in the above embodiments, and the method includes:

[0021] The laser emitting system emits an emitted laser;

[0022] The optical component includes a beam splitter and a mirror, and the beam splitter allows the emitted laser to pass through;

[0023] The optical scanning device changes the direction of the emitted laser passing through the beam splitter and also changes the direction of the returned optical signal; the returned optical signal is the returned laser carrying information related to the target object after the emitted laser responds to the target object;

[0024] The beam splitter and the mirror deflect the returned optical signal from the optical scanning device;

[0025] The laser receiving system receives the returned optical signal deflected by the beam splitter and the mirror.

[0026] The lidar system provided in the above embodiments includes a laser emission system, an optical component, an optical scanning device, and a laser reception system; the optical component includes a beam splitter and a reflector, the beam splitter and the reflector can deflect the received return optical signal, the laser reception system receives the return optical signal deflected by the beam splitter and the reflector, and obtains information of the target object according to the received return optical signal. When the return optical signal reaches the optical component, for the return optical signal reaching the beam splitter, a part of the light that meets the deflection condition is deflected by the beam splitter and then shoots towards the laser reception system; for the return optical signal reaching the reflector part, it is reflected by the reflector and then shoots towards the laser reception system. In this way, when the surface of the target object is smooth, the polarization state signal is weak and the reflectivity signal is strong. After the reflectivity signal in the return optical signal is reflected by the reflector, it is received by the laser reception system; when the surface of the target object is rough, the polarization state signal is strong and the reflectivity signal is weak. After the polarization state signal in the return optical signal is deflected by the beam splitter, it is received by the laser reception system. In this way, regardless of the surface condition of the target object, the laser reception system can have a good response to the return optical signal, increasing the energy of the return optical signal received by the laser reception system and improving the accuracy and precision. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the lidar system provided for one embodiment;

[0028] Figure 2 Schematic diagram of the lidar system provided for another embodiment;

[0029] Figure 3 Schematic flowchart of the lidar control method provided for one embodiment.

[0030] DESCRIPTION OF REFERENCE NUMERALS:

[0031] Lidar system 10; Laser emission system 100; Optical component 200;

[0032] Beam splitter 201; Reflector 202; Optical scanning device 300;

[0033] Laser reception system 400; Target object 500. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0035] Traditional lidar systems have the problem of being difficult to respond to the return optical signals of target objects. For this reason, embodiments of the present invention provide a lidar system and a lidar control method, aiming to solve the above technical problems of the traditional technology.

[0036] The technical solution of the present invention and how the technical solution of the present invention solves the above technical problems will be described in detail below with specific embodiments. These several specific embodiments below can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments.

[0037] Figure 1 Schematic diagram of a lidar system provided for an embodiment. As Figure 1 shown, the lidar system 10 includes: a laser emission system 100 for emitting outgoing laser; an optical component 200 including a beam splitter 201 and a mirror 202 for allowing the outgoing laser to pass through the beam splitter 201 and for deflecting the received return light signal by the beam splitter 201 and the mirror 202; the return light signal is the return laser carrying information related to the target object 500 after the outgoing laser responds to the target object 500; an optical scanning device 300 for changing the direction of the outgoing laser passing through the beam splitter 201 to direct the outgoing laser towards the target object 500 and for changing the direction of the return light signal to direct the return light signal towards the optical component 200; a laser receiving system 400 for receiving the return light signal deflected by the beam splitter 201 and the mirror 202.

[0038] Specifically, the laser emission system 100 is used to emit outgoing laser and transmit the emitted outgoing laser to the optical component 200. Optionally, the laser emission system includes a transmitter and a collimating optical lens group. The transmitter is used to emit outgoing laser, and the collimating optical lens group is used to collimate the outgoing laser emitted by the transmitter. Optionally, there may be one transmitter. Optionally, there may be multiple transmitters, and the multiple transmitters are arranged in a one-dimensional or two-dimensional array.

[0039] The optical component 200 includes a beam splitter 201 and a mirror 202, allowing the outgoing laser to pass through the beam splitter 201 and transmitting the outgoing laser to the optical scanning device 300; the beam splitter 201 and the mirror 202 in the optical component 200 are also used to receive the return light signal from the target object 500 and deflect the return light signal to the laser receiving system 400, where the return light signal is the return laser carrying information related to the target object 500 after the outgoing laser responds to the target object 500. Optionally, the beam splitter 201 deflects the S-state polarized light in the received return light signal to the laser receiving system, and at the same time, after the mirror 202 reflects the received return light signal, it is directed towards the laser receiving system. Optionally, the mirror 202 can be a center-aperture mirror. Optionally, the area of the beam splitter 201 is less than or equal to the area of the center aperture of the mirror 202.

[0040] The above-mentioned optical scanning device 300 changes the direction of the emitted laser light transmitted from the beam splitter 201, so that the emitted laser light is directed towards the target object 500; and receives the return optical signal, changes the direction of the return optical signal, and makes the return optical signal directed towards the optical component 200. Optionally, the optical scanning device 300 is a one-dimensional MEMS, a two-dimensional MEMS, a mechanical galvanometer or a combination thereof.

[0041] The above-mentioned laser receiving system 400 receives the return optical signal deflected by the beam splitter 201 and the mirror 202, and obtains information about the target object 500 according to the received return optical signal. Optionally, the laser receiving system 400 includes a focusing optical lens group and a receiver. The focusing optical lens group is used to converge the received return optical signal onto the receiver, and the receiver is used to receive the return optical signal. Optionally, the receiver can be one or multiple. Optionally, multiple receivers can be arranged in a one-dimensional arrangement or a two-dimensional arrangement.

[0042] In this embodiment, the lidar system includes a laser emission system, an optical component, an optical scanning device, and a laser receiving system; the optical component includes a beam splitter and a mirror. The beam splitter and the mirror can deflect the received return optical signal. The laser receiving system receives the return optical signal deflected by the beam splitter and the mirror, and obtains information about the target object according to the received return optical signal. When the return optical signal reaches the optical component, for the return optical signal reaching the beam splitter, a part of the light that meets the deflection condition is deflected by the beam splitter and directed towards the laser receiving system; for the return optical signal reaching the mirror part, the return optical signal is reflected by the mirror and directed towards the laser receiving system. In this way, when the surface of the target object is smooth, the polarization state signal is weak and the reflectivity signal is strong. After the reflectivity signal in the return optical signal is reflected by the mirror, it is received by the laser receiving system; when the surface of the target object is rough, the polarization state signal is strong and the reflectivity signal is weak. After the polarization state signal in the return optical signal is deflected by the beam splitter, it is received by the laser receiving system. In this way, regardless of the surface condition of the target object, the laser receiving system can have a good response to the return optical signal, enhancing the energy of the return optical signal received by the laser receiving system and improving the accuracy and precision.

[0043] Please continue to refer to Figure 1 , on the basis of the above-mentioned embodiment, as an optional implementation manner, the center of the beam splitter 201 and the center of the mirror 202 are both located on the optical axis of the emitted laser light.

[0044] Specifically, the center of the beam splitter 201 is located on the optical axis of the emitted laser light emitted by the laser emission system 100, and the center of the mirror 202 is also located on the optical axis of the emitted laser light emitted by the laser emission system 100. Optionally, the beam splitter 201 can be a beam splitting prism, a beam splitting flat plate or a semi-transparent and semi-reflective mirror.

[0045] In this embodiment, the beam splitter and the reflector included in the optical component are both located on the optical axis of the outgoing laser emitted by the laser emission system, so that the optical component can receive the outgoing laser to the maximum extent, and at the same time, the optical component can also receive the return optical signal to the maximum extent, improving the intensity of the laser signal received by the optical component; the outgoing laser and the return optical signal are both transmitted along the optical axis, reducing errors.

[0046] Figure 2 Schematic diagram of a lidar system provided for another embodiment. On the basis of the above embodiment, as an optional implementation manner, the reflector 201 is located at the central opening of the reflector 202.

[0047] Specifically, the reflector 202 is a centrally perforated reflector, and the beam splitter 201 is located at the central opening of the reflector 202. Optionally, the area of the beam splitter 201 is equal to the area of the central opening of the reflector 202. Optionally, the shape of the central opening of the centrally perforated reflector can be a circular shape, a rectangular shape or a special shape, such as Figure 2 As shown, in this embodiment, the central opening shape of the perforated reflector is taken as an example of a circular shape for illustration.

[0048] In this embodiment, the reflector in the optical component is a centrally perforated reflector, and the beam splitter is located at the central opening of the reflector, which can minimize the leakage of the return optical signal from the gap, increase the energy of the return optical signal received by the laser receiving system, and improve the accuracy and precision.

[0049] On the basis of the above embodiment, as an optional implementation manner, the system 10 further includes a filter, and the filter is disposed between the optical component 200 and the laser receiving system 400 for filtering out interfering light.

[0050] Specifically, the lidar system 10 further includes a filter, and the filter is disposed between the optical component 200 and the laser receiving system 400 for filtering out the interfering light in the return optical signal transmitted from the optical component 200 to the laser receiving system 400.

[0051] In this embodiment, the lidar system further includes a filter, which filters out the interfering light in the return optical signal transmitted from the optical component to the laser receiving system, improves the accuracy of the optical signal received by the laser receiving system, and further improves the accuracy of the information of the target object obtained.

[0052] Figure 3 Flow chart of a lidar control method provided for an embodiment. As Figure 3 shown, the method includes:

[0053] S301, the laser emission system emits an outgoing laser.

[0054] S302, the optical component includes a beam splitter and a reflector, and the beam splitter allows the emitted laser to pass therethrough.

[0055] S303, the optical scanning device changes the direction of the emitted laser passing through the beam splitter and also changes the direction of the return optical signal; the return optical signal is the return laser carrying information related to the target object after the emitted laser responds to the target object.

[0056] S304, the beam splitter and the reflector deflect the return optical signal from the optical scanning device.

[0057] S305, the laser receiving system receives the return optical signal deflected by the beam splitter and the reflector.

[0058] For the specific limitations on the lidar control method, reference can be made to the limitations on the lidar system in the above text, which will not be elaborated here.

[0059] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0060] The above-described embodiments only represent several implementation manners of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the invention patent should be subject to the appended claims.

Claims

1. A laser radar system, characterized in that: The system comprises: A laser emission system, used for emitting an outgoing laser; An optical component, comprising a beam splitter and a reflector, wherein the centers of the beam splitter and the reflector are both located on the optical axis of the outgoing laser, the reflector is a center-opening reflector, the beam splitter is located at the center opening of the reflector, and the area of ​​the beam splitter is less than or equal to the area of ​​the center opening of the reflector, the optical component is used to allow the outgoing laser to pass through the beam splitter, and is also used to allow the beam splitter to polarize the S-state polarized light in the received return light signal to the laser receiving system, and the reflector reflects the received return light signal and then emits it to the laser receiving system; the return light signal is the return laser carrying the relevant information of the target object after the outgoing laser responds to the target object; an optical scanning device, used to change the direction of the outgoing laser light transmitted from the beam splitter so that the outgoing laser light is directed toward the target object, and also used to change the direction of the return light signal so that the return light signal is directed toward the optical component; The laser receiving system is used to receive the return light signal deflected by the beam splitter and the reflector.

2. The laser radar system according to claim 1, characterized in that: The laser emission system comprises an emitter and a collimating optical lens group; the emitter is used to emit an outgoing laser; the collimating optical lens group is used to collimate the outgoing laser emitted by the emitter.

3. The laser radar system according to claim 2, characterized in that: The number of the emitter is one or more, and the multiple emitters are arranged in one dimension or two dimensions.

4. The laser radar system according to claim 1, characterized in that: The laser receiving system comprises a focusing optical lens group and a receiver. The focusing optical lens group is used to converge the received return light signal onto the receiver, and the receiver is used to receive the return light signal.

5. The laser radar system according to claim 4, characterized in that: The number of the receiver is one or more, and the multiple receivers are arranged in one dimension or two dimensions.

6. The laser radar system according to claim 1, characterized in that: The shape of the central opening of the central opening reflector is circular, rectangular or irregular.

7. The laser radar system according to claim 1, characterized in that: The beam splitter is a beam splitter prism, a beam splitter plate or a semi-transparent and semi-reflective mirror.

8. The laser radar system according to claim 1, characterized in that: The optical scanning device is a one-dimensional MEMS, a two-dimensional MEMS, a mechanical galvanometer or a combination thereof.

9. The laser radar system according to claim 1, characterized in that: The system further comprises an optical filter, which is arranged between the optical component and the laser receiving system and is used for filtering out interfering light.

10. A laser radar control method, characterized in that: A laser radar system applied to any one of claims 1 to 9, the laser radar system comprising a laser emission system, an optical component, a light scanning device and a laser receiving system, the method comprising: The laser emission system emits an outgoing laser; The optical component comprises a beam splitter and a reflector, the centers of the beam splitter and the reflector are both located on the optical axis of the outgoing laser, the reflector is a center-opening reflector, the beam splitter is located at the center opening of the reflector, the area of ​​the beam splitter is less than or equal to the area of ​​the center opening of the reflector, and the beam splitter allows the outgoing laser to pass through it; The optical scanning device changes the direction of the outgoing laser transmitted through the beam splitter, and also changes the direction of the return optical signal; the return optical signal is the return laser carrying the relevant information of the target object after the outgoing laser responds to the target object; The beam splitter polarizes the S-state polarized light in the return light signal from the light scanning device to the laser receiving system, and the reflector reflects the return light signal from the light scanning device and directs it to the laser receiving system; The laser receiving system receives the return light signal deflected by the beam splitter and the reflecting mirror.

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