Laser radar system, optical path structure, and obstacle information acquisition method

Abstract

The invention relates to the technical field of laser radars, in particular to a laser radar system, a light path structure and an obstacle information acquisition method, in the light path structure of the laser radar, a light splitting element is used for receiving light emitted by a laser emitter, and the light passing through the light splitting element irradiates a first deflection element; the light reaches the scanning element through the first deflection element, and the light reaching the scanning element is reflected to the surface of the obstacle through the scanning element to form reflected light; the reflected light enters the light splitting element through the scanning element and the first deflection element, reaches the second deflection element through the light splitting element, and reaches the first light detector through the second deflection element; according to the light path structure of the laser radar, single-transmitting and double-receiving signal processing can be realized, and the ranging performance of the laser radar is improved on the premise of ensuring that the light path structure is simple and the integration level is high.

Description

Technical Field

[0001] The present invention relates to the field of laser radar technology, and in particular to a laser radar system, an optical path structure, and a method for acquiring obstacle information. Background Art

[0002] LiDAR is a radar system that detects the position, direction and other characteristic quantities of a target by measuring the signal difference between the emitted laser beam and the received laser echo signal. Its working principle is to first emit a detection laser beam to the target, and then the receiver receives the echo signal reflected from the target, and measures the time interval between the receiving time and the transmitting time and the scanning parameters at the transmitting time, so as to calculate the direction and distance of the target.

[0003] Since it can detect whether there are obstacles ahead and provide information on the direction and distance of obstacles, the laser radar system is widely used in various fields such as autonomous driving. At present, laser radar mainly adopts rotating mirror laser radar and mechanical rotating laser radar, but rotating mirror laser radar and mechanical rotating laser radar have many disadvantages: the rotating part of the rotating mirror laser radar occupies a large volume, and it is difficult to further reduce the volume to achieve miniaturization in future applications, and the multi-line (such as 64, 128 lines) laser radar transmitting module and receiving module are arranged in pairs, which is difficult to manufacture, not conducive to mass production and high cost; the mechanical rotating laser radar has the problems of short detection distance, large volume, and the detection module has no reference signal and is easy to measure inaccurately. Therefore, in order to solve the shortcomings of the above-mentioned prior art solutions, the present invention provides a laser radar with simple and compact optical structure, high integration, and stable and reliable ranging performance. Summary of the invention

[0004] In view of this, an embodiment of the present invention provides a laser radar system, an optical path structure, and a method for acquiring obstacle information.

[0005] In a first aspect, an embodiment of the present invention provides an optical path structure of a laser radar, the optical path structure comprising:

[0006] A beam splitter element, a first deflection element, a second deflection element, a scanning element, a first light detector, and a second light detector;

[0007] The beam splitter element is used to receive the light emitted by the laser transmitter. The light passing through the beam splitter element is irradiated on the first deflection element and reaches the scanning element through the first deflection element. The light reaching the scanning element is reflected by the scanning element to the obstacle and forms reflected light after reaching the surface of the obstacle.

[0008] The reflected light passes through the scanning element and the first deflection element and enters the beam splitter element, reaches the second deflection element through the beam splitter element, and reaches the first light detector through the second deflection element, so that the first light detector receives a reflected echo signal;

[0009] The second light detector is used to collect ambient light to form an external ambient light signal, and the first light detector and the second light detector are respectively used to connect to a first control module to feed back the reflected echo signal and the external ambient light signal to the first control module.

[0010] In a second aspect, an embodiment of the present invention provides a laser radar system, comprising a first control module, a second control module, a laser emitter and the optical path structure as described in the first aspect, wherein the first control module is respectively connected to the laser emitter, the first light detector and the second light detector, and is used to control the laser emitter to emit laser pulses, control the laser detector to detect reflected echo signals, and control the second light detector to detect ambient light; the second control module is connected to the scanning element and the first control module, and is used to control the rotation of the scanning element and send a rotation signal of the scanning element to the first control module.

[0011] In a third aspect, an embodiment of the present invention provides a method for obtaining obstacle information of a laser radar system, wherein the method for obtaining obstacle information is applied to the laser radar system as described in the second aspect above, and the method for obtaining obstacle information includes:

[0012] The first control module controls the second light detector to acquire an external ambient light signal in real time, and uses the external ambient light signal as a first reference light signal, and adjusts the parameters of the first light detector according to the first reference light signal;

[0013] Using the second control module to control the rotation of the scanning element, and collecting the rotation angle of the scanning element in real time;

[0014] The first control module controls the laser transmitter to emit laser pulses and obtain the emission time of the laser pulses, and controls the first light detector after adjusting the parameters to detect the reflected echo signal and obtain the reception time of the reflected echo signal;

[0015] The target distance information is calculated based on the emission time and the reception time, and the target rotation angle of the scanning element at the middle moment of the two times is determined. The target distance information is mapped to the target rotation angle, and all rotation angles of the scanning element are traversed to obtain the distance between any point on the obstacle surface and the lidar system.

[0016] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0017] The optical path structure provided by the present invention includes a spectroscopic element, a first deflection element, a second deflection element, a scanning element, a first light detector and a second light detector; the spectroscopic element is used to receive light emitted by a laser transmitter, the light passing through the spectroscopic element is irradiated on the first deflection element, and reaches the scanning element through the first deflection element, the light reaching the scanning element is reflected to the obstacle by the scanning element, and forms reflected light after reaching the surface of the obstacle; the reflected light enters the spectroscopic element through the scanning element and the first deflection element, reaches the second deflection element through the spectroscopic element, and reaches the first light detector through the second deflection element, so that the first light detector receives the reflected echo signal; the second light detector is used to collect ambient light to form an external ambient light signal, the first light detector and the second light detector are respectively used to connect to the first control module to provide the reflected echo signal and the external ambient light signal data obtained by the detector to the first control module, and the first control module can process the signal obtained by the first detector according to the signal obtained by the second light detector. The laser radar realizes single-transmit and dual-receive signal processing by transmitting a light signal through a laser transmitter, receiving an external ambient light signal through a second light detector, and receiving a reflected light signal corresponding to the transmitted light signal through a first light detector. This improves the ranging performance of the laser radar while ensuring that the optical path structure of the laser radar is simple and the integration is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0019] Figure 1 is a schematic diagram of an optical path structure of a laser radar provided in Embodiment 1 of the present invention;

[0020] Figure 2 is a schematic diagram of an optical path structure of a laser radar provided in Embodiment 2 of the present invention;

[0021] Figure 3 is a schematic structural diagram of a laser radar system provided in Embodiment 3 of the present invention;

[0022] Figure 4 is a schematic structural diagram of a laser radar system provided by Embodiment 4 of the present invention;

[0023] Figure 5 1 is a flowchart of a method for obtaining obstacle information of a laser radar system provided in Embodiment 5 of the present invention;

[0024] Figure 6 is a structural diagram of a first control module provided by Embodiment 6 of the present invention;

[0025] Among them, 1. optical path structure; 2. laser transmitter; 3. first control module; 4. second control module; 10. spectroscopic element; 11. first deflection element; 12. second deflection element; 13. scanning element; 14. first light detector; 15. second light detector; A. obstacle. DETAILED DESCRIPTION

[0026] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0027] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0028] It should also be understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0029] As used in the present specification and the appended claims, the term "if" may be interpreted as "when" or "upon" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" may be interpreted as meaning "upon determination" or "in response to determining" or "upon detection of [described condition or event]" or "in response to detecting [described condition or event]", depending on the context.

[0030] In addition, in the description of the present specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0031] References to "one embodiment" or "some embodiments" etc. described in the present specification mean that one or more embodiments of the present invention include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0032] It should be understood that the order of execution of the steps in the following embodiments does not imply a precedence of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0033] In order to illustrate the technical solution of the present invention, specific embodiments are provided below for illustration.

[0034] See also Figure 1 , is a schematic diagram of an optical path structure of a laser radar provided in Embodiment 1 of the present invention, such as Figure 1 As shown, the dotted line represents the optical signal path, and the solid line represents the electrical signal path. The optical path structure 1 at least includes: a spectroscopic element 10, a first deflection element 11, a second deflection element 12, a scanning element 13, a first light detector 14 and a second light detector 15.

[0035] The beam splitter element 10 is used to receive the light emitted by the laser emitter 2. The light passing through the beam splitter element 10 is irradiated on the first deflection element 11 and reaches the scanning element 13 through the first deflection element 11. The light reaching the scanning element 13 is reflected by the scanning element 13 to the obstacle A and forms reflected light after reaching the surface of the obstacle A.

[0036] The reflected light passes through the scanning element 13 and the first deflection element 11 and enters the beam splitter element 10, reaches the second deflection element 12 through the beam splitter element 10, and reaches the first light detector 14 through the second deflection element 12, so that the first light detector 14 receives the reflected echo signal;

[0037] The second light detector 15 is used to collect ambient light to form an external ambient light signal. The first light detector 14 and the second light detector 15 are respectively used to connect to the first control module 3 to feed back the reflected echo signal and the external ambient light signal to the first control module 3 .

[0038] The beam splitter element 10 is used to transmit and reflect light, that is, on the one hand, it is used to transmit the light emitted by the laser transmitter, and on the other hand, it is used to reflect the reflected light injected by the first deflection element. The beam splitter element 10 can be any one of an aperture reflector, a semi-transparent and semi-reflective mirror, a polarized beam splitter, and a beam splitter using a coating method, without limitation.

[0039] The first deflection element 11 is used to change the emission direction of the light beam, that is, to change the incident direction of the outgoing light or the reflected light, and the first deflection element can be a reflector or a prism. Similarly, the second deflection element 12 is also used to change the propagation direction of the light beam or to play a partial light splitting role, that is, to change the propagation direction of the incident light or to split the light into two beams, and the second deflection element can be a reflector, a beam splitter or a prism.

[0040] The scanning element 13 may be a MEMS (Micro-Electro-Mechanical Systems) two-dimensional scanning micromirror, which is used to reflect the light emitted by the laser emitter to an obstacle in the two-dimensional space by swinging in the horizontal space or the vertical space, and to form reflected light after reaching the surface of the obstacle, and to irradiate the reflected light on the first deflection element, so as to achieve high-precision scanning of the horizontal and vertical two-dimensional space. Among them, the scanning element 13 swings under the control of the first control module 3. The principle of the first photodetector 14 is to convert the optical signal into an electrical signal, which is mostly used for ranging. Therefore, the first photodetector receives and processes the reflected light to complete the ranging. The first photodetector may be a laser detector, which completes the laser ranging by receiving and processing the light. Secondly, the first photodetector may also be a photoelectric sensor, such as: any one of an avalanche photodiode (APD) photoelectric sensor and a silicon photomultiplier (SiPM), without limitation.

[0041] In other embodiments, the first light detector 14 includes a laser detector and a condenser, and the light passing through the second deflection element enters the condenser to form concentrated light which enters the laser detector.

[0042] The condenser is used to converge the light reflected by the second deflection element, and then emit the converged light into the laser detector. Therefore, the light reflected by the second deflection element enters the condenser to form a concentrated light that enters the laser detector. The condenser can be a lens assembly element, that is, composed of one or more lenses.

[0043] It should be noted that the laser detector 14 also includes a filter, which first allows the light emitted by the second deflection element to enter the filter for filtering, and then allows the filtered light to enter the condenser for convergence, so that the converged light enters the laser detector to avoid interference between different laser radars. It can also constrain the laser transmitter to generate and emit an output light of a preset wavelength, so that the laser detector 14 only receives the reflected light of the output light of the preset wavelength emitted by the laser transmitter.

[0044] The filter may be a narrowband filter or a narrowband filter with a grating, and its main function is to filter out the reflection signals of other light beams other than the aggregated light of a preset wavelength, and to enhance the contrast of the reflection signal of the outgoing light among all signals.

[0045] The second light detector 15 is used to collect ambient light to form an external ambient light signal, and send the external ambient light signal as a reference signal to the first control module, and the first control module can process the signal acquired by the first detector according to the signal acquired by the second light detector. The ambient light detector 15 can be composed of an optical transmission mirror group and an optical detector, wherein the optical detector is used to detect external ambient light, and the optical transmission mirror group is composed of at least one transmission mirror, which is used to transmit the external ambient light detected by the optical detector.

[0046] In summary, the optical path structure of the embodiment of the present invention includes a spectroscopic element, a first deflection element, a second deflection element, a scanning element, a first light detector and a second light detector; the spectroscopic element is used to receive light emitted by a laser transmitter, the light passing through the spectroscopic element is irradiated on the first deflection element, and reaches the scanning element through the first deflection element, the light reaching the scanning element is reflected by the scanning element to the obstacle, and forms reflected light after reaching the surface of the obstacle; the reflected light enters the spectroscopic element through the scanning element and the first deflection element, reaches the second deflection element through the spectroscopic element, and reaches the first light detector through the second deflection element, so that the first light detector receives the reflected echo signal; the second light detector is used to collect ambient light to form an external ambient light signal, the first light detector and the second light detector are respectively used to connect to the first control module to feed back the reflected echo signal and the external ambient light signal to the first control module, the optical path structure of the laser radar realizes single-transmit and dual-receive signal processing by transmitting an optical signal by the laser transmitter, receiving an external ambient light signal by the second light detector, and receiving a reflected light signal corresponding to the transmitted light signal by the first light detector, and improves the ranging performance of the laser radar under the premise of ensuring a simple optical path result and high integration.

[0047] See also Figure 2, a schematic diagram of an optical path structure of a laser radar provided in a second embodiment of the present invention, wherein the optical path structure 1 includes a spectroscopic element 10, a first deflection element 11, a second deflection element 12, a scanning element 13, a first light detector 14 and a second light detector 15. Among them, the spectrometer 10 is used to receive the light emitted by the laser emitter 2. The light passing through the spectrometer 10 is irradiated on the first deflection element 11, and reaches the scanning element 13 through the first deflection element 11. The light reaching the scanning element 13 is reflected to the obstacle A by the scanning element 13, and forms reflected light after reaching the surface of the obstacle A; the reflected light passes through the scanning element 13 and the first deflection element 11 and enters the spectrometer 10, reaches the second deflection element 12 through the spectrometer 10, and reaches the first light detector 14 through the second deflection element 12, so that the first light detector 14 receives the reflected echo signal; the second light detector 15 is connected to the second deflection element 12, and the ambient light passes through the scanning element 13, the first deflection element 11, the spectrometer 10 and the second deflection element 12 in sequence to reach the second light detector 15, so that the second light detector 15 collects the ambient light, and the first light detector 14 and the second light detector 15 are respectively used to connect to the first control module 3 to feed back the reflected echo signal and the external ambient light signal to the first control module 3.

[0048] Among them, the relevant descriptions about the spectroscopic element 10, the first deflection element 11, the second deflection element 12, the scanning element 13, the first light detector 14 and the second light detector 15 have been described in detail in the above-mentioned embodiment 1, and are not repeated here.

[0049] In other embodiments, the light emitted by the laser emitter 2 is split by the splitter element 10 and reaches the second deflection element 12. The light passing through the second deflection element 12 reaches the second light detector 15, so that the second light detector 15 collects the light emitted by the laser emitter.

[0050] Among them, the second photodetector 15 is used to receive the light emitted by the laser emitter, on the one hand to confirm the emission status of the signal of the laser emitter, and on the other hand to serve as a reference signal of the first photodetector to adjust the parameters of the first photodetector. Therefore, the light emitted by the laser emitter 2 is split by the spectroscopic element 10 and reaches the second deflection element 12, and the light passing through the second deflection element 12 reaches the second photodetector 15.

[0051] In summary, the optical path structure of the embodiment of the present invention includes a spectroscopic element, a first deflection element, a second deflection element, a scanning element, a first light detector and a second light detector. The spectroscopic element is used to receive light emitted by a laser transmitter. The light passing through the spectroscopic element is irradiated on the first deflection element and reaches the scanning element through the first deflection element. The light reaching the scanning element is reflected to an obstacle by the scanning element and forms reflected light after reaching the surface of the obstacle. The reflected light passes through the scanning element and the first deflection element and enters the spectroscopic element, reaches the second deflection element through the spectroscopic element, and reaches the first light detector through the second deflection element, so that the first light detector receives the reflected echo signal. The light detector is connected to the second deflection element, and the ambient light passes through the scanning element, the first deflection element, the spectroscopic element and the second deflection element in sequence to reach the second light detector, so that the second light detector collects the ambient light. The first light detector and the second light detector are respectively used to connect to the first control module to feed back the reflected echo signal and the external ambient light signal to the first control module. The optical path structure of the laser radar realizes single-transmission and dual-reception signal processing through the laser transmitter transmitting the light signal, the second light detector receiving the external ambient light signal and the first light detector receiving the reflected light signal corresponding to the transmitted light signal. While ensuring the simplicity of the optical path result and the high integration, the ranging performance of the laser radar is improved.

[0052] Based on the optical path structure of the first embodiment above, see Figure 3 , is a schematic diagram of the structure of a laser radar system provided in Embodiment 3 of the present invention, such as Figure 3 As shown, the laser radar system includes a first control module 3, a second control module 4, a laser emitter 2 and an optical path structure 1. The first control module 3 is respectively connected to the laser emitter 2, the first light detector 14 and the second light detector 15, and is used to control the laser emitter 2 to emit laser pulses, control the first light detector 14 to detect reflected echo signals, and control the second light detector 15 to detect ambient light; the second control module 4 is connected to the scanning element 13 and the first control module 3, and is used to control the rotation of the scanning element 13 and send a rotation signal of the scanning element 13 to the first control module 3.

[0053] The optical path structure 1 includes a spectroscopic element 10, a first deflection element 11, a second deflection element 12, a scanning element 13, a first light detector 14 and a second light detector 15, wherein the spectroscopic element 10 is used to receive light emitted by the laser emitter 2, the light passing through the spectroscopic element 10 is irradiated on the first deflection element 11, and reaches the scanning element 13 through the first deflection element 11, the light reaching the scanning element 13 is reflected to the obstacle A by the scanning element 13, and forms reflected light after reaching the surface of the obstacle A; the reflected light enters the spectroscopic element 10 through the scanning element 13 and the first deflection element 11, reaches the second deflection element 12 through the spectroscopic element 10, and reaches the first light detector 14 through the second deflection element 12, so that the first light detector 14 receives the reflected echo signal; the second light detector 15 is used to collect ambient light to form an external ambient light signal, the first light detector 14 and the second light detector 15 are respectively used to connect to the first control module 3 to feed back the reflected echo signal and the external ambient light signal to the first control module 3.

[0054] The first control module 3 is connected to the laser emitter 2, the first light detector 14, the second light detector 15 and the second control module 4 respectively. The laser emitter 2 generates and emits laser pulses under the control of the first control module 3. The second control module 4 sends the rotation signal of the scanning element 13 to the first control module 3. The first control module 3 analyzes the position information of the obstacle according to the rotation signal. The second light detector 15 sends the detected external environment light signal to the first control module 3. The first control module 3 uses the external environment light signal as a reference signal to adjust the parameters of the first light detector, and then controls the first light detector 14 to detect the reflected echo signal.

[0055] The second control module 4 is connected to the scanning element 13 and is used to control the scanning element 13 to rotate so as to reflect the light reaching the scanning element 13 to the obstacle A via the scanning element 13 .

[0056] In other embodiments, the laser transmitter 2 includes a laser and a collimator, and the light emitted by the laser is collimated by the collimator and then emitted to the beam splitting element.

[0057] Among them, the laser can generate and emit light, and the collimator is used to collimate the divergent light emitted by the laser into parallel light. Therefore, the light emitted by the laser is collimated by the collimator to form output light, which is beneficial to the transmission of the subsequent spectroscopic element.

[0058] In the present invention, the laser can be an edge-emitting semiconductor laser or a vertical cavity emission semiconductor laser, and the laser can generate and emit near-infrared laser pulses. The collimator can be a lens group element, that is, a lens group composed of one or more than two lenses.

[0059] It should be noted that the laser, collimator and spectrometer are on the same horizontal axis, so that the path of the outgoing light is in a parallel state, reducing the emission path of the outgoing light; and the first light detector including the laser detector and the condenser can also be on the same horizontal axis, and be parallel to the horizontal axis formed by the laser, collimator and spectrometer, ensuring that the paths of the emitted light and the reflected light always remain parallel.

[0060] To summarize, the laser radar system in the embodiment of the present invention includes a first control module, a second control module, a laser emitter and an optical path structure. The first control module is respectively connected to the laser emitter, the first light detector and the second light detector, and is used to control the laser emitter to emit laser pulses, control the first light detector to detect reflected echo signals, and control the second light detector to detect ambient light, thereby enhancing the ability of the laser radar to use complex external environments; the second control module is connected to the scanning element, and is used to control the rotation of the scanning element. The second control module is used to be specifically responsible for the control and data transmission of the scanning element, so that the first control module can be more focused on improving the radar ranging performance.

[0061] Based on the optical path structure of the second embodiment, see Figure 4 , is a schematic diagram of the structure of a laser radar system provided by Embodiment 4 of the present invention, such as Figure 4 As shown, the laser radar system includes a first control module 3, a second control module 4, a laser emitter 2 and an optical path structure 1. The first control module 3 is respectively connected to the laser emitter 2, the first light detector 14 and the second light detector 15, and is used to control the laser emitter 2 to emit laser pulses, control the first light detector 14 to detect reflected echo signals, and control the second light detector 15 to detect ambient light; the second control module 4 is connected to the scanning element 13 and the first control module 3, and is used to control the rotation of the scanning element 13 and send a rotation signal of the scanning element 13 to the first control module 3.

[0062] The optical path structure 1 includes a beam splitter element 10, a first deflection element 11, a second deflection element 12, a scanning element 13, a first light detector 14 and a second light detector 15. The beam splitter element 10 is used to receive the light emitted by the laser emitter 2. The light passing through the beam splitter element 10 is irradiated on the first deflection element 11, and reaches the scanning element 13 through the first deflection element 11. The light reaching the scanning element 13 is reflected by the scanning element 13 to the obstacle A, and forms reflected light after reaching the surface of the obstacle A; the reflected light passes through the scanning element 13 and the first deflection element 11 and enters the beam splitter element 10, and passes through the beam splitter element 11. 10 reaches the second deflection element 12, and reaches the first light detector 14 through the second deflection element 12, so that the first light detector 14 receives the reflected echo signal; the second light detector 15 is connected to the second deflection element 12, and the ambient light passes through the scanning element 13, the first deflection element 11, the spectroscopic element 10 and the second deflection element 12 in sequence to reach the second light detector 15, so that the second light detector 15 collects the ambient light, and the first light detector 14 and the second light detector 15 are respectively used to connect to the first control module 3 to feed back the reflected echo signal and the external ambient light signal to the first control module 3.

[0063] Corresponding to the laser radar system of the above embodiment, Figure 5 A flowchart of a method for obtaining obstacle information of a laser radar system provided in a fifth embodiment of the present invention is shown. The method for obtaining obstacle information can be executed in a first control module in the laser radar system, and includes the following steps:

[0064] Step S501: The first control module controls the second light detector to obtain an external ambient light signal in real time, and uses the external ambient light signal as a first reference light signal, and adjusts the parameters of the first light detector according to the first reference light signal.

[0065] Among them, the second light detector is used to obtain the external ambient light signal. Therefore, the second light detector is controlled to obtain the external ambient light signal in real time, and the external ambient light signal is used as the first reference signal of the first light detector. Before the first light detector detects the transmitted echo signal, the parameters of the first light detector are adjusted according to the first reference light signal, so that the reception time of the transmitted echo signal detected by the first light detector later is more accurate, thereby improving the performance of laser ranging.

[0066] Step S502: Use the second control module to control the rotation of the scanning element and collect the rotation angle of the scanning element in real time.

[0067] Among them, the relevant descriptions about the second control module and the scanning element have been described in detail in the above-mentioned laser radar system. For details, please refer to the above-mentioned laser radar system and will not be repeated here.

[0068] Step S503, the first control module controls the laser transmitter to transmit laser pulses and obtains the emission time of the laser pulses, and controls the first optical detector after adjusting the parameters to detect the reflected echo signal and obtains the receiving time of the reflected echo signal.

[0069] Among them, the relevant descriptions about the first control module, the laser emitter, the first light detector, and the second light detector have been described in detail in the above-mentioned laser radar system. For details, please refer to the above-mentioned laser radar system and will not be repeated here.

[0070] The laser emitter generates and emits laser pulses under the control of the first control module. The emission time of the laser pulses is obtained according to the emitted laser pulses. The specific method for obtaining the emission time of the laser pulses is as follows: Figure 3 The laser radar system shown in the figure acquires obstacle information, and the first control module controls the laser transmitter to generate and emit laser pulses, and records the time when the laser pulses are emitted as the emission time; if the laser radar system is used Figure 4 The laser radar system shown acquires obstacle information. The first control module controls the laser emitter to generate and emit laser pulses. The laser pulses pass through the spectroscopic element and the second deflection element in sequence to reach the second light detector, and the time when the second light detector receives the laser pulse is used as the emission time of the laser pulse.

[0071] The laser pulse is transmitted through the spectroscopic element and irradiated on the first deflection element, and is reflected on the first deflection element to reach the scanning element. The scanning element rotates under the control of the second control module, and the laser pulse reaching the scanning element is emitted into the two-dimensional space by the rotation. When there is an obstacle in the two-dimensional space, the laser pulse is reflected to the obstacle through the scanning element. After the laser pulse reaches the surface of the obstacle, a reflected echo signal is formed. The reflected echo signal passes through the scanning element and the first deflection element and enters the spectroscopic element, and is reflected by the spectroscopic element and irradiated on the second deflection element, and is reflected on the second deflection element to reach the first light detector, and then the receiving time when the first control module controls the first light detector to detect the reflected echo signal is recorded.

[0072] Optionally, after the light emitted by the laser emitter is split by the beam splitter and reaches the second deflection element, the light passing through the second deflection element reaches the second light detector, so that when the second light detector collects the light emitted by the laser emitter, after the first control module controls the laser emitter to emit a laser pulse, the method further includes:

[0073] The first control module controls the second optical detector to collect laser pulses to obtain an internal signal, uses the internal signal as a second reference optical signal, confirms the working state of the laser transmitter according to the second reference optical signal, and processes data of the reflected optical signal obtained by the first detector.

[0074] Among them, the second light detector can collect the laser pulses emitted by the laser transmitter. Therefore, the laser pulses are collected by controlling the second light detector, and the laser pulses are referred to as internal signals, and then the internal signal is used as the second reference signal of the first light detector. Before the first light detector detects the emission echo signal, the parameters of the first light detector are adjusted according to the second reference light signal. On the one hand, the emission state of the laser transmitter can be monitored, and on the other hand, the reception time of the emission echo signal detected by the subsequent first light detector is made more accurate, thereby improving the performance of laser ranging.

[0075] Step S504, calculate the target distance information according to the transmission time and the reception time, and determine the target rotation angle of the scanning element at the middle moment of the two times, map the target distance information and the target rotation angle, traverse all the rotation angles of the scanning element, and obtain the distance between any point on the obstacle surface and the laser radar system.

[0076] Among them, since the delay time of the reflected signal of the laser pulse can reflect the distance of the obstacle, the longer the delay time, the farther the obstacle is, and vice versa, the shorter the delay time, the closer the obstacle is, so the time difference is calculated according to the transmission time and the reception time, and then the time difference is substituted into the formula The target distance information is obtained, where L is the target distance information, c is the speed of light in the atmosphere, and t is the time difference. At the same time, the intermediate time between the receiving time and the reflection time is calculated, and the target rotation angle of the scanning element at the intermediate time is obtained, which can reflect the direction of the obstacle.

[0077] The target rotation angle and target distance information are mapped to obtain a distance-azimuth mapping table. For any point on the obstacle surface, according to the corresponding rotation angle of the scanning element, by looking up the distance-azimuth mapping table, the distance between the point and the laser radar system is obtained, and the distance and azimuth of the obstacle are confirmed.

[0078] In summary, in the embodiment of the present invention, the first control module controls the second light detector to obtain the external environment light signal in real time, and uses the external environment light signal as the first reference light signal, and adjusts the parameters of the first light detector according to the first reference light signal; the second control module is used to control the rotation of the scanning element, and the rotation angle of the scanning element is collected in real time; the first control module controls the laser transmitter to emit laser pulses, and obtains the emission time of the laser pulses, and controls the first light detector after adjusting the parameters to detect the reflected echo signal, and obtains the receiving time of the reflected echo signal; according to the emission time and the receiving time, the target distance information is calculated, and the target rotation angle of the scanning element at the middle moment of the two times is determined, the target distance information is mapped with the target rotation angle, and all the rotation angles of the scanning element are traversed to obtain the distance between any point on the obstacle surface and the laser radar system, and the external environment light and the internal signal emitted by the laser transmitter are used to flexibly adjust the parameters of the first light detector, so that the receiving time of the reflected echo signal received by the first light detector is more accurate, and then combined with the rotation angle of the scanning element, the emission time of the laser pulse and the receiving time of the reflected echo signal formed after the laser pulse encounters the obstacle, the distance between any point on the obstacle surface and the laser radar system is obtained. More accurate.

[0079] Figure 6 This is a schematic diagram of the structure of a first control module provided in Embodiment 6 of the present invention. Figure 6 As shown, the first control module of this embodiment includes: at least one processor ( Figure 6 Only one is shown in the figure), a memory, and a computer program stored in the memory and executable on at least one processor, and when the processor executes the computer program, the steps in any of the above-mentioned obstacle information acquisition method embodiments are implemented.

[0080] The first control module may include, but is not limited to, a processor and a memory. Those skilled in the art will understand that Figure 6 This is only an example of the first control module and does not constitute a limitation of the first control module. The first control module may include more or fewer components than shown in the figure, or a combination of certain components, or different components, for example, it may also include a network interface, a display screen, and an input device.

[0081] The processor may be a CPU, or other general-purpose processors, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0082] The memory includes a readable storage medium, an internal memory, etc., wherein the internal memory may be the memory of the first control module, and the internal memory provides an environment for the operation of the operating system and the computer-readable instructions in the readable storage medium. The readable storage medium may be the hard disk of the first control module, and in other embodiments, it may also be an external storage device of the first control module, for example, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. equipped on the first control module. Further, the memory may also include both an internal storage unit of the first control module and an external storage device. The memory is used to store an operating system, an application program, a boot loader (BootLoader), data, and other programs, such as the program code of a computer program, etc. The memory may also be used to temporarily store data that has been output or is to be output.

[0083] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of the present invention. The specific working process of the units and modules in the above-mentioned device can refer to the corresponding process in the above-mentioned method embodiment, which will not be repeated here. If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, which can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of the above-mentioned method embodiment can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may at least include: any entity or device capable of carrying computer program code, recording medium, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium. For example, a USB flash drive, a mobile hard disk, a magnetic disk or an optical disk. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electric carrier signals and telecommunication signals.

[0084] The present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by a computer program product. When the computer program product runs on the first control module, the first control module can implement the steps in the above-mentioned method embodiment when it is executed.

[0085] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0086] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0087] In the embodiments provided by the present invention, it should be understood that the disclosed device / first control module and method can be implemented in other ways. For example, the device / first control module embodiments described above are merely schematic. For example, the division of modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0088] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0089] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention.

Claims

1. An optical path structure of a laser radar, characterized in that: The optical path structure comprises: A beam splitter element, a first deflection element, a second deflection element, a scanning element, a first light detector, and a second light detector; The beam splitter element is used to receive the light emitted by the laser transmitter. The light passing through the beam splitter element is irradiated on the first deflection element and reaches the scanning element through the first deflection element. The light reaching the scanning element is reflected by the scanning element to the obstacle and forms reflected light after reaching the surface of the obstacle. The reflected light passes through the scanning element and the first deflection element and enters the beam splitter element, reaches the second deflection element through the beam splitter element, and reaches the first light detector through the second deflection element, so that the first light detector receives a reflected echo signal; The second light detector is used to collect ambient light to form an external ambient light signal, and the first light detector and the second light detector are respectively used to connect to a first control module to feed back the reflected echo signal and the external ambient light signal to the first control module.

2. The optical path structure according to claim 1, characterized in that: The second light detector is connected to the second deflection element, and the ambient light passes through the scanning element, the first deflection element, the beam splitting element and the second deflection element in sequence to reach the second light detector, so that the second light detector collects the ambient light.

3. The optical path structure according to claim 2, characterized in that: The light emitted by the laser emitter is split by the beam splitter and reaches the second deflection element. The light passing through the second deflection element reaches the second light detector, so that the second light detector collects the light emitted by the laser emitter.

4. The optical path structure according to claim 1, characterized in that: The first light detector includes a laser detector and a condenser, and the light passing through the second deflection element enters the condenser to form concentrated light which enters the laser detector.

5. The optical path structure according to claim 1, characterized in that: The beam splitter element is an apertured reflector, a semi-transparent semi-reflective mirror, a polarized beam splitter, or a beam splitter using a coating method.

6. The optical path structure according to claim 1, characterized in that: The first deflection element is a mirror or a prism, and / or the second deflection element is a mirror, a beam splitter or a prism.

7. A laser radar system, characterized in that: The laser radar system comprises a first control module, a second control module, a laser transmitter and an optical path structure according to any one of claims 1 to 6, wherein the first control module is respectively connected to the laser transmitter, the first light detector and the second light detector, and is used to control the laser transmitter to emit laser pulses, control the first light detector to detect reflected echo signals, and control the second light detector to detect ambient light; The second control module is connected to the scanning element and the first control module, and is used for controlling the rotation of the scanning element and sending a rotation signal of the scanning element to the first control module.

8. The laser radar system according to claim 7, characterized in that: The laser transmitter comprises a laser and a collimator. The light emitted by the laser is collimated by the collimator and then passes through the beam splitting element.

9. A method for obtaining obstacle information of a laser radar system, characterized in that: The obstacle information acquisition method is applied to the laser radar system according to claim 7, and the obstacle information acquisition method comprises: The first control module controls the second light detector to acquire an external ambient light signal in real time, and uses the external ambient light signal as a first reference light signal, and adjusts the parameters of the first light detector according to the first reference light signal; Using the second control module to control the rotation of the scanning element, and collecting the rotation angle of the scanning element in real time; The first control module controls the laser transmitter to emit laser pulses and obtain the emission time of the laser pulses, and controls the first light detector after adjusting the parameters to detect the reflected echo signal and obtain the reception time of the reflected echo signal; The target distance information is calculated based on the emission time and the reception time, and the target rotation angle of the scanning element at the middle moment of the two times is determined. The target distance information is mapped to the target rotation angle, and all rotation angles of the scanning element are traversed to obtain the distance between any point on the obstacle surface and the lidar system.

10. The obstacle information acquisition method according to claim 9, characterized in that: After the light emitted by the laser emitter is split by the light splitting element, it reaches the second deflection element, and the light passing through the second deflection element reaches the second light detector, so that when the second light detector collects the light emitted by the laser emitter, after the first control module controls the laser emitter to emit a laser pulse, it also includes: The first control module controls the second optical detector to collect the laser pulse to obtain an internal signal, uses the internal signal as a second reference optical signal, confirms the working state of the laser transmitter according to the second reference optical signal, and processes data of the reflected optical signal obtained by the first optical detector.

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