Laser radar fault detection method, laser radar and storage medium

Abstract

The embodiment of the invention provides a laser radar fault detection method, a laser radar and a storage medium. The method comprises the steps that the laser radar is controlled to emit laser beams in multiple direction angles, part of energy in the laser beams forms stray light in the laser radar, a detector in the laser radar is controlled to receive the stray light, and then the stray light is received according to the stray light receiving condition of the detector. And determining whether the detector has a fault or not. According to the scheme, the permanent fault of the detector can be detected, potential safety hazards are avoided, the probability of fault false alarm can be reduced, and high robustness is achieved.

Description

Technical Field

[0001] This disclosure relates to the field of optoelectronic technology, and in particular to a fault detection method for lidar, lidar, and storage medium. Background Technology

[0002] LiDAR (Light Detection and Ranging) can detect the position, velocity, and attitude of objects by emitting a laser beam and receiving the echoes reflected back from surrounding objects. LiDAR is widely used in vehicles, drones, and intelligent robots.

[0003] A lidar system consists of a laser and a detector. The laser emits a laser beam, and the detector receives the detected echo. The laser and detector are the core components that enable lidar to perform its detection function. When either the laser or the detector malfunctions, some of the lidar's detection functions become abnormal, reducing its ability to perceive the surrounding environment and posing certain safety hazards.

[0004] The information in the background section is merely information known only to the inventor and does not imply that such information had entered the public domain before the date of this application, nor does it imply that it can be considered prior art in this disclosure. Summary of the Invention

[0005] This disclosure provides a fault detection method for lidar, a lidar, and a storage medium, which can detect permanent faults in detectors or lasers and avoid safety hazards.

[0006] In a first aspect, this disclosure provides a fault detection method, comprising: controlling the lidar to emit laser beams at multiple directional angles, wherein a portion of the energy in the laser beams forms stray light inside the lidar; controlling a detector in the lidar to receive the stray light; and determining whether the detector is faulty based on the detector's reception of the stray light.

[0007] Optionally, controlling the lidar to emit laser beams at multiple directional angles includes: controlling the lidar to emit laser beams at multiple horizontal directional angles respectively; controlling the detector in the lidar to receive the stray light includes: controlling the detector to receive the stray light at the multiple horizontal directional angles respectively.

[0008] Optionally, controlling the lidar to emit laser beams at multiple horizontal directional angles includes controlling at least two lasers in the lidar to emit laser beams in parallel at the multiple horizontal directional angles, wherein the at least two lasers correspond to different vertical directional angles.

[0009] Optionally, determining whether the detector is faulty based on the detector's reception of the stray light includes: obtaining multiple stray light echo pulses obtained by the detector receiving the stray light at multiple horizontal directional angles; and determining whether the detector is faulty based on the multiple stray light echo pulses.

[0010] Optionally, determining whether the detector is faulty based on the plurality of stray light echo pulses includes: determining that the detector is faulty when at least a first number of stray light echo pulses among the plurality of stray light echo pulses have an amplitude less than a preset threshold.

[0011] Optionally, determining whether the detector is faulty based on the plurality of stray light echo pulses includes: determining that the detector is not faulty when at least a second number of stray light echo pulses among the plurality of stray light echo pulses have an amplitude greater than or equal to a preset threshold.

[0012] Optionally, controlling the lidar to emit laser beams at multiple directional angles includes: controlling at least two lasers in the lidar to emit the laser beams in parallel at a horizontal directional angle, wherein the at least two lasers correspond to different vertical directional angles; and controlling the detector in the lidar to receive the stray light includes: controlling the detector to receive the stray light at the horizontal directional angle.

[0013] Optionally, the laser beams emitted by the at least two lasers at different vertical angles form mixed stray light inside the lidar; determining whether the detector is faulty based on the detector's reception of the stray light includes: obtaining stray light echo pulses obtained by the detector receiving the mixed stray light; and determining whether the detector is faulty based on the stray light echo pulses.

[0014] Optionally, determining whether the detector is faulty based on the stray light echo pulse includes: determining that the detector is faulty when the amplitude of the stray light echo pulse is less than a preset threshold.

[0015] Optionally, determining whether the detector is faulty based on the stray light echo pulse includes: determining that the detector is not faulty when the amplitude of the stray light echo pulse is greater than or equal to a preset threshold.

[0016] Optionally, the method is configured to be performed within the detection time window of the lidar.

[0017] Secondly, this disclosure also provides a fault detection method for a lidar, comprising: controlling a laser in the lidar to emit a laser beam, wherein a portion of the energy in the laser beam forms stray light inside the lidar; controlling the lidar to receive the stray light at multiple directional angles; and determining whether the laser is faulty based on the lidar's reception of the stray light at the multiple directional angles.

[0018] Optionally, controlling the laser in the lidar to emit laser beams includes: controlling the laser to emit laser beams at multiple horizontal directional angles respectively; controlling the lidar to receive stray light at multiple directional angles includes: controlling the lidar to receive stray light at the multiple horizontal directional angles respectively.

[0019] Optionally, controlling the lidar to receive the stray light at the plurality of horizontal directional angles includes: controlling at least two detectors in the lidar to receive the stray light in parallel at the plurality of horizontal directional angles, wherein the at least two detectors correspond to different vertical directional angles.

[0020] Optionally, controlling the laser in the lidar to emit a laser beam includes: controlling the laser to emit the laser beam at a horizontal directional angle; controlling the lidar to receive stray light at multiple directional angles includes: controlling at least two detectors in the lidar to receive the stray light in parallel at the horizontal directional angle, wherein the at least two detectors correspond to different vertical directional angles.

[0021] Optionally, determining whether the laser is faulty based on the reception of stray light by the lidar at the multiple directional angles includes: obtaining multiple stray light echo pulses obtained by the lidar from the stray light received at the multiple directional angles; and determining whether the laser is faulty based on the multiple stray light echo pulses.

[0022] Optionally, determining whether the laser is faulty based on the plurality of stray light echo pulses includes: determining that the laser is faulty when at least a first number of stray light echo pulses among the plurality of stray light echo pulses have an amplitude less than a preset threshold.

[0023] Optionally, determining whether the laser is faulty based on the plurality of stray light echo pulses includes: determining that the laser is not faulty when at least a second number of stray light echo pulses among the plurality of stray light echo pulses have an amplitude greater than or equal to a preset threshold.

[0024] Optionally, the method is configured to be performed outside the detection time window of the lidar.

[0025] Thirdly, this disclosure also provides a lidar, comprising: a transmitting unit, a receiving unit, a storage medium, and a processor. The transmitting unit includes multiple lasers, the receiving unit includes multiple detectors, the storage medium stores at least one instruction set for fault detection, and the processor is communicatively connected to the transmitting unit, the receiving unit, and the storage medium. During operation, the processor reads the at least one instruction set and executes the method described in any of the first aspects, or the method described in any of the second aspects, according to the instructions of the at least one instruction set.

[0026] Fourthly, this disclosure also provides a computer-readable non-transitory storage medium storing at least one instruction set, wherein when the at least one instruction set is executed by a processor, it implements the method as described in any of the first aspects, or implements the method as described in any of the second aspects.

[0027] The fault detection method, lidar, and storage medium disclosed herein utilize stray light generated by the lidar to detect faults in detectors or lasers, enabling timely detection of permanent faults and preventing safety hazards. This solution reduces the probability of false alarms caused by weak laser beam energy or weak detector sensitivity at a single angle by controlling the lidar to emit or receive stray light at multiple directional angles, exhibiting high robustness. Furthermore, this solution utilizes the stray light already present within the lidar for detector or laser fault detection, eliminating the need for additional optical emitting or receiving devices within the lidar, resulting in a simple structure and ease of implementation.

[0028] The fault detection method for the lidar, and other functions of the lidar and storage medium provided in this disclosure, will be partially set forth in the following description. The inventive aspects of the lidar fault detection method, lidar, and storage medium provided in this disclosure can be fully explained by practice or by using the methods, apparatus, and combinations described in the detailed examples below. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 A schematic diagram of a lidar provided in some embodiments of this disclosure is shown.

[0031] Figure 2 A schematic diagram of the channel distribution in a lidar provided in some embodiments of this disclosure is shown.

[0032] Figure 3 A schematic diagram of the detection field of view of a lidar provided in some embodiments of this disclosure is shown.

[0033] Figure 4A This illustration shows a schematic diagram of local point cloud data output by a lidar provided in some embodiments of the present disclosure when the detection function is normal.

[0034] Figure 4B The diagram illustrates local point cloud data output by a lidar provided in some embodiments of this disclosure in the event of a partial laser or partial detector failure.

[0035] Figure 5 A schematic diagram of the optical path in a lidar provided in some embodiments of this disclosure is shown.

[0036] Figure 6 A timing diagram illustrating the operation of a lidar provided in some embodiments of this disclosure is shown.

[0037] Figure 7 A flowchart illustrating a fault detection method provided in some embodiments of this disclosure is shown.

[0038] Figure 8 A schematic diagram of a control method for fault detection of a detector is shown in some embodiments of this disclosure.

[0039] Figure 9 A schematic diagram of another control method for fault detection of a detector provided in some embodiments of this disclosure is shown.

[0040] Figure 10 This illustration shows another control method for fault detection of a detector provided in some embodiments of the present disclosure.

[0041] Figure 11 A flowchart illustrating another fault detection method provided in some embodiments of this disclosure is shown.

[0042] Figure 12 A schematic diagram of a control method for fault detection of a laser provided in some embodiments of this disclosure is shown.

[0043] Figure 13This diagram illustrates another control method for fault detection of a laser, as provided in some embodiments of this disclosure.

[0044] Figure 14 This diagram illustrates yet another control method for fault detection of a laser, as provided in some embodiments of this disclosure. Detailed Implementation

[0045] The following description provides specific application scenarios and requirements for this disclosure, intended to enable those skilled in the art to make and use the content of this disclosure. Various partial modifications to the disclosed embodiments will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments and applications without departing from the spirit and scope of this disclosure. Therefore, this disclosure is not limited to the embodiments shown, but rather to the widest scope consistent with the claims.

[0046] The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not restrictive. For example, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” as used herein may also include the plural forms. When used in this disclosure, the terms “comprising,” “including,” and / or “containing” mean that the associated integers, steps, operations, elements, and / or components are present, but do not exclude the presence of one or more other features, integers, steps, operations, elements, components, and / or groups, or that other features, integers, steps, operations, elements, components, and / or groups may be added to the system / method.

[0047] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the specific implementation methods of this disclosure will be described below with reference to the accompanying drawings. The accompanying drawings described below are merely some embodiments of this disclosure. For those skilled in the art, other drawings and other embodiments can be obtained based on these drawings without creative effort. Adjustments and improvements made without departing from the concept of this disclosure are all within the protection scope of this disclosure.

[0048] It should be clearly understood that the accompanying drawings are for illustrative and descriptive purposes only and are not intended to limit the scope of this disclosure. For the sake of brevity, the drawings only schematically show parts relevant to the corresponding embodiments and do not represent the actual structure of the product. Furthermore, for ease of understanding, the drawings schematically depict only some structures or components; in reality, there may be more or fewer similar structures or components. It should also be understood that the drawings are not drawn to scale.

[0049] The flowcharts used in this disclosure illustrate operations implemented according to some embodiments of this disclosure. It should be clearly understood that the operations in the flowcharts may not be implemented sequentially. Instead, the operations may be implemented in reverse order or simultaneously. Furthermore, one or more additional operations may be added to the flowcharts. One or more operations may be removed from the flowcharts.

[0050] LiDAR can be applied in various scenarios, such as vehicle driving, robot walking, drone flight, and industrial applications. Taking vehicle driving as an example, LiDAR can help vehicles perceive their surroundings, identify objects on the road, and improve driving safety. This disclosure does not limit the application scenarios of LiDAR; it can be applied to other scenarios besides those listed above. For ease of understanding, examples in the following text will use vehicle driving as an example.

[0051] Below, in conjunction with Figure 1 The structure and detection principle of lidar are explained.

[0052] Figure 1 A schematic diagram of a lidar provided in some embodiments of this disclosure is shown. For example... Figure 1 As shown, the lidar 100 includes multiple lasers 110 and multiple detectors 120. The lidar 100 also includes a processor 130. The processor 130 is communicatively connected to the multiple lasers 110 and the multiple detectors 120, respectively.

[0053] The aforementioned plurality of lasers 110 and detectors 120 form a plurality of transceiver channels. A transceiver channel can represent the information path through which a lidar emits and receives a single laser beam. The transceiver channel can be simply referred to as a channel, and in this disclosure, "transceiver channel" and "channel" express the same concept. In some embodiments, a channel may include one laser 110 and one detector 120. The laser 110 corresponds to the detector 120, and the detection echo generated after the laser beam emitted by the laser 110 is reflected by an object is incident on the detector 120. In some embodiments, a channel may include a plurality of lasers 110 and one detector 120. The plurality of lasers 110 corresponds to the detector 120, and the detection echo generated after the laser beam emitted by the plurality of lasers 110 is reflected by an object is incident on the detector 120. In some embodiments, a channel may include one laser 110 and a plurality of detectors 120. The laser 110 corresponds to the plurality of detectors 120, and the detection echo generated after the laser beam emitted by the laser 110 is reflected by an object is incident on the plurality of detectors 120. This disclosure does not limit the specific number of lasers or detectors in a channel. Figure 1In the lidar shown, one channel illustrates a laser 110 and a detector 120.

[0054] It should be noted that this disclosure does not limit the number of channels included in the lidar 100. For example, the lidar 100 may include one channel or multiple channels. This disclosure does not limit the distribution of multiple channels. For example, the multiple lasers in the multiple channels may be distributed in one dimension or two dimensions. The multiple detectors in the multiple channels may be distributed in one dimension or two dimensions.

[0055] One channel in a lidar system can correspond to one detection field of view. The laser 110 in that channel emits a laser beam towards the detection field of view, and the detector 120 receives the echo generated after the laser beam is reflected by an object within that detection field of view. This allows the lidar to detect objects within the detection field of view. (Continue to see...) Figure 1 Taking channel 1 as an example, its detection process is as follows: Laser 110 in channel 1, under the control of processor 130, emits a laser beam towards the detection field of view of channel 1 at time T1. The laser beam can also be called a detection beam or detection pulse. The laser beam is reflected by objects within the detection field of view, generating a detection echo. Detector 120 in channel 1 receives this detection echo and converts it into an electrical signal, which is then provided to processor 130. Processor 130 can calculate the flight time ΔT = T2 - T1 of the light based on the laser beam emission time T1 and the detection echo reception time T2. Based on the speed of light c and the flight time ΔT, the flight distance can be determined. The flight distance represents the distance between the object and the lidar. Based on this flight distance d and the detection field of view of channel 1, the processor 130 can determine the object's position information.

[0056] Using a similar approach, the other channels in the lidar 100 can detect object information within their respective detection fields of view. In this way, the processor 130 can generate point cloud data based on the object information detected by all channels and output this point cloud data. This point cloud data reflects the object information within the total detection field of view of the lidar 100.

[0057] The following is combined Figure 2 and Figure 3 The detection methods and detection field of view of lidar are explained.

[0058] Figure 2 A schematic diagram of the channel distribution in a lidar provided in some embodiments of this disclosure is shown. For example... Figure 2 As shown, in some embodiments, multiple channels in the lidar ( Figure 2A gray rectangle (representing a channel) can be arranged sequentially along the vertical direction. Each channel corresponds to a vertical angle. For example, the first channel corresponds to a vertical angle of +20 degrees, and the last channel corresponds to a vertical angle of -25 degrees. During the operation of the lidar, the laser in a channel emits a laser beam in the direction of its corresponding vertical angle, enabling the detection of objects at that vertical angle. In this way, multiple channels in the lidar can achieve a certain detection field of view in the vertical direction.

[0059] In some embodiments, multiple channels in a lidar can be arranged sequentially along a horizontal direction. Each channel can correspond to a horizontal azimuth angle. For example, the first channel corresponds to a horizontal azimuth angle of -60 degrees, and the last channel corresponds to a horizontal azimuth angle of +60 degrees. During the operation of the lidar, the laser in one channel emits a laser beam in the direction of its corresponding horizontal azimuth angle, enabling the detection of objects at that horizontal azimuth angle. In this way, the multiple channels in the lidar can achieve a certain detection field of view in the horizontal direction.

[0060] In some embodiments, multiple channels in a lidar can be arranged in a two-dimensional manner along a first direction and a second direction. The first direction is, for example, a generally vertical direction. The second direction is, for example, a generally horizontal direction. One channel can correspond to one horizontal angle and one vertical angle. During the operation of the lidar, the laser in one channel can emit a laser beam in the direction of its corresponding horizontal or vertical angle. This enables the detection of objects at that horizontal or vertical angle. In this way, the multiple channels in the lidar achieve a certain two-dimensional detection field of view.

[0061] In this disclosure, the sequential arrangement of multiple channels along a vertical direction can include: lasers in multiple channels arranged sequentially along a vertical direction, and detectors in multiple channels arranged sequentially along a vertical direction. The sequential arrangement of multiple channels along a horizontal direction can include: lasers in multiple channels arranged sequentially along a horizontal direction, and detectors in multiple channels arranged sequentially along a horizontal direction. The two-dimensional arrangement of multiple channels along a first direction and a second direction can include: lasers in multiple channels arranged in a two-dimensional arrangement along a first direction and a second direction, and detectors in multiple channels arranged in a two-dimensional arrangement along a first direction and a second direction.

[0062] In some embodiments, multiple channels of the lidar can perform detection sequentially according to a certain time order. For example, channel 1 performs detection in the first time window, and channel 2 performs detection in the second time window. In some embodiments, multiple channels of the lidar can perform detection in parallel. For example, all channels perform detection within the same time window. In some embodiments, multiple channels of the lidar can be grouped for parallel detection. For example, the lidar includes 64 channels, which can be divided into 8 groups, with each group containing 8 channels. The 8 channels in the same group can perform parallel detection within the same time window, and channels in different groups can perform detection in different time windows. For example, in the first time window, the 8 channels in group 1 perform parallel detection, and in the second time window, the 8 channels in group 2 perform parallel detection. It should be noted that this disclosure does not limit the grouping method or the number of groups for multiple channels. For example, channels in the same group can be arranged adjacently or non-adjacently. Furthermore, the number of channels in different groups can be the same or different.

[0063] Figure 2 The lidar shown may further include a scanner (not shown in the figures). The scanner enables the laser beam to scan the detection field of view along a certain direction, such as at least one of the horizontal or vertical directions. During the scanner's movement, the lidar can detect objects at different directional angles, forming a two-dimensional detection field of view in the horizontal or vertical direction. In some embodiments, the lidar may include a single scanner. Optionally, a single scanner can perform one-dimensional scanning. Alternatively, a single scanner can perform two-dimensional scanning. In some embodiments, the lidar may include multiple scanners. Optionally, different scanners can perform field-of-view scanning in different directions. The scanner in this disclosure may include one or more of the following: mechanical rotation, rotating prism, microelectronic scanning, tilting mirror, rotating mirror, and phased array.

[0064] Figure 3 A schematic diagram of the detection field of view of a lidar provided in some embodiments of this disclosure is shown. For example... Figure 3 As shown, a lidar has a certain detection field of view in both the vertical and horizontal directions, enabling the detection of objects in three-dimensional space. After a single detection of the total detection field of view, the lidar generates point cloud data corresponding to that field of view. This point cloud data reflects information about objects within the total detection field of view. Point cloud data can be used to assist in vehicle driving control.

[0065] Figure 4A This illustration shows a schematic diagram of local point cloud data output by a lidar provided in some embodiments of the present disclosure when the detection function is normal. Figure 4BThis diagram illustrates local point cloud data output by a lidar system provided in some embodiments of this disclosure when some lasers or detectors fail. See also... Figure 4A The first column of point cloud data from the left is obtained by the LiDAR through channels i to i+5 at a horizontal angle j; the second column is obtained by the LiDAR through channels i to i+5 at a horizontal angle j+1; and so on, until the sixth column is obtained by the LiDAR through channels i to i+5 at a horizontal angle j+5. Based on this point cloud data and its corresponding vertical and horizontal angles, the LiDAR can accurately obtain relevant information about objects, enabling it to accurately perceive objects in its surrounding environment.

[0066] As described above, the laser and detector are the core components of a lidar system to achieve its detection function. During actual use, the laser and detector may malfunction due to factors such as collisions and aging. When a laser or detector malfunctions, the lidar's ability to detect objects in the corresponding field of view decreases or is even lost, affecting the accuracy of the detection results.

[0067] The laser malfunctions disclosed herein include reduced luminous energy due to laser aging or hardware failure, resulting in the inability to detect objects. The detector malfunctions disclosed herein include reduced photosensitivity due to detector aging or hardware failure, resulting in the inability to detect objects.

[0068] Combination Figure 4A To illustrate, suppose the laser or detector in the (i+2)th channel of a LiDAR system malfunctions. In this case, the (i+2)th channel of the LiDAR system will lose or even completely lose its detection capability. Under this fault condition, the point cloud data generated by the LiDAR system would look like... Figure 4B As shown. See also Figure 4B In the case of a LiDAR system, point cloud data should have been generated in the detection field of view corresponding to the (i+2)th channel. However, due to a malfunction in the laser or detector within that channel, no point cloud data was generated in that detection field of view. This malfunction can also be termed a "blind spot" malfunction. A blind spot malfunction can manifest as follows: during LiDAR detection, effective point cloud data cannot be acquired within certain specific angular areas, creating areas similar to visual blind spots. The LiDAR cannot see or correctly detect these areas.

[0069] When a lidar malfunctions and loses its line of sight, its ability to perceive the surrounding environment will be affected, and the point cloud data it generates will not provide a comprehensive or complete representation of the surrounding environment. Intelligent driving systems use this point cloud data (such as...) Figure 4B The point cloud data shown may pose a safety hazard to vehicle operation.

[0070] This disclosure provides a fault detection method for lidar. It utilizes stray light generated within the lidar to detect faults in the laser or detector, enabling timely detection of malfunctions and preventing potential safety hazards. The fault detection method provided in this disclosure exhibits high robustness, reducing the probability of false alarms caused by environmental or other factors affecting the laser or detector. By utilizing the stray light already present within the lidar, this method eliminates the need for additional light emitting or receiving devices within the lidar, resulting in a simple structure and ease of implementation.

[0071] The following is combined Figure 5 The generation of stray light is explained.

[0072] In this disclosure, stray light of a lidar can refer to a laser beam or its scattered or reflected components that deviate from the predetermined detection path and are not received by the detector as required during the lidar detection process, or, in other words, the component of the laser beam emitted by the laser that does not exit to the outside due to diffuse reflection inside the lidar.

[0073] Figure 5 A schematic diagram of the optical path in a lidar provided in some embodiments of this disclosure is shown. For example... Figure 5 As shown, a portion of the laser beam emitted by the laser passes through the diaphragm and exits to the outside of the lidar. This laser beam, reflected by an object, forms a detection echo, which can be received by the detector. The lidar can then use the signal generated by the detection echo to perceive information about objects in the surrounding environment. (Continue reading...) Figure 5 During the above process, another component of the laser beam emitted by the laser is reflected (e.g., diffuse reflection) at the photomask, forming stray light inside the lidar. Figure 5 Stray light is represented by dashed lines. Stray light can be received by the detector.

[0074] It should be noted that, Figure 5 The illustration shows a case where the laser beam is reflected at the photomask, generating stray light. In practical applications, the laser beam may also be reflected at other components in the lidar (such as beam splitters, housings, etc.), generating stray light. This disclosure does not limit the specific location or cause of stray light generation. The stray light received by the detector may be a mixture of stray light generated at multiple locations.

[0075] Those skilled in the art will understand that the optical path of the laser beam emitted by the laser is related to the physical structure of the lidar, and the generation of stray light is unavoidable due to the influence of the lidar's physical structure. Although there are some solutions to reduce stray light, it cannot be completely eliminated. Stray light exists to varying degrees within a lidar.

[0076] Furthermore, the optical paths of stray light and probe echo are different; the stray light has a shorter optical path than the probe echo. After the laser emits the laser beam, the detector receives the stray light first, and then receives the probe echo. Figure 6 A timing diagram illustrating the operation of a lidar provided in some embodiments of this disclosure is shown. For example... Figure 6 As shown, assume the laser emits a laser beam at time T1, the detector receives stray light at time T2, and receives the detection echo at time T3. Time T3 is after time T2. Since the internal structure of the lidar is fixed, the optical path of the stray light generated by the laser beam inside the lidar is also basically fixed. The time T2 when the detector receives the stray light can be roughly predicted.

[0077] The detector generates stray light echo pulses in response to stray light. The detector generates probe echo pulses in response to probe echoes. The lidar can identify the stray light echo pulse from the echo pulses generated by the detector. For example, the lidar can use the echo pulses generated by the detector within a preset time window as the stray light echo pulse. Combined with... Figure 6 Based on the analysis, the start time of the preset time window can be the laser emission time T1, and the end time of the preset time window is later than time T2 and earlier than time T3. The duration of the preset time window can be determined based on parameters such as the geometric dimensions of the lidar, the structure and position of its internal components, etc. Alternatively, the duration of the preset time window can also be obtained through testing before the lidar leaves the factory. It should be noted that the preset time window can be a fixed time window or a dynamic time window, and this disclosure does not limit it in this way.

[0078] comprehensive Figure 5 and Figure 6As can be seen, when both the laser and the detector are functioning normally, the laser beam emitted by the laser forms stray light inside the lidar, which the detector can receive. When the laser malfunctions, it cannot emit a laser beam or the emitted laser beam is weak, resulting in either no stray light formation or weak stray light formation. The detector either does not respond to weak stray light or the signal strength of the echo pulse generated in response to the stray light is weak. When the detector malfunctions, its photosensitivity is reduced or lost, resulting in no response to stray light or a weak signal strength of the echo pulse generated in response to the stray light. This disclosure allows for the detection of laser or detector malfunctions based on the detector's response to stray light.

[0079] In some embodiments, the processor in a lidar system can control a laser to emit a laser beam and control the corresponding detector to receive stray light generated by the laser beam. The processor can determine whether the laser or detector is faulty based on the detector's response to the stray light. For example, if the amplitude of the stray light echo pulse generated by the detector in response to the stray light is less than a specified threshold, it can be determined that the laser or detector is faulty. Conversely, if the amplitude of the stray light echo pulse generated by the detector in response to the stray light is greater than or equal to a specified threshold, it can be determined that the laser and detector are not faulty. Following this method, multiple lasers and detectors in the lidar system can be polled for detection, thus enabling fault detection of the lidar system.

[0080] In practical applications, some interference factors may cause the instantaneous emission energy of the laser to be lower than normal, or the instantaneous photosensitivity of the detector to be weaker. This will cause the amplitude of the stray light echo pulse generated by the detector to decrease. During fault detection, there is a possibility that this situation may be misdiagnosed as a laser or detector malfunction.

[0081] In some embodiments, this disclosure also provides a more robust fault detection method. Fault detection of the lidar is performed by controlling the lidar to emit laser beams at multiple directional angles, or by controlling the lidar to receive stray light at multiple directional angles. This can reduce the probability of false alarms caused by interference factors, effectively identify transient failures and permanent faults, and accurately locate permanent faults in both the laser and detector. The following describes in detail how to detect permanent faults in the detector and how to detect permanent faults in the laser, respectively, with reference to the accompanying drawings.

[0082] Figure 7A flowchart illustrating a fault detection method P300 provided in some embodiments of this disclosure is shown. The fault detection method P300 can be executed by a processor. The fault detection method P300 can be used to detect permanent faults in a detector. The processor can also process electrical signals, such as extracting echo pulses, determining the arrival time of the echo pulses, or determining the amplitude of the echo pulses. In some embodiments, the processor can be integrated within a lidar system. For example, the processor may be the main controller of the lidar. In some embodiments, the processor can be independent of the lidar. For example, the processor may be located in a vehicle's domain controller, server, etc. During fault detection, the processor can acquire the electrical signals output by the detector. The processor can communicate with the detector, which can be achieved through wired or wireless communication. In some embodiments, the processor can control a laser to emit a laser beam. For example, the processor can output a control signal to the laser's drive circuit to control the laser to emit a laser beam. In some embodiments, the processor can control a detector to receive a beam. For example, the processor can output a control signal to the detector's drive circuit to control the detector to receive a beam. The processor may include units for controlling the laser, units for controlling the detector, units for processing signals, and other units for performing logical judgments.

[0083] It should be understood that the above division of units is only a logical functional division. In actual implementation, they can be fully or partially integrated into a single physical entity, or they can be physically separated. Furthermore, the above units can be implemented by a processor calling software; for example, the system includes a processor connected to memory, which stores instructions. The processor calls the instructions stored in memory to implement any of the above methods or to implement the functions of each unit. The processor can be, for example, a general-purpose processor, such as a central processing unit (CPU), and the memory can be internal or external to the device. Alternatively, the above units can be implemented as hardware circuits. The functions of some or all units can be implemented through the design of the hardware circuit, which can be understood as one or more processors. For example, in one implementation, the hardware circuit is an application-specific integrated circuit (ASIC), and the functions of some or all of the above units are implemented through the design of the logical relationships between the internal components of the circuit. In another implementation, the hardware circuit can be implemented using a programmable logic device (PLD), which can include a large number of logic gates. The logical relationships between the logic gates are configured through a configuration file, thereby implementing the functions of some or all of the above units. All units of the above system can be implemented entirely through processor calling programs, or entirely through hardware circuits, or partially through processor calling programs with the remaining parts implemented through hardware circuits.

[0084] In the embodiments of this disclosure, the processor can be a circuit with signal processing capabilities. For example, the processor can be a circuit with instruction read and execute capabilities, such as a CPU, microprocessor, graphics processing unit (GPU), or digital signal processor (DSP). Furthermore, the processor can implement its functions through the logical relationships of hardware circuits, which can be fixed or reconfigurable. For example, the processor may be a hardware circuit implemented as an ASIC or PLD, such as a field-programmable gate array (FPGA). In a reconfigurable hardware circuit, the process of the processor loading a configuration document to configure the hardware circuit can be understood as the process of the processor loading instructions to implement its functions.

[0085] like Figure 7 As shown, the fault detection method P300 may include steps P310 to P330.

[0086] P310: Controls the lidar to emit laser beams at multiple directional angles, where some of the energy in the laser beams forms stray light inside the lidar.

[0087] A processor can control one or more lasers in a lidar system to emit laser beams. For example, the processor can send control commands to the laser's drive circuitry to drive the laser to emit a laser beam. Some of the energy in the laser beam can form stray light inside the lidar system.

[0088] P320: Controls the detector in the lidar to receive stray light.

[0089] The aforementioned detector can be the detector currently being tested. There can be one detector or multiple detectors. When there is only one detector, the fault detection method P300 can detect whether that single detector has a permanent fault. When there are multiple detectors, the fault detection method P300 can detect whether all detectors have permanent faults. For ease of description and understanding, the following explanation uses a single detector as an example, and to distinguish it from other detectors not being tested in this inspection, the detector to be tested will be referred to as the target detector.

[0090] P330: Determine if the detector is faulty based on its reception of stray light.

[0091] Based on the preceding text Figure 6 According to the relevant description, the processor can identify the presence of stray light echo pulses from the echo pulses generated by the target detector within a preset time window after the lidar sends out the laser beam, and obtain the amplitude information of the stray light echo pulses. The processor can determine whether the target detector is faulty based on the amplitude information of the stray light echo pulses.

[0092] In some embodiments, the multiple directional angles may include multiple horizontal directional angles. In step P310, the processor may control the lidar to emit laser beams at the multiple horizontal directional angles respectively.

[0093] The aforementioned plurality of horizontal directional angles can be at least two horizontal directional angles within the horizontal detection field of view of the lidar. This disclosure does not limit the number of the aforementioned plurality of horizontal directional angles; for example, the number of the aforementioned plurality of horizontal directional angles can be 2, 3, 4, 5, 6, 8, etc. There can be a certain angle interval between two adjacent horizontal directional angles. For example, when the laser beam emitted by the lidar at the first horizontal directional angle is interfered with by an interference source, by emitting laser beams at other horizontal directional angles (such as the second horizontal directional angle, the third horizontal directional angle, etc.) at a certain angle interval, the interference from the aforementioned interference source can be avoided. This disclosure does not limit the angle interval between two adjacent horizontal directional angles; for example, it can be 1 degree, 2 degrees, 3 degrees, 4 degrees, 5 degrees, 8 degrees, or 10 degrees, etc. In some embodiments, the interval between two adjacent horizontal directional angles can be adaptively set according to the influence range of common interference sources in the application scenario of the lidar. For example, when the influence range of the interference source is large, the interval between two adjacent horizontal azimuth angles can be set to a larger value (e.g., greater than 5 degrees); when the influence range of the interference source is small, the interval between two adjacent horizontal azimuth angles can be set to a smaller value (e.g., less than 5 degrees). In some embodiments, the number of the aforementioned multiple horizontal azimuth angles and the interval angle between two adjacent horizontal azimuth angles can exhibit an inverse correlation. For example, when the number of the aforementioned multiple horizontal azimuth angles is large (e.g., 10), the interval angle between two adjacent horizontal azimuth angles can be set to a smaller value (e.g., less than 5 degrees). Conversely, when the number of the aforementioned multiple horizontal azimuth angles is small (e.g., 2 or 3), the interval angle between two adjacent horizontal azimuth angles can be set to a larger value (e.g., greater than 5 degrees).

[0094] In some embodiments, the angle interval between two adjacent horizontal angles may be the same, different, or partially the same and partially different. For example, the angle interval between the first and second horizontal angles may be 1 degree, and the angle interval between the second and third horizontal angles may be 2 degrees. In some embodiments, the angle interval between two adjacent horizontal angles may increase or decrease sequentially according to the order of the above-mentioned plurality of horizontal angles.

[0095] In some embodiments, multiple lasers in a lidar are arranged sequentially along the vertical direction and each corresponds to a different vertical direction angle (e.g., ...). Figure 2The processor can control one laser in the lidar to emit laser beams at multiple horizontal angles. For example, the processor can control the movement of the scanner to achieve this. In some embodiments, multiple lasers in the lidar are arranged sequentially along the horizontal direction, each corresponding to a different horizontal angle. The processor can control at least two lasers in the lidar corresponding to different horizontal angles to emit laser beams. In some embodiments, multiple lasers in the lidar are arranged in a two-dimensional arrangement along the horizontal and vertical directions, with one laser corresponding to one horizontal angle and one vertical angle. The processor can also control at least two lasers in the lidar corresponding to different horizontal angles to emit laser beams.

[0096] The following is based on Figure 2 The fault detection process of the target detector is illustrated using the lidar shown as an example.

[0097] exist Figure 2 In the lidar shown, multiple lasers are arranged vertically and correspond to different vertical angles. In step P310, the processor can control one of the lasers in the lidar to emit laser beams at multiple horizontal angles. For example, the processor can adjust the horizontal angle of the emitted laser beam by controlling the movement of the scanner. It should be noted that the laser can be any one of the multiple lasers in the lidar. For example, the laser can be the laser in the channel where the target detector is located, or it can be the laser in other channels; this disclosure does not limit this. In step P320, the processor can control the target detector to receive stray light formed by the laser beams at multiple horizontal angles. The following is in conjunction with... Figure 8 Let's illustrate with examples.

[0098] Figure 8 A schematic diagram of a control method for fault detection of a detector, provided in some embodiments of this disclosure, is shown. For example... Figure 8 As shown, taking the target detector as the detector in channel C1 and the laser emitting the laser beam as the laser in channel C1 as an example, the processor can control the laser in channel C1 to emit a laser beam at a horizontal angle α1, and control the detector in channel C1 to receive the stray light formed by the laser beam at a horizontal angle α1. The processor can control the laser in channel C1 to emit a laser beam at a horizontal angle α2, and control the detector in channel C1 to receive the stray light formed by the laser beam at a horizontal angle α2. And so on, the processor can control the laser in channel C1 to emit a laser beam at a horizontal angle α2. n The laser beam is emitted from the upper part of the channel, and the detector in channel C1 is controlled to move at a horizontal angle α. n The stray light generated by the laser beam is received. n is an integer greater than 1.

[0099] When the target detector and laser are functioning normally, the target detector generates a stray light echo pulse in response to stray light at a horizontal azimuth angle. The target detector can generate multiple stray light echo pulses in response to stray light at multiple horizontal azimuth angles. In step P330, the processor can obtain the multiple stray light echo pulses and determine whether the target detector is faulty based on the multiple stray light echo pulses.

[0100] If at least a first number of stray light echo pulses among multiple stray light echo pulses have an amplitude less than a preset threshold, then the target detector is determined to be faulty. If at least a second number of stray light echo pulses among multiple stray light echo pulses have an amplitude greater than or equal to the preset threshold, then the target detector is determined not to be faulty.

[0101] The aforementioned preset threshold can be determined based on the critical amplitude of light that the detector can sense and the intensity of stray light inside the lidar. The preset threshold can be calculated based on the parameters of the detector, the laser, and the structural parameters of the lidar. Alternatively, the preset threshold can be determined through testing after the lidar is manufactured. The preset threshold can be adjusted during the use of the lidar. The preset thresholds for different detectors can be the same or different. This disclosure does not limit the specific value of the preset threshold.

[0102] In some embodiments, the first quantity and the second quantity can be the same or different. In some embodiments, the first quantity and the second quantity can be preset fixed values ​​or values ​​related to the number n of multiple horizontal angles. In some embodiments, the first quantity can be greater than n / 2. For example, when n = 5, the first quantity can be one of 3, 4, or 5. The second quantity can be 1, 2, etc.

[0103] In such Figure 8In the illustrated method, the processor controls the laser in the lidar to emit laser beams at multiple horizontal azimuth angles, and controls the target detector to receive stray light at the same multiple horizontal azimuth angles. When interference sources exist at some of these horizontal azimuth angles, the laser beams emitted by the laser at other horizontal azimuth angles are not affected by the interference sources or are only weakly affected. The target detector can respond normally to stray light at other horizontal azimuth angles and generate stray light echo pulses with amplitudes greater than or equal to a preset threshold. Based on the target detector's response to stray light at other horizontal azimuth angles, the processor can more accurately detect whether the target detector has malfunctioned. This scheme can increase the horizontal spatial redundancy of fault testing and reduce the probability of false alarms caused by weak laser emission energy or weak photosensitive ability at specific horizontal azimuth angles due to interference.

[0104] In some embodiments, the multiple directional angles may include multiple vertical directional angles. In step P310, the processor may control the lidar to emit laser beams at the multiple vertical directional angles.

[0105] The aforementioned plurality of vertical directional angles can be at least two vertical directional angles within the vertical detection field of view of the lidar. This disclosure does not limit the number of the plurality of vertical directional angles; for example, the number of the plurality of vertical directional angles can be 2, 3, 4, 5, 6, 8, etc. There can be a certain angle interval between two adjacent vertical directional angles. For example, when the laser beam emitted by the lidar at the first vertical directional angle is interfered with by an interference source, the interference can be avoided by emitting laser beams at other vertical directional angles (such as the second vertical directional angle, the third vertical directional angle, etc.) at a certain angle interval. This disclosure does not limit the angle interval between two adjacent vertical directional angles; for example, it can be 1 degree, 2 degrees, 3 degrees, 4 degrees, 5 degrees, 8 degrees, or 10 degrees, etc. In some embodiments, the interval between two adjacent vertical directional angles can be adaptively set according to the influence range of common interference sources in the application scenario of the lidar. For example, when the influence range of the interference source is large, the interval between two adjacent vertical angles can be set to a larger value (e.g., greater than 5 degrees); when the influence range of the interference source is small, the interval between two adjacent vertical angles can be set to a smaller value (e.g., less than 5 degrees). In some embodiments, the number of the aforementioned multiple vertical angles and the interval angle between two adjacent vertical angles can exhibit an inverse correlation. For example, when the number of the aforementioned multiple vertical angles is large (e.g., 10), the interval angle between two adjacent vertical angles can be set to a smaller value (e.g., less than 5 degrees). Conversely, when the number of the aforementioned multiple vertical angles is small (e.g., 2 or 3), the interval angle between two adjacent vertical angles can be set to a larger value (e.g., greater than 5 degrees).

[0106] The angle interval between any two adjacent vertical angles can be the same, different, or partially the same and partially different. For example, the angle interval between the first and second vertical angles can be 1 degree, and the angle interval between the second and third vertical angles can be 2 degrees. In some embodiments, the angle interval between adjacent vertical angles can increase or decrease sequentially according to the order of the above-mentioned multiple vertical angles.

[0107] In some embodiments, multiple lasers in a lidar are arranged sequentially along the vertical direction and each corresponds to a different vertical direction angle (e.g., ...). Figure 2The processor can control at least two lasers in the lidar to emit laser beams in parallel at a horizontal angle. These at least two lasers correspond to different vertical angles. In some embodiments, multiple lasers in the lidar are arranged sequentially along the horizontal direction and correspond to different horizontal angles. The processor can control one laser in the lidar to emit laser beams at multiple vertical angles. For example, the processor can control the movement of the scanner to achieve this. In some embodiments, multiple lasers in the lidar are arranged in a two-dimensional arrangement along the horizontal and vertical directions, with one laser corresponding to at least one horizontal angle and at least one vertical angle. The processor can also control at least two lasers in the lidar corresponding to different vertical angles to emit laser beams.

[0108] The following is based on Figure 2 The fault detection process of the target detector is illustrated using the lidar shown as an example.

[0109] exist Figure 2 In the lidar shown, multiple lasers are arranged vertically and correspond to different vertical angles. In step P310, the processor can control at least two lasers in the lidar to emit laser beams in parallel at a horizontal angle. These at least two lasers can be any two of the multiple lasers included in the lidar. For example, the at least two lasers may include lasers in the channel where the target detector is located, or they may not include lasers in the channel where the target detector is located. Furthermore, the at least two lasers may be physically adjacent, physically non-adjacent, or partially adjacent and partially non-adjacent. The number of at least two lasers can be determined based on the total number of lasers in the lidar, the number of detectors, the correspondence between lasers and detectors, the number of lasers detecting in parallel, etc. For example, the at least two lasers can be 2-32 lasers, such as including 2, 3, 4, 8, 16, 32 lasers, or other numbers of lasers; this disclosure does not limit this. In some embodiments, the lidar uses a method of grouping lasers for parallel detection. For example, within a time window, a group of lasers emits laser beams in parallel. The aforementioned at least two lasers may include multiple lasers from a set of lasers.

[0110] The laser beams emitted in parallel by at least two lasers form mixed stray light inside the lidar. In this disclosure, mixed stray light can refer to the result of multiple stray lights generated by the reflection (e.g., diffuse reflection) of laser beams emitted in parallel by multiple lasers inside the lidar superimposed on each other. In step P320, the processor can control the target detector to receive the mixed stray light at one of the aforementioned horizontal directional angles. The following is in conjunction with... Figure 9Let's illustrate with examples.

[0111] Figure 9 A schematic diagram illustrating another control method for fault detection of a detector, provided in some embodiments of this disclosure, is shown. For example... Figure 9 As shown, taking the target detector as the detector in channel C1 and at least two lasers including the lasers in channels C1 to C8 as an example, the processor can control the lasers in channels C1 to C8 to emit laser beams in parallel at a horizontal direction angle α1, and control the detector in channel C1 to receive the mixed stray light formed by the above eight laser beams at a horizontal direction angle α1.

[0112] In the above example, channels C1 to C8 can be eight physically continuous channels, eight non-contiguous channels, or eight channels that are partially continuous and partially discontinuous. In some embodiments, the lidar can employ a grouped parallel detection method. For example, the lidar includes 64 channels, divided into eight groups, with each group containing eight channels. The eight channels in the same group perform parallel detection within the same time window, while channels in different groups perform detection within different time windows. Channels C1 to C8 can be eight channels in the same group. Within a time window during lidar detection, the processor can control the lasers in one group of channels (e.g., channels C1 to C8) to emit light in parallel, and identify stray light echo pulses and detection echo pulses in the echo pulses generated by the target detector. The processor can detect whether the target detector is faulty based on the amplitude information of the stray light echo pulses, and determine object information based on the detection echo pulses. Within the lidar's detection time window, the processor utilizes the laser emission operation within that detection time window to achieve both object detection and detector fault detection. By reusing the laser emission time window during the object detection process of the lidar, fault detection of the detector can be performed simultaneously during object detection, eliminating the need to set up an additional time window dedicated to fault detection. In some embodiments, a separate detection time window can also be set for fault detection.

[0113] It should be noted that, Figure 9 The illustration uses eight lasers emitting laser beams in parallel as an example. In practical applications, the number of lasers emitting laser beams in parallel can be other than that, and this disclosure does not limit this.

[0114] Figure 9 In the illustrated configuration, at least two lasers emit laser beams in parallel at different vertical angles, and these laser beams form a mixed stray light within the lidar. The target detector receives this mixed stray light and generates a stray light echo pulse in response.

[0115] In step P330, the processor can obtain the stray light echo pulse and determine whether the target detector is faulty based on the stray light echo pulse. When the amplitude of the stray light echo pulse is less than a preset threshold, it is determined that the target detector is faulty. When the amplitude of the stray light echo pulse is greater than or equal to the preset threshold, it is determined that the target detector is not faulty. The relevant explanation of the preset threshold can be found in the preceding description and will not be repeated here.

[0116] In such Figure 9 In the illustrated method, the processor controls at least two lasers in the lidar to emit laser beams in parallel (e.g., lasers in channels C1 to C8 emit laser beams in parallel). The laser beams emitted in parallel by these at least two lasers form mixed stray light inside the lidar. When an interference source exists at the vertical azimuth angle corresponding to some of the at least two lasers, the laser beams emitted by the other lasers are not affected by the interference source or are only weakly affected. This is in contrast to the stray light formed when only one laser emits a laser beam and the laser beam is interfered with by an interference source. Figure 9 The hybrid stray light generated in the illustrated manner has higher energy. A normal detector can receive this hybrid stray light and respond by generating stray light echo pulses with an amplitude greater than or equal to a preset threshold. Based on the target detector's response to the hybrid stray light, the processor can accurately detect whether the target detector has suffered a permanent fault. This avoids the problem of misjudging detector faults due to weak emission energy of a single laser or continuous interference from a single laser.

[0117] In some embodiments, the multiple directional angles may include multiple horizontal directional angles and multiple vertical directional angles. In step P310, the processor may control the lidar to emit laser beams at the multiple horizontal directional angles and multiple vertical directional angles.

[0118] The relevant explanations of the above-mentioned horizontal and vertical direction angles can be found in the previous descriptions, and will not be repeated here.

[0119] In some embodiments, multiple lasers in a lidar are arranged sequentially along the vertical direction and each corresponds to a different vertical direction angle (e.g., ...). Figure 2The processor can control at least two lasers in the lidar to emit laser beams in parallel at multiple horizontal angles. For example, the processor controls at least two lasers to emit laser beams in parallel at a first horizontal angle, and the processor controls at least two lasers to emit laser beams in parallel at a second horizontal angle. The at least two lasers correspond to different vertical angles. The scanner can adjust the horizontal angles at which the at least two lasers emit their laser beams. In some embodiments, multiple lasers in the lidar are arranged sequentially along the horizontal direction and correspond to different horizontal angles. The processor can control at least two lasers in the lidar to emit laser beams at multiple vertical angles. The at least two lasers correspond to different horizontal angles. The scanner can adjust the vertical angles at which the at least two lasers emit their laser beams. In some embodiments, multiple lasers in the lidar are arranged in a two-dimensional arrangement along the horizontal and vertical directions, with one laser corresponding to at least one horizontal angle and at least one vertical angle. The processor can control some of the lasers in the lidar to emit laser beams, wherein at least two of the lasers correspond to different horizontal angles and at least two of the lasers correspond to different vertical angles.

[0120] The following is based on Figure 2 The fault detection process of the target detector is illustrated using the lidar shown as an example.

[0121] exist Figure 2 In the lidar shown, multiple lasers are arranged vertically and correspond to different vertical angles. In step P310, the processor can control at least two lasers in the lidar to emit laser beams in parallel at multiple horizontal angles. These at least two lasers can be any two of the multiple lasers included in the lidar. For example, the at least two lasers may include lasers in the channel where the target detector is located, or they may not include lasers in the channel where the target detector is located. Furthermore, the at least two lasers may be physically adjacent, physically non-adjacent, or partially adjacent and partially non-adjacent. The number of at least two lasers can be determined based on the total number of lasers in the lidar, the number of detectors, the correspondence between lasers and detectors, the number of lasers detecting in parallel, etc. For example, the at least two lasers can be 2-32 lasers, such as including 2, 3, 4, 8, 16, 32 lasers, or other numbers of lasers; this disclosure does not limit this. In some embodiments, the lidar uses a grouping and parallel detection method. For example, within a time window, a group of lasers emits laser beams in parallel. The aforementioned at least two lasers may include multiple lasers from a set of lasers.

[0122] The laser beams emitted in parallel by at least two lasers at a horizontal azimuth angle can form mixed stray light inside the lidar. In step P320, the processor can control the target detector to receive the mixed stray light at multiple horizontal azimuth angles respectively. The following is in conjunction with... Figure 10 Let's illustrate with examples.

[0123] Figure 10 This diagram illustrates yet another control method for fault detection of a detector, as provided in some embodiments of this disclosure. For example... Figure 10 As shown, taking the target detector as the detector in channel C1, and at least two lasers including those in channels C1 to C8 as an example, the processor can control the lasers in channels C1 to C8 to emit laser beams in parallel at a horizontal angle α1, and control the detector in channel C1 to receive the mixed stray light formed by the above eight laser beams at a horizontal angle α1. The processor can also control the lasers in channels C1 to C8 to emit laser beams in parallel at a horizontal angle α2, and control the detector in channel C1 to receive the mixed stray light formed by the above eight laser beams at a horizontal angle α2. And so on, the processor can control the lasers in channels C1 to C8 to emit laser beams in parallel at a horizontal angle α2. n The laser beam is emitted in parallel, and the detector in channel C1 is controlled at a horizontal angle α. n The device receives the mixed stray light formed by the above 8 laser beams. n is an integer greater than 1. The explanations of channels C1 to C8 can be found in the previous sections and will not be repeated here.

[0124] It should be noted that, Figure 10 The illustration uses eight lasers emitting laser beams in parallel as an example. In practical applications, the number of lasers emitting laser beams in parallel can be other than that, and this disclosure does not limit this.

[0125] Figure 10 In the illustrated configuration, at least two lasers emit laser beams in parallel at different vertical angles, and these laser beams can form mixed stray light within the lidar. A target detector receives the mixed stray light at one horizontal angle and generates a stray light echo pulse in response. The target detector can generate multiple stray light echo pulses by receiving the mixed stray light at multiple horizontal angles.

[0126] In step P330, the processor can obtain multiple stray light echo pulses generated by the target detector at multiple horizontal directional angles, and determine whether the target detector is faulty based on the multiple stray light echo pulses. It should be noted that the method by which the processor determines whether the target detector is faulty based on multiple stray light echo pulses can be found in the previous description, and will not be repeated here.

[0127] In such Figure 10 In the illustrated method, the processor controls at least two lasers in the lidar to emit laser beams in parallel at multiple horizontal azimuth angles. The laser beams emitted in parallel by the at least two lasers at one horizontal azimuth angle create mixed stray light within the lidar. When an interference source exists at the vertical azimuth angle corresponding to some of the at least two lasers, the laser beams emitted by the other lasers are not affected by the interference source or are only weakly affected. This is different from the stray light formed when only one laser emits a laser beam and the laser beam is interfered with by an interference source. Figure 10 The mixed stray light generated in the illustrated manner has higher energy. A normal detector can receive this mixed stray light and respond by generating stray light echo pulses with an amplitude greater than or equal to a preset threshold. Based on the target detector's response to the mixed stray light, the processor can accurately detect whether the target detector has sent a permanent fault, avoiding the problem of false faults caused by weak emission energy of a single laser due to interference sources. When interference sources exist in some of the aforementioned horizontal directional angles, the laser beams in other horizontal directional angles will not be affected by the interference sources or will be only weakly affected. A normal detector can respond to the mixed stray light in other horizontal directional angles and generate stray light echo pulses with an amplitude greater than or equal to a preset threshold. Based on the target detector's response to the mixed stray light in other horizontal directional angles, the processor can more accurately detect whether the target detector has malfunctioned. The above scheme can increase the horizontal spatial redundancy of fault testing and reduce the probability of false detector faults caused by weak emission energy of the laser or weak photosensitivity of the detector in a specific horizontal directional angle due to interference.

[0128] The preceding description uses the detection of a fault in a single detector (e.g., the detector in channel C1) as an example. Those skilled in the art will understand that fault detection for other detectors in a lidar system is performed in a similar manner. The processor can perform similar processing on all detectors in the lidar system as described above, thereby achieving fault detection for all detectors in the lidar system. Furthermore, the fault detection processes for different detectors can be executed sequentially or in parallel; this disclosure does not limit this.

[0129] In summary, the fault detection method P300 provided in this disclosure detects detector faults by utilizing stray light generated by a lidar, enabling timely detection of permanent detector failures and preventing potential safety hazards. By controlling the lidar to emit laser beams at multiple directional angles, the fault detection method P300 reduces the probability of false alarms caused by weak laser beam energy at a single directional angle (e.g., weak energy emitted by a single laser, continuous interference from a single laser, or interference at a specific horizontal directional angle). This results in high robustness. Furthermore, the fault detection method P300 requires no additional light emitting or receiving devices within the lidar, making its structure simple and easy to implement.

[0130] Figure 11 A flowchart of another fault detection method P400 provided in some embodiments of this disclosure is shown. This fault detection method P400 can be executed by a processor. This fault detection method P400 can be used to detect permanent faults in a laser. For details regarding the processor, please refer to the preceding description; it will not be repeated here.

[0131] like Figure 11 As shown, the fault detection method P400 may include steps P410 to P430.

[0132] P410: Controls the laser in the lidar to emit a laser beam, and some of the energy in the laser beam forms stray light inside the lidar.

[0133] The laser mentioned above can be the laser currently being tested. The laser can be any one of multiple lasers included in the lidar. To distinguish it from other lasers not being tested in this detection, the laser to be tested will be referred to as the target laser in the following description. Fault detection method P400 can be used to detect whether the target laser is faulty. In P410, the controller can control the target laser to emit a laser beam. For example, the processor can send control commands to the drive circuit of the target laser to control the drive circuit to drive the target laser to emit a laser beam. Some of the energy in the laser beam can form stray light inside the lidar.

[0134] P420: Controls the lidar to receive stray light at multiple directional angles.

[0135] The processor can control the detectors in the lidar to receive stray light at multiple directional angles. These detectors can be a single detector or multiple detectors.

[0136] P430: Based on the reception of stray light by the lidar at the above multiple directional angles, determine whether the laser is faulty.

[0137] Based on the preceding text Figure 6 According to the relevant description, the processor can identify the presence of stray light echo pulses from the echo pulses generated by the detector within a preset time window after the laser beam is emitted, and obtain the amplitude information of the stray light echo pulses. The processor can determine whether there is a fault in the laser based on the amplitude information of the stray light echo pulses.

[0138] In some embodiments, the aforementioned plurality of directional angles may include a plurality of horizontal directional angles. In step P410, the processor may control the target laser to emit laser beams at the plurality of horizontal directional angles. In step P420, the processor may control the lidar to receive stray light at the plurality of horizontal directional angles. The relevant explanations of the aforementioned plurality of horizontal directional angles can be found in the preceding description and will not be repeated here.

[0139] In some embodiments, multiple detectors in the lidar are arranged sequentially along the vertical direction and each corresponds to a different vertical direction angle (e.g., ...). Figure 2 The processor can control one detector in the lidar to receive stray light at the aforementioned multiple horizontal angles. For example, the processor can control the movement of the scanner to enable the detector to receive stray light at the aforementioned multiple horizontal angles. In some embodiments, the multiple detectors in the lidar are arranged sequentially along the horizontal direction and correspond to different horizontal angles. The processor can control at least two detectors in the lidar corresponding to different horizontal angles to receive stray light. In some embodiments, the multiple detectors in the lidar are arranged in two dimensions along the horizontal and vertical directions, with one detector corresponding to at least one horizontal angle and at least one vertical angle. The processor can control at least two detectors in the lidar corresponding to different horizontal angles to receive stray light.

[0140] The following is based on Figure 2 The following example, using a lidar, illustrates the fault detection process of a target laser.

[0141] exist Figure 2 In the lidar shown, multiple detectors are arranged vertically and correspond to different vertical angles. In step P410, the processor can control the target laser to emit laser beams at multiple horizontal angles. In step P420, the processor can control one detector in the lidar to receive stray light at the aforementioned multiple horizontal angles. The horizontal angles at which the target laser emits its laser beams and the horizontal angles at which the detector receives stray light can be controlled by a scanner. It should be noted that the detector can be any one of the multiple detectors included in the lidar. The detector can be a detector in the channel where the target laser is located, or it can be a detector in other channels; this disclosure does not limit this. The following is in conjunction with... Figure 12 Let's illustrate with examples.

[0142] Figure 12 A schematic diagram of a control method for fault detection of a laser, provided in some embodiments of this disclosure, is shown. For example... Figure 12 As shown, taking the target laser as the laser in channel C1 and the detector receiving stray light as the detector in channel C1 as an example, the processor can control the laser in channel C1 to emit a laser beam at a horizontal angle α1 and control the detector in channel C1 to receive stray light at a horizontal angle α1. The processor can also control the laser in channel C1 to emit a laser beam at a horizontal angle α2 and control the detector in channel C1 to receive stray light at a horizontal angle α2. And so on, the processor can control the laser in channel C1 to emit a laser beam at a horizontal angle α2. n The laser beam is emitted from the upper part of the channel, and the detector in channel C1 is controlled to move at a horizontal angle α. n The device receives stray light. n is an integer greater than 1.

[0143] When the detector and target laser are functioning normally, the detector generates a stray light echo pulse in response to stray light at a horizontal azimuth angle. The detector can generate multiple stray light echo pulses in response to stray light at multiple horizontal azimuth angles. In step P430, the processor obtains these multiple stray light echo pulses and determines whether the target laser is faulty based on them. If at least a first number of stray light echo pulses have an amplitude less than a preset threshold, the target laser is determined to be faulty. If at least a second number of stray light echo pulses have an amplitude greater than or equal to the preset threshold, the target laser is determined not to be faulty.

[0144] The relevant explanations of the above-mentioned preset thresholds and the relevant explanations of the above-mentioned first and second quantities can be found in the previous descriptions, and will not be repeated here.

[0145] In such Figure 12In the illustrated method, the processor controls the target laser to emit laser beams at multiple horizontal angles and controls the detector to receive stray light at the same multiple horizontal angles. When interference sources exist at some of these horizontal angles, the laser beams emitted by the target laser at other horizontal angles are not affected by the interference sources or are only weakly affected. The detector can respond normally to stray light at other horizontal angles and generate stray light echo pulses with amplitudes greater than or equal to a preset threshold. Based on the detector's response to stray light at multiple horizontal angles, the processor can accurately detect whether the target laser is faulty. This scheme can increase the horizontal spatial redundancy of fault testing and reduce the probability of false alarms due to weak laser emission energy at specific horizontal angles caused by interference or weak photosensitive ability of the detector at specific horizontal angles.

[0146] In some embodiments, the plurality of directional angles may include a plurality of vertical directional angles. In step P420, the processor may control the lidar to receive stray light at the plurality of vertical directional angles. The relevant explanations of the plurality of vertical directional angles can be found in the preceding description and will not be repeated here.

[0147] In some embodiments, multiple detectors in the lidar are arranged sequentially along the vertical direction and each corresponds to a different vertical direction angle (e.g., ...). Figure 2 The processor can control at least two detectors in the lidar to receive stray light in parallel, with the at least two detectors corresponding to different vertical azimuth angles. In some embodiments, multiple detectors in the lidar are arranged sequentially along the horizontal direction and each corresponds to a different horizontal azimuth angle. The processor can control one detector in the lidar to receive stray light at multiple vertical azimuth angles. For example, the processor can control the movement of the scanner to enable the detector to receive stray light at the multiple vertical azimuth angles. In some embodiments, multiple detectors in the lidar are arranged in two dimensions along the horizontal and vertical directions, with one detector corresponding to at least one horizontal azimuth angle and at least one vertical azimuth angle. The processor can also control at least two detectors in the lidar corresponding to different vertical azimuth angles to receive stray light.

[0148] The following is based on Figure 2 The fault detection process of a target laser is illustrated using the lidar shown as an example.

[0149] exist Figure 2In the lidar shown, multiple detectors are arranged vertically and correspond to different vertical angles. In step P410, the processor can control the target laser to emit a laser beam at a horizontal angle. In step P420, the processor can control at least two detectors in the lidar to receive stray light formed by the laser beam in parallel at that horizontal angle. The aforementioned at least two detectors can be any at least two of the multiple detectors included in the lidar. For example, the aforementioned at least two detectors may include detectors in the channel where the target laser is located, or may not include detectors in the channel where the target laser is located. For another example, the aforementioned at least two detectors may be physically adjacent, physically non-adjacent, or partially adjacent and partially non-adjacent. The number of the aforementioned at least two detectors can be determined based on the total number of detectors in the lidar, the number of lasers, or the correspondence between lasers and detectors, the number of lasers detected in parallel, etc. For example, the aforementioned at least two detectors can be 2-32 detectors, such as including 2, 3, 4, 8, 16, 32 detectors, or other numbers of detectors; this disclosure does not limit this. In some embodiments, the lidar adopts a grouped parallel detection method. For example, within a time window, a group of detectors perform object detection in parallel. The aforementioned at least two detectors can include multiple detectors from a group of detectors. The following section combines... Figure 13 Let's illustrate with examples.

[0150] Figure 13 A schematic diagram illustrating another control method for laser fault detection provided in some embodiments of this disclosure is shown. For example... Figure 13 As shown, taking the target laser as the laser in channel C1 and at least two detectors including detectors in channels C1 to C8 as an example, the processor can control the laser in channel C1 to emit a laser beam at a horizontal angle α1, and control the detectors in channels C1 to C8 to receive stray light formed by the laser beam in parallel at a horizontal angle α1.

[0151] In the above examples, channels C1 to C8 can be eight physically continuous channels, eight non-contiguous channels, or eight channels that are partially continuous and partially discontinuous; this disclosure does not impose any limitations on this. It should be noted that... Figure 13 The illustration uses eight detectors receiving stray light in parallel as an example. In practical applications, the number of detectors receiving stray light in parallel can be other numbers, and this disclosure does not limit this.

[0152] Figure 13 In the illustrated configuration, multiple detectors receive stray light in parallel. One detector can generate one stray light echo pulse in response to the stray light. These multiple detectors can generate multiple stray light echo pulses (e.g., ...). Figure 13In the example, eight detectors responding to stray light can generate at least eight stray light echo pulses. In step P430, the processor can obtain the aforementioned multiple stray light echo pulses and determine whether the target laser is faulty based on these multiple stray light echo pulses. The method by which the processor determines whether the target laser is faulty based on the aforementioned multiple stray light echo pulses can be found in the preceding description and will not be repeated here.

[0153] In such Figure 13 In the illustrated method, the processor controls at least two detectors in the lidar to receive stray light in parallel (e.g., detectors in channels C1 to C8 receive stray light in parallel). When the photosensitivity of one of the at least two detectors is weak (e.g., due to aging of some detectors, interference at the corresponding vertical angle of some detectors, etc.), the other normally functioning detectors can still respond to the stray light and generate stray light echo pulses with an amplitude greater than or equal to a preset threshold. Based on the responses of the other detectors to the stray light, the processor can accurately detect whether the target laser has malfunctioned. This scheme increases the vertical spatial redundancy of fault testing and reduces the probability of false alarms due to the weak photosensitivity of a single detector.

[0154] In some embodiments, the plurality of directional angles may include a plurality of horizontal directional angles and a plurality of vertical directional angles. In step P420, the processor may control the lidar to receive stray light at the plurality of horizontal directional angles and the plurality of vertical directional angles. For a detailed description of the plurality of horizontal directional angles and the plurality of vertical directional angles, please refer to the preceding description; it will not be repeated here.

[0155] In some embodiments, multiple detectors in the lidar are arranged sequentially along the vertical direction and each corresponds to a different vertical direction angle (e.g., ...). Figure 2The processor can control at least two detectors in the lidar to receive stray light at multiple horizontal angles, with each detector corresponding to a different vertical angle. The scanner can adjust the horizontal angle at which the at least two detectors receive stray light. In some embodiments, multiple detectors in the lidar are arranged sequentially along the horizontal direction and each corresponds to a different horizontal angle. The processor can control at least two detectors in the lidar to receive stray light at multiple vertical angles, with each detector corresponding to a different horizontal angle. The scanner can adjust the vertical angle at which the at least two detectors receive stray light. In some embodiments, multiple detectors in the lidar are arranged in a two-dimensional arrangement along the horizontal and vertical directions, with each detector corresponding to at least one horizontal angle and at least one vertical angle. The processor can control some detectors in the lidar to receive stray light, with at least two of these detectors corresponding to different horizontal angles and at least two of these detectors corresponding to different vertical angles.

[0156] The following is based on Figure 2 The following example, using a lidar, illustrates the fault detection of a target laser.

[0157] exist Figure 2 In the illustrated lidar, multiple detectors are arranged vertically and correspond to different vertical angles. In step P410, the processor controls the target laser to emit laser beams at multiple horizontal angles. In step P420, the processor controls at least two detectors in the lidar to receive stray light in parallel at the aforementioned multiple horizontal angles. For example, the processor controls at least two detectors to receive stray light in parallel at a first horizontal angle, and the processor controls at least two detectors to receive stray light in parallel at a second horizontal angle. These at least two detectors can be any two of the multiple detectors included in the lidar. For example, these at least two detectors may include detectors in the channel where the target laser is located, or they may not include detectors in the channel where the target laser is located. Furthermore, these at least two detectors may be physically adjacent, physically non-adjacent, or partially adjacent and partially non-adjacent. The number of these at least two detectors can be determined based on the total number of detectors in the lidar, the number of lasers, the correspondence between lasers and detectors, the number of lasers being detected in parallel, etc. For example, the aforementioned at least two detectors can be 2-32 detectors, such as 2, 3, 4, 8, 16, 32 detectors, or other numbers of detectors; this disclosure does not limit this. In some embodiments, the lidar employs a grouped parallel detection method. For example, within a time window, a group of detectors performs object detection in parallel. The aforementioned at least two detectors can include multiple detectors from a group of detectors. The following is in conjunction with... Figure 14 Let's illustrate with examples.

[0158] Figure 14 This diagram illustrates yet another control method for laser fault detection provided in some embodiments of the present disclosure. For example... Figure 14 As shown, taking the target laser as the laser in channel C1, and at least two detectors including those in channels C1 to C8 as an example, the processor can control the target laser to emit a laser beam at a horizontal angle α1, and control the detectors in channels C1 to C8 to receive the stray light formed by the laser beam in parallel at the horizontal angle α1. The processor can control the target laser to emit a laser beam at a horizontal angle α2, and control the detectors in channels C1 to C8 to receive the stray light formed by the laser beam in parallel at the horizontal angle α2. And so on, the processor can control the target laser to emit a laser beam at a horizontal angle α2. n The laser beam is emitted from the upper part of the channel, and the detectors in channels C1 to C8 are controlled at a horizontal angle α. n The stray light generated by the laser beam is received in parallel. n is an integer greater than 1. The explanation of channels C1 to C8 can be found in the relevant explanations above, and will not be repeated here.

[0159] It should be noted that, Figure 14 The illustration uses eight detectors receiving stray light in parallel as an example. In practical applications, the number of detectors receiving light in parallel can be other numbers, and this disclosure does not limit this.

[0160] Figure 14 In the illustrated method, it is assumed that the number of detectors receiving light in parallel is k, and the number of horizontal directional angles is n. At one horizontal directional angle, k detectors responding to stray light in parallel can generate k stray light echo pulses. Thus, k detectors responding to stray light in parallel at n horizontal directional angles can generate k*n stray light echo pulses. In step P430, the processor can obtain the aforementioned k*n stray light echo pulses and determine whether the target laser is faulty based on these k*n stray light echo pulses. It should be noted that the method by which the processor determines whether the target laser is faulty based on the aforementioned k*n stray light echo pulses is similar to the previous description and will not be repeated here.

[0161] In such Figure 14In the illustrated method, the processor controls at least two detectors in the lidar to receive stray light in parallel at multiple horizontal angles. When the photosensitivity of one of the at least two detectors is weak (e.g., due to aging of some detectors or interference at the corresponding vertical angles), the other normally functioning detectors can still respond to the stray light and generate stray light echo pulses with amplitudes greater than or equal to a preset threshold. Based on the responses of the other detectors to the stray light, the processor can accurately detect whether the target laser has malfunctioned. This scheme can increase the vertical spatial redundancy of fault testing and reduce the probability of false alarms due to weak photosensitivity of a single detector. Furthermore, when interference sources exist at some of the multiple horizontal angles, the laser beam emitted by the target laser at other horizontal angles will not be affected by the interference sources or will be only weakly affected. The detectors at other horizontal angles can respond to the stray light normally and generate stray light echo pulses with amplitudes greater than or equal to a preset threshold. The processor can accurately detect whether the target laser is faulty based on the detector's response to stray light at other horizontal angles. This scheme can also increase the horizontal spatial redundancy of fault testing, reducing the probability of false alarms due to weaker laser emission energy at specific horizontal angles caused by interference or weaker detector sensitivity at those angles.

[0162] The preceding description uses the example of detecting a fault in a single laser (e.g., the laser in channel C1). Those skilled in the art will understand that fault detection for other lasers in a lidar system is performed in a similar manner. The processor can perform similar processing on all lasers in the lidar system, as described above, thereby achieving fault detection for all lasers in the lidar system.

[0163] In summary, the fault detection method P400 provided in this disclosure detects laser faults by utilizing stray light within the lidar, enabling timely identification of permanent laser malfunctions and preventing safety hazards. By controlling the lidar to receive stray light from multiple directional angles, the fault detection method P400 reduces the probability of false alarms due to weak sensitivity at a single directional angle (e.g., weak sensitivity of a single detector, persistent interference at a single detector, or persistent interference at a specific horizontal directional angle), exhibiting high robustness. Furthermore, the fault detection method P400 utilizes the stray light already present within the lidar to detect laser faults, eliminating the need for additional light emitting or receiving devices within the lidar, resulting in a simple structure and ease of implementation.

[0164] In some embodiments, the processor can execute the fault detection method P300 described above within the detection time window of the lidar, and execute the fault detection method P400 described above outside the detection time window of the lidar. The aforementioned detection time window can refer to the lidar's corresponding detection field of view (e.g., ...). Figure 3 The time window corresponding to the detection within (as shown) is defined. The detection field of view can also be referred to as the field of view (FOV) range. Combined with... Figure 3 To explain, in the case of lidar, such as Figure 3 During scanning within the indicated detection field of view, the processor executes the fault detection method P300 described above to detect faults in the lidar detector. Figure 3 During the scanning process outside the detection field of view shown, the processor executes the fault detection method P400 described above to detect faults in the laser in the lidar.

[0165] For example, a lidar system includes 64 channels, divided into 8 groups, with each group containing 8 channels. The 8 channels within the same group perform parallel detection within the same time window (which can be a sub-time window of the lidar's detection time window), while channels from different groups perform detection within different time windows. Within the detection time window, the processor controls the lasers in one group of channels to emit light in parallel, and identifies stray light echo pulses and detection echo pulses from the echo pulses generated by the target detector. The processor detects whether the detector is faulty based on the amplitude information of the stray light echo pulses and determines object information based on the detection echo pulses. Outside the detection time window, the processor controls the target laser to emit light and controls one or more detectors to receive stray light. The processor detects whether the target laser is faulty based on the amplitude information of the stray light echo pulses generated by the one or more detectors.

[0166] Fault detection method P300 executes within the lidar's detection time window, allowing the processor to reuse the laser emission timing during the lidar's object detection process. This allows for simultaneous fault detection of the detector, facilitating timely detection of detector faults and improving detection efficiency. Fault detection method P400 executes outside the lidar's detection time window, fully utilizing the time outside this window for laser fault detection and preventing the laser fault detection process from affecting the lidar's detection process.

[0167] In some embodiments, the processor may execute the fault detection method P300 described above outside the detection time window of the lidar, and execute the fault detection method P400 described above outside the detection time window of the lidar. This disclosure does not restrict the order in which the processor executes fault detection methods P300 and P400. For example, the processor may execute fault detection method P300 first and then fault detection method P400, or vice versa. As another example, the processor may execute only fault detection method P300 or only fault detection method P400 during the current detection time.

[0168] This disclosure also provides a lidar system, including a transmitting unit, a receiving unit, a storage medium, and a processor. The transmitting unit includes multiple lasers, and the receiving unit includes multiple detectors. The storage medium stores at least one instruction set for fault detection. The processor is communicatively connected to the transmitting unit, the receiving unit, and the storage medium. During processor operation, it reads the at least one instruction set and executes either the fault detection method P300 or the fault detection method P400 described above, according to the instructions of the at least one instruction set. Specific implementation principles and technical effects can be found in the preceding descriptions and will not be repeated here.

[0169] In another aspect, this disclosure provides a computer-readable non-transitory storage medium storing at least one set of instructions for fault detection. When the at least one set of instructions is executed by a processor, the at least one set of instructions instructs the processor to implement the steps of the fault detection method P300 of this disclosure, or to implement the steps of the fault detection method P400 of this disclosure.

[0170] In some possible implementations, various aspects of this disclosure can also be implemented as a program product comprising program code. When the program product is run on the processor of a lidar, the program code causes the processor to perform the steps of the fault detection method P300 or the steps of the fault detection method P400 described in this disclosure. The program product for implementing the above methods can be stored in a portable compact disc read-only memory (CD-ROM) and can run on the processor of the lidar. However, the program product of this disclosure is not limited thereto.

[0171] In this disclosure, a readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system. The program product can take any combination of one or more readable media. A readable medium can be a readable signal medium or a readable storage medium. A readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. Examples of readable storage media include: an electrical connection having one or more wires, a portable disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. A computer-readable storage medium can include a data signal propagated in baseband or as part of a carrier wave, carrying readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. The readable storage medium can also be any readable medium other than a readable storage medium that can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the readable storage medium can be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, etc., or any suitable combination thereof. The program code for performing the operations of this disclosure can be written in any combination of one or more programming languages, including object-oriented programming languages—such as Java, C++, etc.—and conventional procedural programming languages—such as the "C" language or similar programming languages. The program code can be executed entirely on the processor, partially on the processor, as a standalone software package, partially on the processor and partially on a remote computing device, or entirely on a remote computing device.

[0172] The foregoing has described specific embodiments of this disclosure. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are possible or may be advantageous.

[0173] In summary, after reading this detailed disclosure, those skilled in the art will understand that the foregoing detailed disclosure may be presented by way of example only and may not be restrictive. Although not explicitly stated herein, those skilled in the art will understand that the requirements of this disclosure encompass various reasonable changes, improvements, and modifications to the embodiments. These changes, improvements, and modifications are intended to be made by this disclosure and are within the spirit and scope of the exemplary embodiments of this disclosure.

[0174] Furthermore, certain terms used in this disclosure have been used to describe embodiments of this disclosure. For example, "an embodiment," "an embodiment," and / or "some embodiments" mean that a particular feature, structure, or characteristic described in connection with that embodiment may be included in at least one embodiment of this disclosure. Therefore, it is to be emphasized and understood that two or more references to "an embodiment" or "an embodiment" or "alternative embodiment" in various parts of this disclosure do not necessarily refer to the same embodiment. Moreover, specific features, structures, or characteristics may be suitably combined in one or more embodiments of this disclosure.

[0175] It should be understood that in the foregoing description of the embodiments of this disclosure, various features are combined in a single embodiment, drawing, or description for the purpose of simplifying the disclosure and aiding in the understanding of a feature. However, this does not mean that the combination of these features is necessary, and those skilled in the art may readily identify some of the devices as separate embodiments when reading this disclosure. That is, the embodiments in this disclosure can also be understood as an integration of multiple secondary embodiments. And the content of each secondary embodiment is also valid even if it contains fewer than all the features of a single foregoing disclosed embodiment.

[0176] Finally, it should be understood that the embodiments disclosed herein are illustrative of the principles of the embodiments of this disclosure. Other modified embodiments are also within the scope of this disclosure. Therefore, the embodiments disclosed herein are merely examples and not limitations. Those skilled in the art can implement the applications of this disclosure using alternative configurations based on the embodiments in this disclosure. Therefore, the embodiments of this disclosure are not limited to the embodiments precisely described in the applications.

Claims

1. A fault detection method for lidar, characterized in that, include: The lidar is controlled to emit laser beams at multiple directional angles, wherein a portion of the energy in the laser beams forms stray light inside the lidar; Controlling the detector in the lidar to receive the stray light; and Based on the detector's reception of the stray light, it is determined whether the detector is faulty.

2. The method according to claim 1, characterized in that, Controlling the lidar to emit laser beams at multiple directional angles includes: controlling the lidar to emit the laser beams at multiple horizontal directional angles respectively; The method of controlling the detector in the lidar to receive the stray light includes: controlling the detector to receive the stray light at the plurality of horizontal directional angles respectively.

3. The method according to claim 2, characterized in that, Controlling the lidar to emit laser beams at multiple horizontal directional angles includes: The lidar controls at least two lasers to emit laser beams in parallel at multiple horizontal directional angles, wherein the at least two lasers correspond to different vertical directional angles.

4. The method according to claim 2 or 3, characterized in that, The step of determining whether the detector is faulty based on its reception of stray light includes: The detector receives multiple stray light echo pulses from the stray light at the multiple horizontal directional angles; and The presence of a fault in the detector is determined based on the multiple stray light echo pulses.

5. The method according to claim 4, characterized in that, The step of determining whether the detector is faulty based on the plurality of stray light echo pulses includes: If at least a first number of stray light echo pulses among the plurality of stray light echo pulses have an amplitude less than a preset threshold, it is determined that the detector is faulty.

6. The method according to claim 4, characterized in that, The step of determining whether the detector is faulty based on the plurality of stray light echo pulses includes: If at least a second number of stray light echo pulses among the plurality of stray light echo pulses have an amplitude greater than or equal to a preset threshold, it is determined that the detector is not faulty.

7. The method according to claim 1, characterized in that, Controlling the lidar to emit laser beams at multiple directional angles includes: controlling at least two lasers in the lidar to emit laser beams in parallel at a horizontal directional angle, wherein the at least two lasers correspond to different vertical directional angles; and The control of the detector in the lidar to receive the stray light includes: controlling the detector to receive the stray light at a horizontal directional angle.

8. The method according to claim 7, characterized in that, The laser beams emitted by the at least two lasers at different vertical angles form mixed stray light inside the lidar; determining whether the detector is faulty based on its reception of the stray light includes: Obtain the stray light echo pulse obtained by the detector receiving the mixed stray light; and The presence of a fault in the detector is determined based on the stray light echo pulses.

9. The method according to claim 8, characterized in that, The step of determining whether the detector is faulty based on the stray light echo pulse includes: When the amplitude of the stray light echo pulse is less than a preset threshold, it is determined that the detector is faulty.

10. The method according to claim 8, characterized in that, The step of determining whether the detector is faulty based on the stray light echo pulse includes: When the amplitude of the stray light echo pulse is greater than or equal to a preset threshold, it is determined that the detector is not faulty.

11. The method according to any one of claims 1 to 10, characterized in that, The method is configured to be executed within the detection time window of the lidar.

12. A fault detection method for lidar, characterized in that, include: The laser in the lidar is controlled to emit a laser beam, and a portion of the energy in the laser beam forms stray light inside the lidar. Control the lidar to receive stray light at multiple directional angles; as well as Based on the reception of stray light by the lidar at the multiple directional angles, it is determined whether the laser is faulty.

13. The method according to claim 12, characterized in that, The control of the laser in the lidar to emit laser beams includes: controlling the laser to emit laser beams at multiple horizontal directional angles respectively; Controlling the lidar to receive stray light at multiple directional angles includes: controlling the lidar to receive stray light at each of the multiple horizontal directional angles.

14. The method according to claim 13, characterized in that, The control of the lidar to receive stray light at the multiple horizontal directional angles includes: The lidar controls at least two detectors to receive stray light in parallel at multiple horizontal directional angles, wherein the at least two detectors correspond to different vertical directional angles.

15. The method according to claim 12, characterized in that, The control of the laser in the lidar to emit a laser beam includes: controlling the laser to emit the laser beam at a horizontal directional angle; Controlling the lidar to receive stray light at multiple directional angles includes: controlling at least two detectors in the lidar to receive the stray light in parallel at a horizontal directional angle, wherein the at least two detectors correspond to different vertical directional angles.

16. The method according to any one of claims 12 to 15, characterized in that, The determination of whether the laser is faulty based on the reception of stray light by the lidar at multiple directional angles includes: The lidar receives multiple stray light echo pulses from the stray light at the multiple directional angles; and The presence or absence of a fault in the laser is determined based on the multiple stray light echo pulses.

17. The method according to claim 16, characterized in that, The step of determining whether the laser is faulty based on the plurality of stray light echo pulses includes: When at least a first number of stray light echo pulses among the plurality of stray light echo pulses have an amplitude less than a preset threshold, it is determined that the laser is faulty.

18. The method according to claim 16, characterized in that, The step of determining whether the laser is faulty based on the plurality of stray light echo pulses includes: When at least a second number of stray light echo pulses among the plurality of stray light echo pulses have an amplitude greater than or equal to a preset threshold, it is determined that the laser is not faulty.

19. The method according to any one of claims 12 to 18, characterized in that, The method is configured to be performed outside the detection time window of the lidar.

20. A lidar, characterized in that, include: The transmitting unit includes multiple lasers; The receiving unit includes multiple detectors; Storage medium containing at least one instruction set for fault detection; as well as A processor, communicatively connected to the transmitting unit, the receiving unit, and the storage medium, wherein the processor reads the at least one instruction set during operation and executes the method as described in any one of claims 1-11 according to the instructions of the at least one instruction set, or as described in any one of claims 12-19.

21. A computer-readable non-transitory storage medium, characterized in that, The computer-readable non-transitory storage medium stores at least one set of instructions, wherein when the at least one set of instructions is executed by a processor, it implements the method as described in any one of claims 1-11, or implements the method as described in any one of claims 12-19.

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