Lidar

Abstract

The present disclosure provides a laser radar, comprising a first emitter, a first detector, a second emitter and a scanning mirror. The first emitter is configured to emit a probe light beam, the probe light beam being guided by the scanning mirror to the outside of the laser radar. The scanning mirror guides a return wave produced after the probe light beam is reflected on an object to the first detector, so that the first detector generates a first electrical signal in response to the return wave. The laser radar determines the distance of the object according to the first electrical signal. The second emitter is configured to emit a first detection light beam, the first detection light beam being guided by the scanning mirror to the first detector, so that the first detector generates a second electrical signal in response to the first detection light beam. The laser radar determines the working state of the first detector according to the second electrical signal. Wherein, the probe light beam is transmitted along a first optical channel, the first detection light beam is transmitted along a second optical channel, and the first optical channel and the second optical channel are partially different. In this way, the accuracy and precision of the detection of the optical components in the laser radar can be improved.

Description

Technical Field

[0001] This disclosure relates to the field of photoelectric detection technology, and more specifically, to a lidar. Background Technology

[0002] LiDAR (Light Detection and Ranging) is a radar system that uses laser beams to detect the position, velocity, and other characteristics of targets. It is an advanced detection method that combines laser technology with photoelectric detection technology. Due to its advantages such as high resolution, strong resistance to active interference, small size, and light weight, LiDAR is widely used in fields such as autonomous driving, transportation communication, drones, intelligent robots, and resource exploration.

[0003] The transmitter and detector are the core components of a lidar system. During lidar operation, malfunctions in either the transmitter or detector can affect the lidar's performance.

[0004] In related technologies, stray light generated by a laser beam emitted from a laser emitter is scattered by internal radar components (such as structural parts or windows) and enters a laser detector to detect anomalies. However, while this method can detect anomalies in laser detectors, the accuracy and precision of the detection are relatively low because the distribution of stray light is easily affected by fluctuations in the laser emitter's divergence angle, power, and detector response capability.

[0005] The content of the background section is merely the technology known to the inventors of this disclosure and does not necessarily represent the prior art in this field. Utility Model Content

[0006] In view of this, the purpose of this disclosure is to provide a lidar that can not only detect anomalies in the lidar's laser detector, but also improve the accuracy and precision of the detection.

[0007] This disclosure provides a lidar system including a first transmitter, a first detector, a second transmitter, and a scanning mirror. The first transmitter is configured to emit a detection beam. The detection beam is guided by the scanning mirror to the outside of the lidar. The scanning mirror guides the echo generated after the detection beam is reflected from an object to the first detector. The first detector is configured to generate a first electrical signal in response to the echo. The lidar is configured to determine the distance to the object based on the first electrical signal. The second transmitter is configured to emit a first detection beam, which is guided by the scanning mirror to the first detector. The first detector is configured to generate a second electrical signal in response to the first detection beam. The lidar is configured to determine the operating state of the first detector based on the second electrical signal. The detection beam propagates along a first optical channel, and the first detection beam propagates along a second optical channel, wherein the first and second optical channels are partially different.

[0008] Optionally, the lidar further includes a second detector; the first transmitter is also configured to emit a second detection beam, which is guided to the second detector by the scanning mirror. The second detection beam propagates along a portion of the second optical channel. The second detector is configured to generate a third electrical signal in response to the second detection beam. The lidar is configured to determine the operating state of the first transmitter based on the third electrical signal.

[0009] Optionally, the first optical channel and the second optical channel include a common optical channel, and the first optical channel further includes a first deflected optical channel deflected by the scanning mirror to the outside of the lidar, and the second optical channel further includes a second deflected optical channel that transmits the first detection beam to the scanning mirror, with the first deflected optical channel and the second deflected optical channel arranged on both sides of the common optical channel.

[0010] Optionally, the optical element portions included in the first optical channel are different from those included in the second optical channel.

[0011] Optionally, the scanning mirror includes a first reflective surface, the first transmitter emits the detection beam in a first time window and emits the second detection beam toward the first reflective surface in a second time window, and / or the second transmitter emits the first detection beam toward the first reflective surface in the second time window; the first time window and the second time window are different.

[0012] Optionally, the scanning mirror includes a first reflecting surface, and the lidar further includes a second reflecting surface. The second detection beam is reflected by the first reflecting surface and then by the second reflecting surface to the second detector; and / or, the first detection beam is reflected by the second reflecting surface and then by the first reflecting surface to the first detector.

[0013] Optionally, the lidar includes an optomechanical system, with the first transmitter and the first detector disposed within the optomechanical system. The second reflecting surface is a portion of the surface of the optomechanical system, or the second reflecting surface is the reflecting surface of a mirror disposed on the surface of the optomechanical system.

[0014] Optionally, the scanning mirror is a rotating mirror, and at least one reflecting surface of the rotating mirror is the first reflecting surface; or, the scanning mirror is a swing mirror, and a reflecting mirror is disposed on the rotating axis of the swing mirror, and the reflecting surface of the reflecting mirror is the first reflecting surface.

[0015] Optionally, the lidar further includes a first circuit board and a second circuit board. The first transmitter is disposed on the first circuit board, and the second transmitter is disposed on the second circuit board; and / or, the first detector is disposed on the first circuit board, and the second detector is disposed on the second circuit board.

[0016] Optionally, the second circuit board is closer to the scanning mirror than the first circuit board.

[0017] Optionally, the second transmitter and the second detector are arranged on the same board.

[0018] Optionally, the first transmitter and the second transmitter are located in different areas of the same circuit board.

[0019] Optionally, the number of the first transmitters is greater than the number of the second transmitters; and / or, the number of the first detectors is greater than the number of the second detectors.

[0020] The lidar provided in this embodiment includes a first transmitter, a first detector, and a scanning mirror, as well as a second transmitter. When detecting the first detector, the second transmitter emits a dedicated detection beam (e.g., the first detection beam) which is transmitted to the first detector through a second optical channel. Compared to a scheme that uses stray light for detection, this method offers higher accuracy and precision, and stronger robustness.

[0021] Furthermore, since the probe beam emitted by the first transmitter propagates along the first optical channel, and the first detection beam propagates along the second optical channel, and the first and second optical channels are partially different, the influence of the probe beam on the first detection beam can be reduced, which is beneficial to further improving the accuracy and precision of the first detector. Additionally, since the first and second optical channels are partially identical, both the probe beam and the first detection beam are guided by a scanning mirror during propagation, thus simplifying the optical path design.

[0022] To make the above-mentioned objects, features and advantages of this disclosure more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this disclosure and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 A schematic diagram of the structure of a first type of lidar with an exemplary scanning mirror at a first angle, consistent with some embodiments of the present disclosure, is shown.

[0025] Figure 2 A schematic diagram of the structure of a first type of lidar with an exemplary scanning mirror in a second angle, consistent with some embodiments of this disclosure, is shown.

[0026] Figure 3 A schematic diagram of an exemplary second type of lidar consistent with some embodiments of this disclosure is shown;

[0027] Figure 4 A schematic diagram of an exemplary third type of lidar consistent with some embodiments of this disclosure is shown;

[0028] Figure 5 A schematic diagram of an exemplary fourth lidar, consistent with some embodiments of this disclosure, is shown. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. The components of the embodiments of this disclosure described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this disclosure provided in the accompanying drawings is not intended to limit the scope of the claimed disclosure, but merely to illustrate embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without inventive effort are within the scope of protection of this disclosure.

[0030] To keep the drawings simple, each figure only schematically shows the parts related to the corresponding embodiment, and they do not represent the actual structure of the product. In addition, for the sake of simplicity and ease of understanding, some figures only schematically show parts of components with the same structure or function, and there may actually be more or fewer components with the same structure or function.

[0031] In this disclosure, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this disclosure, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0032] In this disclosure, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0033] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0034] Furthermore, the term "and / or" in this document merely describes a relationship, indicating that three relationships can exist. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Additionally, the term "at least one" in this document means any combination of at least two of any one or more elements. For example, including at least one of A, B, and C can mean including any one or more elements selected from the set consisting of A, B, and C.

[0035] A lidar system emits a laser beam into space to detect a target. The beam is reflected by the object, with a portion returning to the lidar as an echo signal. The lidar compares the received echo signal with the emitted signal to obtain information such as the object's distance, position, and motion.

[0036] For example, lidar can be installed on a vehicle to scan the surrounding environment by emitting laser beams to obtain "point cloud" data reflecting the position of at least one object in the environment. The vehicle's processor (such as an onboard computer) can receive, analyze, and process this point cloud data to obtain information about the vehicle's surrounding environment, thereby outputting specific control strategies to control the vehicle's steering, speed changes, start-stop, and other functions, thus achieving intelligent driving.

[0037] In some embodiments, a lidar system with multiple lidar sensors can be deployed around the vehicle. These lidar sensors can be configured with different detection ranges and fields of view (FOVs) to cover the area surrounding the vehicle. In some embodiments, the lidar system may include one or more short-range lidar sensors and one or more mid-range lidar sensors. The lidar system can combine lidar sensors located at different positions on the vehicle to provide a comprehensive view of the environment. Data from these lidar sensors can be fused with data from other sensors, such as cameras and / or millimeter-wave radar. This allows for real-time decisions to be made for safe and efficient autonomous driving. Lidar sensors with different detection ranges, FOVs, and locations can be combined. This achieves a balance between long-range visibility and short-range object detection, while also considering aesthetics and cost.

[0038] The transmitter, detector, and optical elements are the core components of a lidar system. Optical elements are used to collimate, deflect, reflect, and converge the light emitted by the transmitter and reflected light from objects, thereby enabling different optical path designs based on the functional requirements of the lidar. In some embodiments, the optical element may include a convex lens, a concave lens, a plane mirror, a concave mirror, a convex mirror, a semi-transparent mirror, etc.

[0039] During the use of lidar, deviations in the optical path, such as component aging, temperature changes, mechanical vibration, and contamination, can affect the lidar's detection performance. To ensure the detection accuracy of lidar, it is necessary to inspect at least some components in the lidar's optical path.

[0040] This disclosure provides a lidar system that uses an additional detection transmitter to emit a detection beam to a detector, thereby detecting the detector's operational status. Since the detection beam is a dedicated beam emitted by the detection transmitter, compared to methods using stray light for detection, the detection sensitivity is improved, which is beneficial for enhancing the accuracy and precision of the lidar detector.

[0041] The lidar provided in the embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0042] Please also refer to Figure 1 and Figure 2 The lidar 100 provided in this embodiment includes a first transmitter 10, a first detector 20, a second transmitter 30, and a scanning mirror 40.

[0043] The first transmitter 10 can emit a detection beam A. The detection beam A can be guided by the scanning mirror 40 to the outside of the lidar 100. The scanning mirror 40 can guide the echo generated by the detection beam A after it is reflected on an object to the first detector 20. The first detector 20 can generate a first electrical signal in response to the echo. The lidar 100 can determine the distance to the object based on the first electrical signal.

[0044] In addition to the components mentioned above, the lidar 100 may also include other optical elements. For example, these other optical elements may include a transmitting lens assembly 50, a receiving lens assembly 60, a reflector 70, and a beam splitter 80, etc.

[0045] In some embodiments, the number of first transmitters 10 can be multiple. The multiple first transmitters 10 can be arranged in a transmission array. For example, the multiple first transmitters 10 can be arranged in a one-dimensional array. Another example is that the multiple first transmitters 10 can be arranged in a two-dimensional array. The multiple first transmitters 10 can be aligned. Alternatively, the multiple first transmitters 10 can be staggered.

[0046] The second transmitter 30 can emit a first detection beam B. The first detection beam B can be guided to the first detector 20 by the scanning mirror 40. The first detector 20 can generate a second electrical signal in response to the first detection beam B. The lidar 100 can determine the operating state of the first detector 20 based on the second electrical signal. This allows for the detection of the operating state of the first detector 20 and optical components such as the receiving lens assembly 60. The detection beam A is transmitted along the first optical channel T1, and the first detection beam B is transmitted along the second optical channel T2, with the first optical channel T1 and the second optical channel T2 being partially different.

[0047] In some embodiments, the number of second transmitters 30 can be one or more. Optionally, the number of second transmitters 30 can be less than the number of first transmitters 10. Optionally, the intensity of the first detection beam B emitted by the second transmitter 30 can be less than the intensity of the detection beam A emitted by the first transmitter 10.

[0048] In some embodiments, the second transmitter 30 and the first transmitter 10 may be spaced apart. For example, the second transmitter 30 and the first transmitter 10 may be arranged in different areas of the same circuit board. Alternatively, the second transmitter 30 and the first transmitter 10 may be arranged on different circuit boards. The spacing between the second transmitter 30 and the first transmitter 10 ensures that the optical paths of the detection beam A incident on the scanning mirror 40 and the first detection beam B incident on the scanning mirror 40 are kept apart, avoiding mutual interference.

[0049] In some embodiments, the wavelengths of the probe beam A and the first detection beam B may be the same or different. For example, the wavelengths of both the probe beam A and the first detection beam B are within the wavelength range that the first detector 20 can respond to. The wavelength of the probe beam A can be any one of 905 nm, 940 nm, or 1550 nm, or it can be other wavelengths. The wavelength of the first detection beam B can be any one of 905 nm, 940 nm, or 1550 nm, or it can be other wavelengths.

[0050] In some embodiments, the scanning mirror 40 may be a rotating mirror, a swing mirror, a galvanizing mirror, etc. The scanning mirror 40 may have a planar reflector or a curved reflector.

[0051] In some embodiments, the scanning mirror 40 can rotate or oscillate at a corresponding frequency according to control commands. When the scanning mirror 40 rotates to a first angle (e.g., Figure 1 When the detector beam A is reflected by the reflective surface of the scanning mirror 40 to the outside of the lidar 100, as shown, when the scanning mirror 40 rotates to the second angle (as shown), the detector beam A can be reflected by the reflective surface of the scanning mirror 40 to the outside of the lidar 100. Figure 2 When (as shown), the first detection beam B can be reflected to the first detector 20 through the reflective surface of the scanning mirror 40.

[0052] In this embodiment of the disclosure, the first optical channel T1 can represent the optical channel through which the detection beam A emitted by the first transmitter 10 travels from the first transmitter 10 to the window 109 of the lidar 100. The second optical channel T2 can represent the optical channel through which the first detection beam B emitted by the second transmitter 30 travels when it reaches the first detector 20.

[0053] The lidar 100 provided in this embodiment includes a first transmitter 10, a first detector 20, and a scanning mirror 40, as well as a second transmitter 30. When detecting the first detector 20, the second transmitter 30 emits a dedicated detection beam (e.g., a first detection beam B) which is transmitted to the first detector 20 through a second optical channel T2. Compared with a scheme that uses stray light for detection, this method has higher detection accuracy and precision, and stronger robustness.

[0054] Furthermore, since the detection beam A emitted by the first transmitter 10 propagates along the first optical channel T1, and the first detection beam B propagates along the second optical channel T2, and the first optical channel T1 and the second optical channel T2 are partially different, the influence of the detection beam A on the first detection beam B can be reduced, which is beneficial to further improving the accuracy and precision of the detection by the first detector 20. In addition, the first optical channel T1 and the second optical channel T2 are partially identical, and both the detection beam A and the first detection beam B are guided by the scanning mirror 40 during propagation, thereby simplifying the optical path design.

[0055] In some embodiments, the first emitter 10 may include a semiconductor laser, such as a vertical-cavity surface-emitting laser (VCSEL), an edge-emitting laser (EEL), or other semiconductor lasers capable of generating laser light. In other embodiments, the laser may also include a fiber laser.

[0056] In some embodiments, the second emitter 30 may include a semiconductor laser, such as a vertical-cavity surface-emitting laser (VCSEL), an edge-emitting laser (EEL), or other semiconductor lasers capable of generating laser light. In other embodiments, the laser may also include a fiber laser. In some embodiments, the second emitter 30 may include a light-emitting diode (LED). Using LEDs can reduce the cost of lidar.

[0057] In some embodiments, the first detector 20 may include a photodetector. The photodetector may include at least one of an avalanche photodiode (APD), a single-photon avalanche diode (SPAD), and a silicon photomultiplier (SiPM).

[0058] In some embodiments, the first detector 20 may correspond to the first transmitter 10. The echo generated by the detection beam A emitted by the first transmitter 10 after reflection by an object can illuminate the first detector 20 corresponding to the first transmitter 10. Optionally, the first detector 20 may correspond to one or more first transmitters 10. In some embodiments, the first detector 20 may correspond to a second transmitter 30. The first detection beam B emitted by the second transmitter 30 can illuminate the first detector 20 corresponding to the second transmitter 30. The second transmitter 30 may correspond to one or more first detectors 20. For example, the second transmitter 30 may correspond to multiple first detectors 20, and the first detection beam B emitted by the second transmitter 30 may illuminate different first detectors 20. In this way, the detection of multiple first detectors 20 can be achieved with a small number of second transmitters 30. For example, the second transmitter 30 may correspond to all of the first detectors 20. In some embodiments, the spot size emitted by the second transmitter 30 is larger than the spot size emitted by the first transmitter 10.

[0059] In some embodiments, the first optical channel T1 and the second optical channel T2 may include different optical elements. For example, the optical elements included in the first optical channel T1 may include a transmitting lens assembly 50, a reflecting mirror 70, a beam splitter 80, and a scanning mirror 40. The optical elements included in the second optical channel T2 may include a scanning mirror 40, a beam splitter 80, and a receiving lens assembly 60. In this way, the corresponding optical elements can be set according to the actual needs of each optical channel, improving the flexibility of the detection optical path setup. In other embodiments, the first optical channel T1 and the second optical channel T2 may also include the same optical elements. By using shared optical elements, not only can the optical path design be simplified, but the use of optical elements can also be reduced, thus lowering costs.

[0060] In some embodiments, the difference between the first optical channel T1 and the second optical channel T2 means that the first optical channel T1 and the second optical channel T2 have both common and different parts. Optionally, the first optical channel T1 and the second optical channel T2 include a common optical channel T. For example, the common optical channel T includes the optical channel between the scanning mirror 40 and the beam splitter 80. By setting a common optical channel T, the design of the optical path can be simplified and the number of optical components used can be reduced.

[0061] In some embodiments, the first optical channel T1 may further include a first deflected optical channel T11 deflected by the scanning mirror 40 to the outside of the lidar 100, a first sub-optical channel T12 between the beam splitter 80 and the reflector 70, and a second sub-optical channel T13 between the reflector 70 and the first transmitter 10. The second optical channel T2 may further include a second deflected optical channel T21 that transmits the first detection beam B to the scanning mirror, and a third sub-optical channel T22 between the beam splitter 80 and the first detector 20.

[0062] In some embodiments, the first deflection channel T11 and the second deflection channel T21 are located on opposite sides of the common optical channel T. The first deflection channel T11 (the main radar optical path) and the second deflection channel T21 (the diagnostic optical path) can be completely isolated from each other without affecting each other, reducing the risk of introducing new stray light and helping to further improve detection accuracy.

[0063] In some embodiments, see Figure 3 As shown, the lidar 100 may further include a second detector 90. The first transmitter 10 may also emit a second detection beam C. The second detection beam C may be guided to the second detector 90 by the scanning mirror 40. The second detection beam C may be transmitted along a portion of the second optical channel T2.

[0064] The second detector 90 can generate a third electrical signal in response to the second detection beam C. The lidar 100 can determine the operating status of the first transmitter 10 and the transmitting lens assembly 50 based on the third electrical signal. This allows for the detection of the operating status of the first transmitter 10 and optical components such as the transmitting lens assembly 50.

[0065] In some embodiments, the response wavelength range of the second detector 90 includes the wavelength range of the first transmitter 10. This ensures that the second detection beam C emitted by the first transmitter 10 can be detected and identified by the second detector 90.

[0066] In some embodiments, the second detector 90 may include a photodetector. The photodetector may include at least one of an avalanche photodiode (APD), a single-photon avalanche diode (SPAD), and a silicon photomultiplier (SiPM). In other embodiments, the second detector 90 may also include a photodiode (PD).

[0067] Optionally, the number of first detectors 20 is greater than the number of second detectors 90. For example, there can be multiple first detectors 20. These multiple first detectors 20 can be arranged in an array, such as a one-dimensional array or a two-dimensional array. Similarly, there can be one or more second detectors 90. Optionally, the multiple second detectors 90 can be arranged in a one-dimensional array, a two-dimensional array, or distributed dispersedly.

[0068] In some embodiments, the first transmitter 10 may correspond to the first detector 20. The echo generated by the detection beam A emitted by the first transmitter 10 after reflection by an object can illuminate the first detector 20 corresponding to the first transmitter 10. Optionally, the first transmitter 10 may correspond to one or more first detectors 20. In some embodiments, the first transmitter 10 may correspond to the second detector 90. The second detection beam C emitted by the first transmitter 10 can illuminate the second detector 90 corresponding to the first transmitter 10. Optionally, the second detector 90 may correspond to one or more first transmitters 10. For example, the second detection beams C emitted by multiple first transmitters 10 can illuminate the same second detector 90. In this way, the detection of multiple first transmitters 10 can be achieved with a small number of second detectors 90. This reduces the cost of the lidar while enabling the detection of the operating status of the first transmitters 10.

[0069] In some embodiments, the scanning mirror 40 includes a first reflective surface 41. The first transmitter 10 can emit a probe beam A (e.g., ...) within a first time window. Figure 1 (As shown). The first transmitter 10 can emit a second detection beam C toward the first reflecting surface 41 (as shown) in a second time window. Figure 3 (As shown). The second transmitter 30 can emit the first detection beam B towards the first reflecting surface 41 (as shown) in the second time window. Figure 2 (As shown). The first time window and the second time window are different. For example, the first time window is the detection window, while the second time window is the testing window.

[0070] Within the first time window, the scanning mirror 40 can deflect the detection beam A incident on it to the outside of the lidar, and deflect the object echo to the first detector 20. During this first time window, the lidar 100 can detect external objects. In the second time window, the scanning mirror 40 can deflect the first detection beam B incident on it to the first detector 20, enabling the detection of optical components such as the first detector 20 and the receiving lens assembly 60. In the second time window, the scanning mirror 40 can deflect the second detection beam B incident on it to the second detector 90, enabling the detection of optical components such as the first transmitter 10 and the transmitting lens assembly 60. The first and second time windows do not need to overlap. Thus, by performing detection during non-detection times, the detection optical path and the detection optical path can be decoupled, avoiding interference between the detection light and the detection light, which is beneficial for improving detection accuracy.

[0071] In some embodiments, the first time window and the second time window may alternate. For example, after performing one scan detection, a detection of each element may be performed. In some embodiments, multiple scan detections may be performed before a detection of each element is performed. In some embodiments, the rotation angles of the scanning mirror 40 in the first time window and the second time window are different. For example, the same reflective surface 41 of the scanning mirror 40 is at different angles in the first time window and the second time window.

[0072] In some embodiments, the second transmitter 30 and the second detector 90 can be arranged adjacent to each other, for example, both located in the non-FOV region of the lidar 100. Thus, when the scanning mirror 40 rotates to the second angle (e.g., ... Figure 3 As shown, at this time, corresponding to the second time window, the first detection beam B can be emitted to the first detector 20 through the second transmitter 30, and the second detection beam C can be emitted to the second detector 90 through the first transmitter 10. In this way, the first transmitter 10 and the first detector 20 can be detected simultaneously during the second detection window.

[0073] In some embodiments, see Figure 4As shown, the lidar 100 may include an optomechanical system 103. The optomechanical system 103 can support optical elements. The optomechanical system 103 can divide the space within the lidar 100 into a first accommodating region and a second accommodating region. The first accommodating region is located outside the optomechanical system 103. The second transmitter 30 and the second detector 90 can be disposed in the first accommodating region. The second accommodating region can be the internal space of the optomechanical system 103. The first transmitter 10 and the first detector 20 can be located in the second accommodating region. The second transmitter 30 and the second detector 90 are arranged in different accommodating spaces from the first transmitter 10 and the first detector 20. This arrangement allows the second transmitter 30 and the second detector 90 to be positioned close to the scanning mirror 40, facilitating the design of the optical channel. Furthermore, it reduces the impact of the second transmitter 30 and the second detector 90 on the arrangement of the first transmitter 10 and the first detector 20, minimizing modifications to the original optomechanical components of the lidar.

[0074] Optionally, the second transmitter 30 and the second detector 90 can be mounted on the same circuit board. This facilitates the arrangement of the second transmitter 30 and the second detector 90.

[0075] Optionally, the installation positions of the second transmitter 30 and the second detector 90 can be further defined as follows: when the second transmitter 30 and other optical components (such as the reflector 70, beam splitter 80, etc.) are normal, the first detection beam B emitted by the second transmitter 30 can illuminate the first detector 20 after passing through the first reflective surface 41 of the scanning mirror 40; when the first transmitter 10 and other optical components are normal, the second detection beam C emitted by the first transmitter 10 can illuminate the second detector 90 after passing through the first reflective surface 41 of the scanning mirror 40.

[0076] In some embodiments, the lidar 100 may include a first circuit board 101 and a second circuit board 102. Optionally, the first transmitter 10 and the second transmitter 30 may be disposed on different circuit boards. For example, the first transmitter 10 may be disposed on the first circuit board 101, and the second transmitter 30 may be disposed on the second circuit board 102. Optionally, the first detector 20 and the second detector 90 may be disposed on different circuit boards. For example, the first detector 20 may be disposed on the first circuit board 101, and the second detector 90 may be disposed on the second circuit board 102. In this way, the second transmitter 30 and the second detector 90 do not occupy the layout space of the electronic components on the original transceiver circuit board within the lidar 100, thereby decoupling the detection circuit (the second transmitter 30 and the second detector 90) from the transceiver circuit (the first detector 20 and the first transmitter 10), which facilitates the layout and implementation of the circuit.

[0077] Optionally, the first circuit board 101 and the second circuit board 102 can be placed in parallel. Alternatively, the first circuit board 101 and the second circuit board 102 can have an included angle. For example, the first circuit board 101 and the second circuit board 102 are arranged perpendicular to each other.

[0078] Optionally, the second circuit board 102 may be closer to the scanning mirror 40 than the first circuit board 101. Exemplarily, the first circuit board 101 and the second circuit board 102 are stacked, with the scanning mirror 40 disposed on one side of the second circuit board 102 and the first circuit board 101 disposed on the side of the second circuit board 102 opposite to the scanning mirror 40. Exemplarily, the first and second circuit boards may be disposed side-by-side. For example, the scanning mirror 40 may be disposed close to the second circuit board 102.

[0079] In some embodiments, the first detection beam B emitted by the second transmitter 30 can directly reach the beam splitter of the scanning mirror 40. The second detection beam C emitted by the first transmitter 10 can directly reach the second detector 90 after being reflected by the scanning mirror 40. There is a direct optical path between the scanning mirror 40 and the second transmitter 30, and also between the scanning mirror 40 and the second detector 90. This reduces the number of optical elements used during detection.

[0080] In some embodiments, see Figure 4 As shown, the lidar 100 may further include a second reflecting surface 104. Optionally, the second detection beam C, after being reflected by the scanning mirror 40, is then reflected by the second reflecting surface 104 to the second detector 90. Optionally, the first detection beam B, after being reflected by the second reflecting surface 104, is then reflected by the first reflecting surface 41 to the first detector 20. This addition of the second reflecting surface 104 allows for more flexible optical path design, providing more options for the placement of the second transmitter 30 and the second detector 90.

[0081] It should be noted that the specific form of the second reflecting surface 104 is not limited. For example, it can be the reflecting surface of a mirror or the reflecting surface of a beam splitter, as long as it has the function of light reflection.

[0082] In some embodiments, the second reflective surface 104 may be part of the surface of the optomechanical system 103. This avoids the use of additional components and helps reduce production costs. In some embodiments, the second reflective surface 104 may also be the reflective surface of a mirror disposed on the surface of the optomechanical system.

[0083] In some embodiments, the scanning mirror 40 may be a rotating mirror. The rotating mirror may include multiple reflective surfaces. At least one reflective surface of the rotating mirror is a first reflective surface 41. A rotating mirror is a shorthand for a mechanically rotating reflector, which may be a polygonal cylinder (such as a two-sided, three-sided, four-sided, five-sided, or six-sided prism) with a reflective layer coated on its sides or with reflective mirrors attached. It is driven by a motor to rotate at high speed, and the incident light is reflected by the rotating mirror surface to form a scanning bright line.

[0084] In some embodiments, see Figure 5 As shown, the scanning mirror 40 can also be a pendulum mirror. The pendulum mirror can swing back and forth around the rotation axis 42. A reflector can be set on the rotation axis 42 of the pendulum mirror, and the reflecting surface of the reflector is used as the first reflecting surface 41.

[0085] In some embodiments, when the scanning mirror 40 is a tilting mirror, the detection beam can be reflected by the reflecting surface 43. For example, in a first time window, the detection beam is reflected and deflected by the reflecting surface 43, and in a second time window, the first detection beam B and / or the second detection beam C are reflected and deflected by the first reflecting surface 41.

[0086] In some embodiments, the lidar 100 may further include at least one signal processor (not shown). The first detector 20 and the second detector 90 may be connected to different signal processors or to the same signal processor.

[0087] When the first transmitter 10 is working normally, the second detector 90 can receive the second detection beam C and convert it into a third electrical signal. When the first transmitter 10 malfunctions, the second detector 90 cannot receive the second detection beam C, or the intensity of the received second detection beam C is low, resulting in a small amplitude of the generated detection electrical signal. The signal processor can determine whether the first transmitter 10 and the transmitting lens assembly 50 are operating normally based on the third electrical signal. It can also determine whether the first detector 20 and the receiving lens assembly 50 are operating normally based on the second electrical signal generated by the first detector 20.

[0088] When there are multiple first transmitters 10, the signal processor can confirm that multiple first transmitters 10 are working normally when it receives the third electrical signal converted from all the second detection beams C; when it receives the third electrical signal converted from the second detection beams C emitted by some of the first transmitters 10, it can confirm that the first transmitter 10 corresponding to that part of the third detection electrical signal is working normally; when it does not receive the third detection electrical signal converted from the second detection beams C emitted by all the first transmitters 10, it can confirm that multiple first transmitters 10 are working abnormally.

[0089] In some embodiments, the signal processor can determine an abnormal first transmitter 10 among a plurality of first transmitters 10 based on a portion of the received third electrical signal. Optionally, the signal processor can determine the proportion of abnormal first transmitters 10 based on a portion of the received third electrical signal. Optionally, the signal processor can determine the degree of abnormality of the abnormal first transmitter 10 based on the strength of the received third signal. For example, when the third electrical signal is very weak or even absent, the degree of abnormality of the first transmitter 10 is relatively large. For example, when the third electrical signal is small, the degree of abnormality of the first transmitter 10 is relatively small.

[0090] Optionally, the signal processor can determine a safety response strategy based on one or more of the following: the number, proportion, location, and severity of the abnormal first transmitters 10. For example, if the number of abnormal first transmitters 10 is large, their proportion is high, their location is at the center of the laser array, or their severity is high, the signal processor can output a Level 1 fault response command. This could involve shutting down the lidar or severing the data link between the lidar and the device (e.g., vehicle, robot) controller, and outputting an alarm indication and fault information. Alternatively, if the number of abnormal first transmitters 10 is small, their proportion is low, their location is at the edge of the laser array, or their severity is low, the signal processor can output a Level 2 fault response command. This could involve outputting an alarm indication and fault information to the device (e.g., vehicle, robot) controller, reducing the confidence level of the lidar point cloud, or reducing the reference weight of the lidar point cloud in driving control.

[0091] When there are multiple first detectors 20, the signal processor can confirm that multiple first detectors 20 are working normally when it receives the second electrical signal converted by all the first detectors 20; confirm that the second electrical signal converted by some of the first detectors 20 is working normally when it receives the second electrical signal converted by some of the first detectors 20; and confirm that the multiple first detectors 20 are malfunctioning when it does not receive the second electrical signal converted by all the first detectors 20.

[0092] In some embodiments, the signal processor can determine the abnormal first detector 20 among a plurality of first detectors 20 based on the strength of the received second electrical signal. In some embodiments, the signal processor can determine the proportion of abnormal first detectors 20 among a plurality of first detectors 20 based on the strength of the received second electrical signal. Optionally, the signal processor can determine the degree of abnormality of the abnormal first detector 20 based on the number and strength of the received second electrical signal. For example, when the second electrical signal is very weak or even absent, the degree of abnormality of the first detector 20 is relatively large. For example, when the second electrical signal is small, the degree of abnormality of the first detector 20 is relatively small.

[0093] Optionally, the signal processor can determine a safety response strategy based on one or more of the following: the number, proportion, location, and severity of the abnormal first detectors 20. For example, if the number of abnormal first detectors 20 is large, their proportion is high, their location is at the center of the detector array, or their severity is high, the signal processor can output a Level 1 fault response command. This could involve shutting down the lidar or severing the data link between the lidar and the device (e.g., vehicle, robot) controller, and outputting an alarm indication and fault information. Alternatively, if the number of abnormal first detectors 20 is small, their proportion is low, their location is at the edge of the detector array, or their severity is low, the signal processor can output a Level 2 fault response command. This could involve outputting an alarm indication and fault information to the device (e.g., vehicle, robot) controller, reducing the confidence level of the lidar point cloud, or reducing the reference weight of the lidar point cloud in driving control.

[0094] In some embodiments, the second transmitter 30 corresponds to a plurality of first detectors 20, and the plurality of first detectors 20 can be polled and diagnosed. In some embodiments, the plurality of second transmitters 30 correspond to different first detectors 20, and the plurality of first detectors 20 can be diagnosed simultaneously.

[0095] In some embodiments, the second detector 90 corresponds to a plurality of first transmitters 10, and can poll and diagnose the plurality of first transmitters 10. In some embodiments, the plurality of second detectors 90 correspond to different first transmitters 10, and can diagnose the plurality of first transmitters 10 simultaneously.

[0096] It is understood that the structures illustrated in the embodiments of this disclosure do not constitute a specific limitation on the lidar 100. In other embodiments of this disclosure, the lidar 100 may include more or fewer components than illustrated, or combine some components, or split some components, or have different component arrangements.

[0097] Unless otherwise specified, all embodiments mentioned herein can be combined to form new technical solutions. Furthermore, unless otherwise specified, all technical features and preferred features mentioned herein can be combined to form new technical solutions.

[0098] Finally, it should be noted that the above-described embodiments are merely specific implementations of this disclosure, used to illustrate the technical solutions of this disclosure, and not to limit it. The protection scope of this disclosure is not limited thereto. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the scope of the technology disclosed in this disclosure; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this disclosure. All should be covered within the protection scope of this disclosure. Therefore, the protection scope of this disclosure should be determined by the protection scope of the claims.

Claims

1. A lidar, characterized in that, The lidar includes a first transmitter, a first detector, a second transmitter, and a scanning mirror; wherein, The first transmitter is configured to emit a probe beam, which is guided by the scanning mirror to the outside of the lidar; The scanning mirror guides the echo generated after the detection beam is reflected on the object to the first detector; The first detector is configured to generate a first electrical signal in response to the echo; The lidar is configured to determine the distance to the object based on the first electrical signal; The second transmitter is configured to emit a first detection beam, which is guided by the scanning mirror to the first detector; The first detector is configured to generate a second electrical signal in response to the first detection beam; The lidar is configured to determine the operating state of the first detector based on the second electrical signal; The detection beam is transmitted along the first optical channel, and the first detection beam is transmitted along the second optical channel. The first optical channel and the second optical channel are partially different.

2. The lidar according to claim 1, characterized in that, The lidar further includes a second detector; the first transmitter is also configured to emit a second detection beam, the second detection beam being guided to the second detector by the scanning mirror; wherein the second detection beam is transmitted along a portion of the second optical channel; The second detector is configured to generate a third electrical signal in response to the second detection beam; The lidar is configured to determine the operating state of the first transmitter based on the third electrical signal.

3. The lidar according to claim 1 or 2, characterized in that, The first optical channel and the second optical channel include a common optical channel, and the first optical channel further includes a first deflected optical channel that is deflected by the scanning mirror to the outside of the lidar. The second optical channel further includes a second deflected optical channel that transmits the first detection beam to the scanning mirror. The first deflected optical channel and the second deflected optical channel are located on both sides of the common optical channel.

4. The lidar according to claim 2, characterized in that, The optical elements included in the first optical channel are different from those included in the second optical channel.

5. The lidar according to claim 4, characterized in that, The scanning mirror includes a first reflective surface, the first transmitter emits the detection beam in a first time window and emits the second detection beam toward the first reflective surface in a second time window, and / or the second transmitter emits the first detection beam toward the first reflective surface in the second time window; the first time window and the second time window are different.

6. The lidar according to claim 2, characterized in that, The scanning mirror includes a first reflective surface, and the lidar also includes a second reflective surface; The second detection beam is reflected by the first reflecting surface, and then reflected again by the second reflecting surface to the second detector; and / or, The first detection beam is reflected by the second reflective surface and then reflected by the first reflective surface to the first detector.

7. The lidar according to claim 6, characterized in that, The lidar includes an optomechanical system, and the first transmitter and the first detector are disposed within the optomechanical system; The second reflective surface is a part of the optical-mechanical surface, or the second reflective surface is the reflective surface of a mirror disposed on the optical-mechanical surface.

8. The lidar according to claim 5, characterized in that, The scanning mirror is a rotating mirror, and at least one reflecting surface of the rotating mirror is the first reflecting surface; or, The scanning mirror is a swing mirror, and a reflecting mirror is mounted on the swing mirror's axis of rotation. The reflecting surface of the reflecting mirror is the first reflecting surface.

9. The lidar according to claim 2, characterized in that, The lidar also includes a first circuit board and a second circuit board; The first transmitter is mounted on the first circuit board, and the second transmitter is mounted on the second circuit board; and / or, The first detector is mounted on the first circuit board, and the second detector is mounted on the second circuit board.

10. The lidar according to claim 9, characterized in that, The second circuit board is closer to the scanning mirror than the first circuit board.

11. The lidar according to claim 2, characterized in that, The second transmitter and the second detector are mounted on the same board.

12. The lidar according to claim 1 or 2, characterized in that, The first transmitter and the second transmitter are located in different areas of the same circuit board.

13. The lidar according to claim 2, characterized in that, The number of the first transmitters is greater than the number of the second transmitters; and / or, The number of the first detectors is greater than the number of the second detectors.

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