Laser radar

Abstract

The invention provides a laser radar. The laser radar comprises an optical-mechanical structure. The optical-mechanical structure moves around the first rotating shaft; the optical-mechanical structure comprises a transceiver, an optical element and a scanning mirror. The transmitting-receiving piece comprises a laser and a detector; the reflecting surface of the scanning mirror moves around a second rotating shaft, the second rotating shaft is parallel to the reflecting surface, and the included angle between the second rotating shaft and the first rotating shaft is larger than 0 degree. The optical-mechanical structure can realize a laser radar with a larger detection field of view at a lower cost.

Description

Technical Field

[0001] This disclosure relates to the field of laser detection, and in particular 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, good concealment, strong resistance to active interference, good low-altitude detection performance, small size, and light weight, LiDAR is widely used in fields such as autonomous driving, drones, intelligent robots, and resource exploration.

[0003] To achieve comprehensive environmental detection, a larger field of view is a key pursuit in the field of lidar. Some lidar systems employ more lasers and detectors to achieve this, resulting in higher costs.

[0004] How to achieve low-cost, wide-field-of-view lidar is a technical problem that needs to be solved in this field. Summary of the Invention

[0005] The problem addressed in this disclosure is how to achieve a low-cost, wide-field-of-view lidar.

[0006] To address the aforementioned problems, this disclosure provides a lidar, comprising:

[0007] An optomechanical structure is provided, wherein the optomechanical structure moves about a first rotation axis; the optomechanical structure includes a transceiver, optical components, and a scanning mirror; wherein the transceiver includes a laser and a detector; the reflective surface of the scanning mirror moves about a second rotation axis, the second rotation axis is parallel to the reflective surface, and the angle between the second rotation axis and the first rotation axis is greater than 0°.

[0008] Optionally, the detection beam emitted by the laser passes sequentially through the optical element and the scanning mirror before exiting into the environment; the detection beam is reflected by an object to form an echo; the echo passes sequentially through the scanning mirror and the optical element before entering the detector.

[0009] Optionally, the second rotating shaft is perpendicular to the first rotating shaft.

[0010] Optionally, the optical paths of the probe beam and the echo at least partially overlap.

[0011] Optionally, the optical axis of the optical element is perpendicular to the second rotating axis.

[0012] Optionally, the optical axis of the optical element is perpendicular to the first rotating axis.

[0013] Optionally, the optomechanical structure further includes a reflector located in the optical path between the optical element and the scanning mirror.

[0014] Optionally, the optomechanical structure further includes a base, to which the optical components and the transceiver are fixed.

[0015] Optionally, the first pivot is perpendicular to the base.

[0016] Optionally, the second pivot is parallel to the base.

[0017] Optionally, the optical axis of the optical element is parallel to the base.

[0018] Optionally, the scanning mirror includes: a bearing, the reflective surface of which moves around the bearing; and a support member located at both ends of the bearing to fix the bearing.

[0019] Optionally, the support allows the reflective surface of the scanning mirror to move above the base; the transceiver is located between the reflective surface of the scanning mirror and the base.

[0020] Optionally, the reflective surface of the scanning mirror reciprocates around the second axis.

[0021] Optionally, the reflective surface of the scanning mirror rotates unidirectionally around the second axis; the number of reflective surfaces in the scanning mirror is greater than 2.

[0022] Optionally, the optomechanical structure moves around the first rotating axis at a first frequency, and the reflecting surface of the scanning mirror moves around the second rotating axis at a second frequency; wherein the first frequency is less than the second frequency.

[0023] Optionally, the ratio of the second frequency to the first frequency is not an integer.

[0024] Optionally, the transceiver may include multiple lasers.

[0025] Optionally, the optomechanical structure moves around the first rotation axis to form a first field of view; the reflective surface of the scanning mirror moves around the second rotation axis to form a second field of view, wherein the maximum field of view of the first field of view is 360°, and the maximum field of view of the second field of view is greater than or equal to 90°.

[0026] Compared with the prior art, the technical solution disclosed herein has the following advantages:

[0027] In the optomechanical structure disclosed herein, the second rotating axis is parallel to the reflecting surface, and the angle between the second rotating axis and the first rotating axis is greater than 0°. Using the optomechanical structure disclosed herein, a lidar with a larger detection field of view can be realized at a lower cost. Attached Figure Description

[0028] 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 introduced below. The drawings described below are merely embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort. The drawings are used to provide a further understanding of this disclosure and constitute a part of the specification. They are used together with the embodiments of this disclosure to explain this disclosure and do not constitute a limitation of this disclosure. In the drawings:

[0029] Figure 1 A cross-sectional structural schematic diagram of an exemplary lidar consistent with some embodiments of the present disclosure is shown;

[0030] Figure 2 A schematic cross-sectional view of an exemplary lidar model consistent with some embodiments of this disclosure is shown.

[0031] Figure 3 A schematic diagram of the scanning path of an exemplary lidar consistent with some embodiments of this disclosure is shown. Detailed Implementation

[0032] In the following description, only certain exemplary embodiments are shown. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this disclosure. Therefore, the drawings and description are to be considered exemplary in nature and not restrictive.

[0033] In the description of this disclosure, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure. Furthermore, 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. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this disclosure, "a plurality of" means two or more, unless otherwise explicitly specified.

[0034] In the description of this disclosure, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, or connections that allow for communication; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0035] In this disclosure, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0036] The following disclosure provides numerous different embodiments or examples for implementing various structures of this disclosure. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this disclosure. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this disclosure, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0037] To make the above-mentioned objects, features and advantages of this disclosure more apparent and understandable, specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings.

[0038] This disclosure provides a lidar system. The lidar system includes an optomechanical structure. The optomechanical structure moves about a first axis; the optomechanical structure includes a transceiver, optical components, and a scanning mirror. The transceiver includes a laser and a detector. The reflective surface of the scanning mirror moves about a second axis. The second axis is parallel to the reflective surface. The angle between the second axis and the first axis is greater than 0°.

[0039] refer to Figure 1 The diagram shows a cross-sectional structural schematic of an exemplary lidar consistent with some embodiments of the present disclosure.

[0040] The lidar includes an optomechanical structure 110, which moves about a first rotation axis 111. The optomechanical structure 110 includes a transceiver 112, optical components 113, and a scanning mirror 114. The transceiver 112 includes a laser and a detector. The reflective surface 115 of the scanning mirror 114 moves about a second rotation axis, which is parallel to the reflective surface 115. The angle between the second rotation axis and the first rotation axis 111 is greater than 0°.

[0041] The optomechanical structure 110 can support a transceiver 112. The transceiver 112 includes a laser and a detector. The laser can emit optical signals. The detector can receive optical signals. The optomechanical structure can move around a first rotation axis. The optomechanical structure can support an optical component 113. The optical component 113 can be fixedly connected to the optomechanical structure. The optomechanical structure can support a scanning mirror 114. During the movement of the optomechanical structure around the first rotation axis, all components supported by the optomechanical structure move together with the optomechanical structure around the first rotation axis. During the movement of the optomechanical structure around the first rotation axis, the laser can emit optical signals in different directions, and the detector can receive optical signals returned from different directions, enabling the lidar to achieve field-of-view detection in a first direction. For example, when the first rotation axis is a vertical axis, the lidar can achieve horizontal field-of-view detection when the optomechanical structure moves around the first rotation axis.

[0042] In some embodiments, the optomechanical structure can rotate continuously about a first axis of rotation. For example, such as... Figure 1 As shown, the optomechanical structure 110 can rotate 360° unidirectionally around the first rotation axis 111. With the optomechanical structure 110 rotating 360° unidirectionally around the first rotation axis 111, the lidar can achieve a 360° field of view in the first direction.

[0043] In some embodiments, the optomechanical structure can reciprocate around a first axis. For example, the optomechanical structure can reciprocate around the first axis within a preset angle range. When the optomechanical structure reciprocates around the first axis within the preset angle range, the laser can emit light signals in different directions within the preset angle range, and the detector can receive the light signals returned from different directions within the preset angle range. The lidar can then achieve field-of-view detection within the preset angle range in the first direction. The preset angle range is, for example, -60° to +60°, -50° to +50°, -45° to +45°, or -40° to +40°, etc.

[0044] In some embodiments, the optomechanical structure includes a base. The base is movable about a first axis of rotation. Other structures and components of the optomechanical structure may be directly or indirectly connected to the base. As the base moves about the first axis of rotation, the other structures and components of the optomechanical structure can move about the first axis of rotation.

[0045] In some embodiments, the first pivot is perpendicular to the base. For example... Figure 1In some embodiments shown, the base 118 has a platform 118s that is substantially perpendicular to the first pivot 111. At least a portion of the optomechanical structure 110 is fixed to the platform 118s of the base 118. The platform 118s being substantially perpendicular to the first pivot 111 means that the first pivot 111 is perpendicular to the platform 118s, or that the angle between the first pivot 111 and the platform 118s is close to 90°.

[0046] In some embodiments, the first axis of rotation 111 may be perpendicular to the horizontal plane. The movement of the optomechanical structure 110 about the first axis of rotation 111 allows the lidar to scan a horizontal field of view. For example, when the optomechanical structure 110 rotates 360° about the first axis of rotation 111, the lidar can scan a 360° horizontal field of view. As an example, the first axis of rotation 111 is perpendicular to the platform 118s of the base 118, and the platform 118s is parallel to the horizontal plane.

[0047] The optomechanical structure includes a transceiver, optical components, and a scanning mirror. The transceiver includes a laser and a detector. The optical components may include one or more lenses. Lenses can shape the light beam, such as collimating and focusing. The optical components may also include one or more mirrors. Mirrors can change the propagation direction of the light beam. The optical components can transmit the light signal emitted by the laser to the environment, and can also transmit the echo reflected from the environment to the detector. The scanning mirror can change the propagation direction of the light incident on it over time.

[0048] In some embodiments, the lidar includes a base, and optics and a transceiver can be fixed to the base. The transceiver, optics, and scanning mirror can all be at least partially connected to the base. The transceiver, optics, and scanning mirror can move with the base about a first axis of rotation.

[0049] like Figure 1 As shown, the transceiver 112 and the optical component 113 are fixed to the platform 118s of the base 118. For example, the transceiver 112 and the optical component 113 can be fixedly connected to the platform 118s by means of adhesive bonding, fastener fixing, etc.

[0050] The transceiver consists of a laser (not shown in the figure) and a detector (not shown in the figure), wherein the laser can generate an optical signal, and the detector can receive the echo.

[0051] In some embodiments, the laser may include a laser emitting circuit, a vertical-cavity surface-emitting laser (VCSEL), an edge-emitting laser (EEL), a distributed feedback laser (DFB), a fiber laser, or a similar device.

[0052] In some embodiments, the detector may include a photodetector circuit, a single-photon avalanche diode (SPAD), an avalanche photodiode (APD), a silicon photomultiplier (SiPM), or a similar device.

[0053] In some embodiments, the transceiver may include one or more lasers. Optionally, multiple lasers may be arranged in an array, such as in one or more columns. The transceiver may include one or more detectors. Optionally, multiple detectors may be arranged in an array, such as in one or more columns. A laser has at least one corresponding detector that can receive the echo generated by the optical signal emitted by the laser. For example, the number of lasers may be 1-32, such as 1, 2, 4, 8, 16, 32, etc. The number of detectors may be 1-32, such as 1, 2, 4, 8, 16, 32, etc. In some embodiments, a detector may include multiple single-photon avalanche diodes. The number of lasers and the number of detectors may be the same or different. One laser may correspond to one or more detectors. Alternatively, one detector may correspond to one or more lasers. Increasing the number of lasers and detectors in the transceiver can improve point cloud resolution.

[0054] In some embodiments, the transceiver 112 includes multiple lasers and multiple detectors. The multiple lasers and detectors can constitute multiple channels. Optionally, the multiple channels can be activated in parallel, or they can be activated sequentially according to a certain timing sequence, or a first portion of the channels can be activated in parallel at a first time, and a second portion of the channels can be activated in parallel at a second time. The number of channels activated in parallel can be selected based on a comprehensive consideration of factors such as detection distance requirements, optical crosstalk levels and energy consumption, and the complexity of point cloud processing. This can improve the application range and flexibility of the lidar.

[0055] In some embodiments, the number of lasers can be one. The number of detectors can be one. The lasers and detectors can form a single channel. Through the movement of the optomechanical structure and the reflective surface of the scanning mirror, a single-channel lidar can also achieve three-dimensional field-of-view scanning. This allows for large field-of-view detection at a lower cost.

[0056] Optical components can transmit and shape the optical signal generated by the laser. They can also transmit the echo and converge it to a detector. For example, such as... Figure 1As shown, the optical component 113 may include a single optical lens or an optical lens group composed of multiple optical lenses. Optionally, the laser's emitting optical path and the detector's receiving optical path may share some or all of the lenses. Alternatively, the laser's emitting optical path and the detector's receiving optical path may not share lenses.

[0057] In some embodiments, the optical axis of the optical element is parallel to the base. "The optical axis of the optical element is parallel to the base" means that the optical axis of the optical element can be approximately parallel to the surface of the base; for example, the angle between the optical axis of the optical element and the surface of the base can be 0°, or the angle between the optical axis of the optical element and the surface of the base can be less than 5°. Figure 1 As shown, the optical element 113 is disposed on the platform 118s of the base 118, and the optical axis of the optical element 113 is parallel to the platform 118s of the base 118.

[0058] In some embodiments, the optical axis of the optical element is perpendicular to the first rotation axis. The optical axis of the optical element being perpendicular to the first rotation axis means that the first rotation axis can be substantially perpendicular to the optical axis of the optical element; for example, the angle between the first rotation axis and the optical axis of the optical element is 90° or close to 90°, such as within the range of 85°-95°.

[0059] A scanning mirror can reflect light signals transmitted through optical components into the environment, and it can also reflect echoes from the environment back to the optical components.

[0060] The detection beam emitted by the laser passes through the optical components and scanning mirror in sequence before exiting into the environment; the detection beam is reflected by the object to form an echo; the echo passes through the scanning mirror and optical components in sequence before entering the detector.

[0061] Both the detection beam and the echo are transmitted through the scanning mirror 114. When the reflective surface 115 of the scanning mirror 114 moves around the second axis, it reflects the detection beam to different positions in the field of view and receives the echoes from different positions in the field of view. With the movement of the scanning mirror 114, the lidar can achieve field of view detection in the second direction.

[0062] For example, the reflective surface 115 of the scanning mirror 114 moves at an angle greater than or equal to 90° around the second rotation axis, and the maximum field of view of the second field of view is greater than or equal to 90°. This allows the lidar to have an ultra-large field of view greater than a hemisphere.

[0063] In some embodiments, the reflective surface of the scanning mirror can reciprocate about a second axis of rotation. For example... Figure 1As shown, the scanning mirror 114 can be a tilting mirror, and the reflective surface 115 of the scanning mirror 114 can reciprocate around the second axis, enabling the lidar to form a field of view within a preset angle range in the second direction. For example, with the horizontal direction as the reference direction, the preset angle range in the second direction can be -5° to +90°, 0° to +90°, 10° to +50°, etc. The preset angle range can be set according to the application scenario of the lidar.

[0064] In some embodiments, the second rotating shaft can extend horizontally, the reflective surface of the scanning mirror can move around the second rotating shaft, and the lidar can detect in the vertical direction to achieve a vertical field of view.

[0065] The optomechanical structure 110 moves around the first rotating axis 111, and the scanning mirror 114 moves around the second rotating axis. The lidar has two sets of rotating axis systems, which can detect the field of view in two directions respectively. By setting up two axis systems, a large detection field of view of the lidar can be achieved with a small number of lasers and detectors.

[0066] In some embodiments, the optical paths of the probe beam and the echo at least partially overlap. The probe beam and the echo are separated at least at the end closer to the laser and detector, and partially overlap at the end farther from the laser and detector. The optomechanical structure may include a beam-splitting element. The beam-splitting element enables the separation of the probe beam and the echo. For example, the beam-splitting element may be a polarizing beam splitter, a semi-transparent mirror, a pinhole mirror, etc.

[0067] like Figure 1 As shown, in some embodiments, the lidar includes a window 101. The window 101 is disposed above the platform 118s of the base 118. The window 101 can be hemispherical or similar to a hemispherical shape. The optomechanical structure 110 is located within the internal space enclosed by the window 101 and the platform 118s. The detection beam can be emitted in a direction perpendicular to the platform 118s of the base 118 (e.g., Figure 1 (As indicated by the solid black arrow in the middle); the detection beam can be directed towards the edge of the lidar window (e.g., Figure 1 (As indicated by the red dashed arrow in the middle). The range of window 101 allows the probe beam to be emitted at its maximum angle.

[0068] The angle between the second rotating shaft and the first rotating shaft 111 is greater than 0°.

[0069] In some embodiments, the second rotating shaft and the first rotating shaft 111 are tilted relative to each other. The tilt angle can be determined based on the scanning field of view of the lidar.

[0070] In some embodiments, the second axis of rotation is perpendicular to the first axis of rotation. This perpendicularity decouples the rotation of the optomechanical structure around the first axis from the angle of the rotation of the reflecting surface around the second axis relative to the emission direction of the detection beam, effectively simplifying the optical path structure: as the optomechanical structure moves around the first axis, the lidar can scan the field of view in the first direction; as the reflecting surface of the scanning mirror moves around the second axis, the lidar can scan the field of view in the second direction. The first and second directions are orthogonal to each other. When the reflecting surface of the scanning mirror and the optomechanical structure move simultaneously, the lidar can achieve three-dimensional field of view scanning.

[0071] In some embodiments, such as Figure 1 As shown, the first rotating axis 111 is perpendicular to the platform 118s of the base 118; the second rotating axis is parallel to the platform 118s of the base 118. For example, the platform 118s of the base 118 is parallel to the horizontal plane, the first rotating axis is perpendicular to the horizontal plane, and the second rotating axis is parallel to the horizontal plane. As the optomechanical structure 110 moves around the first rotating axis 111, the lidar can scan the horizontal field of view; as the reflective surface 115 of the scanning mirror 114 moves around the second rotating axis, the lidar can scan the vertical field of view; when the reflective surface 115 of the scanning mirror 114 and the optomechanical structure 110 move simultaneously, the lidar can achieve a three-dimensional field of view scan.

[0072] In some embodiments, the optical axis of the optical component is perpendicular to the second rotation axis. This perpendicularity effectively simplifies the optical path structure of the lidar and reduces assembly and adjustment complexity. Figure 1 As shown, the optical axis of the optical component 113 is parallel to the platform 118s of the base 118, the second rotation axis is perpendicular to the platform 118s of the base 118, and the optical axis of the optical component 113 is perpendicular to the second rotation axis.

[0073] In some embodiments, the optomechanical structure includes a mirror, which may be located in the optical path between the optical element and the scanning mirror. The mirror may receive a probe beam transmitted by the optical element and reflect the probe beam to the reflecting surface of the scanning mirror; the mirror may also receive an echo reflected from the reflecting surface of the scanning mirror and reflect the echo back to the optical element.

[0074] like Figure 1 As shown, the reflector 117 is fixed on the platform 118s of the base 118. The reflective surface of the reflector 117 faces the scanning mirror 114. The reflector 117 reflects the light transmitted by the optical component 113 to the reflective surface 115 of the scanning mirror 114, and reflects the echo reflected by the reflective surface 115 of the scanning mirror 114 back to the optical component 113.

[0075] In some embodiments, the scanning mirror includes a bearing and a support. The reflective surface of the scanning mirror moves about the bearing. The support is located at both ends of the bearing to secure it. The bearing extends along a second axis of rotation to allow rotation of the reflective surface of the scanning mirror. The support supports the bearing to secure it to the platform of the base.

[0076] In some embodiments, such as Figure 1 As shown, the optomechanical structure 110 includes a base 118, with a second rotating shaft parallel to the platform 118s of the base 118. A bearing 114a is parallel to the platform 118s of the base 118. A support member 114b can be at a certain angle to the platform 118s of the base 118, supporting the bearing 114a above the platform 118s. The bearing 114a is fixed to the end of the support member 114b away from the platform 118s of the base 118. Along a direction perpendicular to the platform 118s of the base 118, the dimensions of different support members 114b can be equal, allowing the bearing 114a to be arranged parallel to the platform 118s of the base 118.

[0077] In some embodiments, the reflective surface of the scanning mirror can rotate unidirectionally about a second axis. The number of reflective surfaces in the scanning mirror is greater than two.

[0078] For example, the scanning mirror is a rotating mirror with multiple reflective surfaces, which rotate unidirectionally about a second axis. Figure 2 A schematic cross-sectional view of an exemplary lidar consistent with some embodiments of this disclosure is shown.

[0079] Reference Figure 2 In some embodiments, in the optomechanical structure 210 located on the base 218, the scanning mirror 214 is an octagonal rotating mirror with eight reflective surfaces 215. The reflective surfaces 215 of the scanning mirror 214 rotate 360° around the bearing 214a. Optionally, the rotating mirror may include four, five, six, twelve, or other numbers of mirrors.

[0080] like Figure 2 As shown, transceiver 212 includes a laser and a detector. The probe light generated by the laser is transmitted through optical element 213 and reflected by mirror 217 onto a reflecting surface 215 of scanning mirror 214. The probe light, after being reflected by mirror 215, is emitted into the environment. The echo is incident on the reflecting surface 215 of scanning mirror 214, reflected by mirror 215, and then incident on mirror 217. The echo, after being reflected by mirror 217, is incident on optical element 213. Optical element 213 can converge the echo, causing it to be incident on the detector.

[0081] In some embodiments, the transceiver can be located in the space between the reflective surface of the scanning mirror and the base. This can effectively reduce the overall size of the lidar.

[0082] In some embodiments, the optomechanical structure moves about a first axis at a first frequency, and the reflecting surface of the scanning mirror moves about a second axis at a second frequency. The first frequency may be lower than the second frequency. The lower first frequency of the optomechanical structure's movement about the first axis and the lower second frequency of the scanning mirror's movement about the second axis effectively control the energy consumption of driving the movement of the optomechanical structure about the first axis and the scanning mirror's movement about the second axis, thereby effectively controlling the energy consumption of the lidar. In some embodiments, the first frequency may be higher than the second frequency.

[0083] In some embodiments, the ratio of the second frequency to the first frequency can be a non-integer. The scanning trajectories of adjacent frames of the lidar do not overlap, enabling the lidar to operate in a non-repetitive scanning mode. By scanning multiple frames, the point cloud density can be increased without increasing the number of channels.

[0084] In some embodiments, the ratio of the second frequency to the first frequency can be an integer. The scanning trajectories of adjacent frames of the lidar overlap, allowing the lidar to operate in a repetitive scanning mode. This enables the achievement of a high scanning frame rate.

[0085] Figure 3 This diagram illustrates a scanning path of an exemplary lidar consistent with some embodiments of the present disclosure. When the ratio of the second frequency to the first frequency is 10, the partial scanning path obtained by the lidar is as follows: Figure 3 As shown.

[0086] In some embodiments, the ratio of the second frequency to the first frequency can be a fixed value. Alternatively, the ratio of the second frequency to the first frequency can be an adjustable value. For example, the ratio of the second frequency to the first frequency can be changed by changing at least one of the first frequency or the second frequency. This allows the LiDAR to adjust the scanning mode and point cloud density according to the application scenario.

[0087] In summary, in the optomechanical structure disclosed herein, the second rotating axis is parallel to the reflecting surface, and the angle between the second rotating axis and the first rotating axis is greater than 0°. Using the optomechanical structure disclosed herein, a lidar with a larger detection field of view can be realized at a lower cost.

[0088] While the above disclosure is provided, it is not limited thereto. Any person skilled in the art may make various alterations and modifications without departing from the spirit and scope of this disclosure; therefore, the scope of protection of this disclosure shall be determined by the scope defined in the claims.

Claims

1. A lidar, characterized in that, include: An optomechanical structure, wherein the optomechanical structure moves about a first rotation axis; The optomechanical structure includes a transceiver, optical components, and a scanning mirror; The transceiver includes a laser and a detector; The scanning mirror includes a reflective surface that moves about a second axis, which is parallel to the reflective surface and the angle between the second axis and the first axis is greater than 0°.

2. The lidar as described in claim 1, characterized in that, The detection beam emitted by the laser passes through the optical element and the scanning mirror in sequence before exiting into the environment; the detection beam is reflected by an object to form an echo; the echo passes through the scanning mirror and the optical element in sequence before entering the detector.

3. The lidar as described in claim 1, characterized in that, The second rotating shaft is perpendicular to the first rotating shaft.

4. The lidar as described in claim 1, characterized in that, The optical paths of the detection beam and the echo at least partially overlap.

5. The lidar as described in claim 4, characterized in that, The optical axis of the optical component is perpendicular to the second rotating axis.

6. The lidar as described in claim 4, characterized in that, The optical axis of the optical component is perpendicular to the first rotating shaft.

7. The lidar as described in claim 1, characterized in that, The optomechanical structure also includes a reflector located in the optical path between the optical element and the scanning mirror.

8. The lidar as described in claim 1, characterized in that, The optomechanical structure further includes a base, to which the optical components and the transceiver are fixed.

9. The lidar as described in claim 8, characterized in that, The first rotating shaft is perpendicular to the base.

10. The lidar as described in claim 8, characterized in that, The second rotating shaft is parallel to the base.

11. The lidar as described in claim 8, characterized in that, The optical axis of the optical component is parallel to the base.

12. The lidar as described in claim 1, characterized in that, The scanning mirror includes: The bearing, the reflective surface of the scanning mirror moves around the bearing; Support members are located at both ends of the bearing to secure the bearing.

13. The lidar as described in claim 12, characterized in that, The support allows the reflective surface of the scanning mirror to move above the base; The transceiver is located between the reflective surface of the scanning mirror and the base.

14. The lidar as described in claim 1, characterized in that, The reflective surface of the scanning mirror reciprocates around the second axis.

15. The lidar as described in claim 1, characterized in that, The reflective surface of the scanning mirror rotates unidirectionally around the second axis; the number of reflective surfaces in the scanning mirror is greater than 2.

16. The lidar as described in claim 1, characterized in that, The optomechanical structure moves around the first rotating axis at a first frequency, and the reflective surface of the scanning mirror moves around the second rotating axis at a second frequency. Wherein, the first frequency is less than the second frequency.

17. The lidar as described in claim 16, characterized in that, The ratio of the second frequency to the first frequency is not an integer.

18. The lidar as described in claim 1, characterized in that, The transceiver includes multiple lasers.

19. The lidar as described in claim 1, characterized in that, The optomechanical structure moves around the first rotation axis to form a first field of view; the reflective surface of the scanning mirror moves around the second rotation axis to form a second field of view, wherein the maximum field of view of the first field of view is 360°, and the maximum field of view of the second field of view is greater than or equal to 90°.

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