Laser radar and device with detection function

Abstract

The embodiment of the present application discloses a laser radar and a device with a detection function. The laser radar comprises a window with optical power, a laser system, a scanning system and an off-axis optical unit. The laser system comprises a laser unit and a mirror group unit, the laser unit is used for emitting or receiving a light beam to form a laser light path between the window and the laser unit, and the mirror group unit is located on the laser light path. The scanning unit is located between the mirror group unit and the window on the laser light path, the laser light path forms a first off-axis amount between the optical axis between the scanning unit and the window and the optical axis of the window, the off-axis optical unit is located between the laser unit and the scanning unit and forms a second off-axis amount with the laser light path, and the second off-axis amount is used for compensating for the aberration caused by the first off-axis amount. The present application can realize the miniaturization of the laser radar, reduce or eliminate the off-axis aberration, and improve the quality of the laser radar.

Description

Technical Field

[0001] This invention relates to the field of laser detection technology, and more particularly to a lidar and a device with detection capabilities. Background Technology

[0002] LiDAR is an active detection system that can accurately detect the depth and distance of objects, both day and night. Compared to millimeter-wave radar and ultrasonic radar, LiDAR has a smaller wavelength, higher resolution, and higher ranging capability, making it an indispensable technology and direction in both military and civilian fields. Currently, the research and design of LiDAR faces many difficulties and challenges. Among them, achieving miniaturization of LiDAR systems while ensuring high performance and high quality is a key research direction for the industry. Summary of the Invention

[0003] This application provides a lidar and a device with detection function, which can ensure that the lidar is small in size while meeting the quality requirements of lidar.

[0004] In a first aspect, embodiments of this application provide a lidar, including a window, a laser system, a scanning unit, and an off-axis optical unit. The window has optical power in a first direction, which is either the collimation direction or the divergence direction of the laser system. The laser system includes a laser unit and a mirror unit. The laser unit is used to emit and / or receive a light beam (i.e., the laser unit can be an emitting unit or a receiving unit, or a general term for laser units with both emitting and receiving units), forming a laser optical path between the window and the laser unit. The mirror unit is located on the laser optical path. The scanning unit is located on the laser optical path between the mirror unit and the window, and is used to scan the light beam. The laser optical path is formed between the scanning unit and the window. A first optical axis is formed between the windows. In the first direction, a first off-axis amount is formed between the first optical axis and the second optical axis. The second optical axis is the optical axis of the window that is parallel to the first optical axis, i.e., the window has a center, and the position of the second optical axis is a line drawn from the center parallel to the first optical axis. An off-axis optical unit is located on the laser optical path and between the scanning unit and the laser unit. The laser optical path forms a third optical axis between the laser unit and the scanning unit. The optical axis of the off-axis optical unit is a fourth optical axis, which is parallel to the third optical axis. In the first direction, a second off-axis amount is formed between the fourth optical axis and the third optical axis. The second off-axis amount is used to compensate for the aberrations caused by the first off-axis amount.

[0005] The first optical axis can be understood as the line connecting the light reflection point on the scanning unit and the imaging spot of the laser light path; specifically, it can be the line connecting the center of the light reflection point and the center of the spot. The third optical axis can be understood as the line connecting the light emission / incidence position of the laser light path on the laser unit and the light reflection point on the scanning unit; specifically, it can be the line connecting the center of the light emission / incidence position and the center of the light reflection point.

[0006] This application achieves miniaturization of the lidar by setting the viewing window to have optical power, thus reducing the size of the lidar. However, due to the optical power of the viewing window, the non-collinearity between the first and second optical axes during scanning will generate off-axis aberration. Off-axis aberration refers to the asymmetric aberration caused by the non-collinearity between the first and second optical axes. Aberration refers to the discrepancy between the results obtained from non-paraxial ray tracing and paraxial ray tracing in actual optical lenses, deviating from the ideal state of Gaussian optics (first-order approximation theory or paraxial rays). The existence of off-axis aberration directly affects the image quality of the environment detected by the lidar.

[0007] Specifically, the presence of the first off-axis amount is the main factor causing off-axis aberration and affecting the quality of the image of the target environment detected by the lidar. This application compensates for the aberration caused by the first off-axis amount by setting an off-axis optical unit in the laser optical path. The setting of the off-axis optical unit can reduce or eliminate the aberration caused by the first off-axis amount. It can be understood that this application achieves complete or partial compensation for the aberration caused by the first off-axis amount by using a second off-axis amount. Therefore, this application can achieve miniaturization of lidar while reducing or eliminating off-axis aberration and improving the quality of lidar.

[0008] In one possible implementation, the off-axis optical unit is located between the scanning unit and the mirror assembly unit. Specifically, the off-axis optical unit and the mirror assembly unit are independent of each other and can have independent mounting structures. The driving and control of the off-axis optical unit by the control module can be independent of the driving and control of the mirror assembly unit. In this scheme, the off-axis optical unit can be used with different mirror assembly units, and different forms of off-axis optical units can be selected according to the internal configuration environment of the lidar, providing greater flexibility.

[0009] In one specific embodiment, the off-axis optical unit includes a first lens barrel, and the lens group unit includes a second lens barrel. By adjusting the positional relationship between the first lens barrel and the second lens barrel, the position of the off-axis optical unit is changed, and the second off-axis amount is adjusted.

[0010] In one specific embodiment, the lidar is provided with a sliding rail, the first lens barrel is slidably connected to the sliding rail, and the extension direction of the sliding rail is perpendicular to the direction of the fourth optical axis.

[0011] In one specific embodiment, the sliding track is provided with multiple positioning structures, and the off-axis optical unit is positioned at different positions through the cooperation of the positioning structures and the second lens barrel.

[0012] In one possible implementation, the off-axis optical unit is located within the mirror assembly unit. That is, the off-axis optical unit is integrated into the mirror assembly unit. The off-axis optical unit does not require a separate lens barrel structure; only the off-axis lens assembly of the off-axis optical unit needs to be installed within the lens barrel of the mirror assembly unit, with space reserved in the lens barrel for this installation. The advantage of this solution is that by integrating the off-axis optical unit and the mirror assembly unit into a single unit, an optical component with a second off-axis capability is formed. During the assembly of the lidar, only the lens barrel of the mirror assembly unit needs to be installed, saving internal space in the lidar, facilitating assembly, and reducing the manufacturing cost of the lidar.

[0013] In one possible implementation, the third optical axis and the fourth optical axis are not collinear, the second off-axis amount is a fixed value, and the first off-axis amount is a variable value. This solution can select a suitable value for the second off-axis amount based on the variation of the first off-axis amount to accommodate all possible first off-axis amounts during the scanning process of the scanning unit, thus compensating for aberrations caused by the first off-axis amount. Although the accuracy of the second off-axis amount in compensating for off-axis aberrations in this solution is not high, because the second off-axis amount is a fixed value, the design difficulty and manufacturing cost for LiDAR are relatively low. It can be used according to the specific application requirements; for example, in some scenarios where high accuracy in compensating for off-axis aberrations is not required, a low-cost LiDAR provided by this solution can be used. In a scheme where the second off-axis distance is fixed, this can be achieved by fixing the positions of the third and fourth optical axes. For example, both the off-axis optical unit and the laser system can be designed to be fixed inside the lidar housing. Alternatively, it can be achieved by fixing the positions of the third and fourth optical axes relatively. For example, the position of the off-axis optical unit can be movable, but the laser system also moves during the movement of the off-axis optical unit, ensuring that the distance between the third and fourth optical axes is a fixed value.

[0014] In one possible implementation, both the first off-axis amount and the second off-axis amount are variable values. This solution can adjust the value of the second off-axis amount according to the change of the first off-axis amount, thereby improving the accuracy of off-axis aberration compensation, performing real-time compensation, and improving the image quality of the lidar.

[0015] In one possible implementation, while the scanning unit scans the beam, the laser system remains stationary, and the off-axis optical unit is driven to move via a control module to change the second off-axis amount. This solution provides a more accurate real-time compensation method for off-axis aberrations.

[0016] In one possible implementation, when the first off-axis amount is within a first numerical range, and the second off-axis amount is at a first value, this can be understood as: a specific value of the second off-axis amount corresponds to a specific value of the first off-axis amount within a numerical range, i.e., a one-to-many relationship. Specifically, this scheme can achieve zoned compensation for off-axis aberrations. Compared to a scheme where the off-axis optical unit remains fixed, this scheme can achieve refined off-axis aberration compensation. Since the second off-axis amount can remain unchanged during scanning within a specific zone, the driving structure and control module for the second off-axis amount are easier to design, and costs can be better controlled.

[0017] In one possible implementation, during the scanning process of the scanning unit, the first off-axis amount includes N different first values, and the second off-axis amount includes N different second values, with a one-to-one correspondence between the N different first values ​​and the N different second values. This can be understood as follows: as the first off-axis amount changes, the second off-axis amount changes synchronously to achieve real-time compensation for aberrations caused by the first off-axis amount. This solution can achieve refined compensation and improve the imaging effect of the lidar.

[0018] In one possible implementation, the lidar further includes a storage module and a control module. The storage module stores the correspondence between the positions of the scanning unit and the off-axis optical unit. The control module is used to determine the target position of the off-axis optical unit corresponding to the real-time position of the scanning unit, and control the off-axis optical unit to move to the target position.

[0019] Specifically, the control module can be a processor, which may also be referred to as a control unit, controller, microcontroller, or other suitable term. The storage module can be a memory, which may be coupled to the processor or connected to the processor via a bus, for storing various software programs and / or multiple sets of instructions and data. In specific implementations, the memory may include high-speed random access memory, and may also include non-volatile memory, such as one or more disk storage devices, embedded multi-media cards (EMMC), universal flash storage (UFS), read-only memory (ROM), or flash memory, or other types of static memory capable of storing static information and instructions. The memory may also store one or more computer programs, which include program instructions for the methods described in this application. The memory may also store communication programs that can be used to communicate with a terminal.

[0020] Specifically, in one particular scheme, the storage module has a data table, which is a correspondence table of the positions of the scanning unit and the off-axis optical unit. The control module is used to retrieve the target position of the off-axis optical unit corresponding to the real-time position of the scanning unit from the data table according to the real-time position of the scanning unit, and drive the off-axis optical unit to move to the target position.

[0021] In one possible implementation, the first off-axis amount is L1, the second off-axis amount is L2, and |L2 / L1|≥0.1. This embodiment limits the relationship between the first and second off-axis amounts within this range, ensuring better off-axis aberration compensation. If the relationship between the first and second off-axis amounts exceeds this range, the compensation effect of the off-axis optical unit will be unsatisfactory.

[0022] In one possible implementation, the focal length of the off-axis optical unit is f1, the focal length of the viewport is f2, and 5 ≥ |f1 / f2| ≥ 0.2. This application's embodiments define the relationship between the focal lengths of the off-axis optical unit and the viewport, ensuring the effectiveness of off-axis aberration compensation. This can be understood as requiring the selection of a suitable off-axis optical unit to achieve the desired off-axis aberration compensation effect. If the relationship between the off-axis optical unit and the viewport is not within this range, the compensation effect of the off-axis optical unit will be unsatisfactory.

[0023] In one possible implementation, the focal length of the laser system is fr, and the focal length of the viewport is f2, where |f2 / fr| ≥ 0.5. Specifically, the focal lengths of the laser emitting system and the laser receiving system are within the range of 1mm to 100mm to ensure good off-axis aberration compensation for the off-axis optical unit. If this range is exceeded, the focal length of the viewport is too small, resulting in excessive off-axis aberration and unsatisfactory compensation from the off-axis optical unit.

[0024] In one possible implementation, the first direction is the collimation direction of the laser system, and the viewing window has positive optical power in the first direction. This solution can effectively reduce the spot size between the laser system and the viewing window, thereby reducing the size of the lidar, and can also utilize the optical power of the viewing window to achieve better collimation.

[0025] In one possible implementation, the first direction is the divergence direction of the laser system, and the window has a negative optical power in the first direction. This solution not only achieves a larger divergence angle but also effectively reduces the size of the window, thereby reducing the volume of the lidar.

[0026] In one possible implementation, the laser unit includes a transmitting unit and a receiving unit, which are arranged adjacent to each other on the same side of the scanning unit, or separately on opposite sides of the scanning unit. This solution defines a specific laser unit arrangement scheme.

[0027] In one possible implementation, the configuration of the transmitting unit and the receiving unit is adapted, and the mirror group unit includes a transmitting mirror unit and a receiving mirror unit, wherein the transmitting mirror unit is located between the transmitting unit and the scanning unit, and the receiving mirror unit is located between the receiving unit and the scanning unit.

[0028] In one possible implementation, the off-axis optical unit includes a first off-axis unit located between the transmitting unit and the scanning unit, and the optical axis of the first off-axis unit is the fourth optical axis. This solution defines a specific configuration scheme for the off-axis optical unit in a lidar, placing the first off-axis unit between the transmitting unit and the scanning unit, emphasizing off-axis compensation for the optical path of the transmitting unit. This implementation is beneficial for saving internal space in the lidar and for miniaturizing the lidar design.

[0029] In one possible implementation, the off-axis optical unit includes a second off-axis unit located between the receiving unit and the scanning unit, and the optical axis of the second off-axis unit is the fourth optical axis. This solution introduces a second off-axis unit based on the aforementioned first off-axis unit, adding an off-axis compensation scheme between the receiving unit and the scanning unit to achieve better imaging performance for the lidar.

[0030] In one possible implementation, the viewing window has optical power in the second direction. When the first direction is the collimation direction of the laser system, the second direction is the divergence direction of the laser system; when the first direction is the divergence direction of the laser system, the second direction is the collimation direction of the laser system. In the second direction, the laser optical path forms a third off-axis amount between the first optical axis formed between the scanning unit and the viewing window and the second optical axis of the viewing window. The fourth optical axis of the off-axis optical unit and the third optical axis formed between the laser optical path and the scanning unit form a fourth off-axis amount. This fourth off-axis amount is used to compensate for the aberrations caused by the third off-axis amount. This solution introduces an off-axis compensation scheme in the second direction. By setting off-axis compensation schemes in both the first and second directions, the imaging accuracy of the lidar is improved.

[0031] Secondly, embodiments of this application provide a device with detection capabilities, including a control center and a lidar as described in any possible implementation of the first aspect. The lidar is used to detect target signals and transmit the target signals to the control center. The control center can be a processor in the device with detection capabilities. In one specific embodiment, the control center is a microcontroller unit (MCU). The control center can also be used to control other electronic devices in the device, such as audio devices, display devices, etc. The audio devices and display devices can even be associated with the lidar. For example, the target signal collected by the lidar can be sent as an audio signal to the user through the audio device, or the target signal collected by the lidar can be displayed through the display device. The device with detection capabilities can be, but is not limited to, detection devices used in vehicles, robots, smart docks, and traffic roads.

[0032] Thirdly, embodiments of this application provide a device with detection capabilities, including a control module and the lidar described in the first aspect. The control module is used to drive the off-axis optical unit to move, thereby changing the second off-axis amount. This solution utilizes a control module within the device with detection capabilities, and since this control module is located outside the lidar, controlling the movement of the off-axis optical unit ensures the small size design of the lidar. The control module can also perform other control functions within the device with detection capabilities. The control module can be a processor within the device with detection capabilities.

[0033] Fourthly, embodiments of this application also provide a control system for a lidar system. The control system includes a first driving unit, a signal acquisition unit, a signal retrieval unit, and a second driving unit. The first driving unit drives a scanning unit; specifically, the first driving unit sends a driving signal to the scanning unit, causing the scanning unit to begin scanning the light beam. The signal acquisition unit detects the specific position of the scanning unit and acquires its position information. The signal retrieval unit retrieves target position information corresponding to an off-axis optical unit from a storage module based on the position information acquired by the signal acquisition unit. The second driving unit drives the off-axis optical unit to move to the target position based on the target position information of the off-axis optical unit obtained by the signal retrieval unit.

[0034] Fifthly, embodiments of this application provide a control method for a lidar, comprising the following steps:

[0035] Send a drive signal to the scanning unit;

[0036] The scanning unit begins scanning the beam;

[0037] During the scanning process of the scanning unit, the position information of the scanning unit is detected. Specifically, the position information can be the angle, coordinates, or positional relationship (e.g., distance) of the scanning unit relative to a certain reference.

[0038] The target position of the off-axis optical unit corresponding to the position information is determined based on the position information of the scanning unit. Specifically, the position information of the off-axis optical unit can be retrieved from the data table of the storage module by the control module, or the position information of the off-axis optical unit can be obtained by indexing.

[0039] Drive the off-axis optical unit to move to the target position. This target position is consistent with the position information corresponding to the retrieved off-axis unit. Specifically, the target position can be the specific coordinate position of the optical axis of the off-axis optical unit, or it can be the amount of movement of the off-axis optical unit, or its target position can be determined by the movement time. Therefore, in a specific driving scheme, the target position of the off-axis optical unit can be determined according to different physical properties or methods. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the background art, the accompanying drawings used in the embodiments of the present invention or the background art will be described below.

[0041] Figure 1 This is a schematic diagram of the first application scenario of the lidar provided in this application;

[0042] Figure 2 This is a schematic diagram of the second application scenario of the lidar provided in this application;

[0043] Figure 3 This is a schematic diagram of the third application scenario of the lidar provided in this application;

[0044] Figure 4 This is a schematic diagram of the fourth application scenario of the lidar provided in this application;

[0045] Figure 5 This is a schematic diagram of two different types of lidar provided in one embodiment of this application;

[0046] Figure 6 This is a schematic diagram of the internal structure of a lidar provided in one embodiment of this application;

[0047] Figure 7A , Figure 7B and Figure 8 This is a partial schematic diagram of a lidar provided in one embodiment of this application. Figure 7A and Figure 7B This is a schematic diagram of the cross-section of a lidar system on a plane defined by the X and Y directions. Figure 7A and Figure 7B These are schematic diagrams showing the scanning unit at different scanning positions. Figure 8 This is a cross-sectional schematic diagram of a lidar on a plane defined by the X and Z directions;

[0048] Figure 9A and Figure 9B This is a partial schematic diagram of a lidar provided in one embodiment of this application. Figure 9A and Figure 9B These are schematic diagrams of the scanning unit at different scanning positions;

[0049] Figure 10A and Figure 10B This is a partial schematic diagram of a lidar provided in one embodiment of this application. Figure 10A and Figure 10B These are schematic diagrams of the scanning unit at different scanning positions;

[0050] Figure 11A , Figure 11B and Figure 11C This is a schematic diagram of three specific structural arrangements between the off-axis optical unit and the mirror group unit in a lidar provided in one embodiment of this application;

[0051] Figure 12 This is a partial schematic diagram of a lidar provided in one embodiment of this application;

[0052] Figure 13A This is a schematic diagram of the internal optical path structure of a lidar according to one embodiment of this application;

[0053] Figure 13B yes Figure 13A The diagram shows the optical path of the lidar.

[0054] Figure 14 This is a diagram showing the internal optical path of a lidar according to one embodiment of this application. Detailed Implementation

[0055] The embodiments of the present invention will now be described with reference to the accompanying drawings.

[0056] The lidar provided in this application is used in devices with detection capabilities. LiDAR is used to detect and perceive objects in the spatial environment and can be applied in fields such as autonomous driving and robotics. The lidar involved in this application achieves external perception, acquires environmental data, and provides feedback on depth and contour information through active illumination and detection, assisting in various extended applications, such as autonomous driving, automatic route planning, automatic start or braking, and automatic parking. Specifically, the detection-capable devices can be, but are not limited to, detection devices used in vehicles, robots, smart ports, and traffic roads, covering numerous scenarios, such as... Figures 1 to 4 As shown, the details are as follows.

[0057] like Figure 1 As shown, in one embodiment, the device 1000 with detection function is a car. The lidar 100 is installed in the center of the front bumper or at one of the four corners. The lidar 100 can be used for automated driving assistance. Specifically, the lidar 100 can be a reversing radar or a front radar. As a safety device, the lidar 100 used in a car primarily functions to provide voice prompts and sound alarms to the driver in situations with no visibility or very poor visibility, or when encountering unpredictable obstacles, thereby preventing, reducing, or mitigating accidents. Figure 1As shown, three lidar sensors 100 (front-facing sensors) are installed at the front of the vehicle, and two lidar sensors 100 (reversing sensors) are installed at the rear. Specifically, the device 1000 with detection function includes a control center 200, which is electrically connected to the lidar sensors 100. The lidar sensors 100 are used to detect target signals and transmit the target signals to the control center 200. The lidar installation location shown in this application is merely an example, and this application does not limit the installation location of the lidar sensors.

[0058] The control center 200 can be a processor in a device with detection capabilities. In one specific embodiment, the control center 200 is a microcontroller unit (MCU). The control center 200 can also be used to control other electronic devices in the device 1000 with detection capabilities, such as audio devices, display devices, etc. It can even associate audio devices and display devices with the LiDAR. For example, the target signal collected by the LiDAR 100 can be sent to the user through the audio device, or the target signal collected by the LiDAR 100 can be displayed through the display device.

[0059] like Figure 2 and Figure 3 As shown, the detection device 1000 can be installed at smart docks or on transportation routes, for example, Figure 2 As shown, a detection device 1000 is installed at the intersection. The detection device 1000 can be a roadside bracket or utility pole (or other supporting equipment, such as temporary vehicles, guard booths, etc.). A lidar unit 100 is installed on the bracket or utility pole to detect the traffic environment at this intersection. Figure 3 As shown, a detection device 1000 is installed on the central safety island of a crossroads to detect the traffic environment around the intersection. The detection device 1000 can be a carrier (such as a billboard or sign) set on the central safety island of a crossroads, and the lidar 100 is installed on this carrier.

[0060] like Figure 4 As shown, in one embodiment, the device 1000 with detection function is a robot. The robot's head is equipped with a lidar 100. The lidar 100 can be located on the top of the robot's head to allow for rotation and expanded detection angles, or it can be located in other positions on the robot, such as the neck or chest. For the robot, radar detection is an essential functional component. The lidar 100 provides a portable and effective environmental description for the robot's navigation. For example, the lidar 100 can perform distance detection (or detection of other parameters).

[0061] In other embodiments, the device 1000 with detection function may also be a control device installed on the dock or a monitoring device installed on a building.

[0062] Figure 5 The diagram shown illustrates two different models of lidar 100 provided in one embodiment of this application. Figure 6 The diagram shown is a schematic representation of the internal structure of a lidar 100 provided in one embodiment of this application. (See attached diagram.) Figure 5 and Figure 6 The lidar 100 includes a housing 10 and a functional module disposed inside the housing 10. The housing 10 includes a main body 11 and a window 12. The main body 11 encloses a receiving space 111, and the functional module is located inside the receiving space 111. The main body 11 has an opening 112 connecting the receiving space 111 and the external space. The window 12 is connected to the main body 11 and blocks the opening 112. The light beam emitted by the lidar 100 shines through the window 12 onto the external environment to be detected, and the light from the external environment to be detected enters the interior of the lidar 100 through the window 12. Figure 5 The lidar 100 shown in the upper figure has a window 12 with optical power. The outer surface of the window 12 is arc-shaped, and the inner surface of the window 12 can be either arc-shaped or flat. Figure 5 The lidar 100 shown in the lower figure also has an optical power in its window 12. The outer surface of the window 12 is planar, and the inner surface of the window 12 is curved. This application reduces the spatial volume of the lidar 100 by setting the window 12 to an optical power architecture, thereby achieving a miniaturized design of the lidar 100.

[0063] Laser emission systems can be classified into two categories based on the shape of the emitted light: point emission and line emission. Point emission requires the emitted beam to be collimated, so that the emitted light spot is a point at long distances, thereby defining the collimation direction of the emitted beam. Line emission requires the emitted beam to be a long, thin line beam. Therefore, a lidar has two directions (collimation direction and divergence direction). If the emitted beam is a long, thin line in the longitudinal direction, then the transverse direction is the collimation direction, and the longitudinal direction is the divergence direction. This application defines the first direction as either the collimation direction or the divergence direction of the laser system. When the first direction is the collimation direction of the laser system, the second direction is the divergence direction of the laser system; when the first direction is the divergence direction of the laser system, the second direction is the collimation direction of the laser system.

[0064] In one embodiment, the window 12 has a positive optical power in the collimation direction of the laser system, which can effectively reduce the spot size between the laser system and the window 12, thereby reducing the volume of the lidar 100. It can also achieve better collimation by utilizing the optical power of the window 12. In another embodiment, the window 12 has a negative optical power in the divergence direction of the laser system, which not only provides a larger divergence angle but also effectively reduces the size of the window 12, thereby reducing the volume of the lidar 100. In yet another embodiment, the window 12 has a positive optical power in the collimation direction of the laser system and a negative optical power in the divergence direction of the laser system.

[0065] For window 12, the focal length in the meridional direction and the focal length in the arcuate direction may differ. The meridional direction and the arcuate direction refer to two mutually perpendicular directions of the arcuate surface (the part with optical power) of the window. The focal length f2 of window 12 mentioned later in this application can be either the focal length of window 12 in the meridional direction or the focal length of window 12 in the arcuate direction.

[0066] like Figure 6 As shown, the functional modules housed within the housing 10 include at least a laser system 20, a scanning unit 30, an off-axis optical unit 40, a storage module 50, and a control module 60.

[0067] The laser system 20 includes a laser unit 21 and a mirror unit 22. The laser unit 21 is used to emit and / or receive a light beam to form a laser optical path between the viewing window 12 and the laser unit 21. The mirror unit 22 is located on the laser optical path and is used to adjust the light beam, for example, by changing the divergence, beamwidth and cross-sectional area of ​​the emitted light beam, collimating and shaping the light beam, adjusting the field of view, and eliminating stray light.

[0068] The lens group unit 22 may include multiple lenses, which may include, but are not limited to: spherical lenses, aspherical lens groups, cylindrical lenses, cylindrical lens groups, cylindrical lens plus spherical lens groups, spherical plus aspherical combined lens groups, etc.

[0069] The scanning unit 30 may include, but is not limited to: MEMS two-dimensional scanning element, multi-faceted mirror rotating scanning element, one-dimensional pendulum mirror scanning element, and wedge prism group rotating scanning element. By rotating or oscillating the scanning unit 30, the beam transmitted and received by the laser unit 21 can be scanned, so that the beam transmitted and received by the laser unit 21 can cover the scene to be detected.

[0070] The off-axis optical unit 40 may include a lens with optical power. The off-axis optical unit 40 is disposed between the laser unit 21 and the scanning unit 30, and the optical axis of the off-axis optical unit 40 is not collinear with the optical axis of the mirror group unit 22. The optical axis of the off-axis optical unit 40 and the optical axis of the mirror group unit 22 can be parallel to each other or form an angle. Specifically, the off-axis optical unit 40 and the mirror group unit 22 need to be provided in both the emission and receiving optical paths of the laser system 20.

[0071] The control module 60 may be a processor, which may also be referred to as a control unit, controller, microcontroller, or other suitable term. The storage module 50 may be a memory, which may be coupled to the processor or connected to the processor via a bus, for storing various software programs and / or multiple sets of instructions and data. Specifically, the memory may include high-speed random access memory, and may also include non-volatile memory, such as one or more disk storage devices, embedded multi-media cards (EMMC), universal flash storage (UFS), read-only memory (ROM), or flash memory, or other types of static memory capable of storing static information and instructions. The memory may also store one or more computer programs, which include program instructions for the methods described in this application. The memory may also store a communication program that can be used to communicate with a terminal.

[0072] In one embodiment, the storage module 50 contains a data table that represents the correspondence between the positions of the scanning unit 30 and the off-axis optical unit 40. Alternatively, the correspondence can be established using an index. The control module 60 is electrically connected to the storage module 50. The control module 60 can read the data table from the storage module 50. The control module 60 is also used to control the movement of the scanning unit 30 and the off-axis optical unit 40. In summary, the control module 60 retrieves the target position of the off-axis optical unit 40 corresponding to the real-time position of the scanning unit 30 from the data table and drives the off-axis optical unit 40 to move to the target position.

[0073] Figure 7A , Figure 7B and Figure 8 The image shown is a partial schematic diagram of a lidar system provided in one embodiment. Figure 7A and Figure 7B This is a schematic diagram of the cross-section of a lidar system on a plane defined by the X and Y directions. Figure 7A and Figure 7BThese are schematic diagrams of the scanning unit 30 at different scanning positions. Figure 8 This is a cross-sectional schematic diagram of a lidar on a plane defined by the X and Z directions.

[0074] Figure 7A and Figure 7B The diagram schematically illustrates the laser optical path between laser unit 21 and viewport 12. For example... Figure 7B As shown, the laser unit 21 includes a transmitting unit 211 and a receiving unit 212. The transmitting unit 211 is used to emit a laser beam. The transmitting unit 211 is also called a laser source. The transmitting unit 211 includes, but is not limited to, semiconductor, fiber, gas, and solid-state lasers. The wavelength λ of the laser emitted by the transmitting unit 211 satisfies the condition 850nm≤λ≤2000nm. The receiving unit 212 is used to receive the laser beam and perform photoelectric conversion, converting the optical signal into an electrical signal. The receiving unit 212 is also called a laser receiver detector. The receiving unit 212 includes, but is not limited to, avalanche diodes (APDs), silicon photomultiplier tubes (SIPMs), APD arrays, multi-pixel photon counters (MPPCs), photomultiplier tubes (PMTs), and single-photon avalanche diodes (SPADs). Both the transmitting unit 211 and the receiving unit 212 require mirror units 22. In the laser optical path, the beam is received by the receiving unit 212 after passing through the mirror unit 22. The beam emitted by the transmitting unit 211 also needs to pass through the mirror unit 22 to form a laser optical path. Specifically, the light beam emitted by the transmitting unit 211 passes through the mirror group unit 22 and is reflected by the scanning unit 30 to the viewing window 12. The light beam then exits through the viewing window 12 and illuminates the scene to be detected, thus forming a laser light path between the transmitting unit 211 and the viewing window 12. The path of the light beam received by the receiving unit 212 is as follows: the light beam in the scene to be detected enters the interior of the lidar 100 through the viewing window 12, is reflected by the scanning unit 30 to the mirror group unit 22, and converges at the receiving unit 212 after passing through the mirror group unit 22, thus forming a laser light path between the receiving unit 212 and the viewing window 12. The scanning unit 30 in the lidar 100 provided in this application is positioned between the mirror group unit 22 and the viewing window 12 on the laser light path.

[0075] In this embodiment, the transmitting unit 211 and the receiving unit 212 are arranged adjacent to each other on the same side of the scanning unit 30. In a specific embodiment, the transmitting unit 211 and the receiving unit 212 are arranged side by side with a gap between them. This gap is for assembling optical elements, and there are no other optical elements, electronic devices, or mechanical structural components between the transmitting unit 211 and the receiving unit 212. This embodiment is beneficial for saving internal space of the lidar and for miniaturizing the lidar design.

[0076] Figure 8 from Figure 7AAnother direction shows the positional relationship between the transmitting unit 211 and the receiving unit 212. There are two mirror units 22, one of which is located between the transmitting unit 211 and the scanning unit 30, and the other of which is located between the receiving unit 212 and the scanning unit 30. There are two off-axis optical units 40, one of which is located between the transmitting unit 211 and the scanning unit 30, and the other of which is located between the receiving unit 212 and the scanning unit 30.

[0077] Figure 7A , Figure 7B The illustrated embodiment is a schematic diagram of the optical path of the laser system in the first direction. The first direction is the collimation direction of the laser system, which can be understood as the optical path architecture on the plane defined by the X and Y directions. In this embodiment, the window 12 has positive optical power in the collimation direction and can have either positive or negative optical power in the divergence direction. For example, the specific shape of the window 12 is as follows: the outer surface of the window 12 is an outwardly protruding arc-shaped surface, and the inner surface of the window 12 is a plane. This solution does not limit the specific shape of the window 12. When the outer surface of the window 12 is an outwardly protruding arc-shaped surface, the inner surface of the window 12 can also be a protruding arc surface or a concave arc surface.

[0078] like Figure 7A , Figure 7B and Figure 8As shown, the laser light path forms a first optical axis A1 between the scanning unit 30 and the viewing window 12, and a third optical axis A3 between the scanning unit 30 and the laser unit 21. During the scanning process, the position of the third optical axis A3 is fixed, while the position of the first optical axis A1 changes with the position of the scanning unit 30. Since the viewing window 12 has optical power, its optical axis is the second optical axis A2. Specifically, the viewing window 12 includes an arc-shaped surface with a center. The viewing window 12 may have multiple optical axes, all of which are lines passing through the center. The second optical axis A2 is a line drawn from the center of the viewing window 12, parallel to the first optical axis A1. The first optical axis A1 and the second optical axis A2 are not collinear, and the second optical axis A2 of the viewing window corresponding to the first optical axis A1 of the laser light path at different positions is also different. Because the viewing window 12 has optical power, during the scanning process, the non-collinearity between the first optical axis A1 and the second optical axis A2 of the scanning unit 30 will generate off-axis aberration. The existence of off-axis aberration directly affects the image quality of the environment to be detected by the lidar 100. Specifically, the second optical axis A2 of the viewing window 12 and the first optical axis A1 of the laser optical path constitute a first off-axis amount L1. The existence of the first off-axis amount L1 is the main factor causing off-axis aberration and affecting the image quality of the environment to be detected by the lidar 100. This application compensates for the aberration caused by the first off-axis amount L1 by setting an off-axis optical unit 40 on the laser optical path. That is, by setting the off-axis optical unit 40, the aberration caused by the first off-axis amount can be reduced or eliminated, achieving complete or partial compensation for the aberration caused by the first off-axis amount L1. Specifically, the off-axis optical unit 40 is disposed between the scanning unit 30 and the laser unit 21. The optical axis of the off-axis optical unit 40 is the fourth optical axis A4. The fourth optical axis A4 and the third optical axis A3 constitute the second off-axis amount L2. The second off-axis amount L2 is used to compensate for the aberration caused by the first off-axis amount L1. Figure 7A and Figure 7B The dotted lines in the diagram represent the first optical axis A1, the second optical axis A2, the third optical axis A3, and the fourth optical axis A4.

[0079] The relationship between the second off-axis amount L2 and the first off-axis amount L1 satisfies: |L2 / L1|≥0.1. This embodiment limits the relationship between the first off-axis amount L1 and the second off-axis amount L2 to this range, ensuring better off-axis aberration compensation. If the relationship between the first off-axis amount L1 and the second off-axis amount L2 exceeds this range, the compensation effect of the off-axis optical unit 40 may not be as good as within this range.

[0080] The focal length of the off-axis optical unit 40 is f1, and the focal length of the window 12 is f2, where 5 ≥ |f1 / f2| ≥ 0.2. This embodiment of the application defines the relationship between the focal lengths of the off-axis optical unit 40 and the window 12, which can ensure a better effect of off-axis aberration compensation. It can be understood that only by selecting a suitable off-axis optical unit 40 can the ideal off-axis aberration compensation effect be achieved. If the relationship between the off-axis optical unit 40 and the window 12 is not within this range, the compensation effect of the off-axis optical unit 40 may not be as good as that within this range.

[0081] The emitting unit 211 emits a laser beam, which is reflected by the scanning unit 30 and then emitted from the viewing window 12 to form a laser emitting system. The relationship between the focal length ft of the laser emitting system and the focal length f2 of the viewing window satisfies: |f2 / ft|≥0.5. The receiving unit 212 receives the laser beam through a path where the beam enters the lidar from the viewing window, is reflected by the scanning unit, and is received by the receiving unit 212 through the mirror group unit 22 to form a laser receiving system. The relationship between the focal length fr of the laser receiving system and the focal length f2 of the viewing window 12 satisfies: |f2 / fr|≥0.5. In a specific embodiment, the focal lengths of the laser emitting system and the laser receiving system are within the range of 1mm to 100mm to ensure that the off-axis optical unit 40 has a good off-axis aberration compensation effect. If this range is exceeded, the focal length of the viewing window 12 is too small, and the resulting off-axis aberration will be too large, resulting in an unsatisfactory compensation effect of the off-axis optical unit 40.

[0082] Figure 7A Figure 7B shows the specific positions of the first optical axis A1 and the second optical axis A2 of the scanning unit 30 in the first position. Figure 7B shows the specific positions of the first optical axis A1 and the second optical axis A2 of the scanning unit 30 in the second position. In this embodiment, the positions of the third optical axis A3 and the fourth optical axis A4 of the scanning unit 30 are fixed in both the first and second positions. This can be understood as the positional relationship between the laser unit 21, the mirror group unit 22, and the off-axis optical unit 40 being fixed. In other embodiments, the off-axis optical unit 40 can also be set to a movable state. During the scanning process of the scanning unit 30, the off-axis optical unit 40 moves synchronously, and thus the position of the fourth optical axis A4 also changes accordingly.

[0083] like Figure 8As shown, a transmitting mirror unit 22A and a first off-axis unit 40A are arranged in the laser optical path between the transmitting unit 211 and the scanning unit 30, and a receiving mirror unit 22B and a second off-axis unit 40B are arranged in the laser optical path between the receiving unit 212 and the scanning unit 30. The configuration of the transmitting mirror unit 22A and the receiving mirror unit 22B (referring to the number, size, and structural form of the lenses) can be the same or different; the configuration of the first off-axis unit 40A and the second off-axis unit 40B (referring to the number, size, and structural form of the lenses) can be the same or different.

[0084] Figure 9A and Figure 9B The implementation methods shown are the same as Figure 7A and Figure 7B The main difference between the embodiments shown is: Figure 9A and Figure 9B The diagram shows the optical path of the laser system in the second direction, which is the divergence direction of the laser system. The second direction can be understood as the optical path architecture on the plane defined by the X and Z directions. In this embodiment, the window 12 has a negative optical power in the divergence direction of the laser system. For example, the outer surface of the window 12 is planar, and the inner surface of the window 12 is a concave arc-shaped surface. Figure 9A The image shows the specific positions of the first optical axis A1 and the second optical axis A2 of the scanning unit 30 in the first position. Figure 9B The diagram shows the specific positions of the first optical axis A1 and the second optical axis A2 of the scanning unit 30 in the second position. In this embodiment, the position of the third optical axis A3 of the scanning unit 30 is fixed in both the first and second positions. This can be understood as the positional relationship between the laser unit 21 and the mirror group unit 22 being fixed, but the position of the off-axis optical unit 40 changing, causing the position of the fourth optical axis A4 to change. Figure 9A and Figure 9B This is merely a schematic representation of the different positions of the off-axis optical unit 40 and the fourth optical axis A4 in two states, and is not intended to limit the specific positional relationship between the off-axis optical unit 40 and the scanning unit 30. Depending on the specific application environment, the positions of the off-axis optical unit 40 and the fourth optical axis A4 may change.

[0085] Figure 10A and Figure 10B The implementation methods shown are the same as Figure 9A and Figure 9B The main difference between the embodiments shown is: Figure 10A and Figure 10BThe diagram shows the optical path of the laser system in the first direction, which is the collimation direction of the laser system. The first direction can be understood as the optical path architecture on the plane defined by the X and Y directions. In this embodiment, the window 12 has positive optical power in the collimation direction of the laser system. The outer surface of the window 12 is an outwardly protruding arc-shaped surface, and the inner surface of the window 12 is a concave arc-shaped surface. Figure 10A and Figure 10B In the embodiment shown, the center position O of the arc surface of the window 12 is shown, and the second optical axis A2 is located on a line parallel to the first optical axis A1, which is drawn from this center O.

[0086] In one embodiment, the off-axis optical unit 40 is located between the scanning unit 30 and the mirror group unit 22. Figure 11A , Figure 11B and Figure 11C The diagram shows three specific implementations of the structural arrangement between the off-axis optical unit 40 and the lens group unit 22.

[0087] Figure 11A In the illustrated embodiment, the off-axis optical unit 40 and the lens group unit 22 are independent of each other and can have independent mounting structures. No connection may be established between the off-axis optical unit 40 and the lens group unit 22. The control module's driving and control of the off-axis optical unit 40 and the driving and control of the lens group unit 22 can be independent of each other. In this scheme, the off-axis optical unit 40 can be used with different lens group units 22, and different forms of off-axis optical units 40 can be selected according to the internal configuration environment of the lidar, offering greater flexibility. Specifically, the off-axis optical unit 40 includes an off-axis lens group 41 and a first lens barrel 42. The first lens barrel 42 is used to mount the off-axis lens group 41 and connect the off-axis lens group 41 to the inside of the lidar 100. The first lens barrel 42 may be fixedly connected inside the lidar. The off-axis lens group 41 can be composed of one lens or a combination of at least two lenses. Figure 11A This is merely an illustrative representation that the off-axis lens group 41 has two lenses, and does not constitute a limitation on the shape, number, or positional relationship of the lenses in the off-axis lens group 41. The lens group unit 22 includes an optical lens group 221 and a second lens barrel 222. The second lens barrel 222 is used to mount the optical lens group 221 and fix the optical lens group 221 inside the lidar 100. The optical lens group 221 can be a single lens or a combination of at least two lenses. Figure 11A This is merely a schematic representation that the optical lens group 221 has three lenses, and does not constitute a limitation on the shape, number, or positional relationship of the lenses in the optical lens group 221. Figure 11AIn the illustrated embodiment, both the first lens barrel 42 and the second lens barrel 222 are fixedly disposed inside the lidar 100. The second off-axis amount L2 is a fixed value. This solution can select a suitable value for the second off-axis amount L2 based on the change of the first off-axis amount L1 to accommodate all possible occurrences of the first off-axis amount L1 during the scanning process of the scanning unit 30, thereby compensating for the aberrations caused by the first off-axis amount L1. Since the second off-axis amount is a fixed value, the design difficulty and manufacturing cost of the lidar are relatively low. Depending on the specific application scenario, for example, in some scenarios where high accuracy in compensating for off-axis aberrations is not required, the low-cost lidar provided by this solution can be used.

[0088] Figure 11B The implementation methods shown are the same as Figure 11A The difference between the embodiments shown is that: Figure 11BIn the illustrated embodiment, the position of the off-axis optical unit 40 can be changed by adjusting the positional relationship between the first lens barrel 42 and the second lens barrel 222, thereby adjusting the value of the second off-axis amount L2. For example, the first lens barrel 42 can be slidably connected inside the lidar, and the second off-axis amount L2 can be changed by driving the first lens barrel 42 to slide via a motor. Specifically, a sliding track 43 is provided inside the lidar, extending along the radial direction RR (i.e., perpendicular to the fourth optical axis). The first lens barrel 42 is slidably connected to this sliding track 43. The sliding track 43 is also provided with multiple positioning structures 432 spaced apart along the radial direction RR. The positioning structures 432 are used to position the first lens barrel 42. Through the cooperation between the specific positioning structures 432 and the first lens barrel 42, the off-axis optical unit 40 can be switched between multiple different positions. During the scanning process of the scanning unit 30, the scanning position of the scanning unit 30 can be divided into multiple regions, each region corresponding to a specific position defined by the positioning structure 432. By positioning the off-axis optical unit 40 at different positions, each different position can correspond to a region scanned by the scanning unit 30. That is, in this embodiment, the value of a second off-axis amount L2 corresponds to a range of a first off-axis amount L1. When the second off-axis amount L2 is a first value, the first off-axis amount L1 is within a first numerical range, and the first numerical range includes at least two different second off-axis amounts L2. In the data table of the storage module, the scanning position of the scanning unit 30 and the position of the off-axis optical unit 40 can have a many-to-one relationship. In other embodiments, the first lens barrel 42 can be positioned at any position on the sliding track 43. For example, the sliding track 43 and the first lens barrel 42 are limited by friction, eliminating the need for a specific positioning structure. Friction as a limiting structure can limit the first lens barrel 42 to any position. In this solution, during the scanning process of the scanning unit 30, as the first off-axis amount L1 changes, the second off-axis amount L2 changes synchronously to achieve real-time compensation for the aberration caused by the first off-axis amount L1. That is, during the scanning process of the scanning unit 30, the first off-axis amount L1 has N different first values, and the second off-axis amount L2 has N different second values. There is a one-to-one correspondence between the N different first values ​​and the N different second values. Each value of the first off-axis amount L1 corresponds to a different value of the second off-axis amount L2. In the data table of the storage module, the scanning position of the scanning unit 30 and the position of the off-axis optical unit 40 are in a one-to-one correspondence, rather than a many-to-one relationship.

[0089] Figure 11CIn the illustrated embodiment, the off-axis optical unit 40 is housed within the lens assembly unit 22. This means the off-axis optical unit 40 is integrated into the lens assembly unit 22. The off-axis optical unit 40 does not require a separate lens barrel structure; only the off-axis lens group 41 of the off-axis optical unit 40 needs to be installed within the lens barrel 223 of the lens assembly unit 22. The lens barrel 223 of the lens assembly unit 22 is reserved to accommodate the off-axis lens group 41 of the off-axis optical unit 40. Alternatively, this solution can be understood as having some lenses in the lens assembly unit 22 with the optical axis of the third optical axis A3 and others with the optical axis of the fourth optical axis A4. The advantage of this solution is that by integrating the off-axis optical unit 40 and the lens assembly unit 22 into a single unit, forming an optical component with a second off-axis amount, only the lens barrel of the lens assembly unit 22 needs to be installed during the assembly of the lidar. This not only saves internal space in the lidar but also facilitates assembly, reducing the manufacturing cost of the lidar. Specifically, the lens barrel 223 of the lens assembly unit 22 includes a first region 2231 and a second region 2232. The first region 2231 is used to mount a lens with the optical axis of the third optical axis A3, and this part of the lens is the optical lens assembly 221 of the lens assembly unit 22. The second region 2232 is used to mount a lens with the optical axis of the fourth optical axis A4, and this part of the lens is the off-axis lens assembly 41 of the off-axis optical unit 40. In one embodiment, the dimension of the second region 2232 in the direction perpendicular to the third optical axis A3 is larger than the radial dimension of the off-axis lens assembly 41 in the second region 2232, and the space within the second region 2232 can allow the off-axis lens assembly 41 therein to move radially. In one embodiment, a moving track 224 is provided in the second region 2232 of the lens barrel 223. The moving track 224 extends in the direction perpendicular to the third optical axis A3. The off-axis lens assembly 41 of the off-axis optical unit 40 is slidably connected to the moving track 224, and the second off-axis amount L2 can be changed by the movement of the off-axis lens 41 on the moving track 224. A limiting structure 2242 can also be set on the moving track 224. The limiting structure 2242 is used to limit the off-axis lens group 41 to multiple different positions. In this solution, the optical lens group 221 of the lens group unit 22 (i.e., the part of the lens with the optical axis of the third optical axis A3) can be fixed inside the lens barrel 223. That is, the position of the third optical axis A3 is fixed relative to the position of the lens barrel 223. By setting the part of the off-axis lens group 41 with the optical axis of the fourth optical axis A4 to be slidably connected to the lens barrel 223, the position of the fourth optical axis A4 can be changed, thereby changing the second off-axis amount L2.

[0090] Figure 11B and Figure 11C The embodiments shown all involve setting the second off-axis amount L2 from the first direction. Alternatively, the second off-axis amount L2 can be adjusted. The first direction can be understood as the optical path architecture on the plane defined by the X and Y directions. For example, the second off-axis amount L2 can be set in the collimation direction of the laser system, or it can be adjusted.

[0091] In one specific implementation, an off-axis optical element can also be configured in the second direction to perform off-axis aberration compensation. The second direction can be understood as the optical path architecture on the plane defined by the X and Z directions. When the first direction is the collimation direction of the laser system, the second direction is the divergence direction of the laser system; when the first direction is the divergence direction of the laser system, the second direction is the collimation direction of the laser system. In the second direction, the optical axis formed between the scanning unit and the viewing window and the optical axis of the viewing window constitute a third off-axis amount. The optical axis of the off-axis optical element and the optical axis formed between the scanning unit and the laser unit constitute a fourth off-axis amount. This fourth off-axis amount is used to compensate for the aberrations caused by the third off-axis amount.

[0092] In summary, in the lidar provided by this application embodiment, during the scanning process of the scanning unit 30, the first off-axis amount L1 is a variable value. As the scanning unit 30 scans at different positions, the position of the second optical axis A2 of the viewing window 12 is different, therefore the first off-axis amount L1 between the second optical axis A2 and the first optical axis A1 of the laser optical path is also different. As for the second off-axis amount L2, when the off-axis optical unit 40 is fixedly disposed inside the lidar 100, the second off-axis amount L2 is also a fixed value; when the off-axis optical unit 40 is slidably connected inside the lidar 100, the off-axis optical unit 40 moves synchronously during the scanning process of the scanning unit 30, and the second off-axis amount L2 changes accordingly. Therefore, the second off-axis amount L2 can also be a variable value, so that during the scanning process of the scanning unit 30, the off-axis optical unit 40 can compensate for off-axis aberrations in real time, ensuring the image quality of the lidar 100.

[0093] The scheme for making the second off-axis amount L2 a variable value can include two specific schemes. In the first specific scheme, during the scanning process of the scanning unit 30 scanning the beam, the second off-axis amount L2 can have multiple different values. Each specific value of the second off-axis amount L2 corresponds to at least two different values ​​of the first off-axis amount L1. That is, each value of the second off-axis amount L2 corresponds to different values ​​of the first off-axis amount L1 within a certain range, realizing zoned compensation for off-axis aberration. Compared with the scheme where the off-axis optical unit 40 is fixed, this scheme can achieve fine-grained off-axis aberration compensation. Since the second off-axis amount L2 can remain unchanged during the scanning process within a specific zone, the driving structure and control module of the second off-axis amount L2 are easier to design, and the cost can be better controlled. In the second specific scheme, during the scanning process of the scanning unit 30 scanning the beam, the second off-axis amount L2 and the first off-axis amount L1 are in a one-to-one correspondence. As the first off-axis amount L1 changes, the second off-axis amount L2 changes synchronously to achieve real-time compensation for the aberration caused by the first off-axis amount L1. The real-time compensation scheme for off-axis aberration provided by this scheme has higher accuracy.

[0094] In the above scheme, during the scanning process of the scanning unit 30, the laser system (referring to the emitting unit, the receiving unit, and their corresponding mirror group units) remains stationary, and the second off-axis amount L2 is changed by the movement of the off-axis optical unit 40. In other embodiments, the second off-axis amount L2 can also be changed by synchronously changing the laser system, that is, by synchronously changing the positions of the third optical axis A3 and the second optical axis A2; or, by changing the position of the third optical axis A3 while keeping the position of the second optical axis A2 unchanged.

[0095] Figure 12 The diagram shows a schematic of a lidar according to one embodiment. The laser unit 21 includes a transmitting unit 211 and a receiving unit 212, which are separately disposed on opposite sides of the scanning unit 30. There are two mirror units 22: a transmitting mirror unit 22A and a receiving mirror unit 22B. The transmitting mirror unit 22A is located between the transmitting unit 211 and the scanning unit 30, and the receiving mirror unit 22B is located between the receiving unit 212 and the scanning unit 30. There are two off-axis optical units 40: a first off-axis unit 40A and a second off-axis unit 40B. The first off-axis unit 40A is located between the transmitting unit 211 and the scanning unit 30, and the second off-axis unit 40B is located between the receiving unit 212 and the scanning unit 30. This solution improves the detection accuracy of the lidar 100 by arranging the transmitting unit 211 and the receiving unit 212 on opposite sides of the scanning unit 30, thus separating the laser emission path and the laser reception path. Figure 12 In the embodiment shown, there are two of each of the first optical axis A1, the second optical axis A2, the third optical axis A3, and the fourth optical axis A4. Both second optical axes A2 are located on lines parallel to the corresponding first optical axis A1, drawn from the center O of the arc surface of the viewing window 12.

[0096] Figure 13A and Figure 13B The diagram shown is a schematic representation of the internal optical path of a lidar according to one embodiment of this application, where the scanning unit 30 is not shown. Figure 13A In this embodiment, the window 12 has negative optical power in the divergence direction of the laser system, the inner surface of the window 12 is a concave arc surface, the outer surface of the window 12 is a convex arc surface, and the off-axis optical unit 40 is composed of a lens with positive optical power. Figure 13A In the illustrated embodiment, the focal length f1 of the off-axis optical unit 40 and the focal length f2 of the viewing window satisfy: f1 / f2 = -0.9; the second off-axis amount L2 of the fourth optical axis A4 of the off-axis optical unit 40 relative to the third optical axis A3 of the laser system 20 (laser unit 21 and mirror group unit 22) and the first off-axis amount L1 of the first optical axis A1 of the laser system relative to the optical axis (second optical axis A2) of the viewing window 12 satisfy: L2 / L1 = -0.73; the focal length f2 of the viewing window and the focal length ft of the laser emitting system (composed of emitting unit 211 and mirror group unit 22) satisfy f2 / ft = -7; the focal length f2 of the viewing window and the focal length fr of the laser receiving system (composed of receiving unit 212 and mirror group unit 22) satisfy f2 / ft = -7. Figure 13B for Figure 13A The illustrated embodiment provides a specific optical path diagram of the lidar.

[0097] Figure 14 The diagram shown is an internal optical path unfolded diagram of a lidar according to one embodiment of this application, where the scanning unit 30 is not shown. In this embodiment, the optical power of the window 12 is positive, and the off-axis optical unit 40 is composed of a lens with negative optical power. Specifically, the focal length f1 of the off-axis optical unit 40 and the focal length f2 of the window satisfy f1 / f2 = -0.32; the second off-axis amount L2 of the fourth optical axis A4 of the off-axis optical unit 40 relative to the third optical axis A3 of the laser system (laser unit 21 and mirror group unit 22) and the first off-axis amount L1 of the first optical axis A1 of the laser system relative to the optical axis (second optical axis A2) of the window satisfy L2 / L1 = 0.78; the focal length f2 of the window and the focal length ft of the laser emitting system (composed of emitting unit 211 and mirror group unit 22) satisfy f2 / ft = 12; the focal length f2 of the window and the focal length fr of the laser receiving system (composed of receiving unit 212 and mirror group unit 22) satisfy f2 / ft = 12.

[0098] Figure 13A and Figure 14In the embodiments shown, the off-axis optical unit 40 has one lens. In other embodiments, the off-axis optical unit 40 may also have multiple lenses. For example, the number of lenses in the off-axis optical unit 40 can be controlled within the range of 1-5 lenses, taking into account both the optimization of space ratio and the performance of compensating for off-axis aberrations.

[0099] Figure 6 In the illustrated embodiment, the storage module 50 and control module 60 can be housed inside the casing as an internal system of the lidar 100. This allows the lidar 100 to have independent storage and control functions, independent of systems outside the lidar 100, thus enhancing its data storage and processing capabilities. In other embodiments, at least one of the storage module 50 and control module 60 can be located outside the lidar 100. For example, the control module can be located in a device with detection capabilities, and the lidar has a signal interface that is electrically connected to the control module in the device with detection capabilities via a data cable. Similarly, the storage module can also be located in a device with detection capabilities, electrically connected between the lidar and the storage module via a data cable. This approach helps save internal space in the lidar, enabling lightweight and miniaturized lidar design.

[0100] This application also provides a control system and method for a lidar. The control system includes a first driving unit, a signal acquisition unit, a signal retrieval unit, and a second driving unit. The first driving unit drives a scanning unit; specifically, the first driving unit sends a driving signal to the scanning unit, causing the scanning unit to begin scanning the light beam. The signal acquisition unit detects the specific position of the scanning unit and acquires its position information. The signal retrieval unit retrieves the corresponding position information of an off-axis optical unit from a data table in a storage module based on the position information acquired by the signal acquisition unit. The second driving unit drives the off-axis optical unit to move to a target position based on the position information of the off-axis optical unit obtained by the signal retrieval unit.

[0101] The control method for lidar provided in this application includes the following steps:

[0102] Send a drive signal to the scanning unit;

[0103] The scanning unit begins scanning the beam;

[0104] During the scanning process of the scanning unit, the position information of the scanning unit is detected. Specifically, the position information can be the angle, coordinates, or positional relationship (e.g., distance) of the scanning unit relative to a certain reference.

[0105] The target position of the off-axis optical unit corresponding to the position information is determined based on the position information of the scanning unit. Specifically, the position information corresponding to the off-axis optical unit can be retrieved from the data table of the storage module by the control module, or the position information corresponding to the off-axis optical unit can be obtained by indexing.

[0106] Drive the off-axis optical unit to move to the target position. This target position is consistent with the position information corresponding to the retrieved off-axis unit. Specifically, the target position can be the specific coordinate position of the optical axis of the off-axis optical unit. The target position can also be the amount of movement of the off-axis optical unit or the target position determined by the movement time. Therefore, in a specific driving scheme, the target position of the off-axis optical unit can be determined according to different physical properties or methods.

[0107] The terms "first," "second," "third," "fourth," and various numerical designations used herein are merely for descriptive convenience and are not intended to limit the scope of this application.

[0108] It should be understood that in the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0109] The functional units (or modules) in the device of this application embodiment can be merged, divided, and deleted according to actual needs.

[0110] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A lidar, characterized in that, It includes a viewing window, a laser system, a scanning unit, and an off-axis optical unit, wherein: The viewing window has optical power in a first direction, which is either the collimation direction of the laser system or the divergence direction of the laser system. The laser system includes a laser unit and a mirror unit. The laser unit is used to emit and / or receive a light beam to form a laser optical path between the viewing window and the laser unit. The mirror unit is located on the laser optical path. The scanning unit is located between the mirror group unit and the viewing window on the laser optical path. The scanning unit is used to scan the laser beam. The laser optical path forms a first optical axis between the scanning unit and the viewing window. In the first direction, a first off-axis amount is formed between the first optical axis and the second optical axis. The second optical axis is the optical axis of the viewing window that is parallel to the first optical axis. The off-axis optical unit is located on the laser optical path and between the scanning unit and the laser unit. The laser optical path forms a third optical axis between the laser unit and the scanning unit. The optical axis of the off-axis optical unit is a fourth optical axis, which is parallel to the third optical axis. In the first direction, the fourth optical axis and the third optical axis constitute a second off-axis amount. The second off-axis amount is used to compensate for the aberrations caused by the first off-axis amount.

2. The lidar as described in claim 1, characterized in that, The off-axis optical unit is located between the scanning unit and the lens group unit.

3. The lidar as described in claim 1, characterized in that, The off-axis optical unit is located within the lens assembly unit.

4. The lidar as described in any one of claims 1-3, characterized in that, The third optical axis and the fourth optical axis are not collinear, the second off-axis amount is a fixed value, and the first off-axis amount is a variable value.

5. The lidar as described in any one of claims 1-3, characterized in that, Both the first off-axis amount and the second off-axis amount are variable values.

6. The lidar as described in claim 5, characterized in that, During the scanning process of the scanning unit, the laser system remains stationary, while the off-axis optical unit is driven to move by the control module to change the second off-axis amount.

7. The lidar as described in claim 6, characterized in that, When the first off-axis amount is within the first numerical range, the second off-axis amount is the first value.

8. The lidar as described in claim 6, characterized in that, When the first off-axis amount is a first value, the second off-axis amount is a second value, and the first value corresponds to the second value.

9. The lidar as described in any one of claims 6-8, characterized in that, The control module is located in the lidar. The lidar also includes a storage module that stores the correspondence between the positions of the scanning unit and the off-axis optical unit. The control module is used to determine the target position of the off-axis optical unit corresponding to the real-time position of the scanning unit, and control the off-axis optical unit to move to the target position.

10. The lidar as described in any one of claims 1-3, characterized in that, The first off-axis amount is L1, the second off-axis amount is L2, and |L2 / L1|≥0.

1.

11. The lidar as described in any one of claims 1-3, characterized in that, The focal length of the off-axis optical unit is f1, the focal length of the window is f2, and 5 ≥ |f1 / f2| ≥ 0.

2.

12. The lidar as described in any one of claims 1-3, characterized in that, The focal length of the laser system is fr, and the focal length of the window is f2, where |f2 / fr|≥0.

5.

13. The lidar as described in any one of claims 1-3, characterized in that, The first direction is the collimation direction of the laser system, and the window has positive optical power in the first direction.

14. The lidar as described in any one of claims 1-3, characterized in that, The first direction is the divergence direction of the laser system, and the window has negative optical power in the first direction.

15. The lidar as described in any one of claims 1-3, characterized in that, The laser unit includes a transmitting unit and a receiving unit, which are arranged adjacent to each other on the same side of the scanning unit, or separately on opposite sides of the scanning unit. The mirror unit includes a transmitting mirror unit and a receiving mirror unit. The transmitting mirror unit is located between the transmitting unit and the scanning unit, and the receiving mirror unit is located between the receiving unit and the scanning unit.

16. The lidar as described in claim 15, characterized in that, The off-axis optical unit includes a first off-axis unit located between the emission unit and the scanning unit, the optical axis of the first off-axis unit being the fourth optical axis; or / and The off-axis optical unit includes a second off-axis unit, which is located between the receiving unit and the scanning unit, and the optical axis of the second off-axis unit is the fourth optical axis.

17. The lidar as described in any one of claims 1-3, characterized in that, The viewing window has optical power in the second direction, wherein when the first direction is the collimation direction of the laser system, the second direction is the divergence direction of the laser system, and when the first direction is the divergence direction of the laser system, the second direction is the collimation direction of the laser system. In the second direction, the laser optical path forms a third off-axis amount between the first optical axis formed between the scanning unit and the window and the second optical axis of the window; In the second direction, the fourth optical axis of the off-axis optical unit and the laser optical path constitute a fourth off-axis amount between the third optical axis formed between the scanning unit and the laser unit, and the fourth off-axis amount is used to compensate for the aberrations caused by the third off-axis amount.

18. A device with a detection function, characterized in that, It includes a control center and a lidar as described in any one of claims 1-17, the lidar being used to detect target signals and transmit the target signals to the control center.

19. A device with a detection function, characterized in that, The system includes a control module and a lidar as described in any one of claims 1-8 or 10-17, wherein the control module is used to drive the off-axis optical unit to move in order to change the second off-axis amount.

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