Scanning module, detection apparatus, laser radar, and terminal

Abstract

A scanning module, a detection apparatus, a laser radar, and a terminal, which can be applied to fields such as optical detection technology. By means of designing and adjusting included angles (i.e., third angles θ) between reflective surfaces of a scanning module (203) and included angles between the reflective surfaces and a rotating shaft (i.e., first angles β and second angles α), encrypted scanning of an ROI area is achieved, and the precision of detection of the ROI area is improved. Compared with a solution in which the number of pixels of a receiving chip is directly increased, the described solution has lower costs, and may not significantly increase the costs of the detection apparatus. Compared with a solution of repeated scanning, the present solution scans from a plane B to a plane A in one scan, and no extra scanning is carried out, so that the efficiency of detection is ensured. In conclusion, the present solution can complete encrypted scanning of an ROI area without significantly increasing the costs of the detection device, and the precision of detection of the ROI area is improved, while efficiency of detection can be ensured.

Description

Scanning module, detection device, laser radar and terminal Technical Field

[0001] The present application relates to the field of light detection technology, and in particular to a scanning module, a detection device, a laser radar and a terminal. Background Art

[0002] With the development of information technology and computer vision, detection technology has made rapid progress. Various detection devices have brought great convenience to people's lives and travel. Detection devices include vision sensors such as cameras and radar sensors such as millimeter-wave radar, lidar, and ultrasonic radar.

[0003] In the field of view that the radar can detect, the detection results of different fields of view may have different values. Among them, the field of view with high value, also commonly referred to as the region of interest (ROI), also requires higher detection accuracy for detection. In some solutions, the detection accuracy can be improved by increasing the number of pixels of the receiving chip or repeating the scan. Among them, increasing the number of pixels of the receiving chip can improve the detection accuracy of the detection device, but this method will lead to an increase in the area of ​​the single board, resulting in an increase in cost. Repeated scanning refers to scanning the same field of view multiple times, thereby improving the detection accuracy of the detection device, but this method will cause the time taken to obtain a frame of detection results to be longer, and the detection efficiency will be reduced.

[0004] Therefore, how to improve the detection accuracy of the ROI area without significantly increasing the cost of the detection device and ensuring the detection efficiency is a hot topic being studied by those skilled in the art.

[0005] Summary of the Invention

[0006] The present application provides a scanning module, a detection device, a laser radar and a terminal, which can complete encrypted scanning of the ROI area without significantly increasing the cost of the detection device, thereby improving the detection accuracy of the ROI area.

[0007] In a first aspect, the present application provides a scanning module comprising N reflective surface groups arranged around a rotation axis, where N is a positive integer and N ≥ 3. The N reflective surface groups are symmetrical about the center of the rotation axis, and a first reflective surface group among the N reflective surface groups comprises a first reflective surface and a second reflective surface that are connected at their edges. The first reflective surface has a different angle with the two adjacent reflective surfaces. Along the direction of the rotation axis, the line connecting the edge of the first reflective surface and the rotation axis is a first angle, the line connecting the edge of the second reflective surface and the rotation axis is a second angle, and the line connecting the edge of the first reflective surface and the edge of the second reflective surface is a third angle.

[0008] The sum of the first angle and the third angle is less than 180° (or π), that is, the difference between 180° and the first angle is greater than the third angle. The sum of the second angle and the third angle is less than 180° (or π), that is, the difference between 180° and the second angle is greater than the third angle.

[0009] Illustratively, the angular relationship between the first angle (for example, expressed as β), the second angle (for example, expressed as α), and the third angle (for example, expressed as θ) may satisfy the following formula: θ+α<π, θ+β<π.

[0010] In the present application, by designing the first angle β, the second angle α and the third angle θ to satisfy a certain relationship, the area scanned by the laser signal after passing through the first reflective surface overlaps with the area scanned after passing through the second reflective surface. For example, the laser signal is reflected by the first reflective surface (for example, represented as surface B) in the first direction (for example, represented as the horizontal direction) to scan the first angle range, and the laser signal is reflected by the second reflective surface (for example, represented as surface A) connected to the edge of surface B to scan the second angle range. The first angle range and the second angle range overlap, and the overlapping area is the ROI area. The overlapping area has been scanned by the laser signal reflected by surface B and the laser signal reflected by surface A, that is, the overlapping area has been repeatedly scanned by the laser signal reflected by the two reflective surfaces, and the repeatedly scanned area is equivalent to being detected multiple times. Therefore, based on the angle design of the angles between the reflective surfaces and the angles between the reflective surface and the rotation axis in the scanning module provided by the present application, encrypted scanning of the ROI area can be achieved, thereby improving the detection accuracy of the ROI area.

[0011] This application realizes encrypted scanning of the ROI area by designing and adjusting the angle between the reflecting surfaces of the scanning module (i.e., the third angle θ), as well as the angle between the reflecting surface and the rotation axis (i.e., the first angle β and the second angle α), thereby improving the detection accuracy of the ROI area. Compared with the solution of directly increasing the number of pixels of the receiving chip, the solution of designing the scanning module is less expensive and can not significantly increase the cost of the detection device. Compared with the solution of repeated scanning, the scanning from surface B to surface A in this application is a complete scan without additional scanning, thereby ensuring the detection efficiency.

[0012] In summary, the present application can complete the encrypted scanning of the ROI area without significantly increasing the cost of the detection device, thereby improving the detection accuracy of the ROI area and ensuring the detection efficiency.

[0013] Furthermore, in this application, the overlapping angle range of the scanning of surface B and surface A is located in the central area of ​​the field of view. By performing encrypted scanning on the central area of ​​the field of view, the detection accuracy of the central area can be improved, which can effectively improve the value of the detection results and is beneficial to the calculation and decision-making related to the perception results.

[0014] For example, the present application can be applied to scenarios such as vehicle perception, intelligent driving, mapping, and robot perception. Taking the vehicle perception scenario as an example, the central area of ​​the field of view usually includes the space where the vehicle is likely to travel, which is a high-value field of view (i.e., ROI area). Through the embodiments of the present application, the detection accuracy of the ROI area is improved, the effectiveness of the detection information is improved, and the driving safety of the vehicle is improved, while the detection efficiency can also be guaranteed. Especially for intelligent driving systems, the higher the detection accuracy of the ROI, the more conducive it is to the calculation and decision-making of the intelligent driving system, thereby improving the safety and comfort of the intelligent driving system.

[0015] Optionally, the third angle is greater than 90°, or the first angle is greater than 120°.

[0016] In one possible embodiment, the scanning module is used to scan the laser signal into the object space, and the laser signal is used to detect the object space. The field of view angle formed by the laser signal in the object space through the first reflective surface is the angle formed by the laser signal passing through and scanning the fourth angle to the fifth angle in the first direction from the first edge of the first reflective surface to the second edge of the first reflective surface. The field of view angle formed by the laser signal in the object space through the second reflective surface is the angle formed by the laser signal passing through and scanning the sixth angle to the seventh angle in the first direction from the third edge of the second reflective surface to the fourth edge of the second reflective surface, and the second edge of the first reflective surface is connected to the third edge of the second reflective surface. The field of view angle formed by the laser signal in the object space through the first reflective surface overlaps with the field of view angle formed by the laser signal in the object space through the second reflective surface in the angular space, and the overlapping angle range is the angle formed by the laser signal scanning the fifth angle to the sixth angle, and the width of the overlapping angle range is negatively correlated with the third angle.

[0017] In the above embodiment, the relative angular relationship between the first angle β, the second angle α, and the third angle θ of the scanning module can be designed to form an encrypted scanning trajectory in the central area. For example, the field of view angle formed by the laser signal passing through the first reflective surface in object space (e.g., the angular width is represented by β′) and the field of view angle formed by the laser signal passing through the second reflective surface in object space (e.g., the angular width is represented by α′) overlap in angular space. The resulting overlapping angular range (e.g., the angular width is represented by θ′) constitutes the repeated scanning portion formed by the encryption of the RIO area.

[0018] Optionally, the angular relationship between the width of the overlapping angle range and the third angle may satisfy the following formula: θ′=2(π-θ).

[0019] In yet another possible implementation, a field of view angle formed in the object space by the laser signal passing through the first reflecting surface is twice the first angle.

[0020] Optionally, an angular relationship between a field angle β′ formed by the laser signal passing through the first reflecting surface in the object space and the first angle β may satisfy the following formula: β′=2β.

[0021] In yet another possible implementation, a field of view angle formed in the object space by the laser signal passing through the second reflecting surface is twice the second angle.

[0022] Optionally, the angular relationship between the field angle α′ formed by the laser signal passing through the second reflecting surface in the object space and the second angle α may satisfy the following formula:

[0023] α′=2α. In another possible embodiment, in the second direction, a path (scanning line) of the laser signal spot reflected by the first reflection surface and a path (scanning line) of the laser signal spot reflected by the second reflection surface are spaced apart.

[0024] In the above embodiment, when there is a gap between the paths of the laser signal spots reflected by different reflective surfaces, a certain width exists between the horizontal scanning tracks of the first and second reflective surfaces, thereby achieving repeated scanning of the ROI area. Furthermore, to reduce motion blur caused by repeated scanning, the time interval between two scans of the ROI area should be as short as possible. This minimizes the time interval between the two scans of the ROI area and reduces the motion blur effect.

[0025] It should be understood that the second direction is different from the first direction. For example, the first direction and the second direction may be perpendicular. For example, the first direction may be horizontal and the second direction may be vertical. The horizontal direction may be the direction of the ground, or the horizontal direction may be predefined.

[0026] In yet another possible implementation, the N reflective surface groups of the scanning module rotate around the rotation axis.

[0027] In another possible implementation, in a direction parallel to the rotation axis, a first angle exists between the first reflecting surface and the rotation axis, and the second reflecting surface is parallel to the rotation axis.

[0028] In the above embodiment, a situation is provided in which there is an angular difference between the first reflecting surface and the rotation axis in the vertical direction.

[0029] In another possible implementation, a third angle exists between the laser signal reflected by the first reflection surface and the laser signal reflected by the second reflection surface in the second direction, and the third angle is positively correlated with the first angle.

[0030] Optionally, the angular relationship between the third angle (for example, expressed as γ′) and the first angle γ satisfies the following formula: γ′=2γ.

[0031] In the above embodiment, there is an angular difference between the first reflecting surface and the second reflecting surface in the second direction.

[0032] In another possible implementation, in a direction parallel to the rotation axis, the first reflecting surface forms a first angle in a positive direction with the rotation axis, and the second reflecting surface forms a second angle in a negative direction with the rotation axis.

[0033] Among them, the positive direction and the negative direction are opposite.

[0034] In another possible embodiment, in a direction parallel to the rotation axis, the first reflecting surface forms a first positive angle (γ1) with the rotation axis, and the second reflecting surface forms a second negative angle (γ2) with the rotation axis. The laser signal reflected by the first reflecting surface and the laser signal reflected by the second reflecting surface form a third angle (γ′) in a second direction, and the third angle is related to the first angle and the second angle.

[0035] Optionally, the third angle and the first angle satisfy the following formula: γ′=2(γ1+γ2).

[0036] In the above embodiment, a situation is provided where both the first reflecting surface and the second reflecting surface have an angular difference with the rotation axis in the vertical direction.

[0037] In a second aspect, embodiments of the present application provide a detection device comprising a transmitting module, a receiving module, and a scanning module. The transmitting module is configured to transmit a laser signal. The scanning module comprises N reflecting surfaces that rotate about a rotation axis to scan the laser signal into an object space. The laser signal is used to detect the object space. The scanning module is further configured to provide a return signal of the laser signal from the object space to the receiving module. The scanning module comprises any of the scanning modules described in the first aspect.

[0038] In a possible implementation, the transmitting module and the receiving module are located on the same side or on different sides of the scanning module along a direction perpendicular to the rotation axis.

[0039] In another possible embodiment, when the transmitting module and receiving module are located on the same side, the detection device further includes a coaxial module for achieving coaxial alignment between the laser signal and its return signal. The laser signal sequentially passes through the output port of the detection device, a polarization beam splitter, and a quarter-wave plate before being provided to the scanning module. The return signal from the scanning module sequentially passes through the quarter-wave plate and the polarization beam splitter before being provided to the receiving port of the detection device.

[0040] In another possible implementation, the coaxial module includes a perforated reflector, or the coaxial module includes a polarization beam splitter (PBS) and a quarter-wave plate.

[0041] In a third aspect, an embodiment of the present application provides a laser radar, which includes the detection device of any one of the second aspects, the detection device including a transmitting module, a scanning module and a receiving module, the transmitting module including a laser, the receiving module including a detector, the laser being used to transmit a laser signal, the scanning module being used to scan the laser signal into the object space, the laser signal being used to detect the object space, and the detector being used to obtain relevant information about the target in the object space based on the return signal of the laser signal.

[0042] In a fourth aspect, an embodiment of the present application provides a terminal, which includes the detection device described in any one of the second aspects, or the terminal includes the laser radar of the third aspect.

[0043] Optionally, the terminal is a vehicle, a drone or a robot. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] FIG1 is a schematic diagram of a possible transmitting optical path and receiving optical path provided in an embodiment of the present application;

[0045] FIG2 is a schematic structural diagram of a detection device 20 provided in an embodiment of the present application;

[0046] FIG3A is a schematic diagram of a possible coaxial optical path provided in an embodiment of the present application;

[0047] FIG3B is a schematic diagram of another possible coaxial optical path provided in an embodiment of the present application;

[0048] FIG4 is a schematic diagram of another possible coaxial optical path provided in an embodiment of the present application;

[0049] FIG5 is a schematic diagram of a four-sided polygon reflective surface provided in an embodiment of the present application;

[0050] FIG6A is a schematic diagram of a scanning pattern provided in an embodiment of the present application;

[0051] FIG6B is a schematic diagram of another scanning pattern provided in an embodiment of the present application;

[0052] FIG7 is a schematic diagram of an embodiment of the present application in which a reflecting surface has an angular difference with respect to a rotation axis;

[0053] FIG8 is a schematic diagram of a 5-sided Polygon provided in an embodiment of the present application;

[0054] FIG9 is a schematic structural diagram of a possible terminal 90 provided in an embodiment of the present application. DETAILED DESCRIPTION

[0055] The embodiments of the present application provide a scanning module, a detection device, a laser radar, and a terminal, which are used to improve the detection accuracy of the ROI area without significantly increasing the cost of the detection device and ensuring the detection efficiency.

[0056] The following describes the embodiments of the present application in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present application, rather than all the embodiments. Those skilled in the art will appreciate that with the development of technology and the emergence of new scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0057] The terms "first," "second," and the like in the specification and claims of this application and in the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "including" and "having," as well as any variations thereof, are intended to cover non-exclusive inclusions, e.g., a process, method, system, product, or apparatus comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or that are inherent to these processes, methods, products, or apparatus.

[0058] The following first introduces relevant terms and concepts that may be involved in the embodiments of this application.

[0059] 1. Detection device

[0060] The detection device mentioned in the embodiments of the present application can be a laser radar or other optical detection device, such as a fusion detection device (for example, a detection device integrating a radar detector and an image sensor). Its working principle is to detect targets within the field of view by emitting laser signals and receiving echoes.

[0061] As a possible usage scenario, the detection device in the embodiment of the present application can be used in various fields such as intelligent driving, intelligent transportation, intelligent manufacturing, environmental detection, surveying and mapping, drones, etc., and can complete one or more functions of target detection, distance measurement, speed measurement, target tracking, imaging recognition, etc.

[0062] As a possible application location, the detection device in the embodiments of the present application can be applied to a vehicle-mounted detection device (e.g., a vehicle-mounted radar), a roadside detection device (e.g., an intersection radar), etc. It can also be applied to other detection devices, such as detection devices installed on drones, robots, rail cars, bicycles, traffic lights, speed measuring devices, or base stations. This application does not limit the location where the detection device is installed.

[0063] 2. Return signal

[0064] In the embodiments of the present application, the optical signal received by the detection device is referred to as the return signal of the laser signal. The laser signal includes the signal emitted by the detection device. The return signal includes the reflection signal of the signal emitted by the detection device.

[0065] 3. Field of view (FOV)

[0066] There needs to be a line of sight (LOS) between the transmitter of the detection device and the target object, and / or between the receiver of the detection device and the target object, where signal (e.g., radio waves, laser) transmission is uninterrupted. This line of sight can be understood as the field of view.

[0067] In some scenarios, the angle formed by the two edges of the maximum range illuminated by the laser signal is called the field of view. The size of the field of view angle determines the field of view of the optical instrument; the larger the field of view angle, the wider the field of view. In some solutions, the field of view angle can include horizontal field of view angle and vertical field of view angle. The horizontal field of view angle refers to the angle formed by the two edges of the maximum range that can be detected in the horizontal direction, and the vertical field of view angle refers to the angle formed by the two edges of the maximum range that can be detected in the vertical direction.

[0068] The above description of technical terms may be optionally used in the following embodiments.

[0069] The detection principle of the detection device is to obtain relevant information of the target by emitting a laser signal and receiving a return signal corresponding to the laser signal. Figure 1 is a schematic diagram of a possible transmitting optical path and a receiving optical path provided by an embodiment of the present application. The transmitting end of the detection device emits a laser signal 1, and the laser signal 1 is reflected on the target in the field of view to form a return signal 2. The return signal 2 falls into the detector and is received by the receiving end of the detection device. Because in the field of view that the radar can detect, the detection results of different field of view areas may have different values. Among them, the high-value field of view range, also commonly referred to as the ROI area, requires higher detection accuracy for detection. However, although the current detection methods in the industry can improve detection accuracy, it will lead to increased costs and decreased detection efficiency.

[0070] To address the above issues, embodiments of the present application provide a scanning module, a detection device, a laser radar, and a terminal. This application can perform encrypted scanning of the ROI region without significantly increasing the cost of the detection device, improving the detection accuracy of the ROI region while also ensuring detection efficiency. Optionally, the ROI region can be the middle portion of the field of view, or a predefined field of view area.

[0071] The following first introduces a detection device provided by this application.

[0072] Please refer to FIG2 , which is a schematic diagram of the structure of a detection device 20 provided in an embodiment of the present application. The detection device 20 includes a transmitting module 201 , a receiving module 202 and a scanning module 203 .

[0073] The emission module 201 is used to generate a laser signal. Optionally, the emission module 201 may include a laser. For example, the laser includes, but is not limited to, one or more light-emitting elements such as a laser diode (LD), a vertical cavity surface emitting laser (VCSEL), a photonic crystal surface emitting semiconductor lasers (PCSEL), an edge emitting laser (EEL), a distributed feedback laser diode (DFB-LD), a grating coupled sampling reflection laser diode (GCSR-LD), or a micro opto electromechanical system laser diode (MOEMS-LD).

[0074] The receiving module 202 is used to receive the return signal corresponding to the laser signal emitted by the transmitting module 201. For example, the receiving module 202 may include a detector. Further optionally, the detector may include one or more detection elements. For example, the detector may include but is not limited to one or more detection elements such as a single-photon avalanche diode (SPAD), a silicon photomultiplier (SiPM), a semiconductor avalanche photodiode (APD), a multi-pixel photon counter (MPPC), or an electron multiplying charge-coupled device (EMCCD).

[0075] The scanning module 203 is used to change the propagation direction of light. For example, the laser signal emitted by the transmitting module 201 can be irradiated onto the detection area in the field of view through N reflecting surface groups arranged around the rotation axis. Among them, the scanning module 203 can include a mechanical scanning device, an electrical scanning device, etc. The scanning module 203 can include one or more of the following optical elements: a reflector, a lens, a spectrometer, a swing mirror, a rotating mirror (Polygon), or a micro-electro-mechanical system (MEMS) galvanometer, etc. Optionally, the N reflecting surface groups are symmetrical relative to the center of the rotation axis, and each of the N reflecting surface groups includes a first reflecting surface and a second reflecting surface whose edges are connected.

[0076] In an embodiment of the present application, the transmitting module 201 can transmit the laser signal to the object space through the first reflecting surface of the scanning module 203, so that the target in the object space can be illuminated by the laser signal. The first reflecting surface is a general term for the reflecting surface currently used to reflect the laser signal emitted by the transmitting module 201. The receiving module 202 can receive the return signal formed by the reflection of the laser signal on the target through the second reflecting surface of the scanning module 203, and measure the relevant information of the target based on the return signal. The second reflecting surface is a general term for the reflecting surface that reflects the return signal. The transmitting field of view is the object space covered by the laser signal emitted by the transmitting module, and the receiving field of view is the object space where the receiving module can receive light.

[0077] In one possible design, the transmitting module 201 and the receiving module 202 in the detection device 20 are located on different sides of the scanning module 203 along a direction perpendicular to the rotation axis, that is, the light transmission and receiving paths can be off-axis.

[0078] For example, the transmitting module 201 transmits a laser signal, which is reflected by the transmitting lens onto a target within the field of view, forming a return signal, which is received by the receiving module 202 through the receiving lens. The optical axes of the laser signal and the return signal are different.

[0079] In another possible design, the transmitting module 201 and receiving module 202 in the detection device 20 of the present application are located on the same side of the scanning module 203 along a direction perpendicular to the rotation axis. In other words, the light transmission and receiving paths can be coaxial. The following describes several coaxial implementation methods:

[0080] In a first implementation, the transmitting module 201 and the receiving module 202 are integrated together. That is, the transmitting module and the receiving module can be integrated into the same module. For example, the optical path integration of transmitting and receiving is achieved through an optical fiber array or a waveguide array.

[0081] In the second implementation mode, the transmitting module 201 and the receiving module 202 are separately provided. The detection device 20 further includes a coaxial module, which is used to achieve the coaxiality of the laser signal and the return signal of the laser signal.

[0082] As an example of a coaxial module, the coaxial module includes one or more reflectors (or optical elements with a reflective function), such as a perforated reflector. Figure 3A is a schematic diagram of a possible coaxial optical path provided by an embodiment of the present application. The coaxial module uses reflector 301 to achieve coaxiality between the laser signal and the return signal of the laser signal. The laser signal is reflected into the object space by reflector 301, and the return signal does not pass through reflector 301 (for example, it passes through both sides of reflector 301) and is received by the receiving module.

[0083] FIG3B is a schematic diagram of another possible coaxial optical path provided by an embodiment of the present application. The coaxial module achieves coaxiality between the laser signal and the return signal of the laser signal through a perforated reflector 302. The laser signal passes through the central circular hole of the perforated reflector 302 and is emitted into the object space. The return signal is received by the receiving module through the perforated reflector 302. In both the coaxial optical paths shown in FIG3A and FIG3B, the propagation direction of the laser signal can be changed by a reflector. This application does not limit the number and location of the reflectors.

[0084] As an example of a coaxial module, the coaxial module includes a polarization beam splitter (PBS) and a quarter wave plate (QWP).

[0085] For example, Figure 4 is a schematic diagram of another possible coaxial optical path provided by an embodiment of the present application. As shown in Figure 4, the detection signal light is emitted into space through the transmitting module, passes through the transmitting lens and PBS, and is transmitted to the QWP. At this time, the polarization direction of the detection signal light is P polarization. The QWP will change the polarization direction of the detection signal light and convert the linear polarization into circular polarization. Therefore, the detection signal light after passing through the QWP is circularly polarized. The circularly polarized light is reflected on the target within the field of view to form a return signal light (still circularly polarized). When the return signal light passes through the QWP again, the polarization direction changes to form a return signal light with an S polarization direction. The S-polarized return signal light is reflected after passing through the PBS and reaches the receiving module through the receiving lens. The optical axis of the detection signal light and the reflected signal light is the same. Optionally, the detection signal light is P polarized light.

[0086] As an example of some coaxial modules, the coaxial module can realize the coaxiality of the laser signal and the return signal of the laser signal through optical devices such as a circulator and a semi-transparent and semi-reflective mirror. Among them, the semi-transparent and semi-reflective mirror can split a beam of light into two beams of light with roughly the same spectral components. For example, in a certain wavelength region, such as the wavelength range of 300nm to 100μm, each wavelength has the same (the same here does not necessarily mean completely the same, and there can be fluctuations within a certain range) transmittance and reflectivity. At this time, after the N laser signals pass through the semi-transparent and semi-reflective mirror, each laser signal is partially reflected and partially transmitted, resulting in energy loss of the N laser signals propagating to the receiving module. Similarly, the N return signals from the receiving module are also partially transmitted and partially transmitted after passing through the semi-transparent and semi-reflective mirror, resulting in a certain loss of energy in the N return signals.

[0087] A circulator is a multi-port device that transmits the laser signal entering any port to the next port in the order determined by the static bias magnetic field. Its outstanding feature is the unidirectional transmission of energy and the control of electromagnetic waves to be transmitted along a certain circular direction. For example, a circulator has three ports, and the light beam goes from port 1 to port 2, from port 2 to port 3, and from port 3 to port 1. The other paths are blocked, that is, it is impossible to go from port 2 to port 1 (that is, it has high isolation). At this time, the laser signal can enter from port 1 and exit from port 2 to reach the receiving module, while the return signal from the receiving module can enter from port 2 and exit from port 3, thereby achieving coaxial transmission and reception.

[0088] Of course, the above-mentioned several methods in combination with FIG. 3A , FIG. 3B , and FIG. 4 are merely exemplary introductions, and are not intended to limit the coaxial and off-axis solutions of the present application to be implemented in the above-mentioned methods.

[0089] The detection device 20 involved in the embodiments of the present application is not limited to the number, placement, placement order, size, etc. of the optical elements in the detection device 20. It should be understood that the number and installation position of the transmitting modules, receiving modules, optical elements, etc. in the embodiments of the present application are not limited. Figure 2 is only a possible situation for the convenience of description and does not limit the detection device 20.

[0090] The following describes a scanning module provided by the present application. Optionally, the scanning module can be applied to the detection device 20 shown in FIG. 2 .

[0091] An embodiment of the present application provides a scanning module 203. In conjunction with Figure 2, the scanning module 203 is a polyhedron (Polygon), including a plurality of reflection surface groups arranged around a rotation axis. For ease of description, the number of reflection surface groups is designed to be N, where N is a positive integer and N≥3. The N reflection surface groups are rotationally symmetric relative to the center of the rotation axis, and each of the N reflection surface groups includes a first reflection surface and a second reflection surface connected at the edges. For example, taking N=4 as an example, please refer to Figure 5, which is a schematic diagram of a reflection surface of a 4-sided Polygon provided in an embodiment of the present application. The scanning module 203 includes four reflection surface groups, each reflection surface group includes two reflection surfaces, which is convenient for distinguishing the two reflection surfaces and representing them as the first reflection surface and the second reflection surface respectively.

[0092] The scanning module shown in Figure 5 includes four reflective surface groups, each of which includes two reflective surfaces. Therefore, the scanning module has a total of eight reflective surfaces, namely, surface B1, surface A1, surface B2, surface A2, surface B3, surface A3, surface B4, and surface A4. These eight reflective surfaces belong to four reflective surface groups, for example, surface B1 and surface A1 belong to one reflective surface group, surface B2 and surface A2 belong to one reflective surface group, surface B3 and surface A3 belong to one reflective surface group, and surface B4 and surface A4 belong to another reflective surface group. The area enclosed by the four edges formed by connecting the non-connected edges of the four groups of reflective surfaces of the four-sided Polygon is used to indicate that the cross-section of the four-sided Polygon is a regular quadrilateral. Accordingly, the four-sided Polygon is a regular tetrahedron.

[0093] As can be seen from the top view of the 4-sided Polygon shown in Figure 5, face B1 and face A1 are formed by patching the cross-section of the 4-sided Polygon, which is a regular quadrilateral. The line connecting the non-connected edges of face B1 and face A1 (that is, the area formed by the dotted line below face B1 and face A1 shown in Figure 5) should be a side of the regular quadrilateral. It should be understood that the regular tetrahedron here is only an exemplary introduction, and this application is still applicable to polyhedrons such as regular pentahedrons and regular hexahedrons.

[0094] Optionally, the four-sided Polygon may be an irregular tetrahedron, for example, faces B1 and A1 are not rotationally symmetric with respect to the rotation axis.

[0095] In one possible design, the first reflective surface has different included angles with its two adjacent reflective surfaces. For example, the included angle (e.g., represented by θ in FIG5 ) between surface B1 and surface A1 in the first reflective surface group is 155°, and the included angle between surface B1 and adjacent surface A4 is 115°.

[0096] Optionally, when the scanning module includes multiple reflective surface groups (for example, a scanning module including three, four, or more reflective surface groups), the structure of each reflective surface group is the same as or similar to the hierarchical structure of a reflective surface group described in the various embodiments of this application. Next, the scanning process of a four-sided polygon is described in detail, using surfaces B1 and A1 of the first reflective surface group included in the scanning module as an example.

[0097] For example, FIG5 takes a side view of the first reflective surface group of the scanning module 203 as an example (only one end face is shown). Along the direction of the rotation axis, the line between the edge of the B1 surface and the rotation axis is a first angle (for example, expressed as β), the line between the edge of the A1 surface and the rotation axis is a second angle (for example, expressed as α), and the line between the edge of the B1 surface and the edge of the A1 surface is a third angle θ.

[0098] Optionally, the first angle β and the second angle α may be the same or different in magnitude. The angular relationship among the first angle β, the second angle α and the third angle θ may satisfy the following formula: θ+α<π, θ+β<π.

[0099] By designing the relative angular relationship between the first angle β, the second angle α and the third angle θ, the area scanned by the laser signal after passing through the B1 surface overlaps with the area scanned after passing through the A1 surface. For example, the laser signal can scan the first angle range after being reflected by the B1 surface in the first direction (for example, expressed as the horizontal direction), and the laser signal can scan the second angle range after being reflected by the A1 surface connected to the edge of the B1 surface. The first angle range and the second angle range overlap, and the overlapping area is the ROI area. The overlapping area has been scanned by the laser signal reflected by the B1 surface and the laser signal reflected by the A1 surface, that is, the overlapping area has been repeatedly scanned by the laser signal reflected by the reflecting surface twice, and the repeatedly scanned area is equivalent to being detected multiple times. Therefore, based on the angle design of the angles between the reflecting surfaces and between the reflecting surface and the rotation axis in the scanning module provided by this application, it is possible to achieve encrypted scanning of the ROI area and improve the detection accuracy of the ROI area. For example, if the difference in size between the first angle β and the second angle α is designed to be small, in this case the third angle θ will be relatively large, even approaching 180°. The scanning pattern formed based on this situation is a scanning trajectory in which the reflective surface corresponding to the first angle β is scanned once (for example, the angle width β′ shown in Figure 6A or Figure 6B), and a scanning trajectory in which the reflective surface corresponding to the second angle α is also scanned once (for example, the angle width α′ shown in Figure 6A or Figure 6B). The following describes the scanning patterns formed by the two scanning modules based on different channels when scanning with Figures 6A and 6B.

[0100] Referring to FIG6A , the field of view angle formed in object space by the laser signal passing through surface B1 is the angle α′ formed by the laser signal sequentially passing and scanning from the first edge of surface B1 to the second edge of surface B1, from the fourth angle to the fifth angle in the first direction (e.g., a direction parallel to the axis of rotation, which may also be referred to as the aforementioned horizontal direction). As shown in FIG6A (c), x0 to x3 represent azimuth angles, with the center of the field of view being 0° azimuth, with the left side of 0° being negative angles and the right side being positive angles. The fourth angle is x0 shown in FIG6A (c), and the fifth angle is x2 shown in FIG6A (c). The scanning trajectory of a single channel is shown in (c) in Figure 6A. The scanning pattern shown in (d) in Figure 6A can be formed by the laser signals of 4 channels (or called 4 lines) (for example, channel 1, channel 2, channel 3 and channel 4 shown in (a) in Figure 6A) passing through the B1 surface and the A1 surface once. The scanning patterns shown in (e) to (g) in Figure 6A can be inferred with reference to the scanning pattern shown in (d) in Figure 6A.

[0101] In some embodiments, the scanning pattern shown in (d) in FIG6B can also be formed by the laser signal of a single channel (such as channel 1) shown in (a) in FIG6B passing through the B1 surface and the A1 surface once, the B2 surface and the A2 surface once, the B3 surface and the A3 surface once, and the B4 surface and the A4 surface once. (b) in FIG6B is a top view cross-section of the scanning module 1 in (a) in FIG6B. x0 to x3 in (c) in FIG6B represent azimuth angles, with the center of the field of view as 0 azimuth angle (0°), the left side of 0 azimuth angle is a negative angle, and the right side is a positive angle. Of course, the present application is also applicable to laser signals with more channels or fewer channels, and is also applicable to 1D and 2D scanning.

[0102] In some cases, the field angle β′ formed by the laser signal passing through the first reflection surface in the object space is twice the second angle β, and this angle relationship may satisfy the following formula: β′=2β.

[0103] Continuing with FIG6A , the field of view angle formed in object space by the laser signal passing through surface B1 is the angle formed by the laser signal sequentially passing through and scanning the sixth to seventh angles in the horizontal direction from the third edge to the fourth edge of surface B1 (e.g., an angular width of β′). Continuing with FIG6A , the sixth angle is x1 shown in FIG6A(c), the seventh angle is x3 shown in FIG6A(c), and the second edge of surface B1 is in contact with the third edge of surface A1.

[0104] In some other cases, the field angle α′ formed by the laser signal passing through the second reflection surface in the object space is twice the first angle α, and the angle relationship may satisfy the following formula: α′=2α.

[0105] The field of view angle formed by the laser signal passing through the first reflective surface in object space overlaps with the field of view angle formed by the laser signal passing through the second reflective surface in object space in angular space. The overlapping angle range is the angle formed by the laser signal scanning from the fifth angle to the sixth angle (for example, the angle width is represented by θ′). Continuing with FIG6A , the overlapping angle range is from x1 to x2 as shown in (c) of FIG6A . The width θ′ of the overlapping angle range is negatively correlated with the third angle θ, and this angular relationship can satisfy the following formula: θ′=2(π-θ).

[0106] As can be seen from the above formula, the larger θ is, the smaller θ′ is. For ease of understanding, the relationship between θ and θ′ is described below with reference to FIG. 6A .

[0107] Taking the two reflective surfaces, A1 and B1, as an example, the presence of two reflective surfaces results in two different normals. When the four-sided polygon rotates, after the laser signal passes through surface B1, before it has time to pass through surface A1, it will hit the intersection between surfaces B1 and A1. Because the incident light is the same but the two normals are different, there will be two different reflected lights. When the angle θ between surfaces B1 and A1 does not change much, the change between the two normals does not change much, and therefore the scanning trajectory between surfaces B1 and A1 does not change much either, resulting in the scanning pattern shown in Figures 6A (c) to (g) or 6B (d). When θ approaches 180°, it is equivalent to having only one normal, and the overlapping angle range is very small, meaning that θ′ is very small. In summary, the larger θ is, the smaller θ′ is. Since the scanning signals overlap in the middle area of ​​the field of view, the return signals also overlap in the middle area of ​​the field of view. In the detection data obtained, the point cloud density in the middle area of ​​the field of view is higher than the point cloud density in the area at the edge of the field of view, thereby improving the detection accuracy of the middle area of ​​the detection area.

[0108] In one possible implementation, in the second direction (for example, the direction perpendicular to the rotation axis, which may also be referred to as the aforementioned vertical direction), the path of the light spot of the laser signal reflected by the first reflective surface (i.e., the scanning line) and the path of the light spot of the laser signal reflected by the second reflective surface (the scanning line) are spaced apart. When there is a gap between the paths of the light spots of the laser signal reflected by different reflective surfaces, there will be a certain width between the scanning tracks generated by the first reflective surface and the second reflective surface when scanned in the horizontal direction, thereby achieving the effect of repeated scanning of the ROI area. When the paths of the light spots are repeated, the field of view angles formed by the laser signal passing through two different reflective surfaces in the object space have an overlapping angle range. The overlapping part is equivalent to multiple detections, which increases the point cloud density, thereby improving the accuracy of the detection results.

[0109] As a possible design, in a direction parallel to the rotation axis, a first angle (for example, expressed as γ) exists between the first reflecting surface and the rotation axis, and the second reflecting surface is parallel to the rotation axis.

[0110] Among them, there is a third angle (for example, expressed as γ′) between the laser signal reflected by the first reflecting surface and the laser signal reflected by the second reflecting surface in the second direction, and the third angle γ′ is positively correlated with the first angle γ. The angular relationship between the third angle γ′ and the first angle γ can satisfy the following formula: γ′=2γ.

[0111] Please refer to Figure 7, which is a schematic diagram of an embodiment of the present application in which a reflecting surface has an angle difference relative to the rotation axis. The direction of the X-axis is parallel to the rotation axis, the direction of the Z-axis is pointing to the ground, and the direction of the Y-axis is perpendicular to the rotation axis. The direction from the Z-axis to the X-axis represents the negative direction, and the direction from the X-axis to the Z-axis represents the positive direction. As shown in (a) in Figure 7, taking the first reflecting surface as the B1 surface and the second reflecting surface as the A1 surface as an example, when the opening direction of the first angle γ is from the X-axis to the Z-axis, the B1 surface has a first angle γ in the positive direction relative to the rotation axis (for example, the first angle γ is 0.05°), and the A1 surface is parallel to the rotation axis. The laser signal reflected by the B1 surface and the laser signal reflected by the A1 surface have a third angle γ′ in the direction perpendicular to the rotation axis (for example, the third angle γ′ is 0.1°).

[0112] As shown in Figure 7(b), taking the first reflective surface as surface B1 and the second reflective surface as surface A1 as an example, when the opening direction of the first angle γ points from the Z axis to the X axis, surface B1 has a first angle γ in the negative direction relative to the rotation axis (for example, the first angle γ is 0.05°), and surface A1 is parallel to the rotation axis. The laser signal reflected by surface B1 and the laser signal reflected by surface A1 have a third angle γ′ in a direction perpendicular to the rotation axis (for example, the third angle γ′ is 0.1°).

[0113] As a possible design, in a direction parallel to the rotation axis, the first reflecting surface and the rotation axis form a first angle in a positive direction (e.g., represented by γ1), and the second reflecting surface and the rotation axis form a second angle in a negative direction (e.g., represented by γ2). The laser signal reflected by the first reflecting surface and the laser signal reflected by the second reflecting surface form a third angle γ′ in the second direction, and the third angle is related to the first angle and the second angle. The angular relationship between the third angle γ′, the first angle γ1, and the second angle γ2 can satisfy the following formula: γ′=2(γ1+γ2).

[0114] As shown in (c) in Figure 7, taking the first reflecting surface as surface B1 and the second reflecting surface as surface A1 as an example, when the opening direction of the first angle γ1 is from the Z axis to the X axis, and the opening direction of the second angle γ2 is from the X axis to the Z axis, the B1 surface has a first angle γ1 in the negative direction relative to the rotation axis (for example, the first angle γ1 is 0.05°), and the A1 surface has a second angle γ2 in the positive direction relative to the rotation axis (for example, the second angle γ2 is 0.05°), and the laser signal reflected by the B1 surface and the laser signal reflected by the A1 surface have a third angle γ′ in the direction perpendicular to the rotation axis (for example, the third angle γ′ is 0.2°).

[0115] This application designs an angular difference between the first reflective surface and / or the second reflective surface and the rotation axis. When the scanning device is used for rotational scanning, there is an angular difference between the line beam passing through the first reflective surface and the line beam passing through the second reflective surface, so that the scanning of the first reflective surface and the scanning of the second reflective surface do not overlap, thereby achieving the effect of encrypted scanning. In conjunction with Figure 6A or Figure 6B, it can be seen that the scanning line beam passing through the A1 surface can be located between the "gaps" of the scanning line beam passing through the B1 surface. Correspondingly, the scanning line beam passing through the B1 surface is also located between the "gaps" of the scanning line beam passing through the A1 surface, so that the scanning line beams of the A1B1 surfaces are intertwined without completely overlapping each other, thereby increasing the point cloud density and improving the resolution of the overlapping area.

[0116] Of course, the pre-definition of the directions of the X-axis, Y-axis, and Z-axis in combination with Figure 7 is only an exemplary introduction and is not intended to limit the several possible designs of this application to be implemented in the directions defined above. They can also be implemented in other defined directions.

[0117] Optionally, the scanning modules in the above figures all take the scanning process of a 4-sided Polygon as an example. The scanning module can also be a 5-sided Polygon, a 6-sided Polygon, etc. The present application does not limit the shape of the Polygon matrix. Please refer to Figure 8. Figure 8 is a schematic diagram of a 5-sided Polygon provided in an embodiment of the present application. The principle of the scanning process of the 5-sided Polygon is the same as that of the aforementioned embodiment. Please refer to the aforementioned embodiment for details and will not be repeated here.

[0118] In the present application, by designing the first angle β, the second angle α and the third angle θ to satisfy a certain relationship, the area scanned by the laser signal after passing through the first reflective surface overlaps with the area scanned after passing through the second reflective surface. For example, the laser signal is reflected in a first direction (for example, expressed as a horizontal direction) by a first reflective surface (for example, expressed as a B1 surface) to scan a first angle range, and the laser signal is reflected by a second reflective surface (for example, expressed as an A1 surface) connected to the edge of the B surface to scan a second angle range. The first angle range and the second angle range overlap, and the overlapping area is the ROI area. The overlapping area has been scanned by the laser signal reflected by the B1 surface and the laser signal reflected by the A1 surface, that is, the overlapping area has been repeatedly scanned by the laser signal reflected by the two reflective surfaces, and the repeatedly scanned area is equivalent to having been detected multiple times. Therefore, based on the angle design of the angles between the reflective surfaces and the angles between the reflective surface and the rotation axis in the scanning module provided by the present application, encrypted scanning of the ROI area can be achieved, thereby improving the detection accuracy of the ROI area.

[0119] The present application realizes encrypted scanning of the ROI area by designing and adjusting the angle between the reflecting surfaces of the scanning module (i.e., the third angle θ), as well as the angle between the reflecting surface and the rotation axis (i.e., the first angle β and the second angle α), thereby improving the detection accuracy of the ROI area. Compared with the solution of directly increasing the number of pixels of the receiving chip, the solution of designing the scanning module is less expensive and can not significantly increase the cost of the detection device. Compared with the solution of repeated scanning, taking the first reflecting surface as the B1 surface and the second reflecting surface as the A1 surface as an example, the scan from the B1 surface to the A1 surface in the present application is a complete scan, without additional scanning, thereby ensuring the detection efficiency.

[0120] In summary, the present application can complete the encrypted scanning of the ROI area without significantly increasing the cost of the detection device, thereby improving the detection accuracy of the ROI area and ensuring the detection efficiency.

[0121] Furthermore, the overlapping angle range of the scanning of the B1 surface and the A1 surface in this application is located in the central area of ​​the field of view. By performing encrypted scanning on the central area of ​​the field of view, the detection accuracy of the central area can be improved, which can effectively improve the value of the detection results and is beneficial to the calculation and decision-making related to the perception results.

[0122] For example, the present application can be applied to scenarios such as vehicle perception, intelligent driving, mapping, and robot perception. Taking the vehicle perception scenario as an example, the central area of ​​the field of view usually includes the space where the vehicle is likely to travel, which is a high-value field of view (i.e., ROI area). Through the embodiments of the present application, the detection accuracy of the ROI area is improved, the effectiveness of the detection information is improved, and the driving safety of the vehicle is improved, while the detection efficiency can also be guaranteed. Especially for intelligent driving systems, the higher the detection accuracy of the ROI, the more conducive it is to the calculation and decision-making of the intelligent driving system, thereby improving the safety and comfort of the intelligent driving system.

[0123] An embodiment of the present application also provides a laser radar, which includes a scanning module, a transmitting module and a receiving module. The transmitting module includes a laser, the receiving module includes a detector, the laser is used to transmit a laser signal, the scanning module is used to scan the laser signal into the object space, the laser signal is used to detect the object space, and the detector is used to obtain relevant information about the target in the object space based on the return signal of the laser signal.

[0124] Optionally, the scanning module includes the scanning device described in the aforementioned embodiment, such as the scanning module of the embodiment shown in FIG. 2 , or other possible designs.

[0125] Alternatively, the above-mentioned laser radar can also be replaced by other detection devices, such as a fusion detection device.

[0126] The present application also provides a terminal including the aforementioned detection device, such as detection device 20, and the aforementioned laser radar. The terminal (or specifically, the detection device in the terminal) includes the scanning module described in the aforementioned embodiments, such as the scanning module of the embodiment shown in FIG. 2 , or a possible design thereof.

[0127] Please refer to Figure 9, which is a schematic diagram of the structure of a possible terminal 90 provided in an embodiment of the present application. Terminal 90 includes a processor 901 and the aforementioned detection device 20. Processor 901 and detection device 20 can be connected or communicate with each other, and the specific implementation methods of the connection and communication are not limited in this embodiment of the present application.

[0128] The processor 901 is configured to obtain detection data regarding objects in the field of view based on the return signal received by the receiving module of the detection device 20. The detection data may specifically be point cloud data corresponding to the field of view, or the detection data may include one or more of the following: the distance, orientation, pixel area occupied by the target, height, speed, posture, or shape information of the target in the field of view.

[0129] Optionally, the processor 901 is a module that performs arithmetic operations and / or logical operations, and may specifically include one or more of the following devices: a central processing unit (CPU), an application processor (AP), a time-to-digital converter (TDC), a filter, a graphics processing unit (GPU), a microprocessor unit (MPU), an application specific integrated circuit (ASIC), an image signal processor (ISP), a digital signal processor (DSP), a field programmable gate array (FPGA), a complex programmable logic device (CPLD), a coprocessor (assisting the central processing unit to complete corresponding processing and applications), a microcontroller unit (MCU), and / or a neural-network processing unit (NPU), etc.

[0130] Optionally, the above-mentioned terminal may include a mobile platform or transportation tool such as a vehicle, a ship, an airplane, a train, a spacecraft, an unmanned aerial vehicle, or a robot.

[0131] The embodiments of the present application can also be applied to the field of smart car technology, such as vehicle to everything (V2X), long-term evolution of vehicle communication technology (LTE-V), vehicle to vehicle (V2V), etc.

[0132] In the description of this application, the terms "center", "up", "down", "vertical", "horizontal", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on this application.

[0133] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, a conflicting connection or an integrated connection; for ordinary technicians in this field, the specific meaning of the above terms in this application can be understood according to specific circumstances.

[0134] In the embodiments of this application, words such as "exemplarily" or "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design described in this application as "exemplary" or "for example" should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplarily" or "for example" is intended to present the relevant concepts in a concrete manner.

[0135] The “at least one” mentioned in the embodiments of this application refers to one or more, and “plurality” refers to two or more. “At least one of the following items” or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can represent: a, b, c, (a and b), (a and c), (b and c), or (a and b and c), where a, b, c can be single or multiple. “And / or” describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character “ / ” generally indicates that the previous and next associated objects are in an “or” relationship.

[0136] Furthermore, unless otherwise indicated, ordinal numbers such as "first" and "second" in the embodiments of this application are used to distinguish multiple objects and are not used to define the order, timing, priority, or importance of multiple objects. For example, the first reflective surface and the second reflective surface are merely for ease of description and do not indicate a difference in their origin, order, or importance. In some embodiments, the first reflective surface and the second reflective surface may be the same reflective surface.

[0137] In the above embodiments, the term "when" can be interpreted to mean "if...", "after...", "in response to determining...", or "in response to detecting...", depending on the context. The above are merely optional embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the concepts and principles of the present application shall be included within the scope of protection of the present application.

[0138] Those skilled in the art will understand that all or part of the steps to implement the above embodiments may be accomplished by hardware, or by a program to instruct the relevant hardware, and the program may be stored in a computer-readable storage medium, which may be a read-only memory, a disk, or an optical disk, etc.

Claims

1. A scanning module, characterized in that, the scanning module includes N reflection surface groups arranged around a rotation axis, N is a positive integer and N≥3, the N reflection surface groups are centrosymmetric with respect to the center of the rotation axis, and a first reflection surface group in the N reflection surface groups includes a first reflection surface and a second reflection surface that are edge-connected, and the included angle between the first reflection surface and two adjacent reflection surfaces is different; Along the direction of the rotation axis, the line connecting the edge of the first reflection surface and the rotation axis is a first angle, and the line connecting the edge of the second reflection surface and the rotation axis is a second angle, the line connecting the edge of the first reflection surface and the edge of the second reflection surface is a third angle, the difference between 180° and the first angle is greater than the third angle, and the difference between 180° and the second angle is greater than the third angle.

2. The scanning module according to claim 1, wherein The scanning module is used to scan a laser signal into an object space, and the laser signal is used to detect the object space, wherein, the field of view angle formed by the laser signal passing through the first reflection surface in the object space is the angle formed by the laser signal passing through and scanning the fourth angle to the fifth angle in the first direction in sequence from the first edge of the first reflection surface to the second edge of the first reflection surface, the field of view angle formed by the laser signal passing through the second reflection surface in the object space is the angle formed by the laser signal passing through and scanning the sixth angle to the seventh angle in the first direction in sequence from the third edge of the second reflection surface to the fourth edge of the second reflection surface, and the second edge of the first reflection surface is connected to the third edge of the second reflection surface; the field of view angle formed by the laser signal passing through the first reflection surface in the object space and the field of view angle formed by the laser signal passing through the second reflection surface in the object space overlap in angular space, and the overlapping angle range is the angle formed by the laser signal scanning the fifth angle to the sixth angle, and the width of the overlapping angle range is negatively correlated with the third angle.

3. The scanning module according to claim 1 or 2, characterized in that, the field of view angle formed by the laser signal passing through the first reflection surface in the object space is twice the first angle, and the field of view angle formed by the laser signal passing through the second reflection surface in the object space is twice the second angle.

4. The scanning module according to any one of claims 1-3, characterized in that, In a second direction, the path of the light spot of the laser signal reflected by the first reflection surface and the path of the light spot of the laser signal reflected by the second reflection surface have a gap.

5. The scanning module according to any one of claims 1-4, characterized in that, The N reflection surface groups of the scanning module rotate around the rotation axis.

6. The scanning module according to any one of claims 1-5, characterized in that, In a direction parallel to the rotation axis, the first reflection surface has a first included angle with the rotation axis, and the second reflection surface is parallel to the rotation axis.

7. The scanning module according to claim 6, wherein There is a third included angle between the laser signal reflected by the first reflection surface and the laser signal reflected by the second reflection surface in the second direction, and the third included angle is positively correlated with the first included angle.

8. The scanning module according to any one of claims 1-5, characterized in that, In a direction parallel to the rotation axis, the first reflecting surface forms a first angle with the rotation axis in the positive direction, and the second reflecting surface forms a second angle with the rotation axis in the negative direction.

9. The scanning module according to claim 8, wherein In a direction parallel to the rotation axis, the first reflecting surface forms a first angle with the rotation axis in the positive direction, and the second reflecting surface forms a second angle with the rotation axis in the negative direction; The laser signal reflected by the first reflecting surface and the laser signal reflected by the second reflecting surface form a third angle in a second direction, and the third angle is related to the first angle and the second angle.

10. A detection device, characterized in that, The detection device includes a transmitting module, a receiving module, and the scanning module according to any one of claims 1-9. The transmitting module is configured to emit a laser signal. The N reflecting surface groups of the scanning module rotate around the rotation axis to scan the laser signal into the object space, and the laser signal is used to detect the object space. The scanning module is further configured to provide the return signal of the laser signal from the object space to the receiving module.

11. The detection device according to claim 10, wherein, The transmitting module and the receiving module are located on the same side or different sides of the scanning module in a direction perpendicular to the rotation axis.

12. The detection device according to claim 10 or 11, characterized in that, When the transmitting module and the receiving module are located on the same side, the detection device further includes a coaxial module. The coaxial module is configured to coaxialize the laser signal and the return signal of the laser signal.

13. The detection device according to claim 12, wherein, The coaxial module includes a perforated mirror, or the coaxial module includes a polarization beam splitter PBS and a quarter-wave plate.

14. A lidar, characterized in that, The lidar includes the detection device according to any one of claims 10-13. The detection device includes a transmitting module, a scanning module, and a receiving module. The transmitting module includes a laser, and the receiving module includes a detector. The laser is configured to emit a laser signal. The scanning module is configured to scan the laser signal into the object space, and the laser signal is used to detect the object space. The detector is configured to obtain relevant information about the target in the object space according to the return signal of the laser signal.

15. A terminal, characterized in that, The terminal includes the detection device according to any one of claims 10-13 or the lidar according to claim 14.

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