Scanning module and laser radar

Abstract

The present application provides a scanning module and a laser radar, and relates to the field of laser radar technology. The scanning module includes a refractive optical element, a refractive driving element, a first reflective optical element and a reflective driving element, wherein the refractive driving element is used to drive the refractive optical element to rotate, the rotation axis of the refractive optical element is parallel to the first direction, and the exit surface and the incident surface of the refractive optical element are close to each other and are arranged at an angle facing each other; the reflective driving element is used to drive the first reflective optical element to rotate, the rotation axis of the first reflective optical element is arranged parallel to the first direction, and the angle between the reflective surface of the first reflective optical element and the rotation axis of the first reflective optical element is 45°; wherein the refractive driving element and the reflective driving element are arranged at intervals in the first direction. The present application has the characteristic of symmetric pitch field angle, and has a wider range of applications.

Description

Technical Field

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

[0002] Generally, semi-solid mechanical large field of view laser radar has only the scanning system moving and the optical system is not moving. Due to its limited structure, the elevation field of view is partially blocked. In order to make the field of view not blocked, the radar is made into an asymmetric elevation field of view system, which limits the application scenarios. For example, it cannot be widely used in the surveying and mapping industry. Summary of the invention

[0003] In view of this, the purpose of this application is to overcome the deficiencies in the prior art and to provide a scanning module and a laser radar having the characteristics of symmetrical pitch and elevation field of view and a wider range of applications.

[0004] This application provides the following technical solutions:

[0005] In a first aspect, an embodiment of the present application provides a scanning module, the scanning module comprising:

[0006] a refractive optical element and a refractive driving element, wherein the refractive driving element is connected to the refractive optical element, the refractive driving element is used to drive the refractive optical element to rotate, the rotation axis of the refractive optical element is parallel to a first direction, the refractive optical element is used to receive and refract the light beam incident along the first direction, and the exit surface and the incident surface of the refractive optical element are arranged at ends close to each other and are tilted toward each other;

[0007] A first reflective optical element and a reflective driving element, wherein the reflective driving element is connected to the first reflective optical element, the reflective driving element is used to drive the first reflective optical element to rotate, the rotation axis of the first reflective optical element is arranged parallel to the first direction, the first reflective optical element is used to receive and reflect the light beam refracted by the refractive optical element, and the angle between the reflective surface of the first reflective optical element and the rotation axis of the first reflective optical element is 45°; wherein the refractive driving element and the reflective driving element are arranged at intervals in the first direction.

[0008] In some embodiments of the first aspect, the scanning module further includes:

[0009] a focusing optical element, wherein the refractive optical element is located between the focusing optical element and the first reflecting optical element, and the focusing optical element is used to receive and focus the return light beam propagating along the first direction;

[0010] at least one second reflecting optical element, the at least one second reflecting optical element being used to receive and reflect the returning light beam focused by the focusing optical element;

[0011] A detector is used to receive the return light beam reflected by the second reflective optical element.

[0012] In some embodiments of the first aspect, the scanning module further includes:

[0013] a laser, the laser being used to emit the light beam;

[0014] at least one third reflecting optical element, the at least one third reflecting optical element being used to receive and reflect the light beam emitted by the laser, so that the reflected light beam propagates along the first direction;

[0015] At least one collimating optical element, wherein the at least one collimating optical element is used to shrink the divergence angle of the light beam; wherein at least one of the third reflecting optical elements is located between the focusing optical element and the refractive optical element, and the laser and the detector are sequentially arranged on the peripheral side of the focusing optical element.

[0016] In some embodiments of the first aspect, the scanning module further includes:

[0017] A filtering optical element is disposed between the third reflecting optical element and the focusing optical element, and is used for filtering out ambient light in the return light beam propagating to the focusing optical element.

[0018] In some embodiments of the first aspect, the refractive optical element comprises a wedge-shaped mirror;

[0019] and / or, the first reflecting optical element comprises a first reflecting prism;

[0020] and / or, the second reflecting optical element comprises a second reflecting prism;

[0021] and / or, the third reflecting optical element comprises a third reflecting prism;

[0022] and / or, the focusing optical element comprises a receiving lens;

[0023] And / or, the collimating optical element comprises a collimating mirror.

[0024] In some embodiments of the first aspect, a slope of the exit surface is smaller than a slope of the incident surface.

[0025] In some embodiments of the first aspect, the scanning module further includes a weight element, the refractive optical element is formed with a thick end and a thin end, and the weight element is disposed on the thin end.

[0026] In some embodiments of the first aspect, the refractive drive element includes a refractive drive motor, a main shaft of the refractive drive motor is configured as a hollow shaft, an axis of the hollow shaft coincides with the rotation axis of the refractive optical element; wherein the refractive optical element is disposed in the hollow shaft.

[0027] In some embodiments of the first aspect, the reflection drive element includes a reflection drive motor, a main shaft of the reflection drive motor is connected to the first reflection optical element, and an axis of the main shaft of the reflection drive motor is arranged parallel to the first direction.

[0028] In a second aspect, the present application further provides a laser radar, the laser radar comprising:

[0029] A scanning module as described in any one of the above embodiments;

[0030] A light-transmitting cover is disposed on the scanning module and is configured to only transmit the light beam.

[0031] The embodiments of the present application have the following advantages:

[0032] The present application provides a scanning module that achieves symmetry in pitch and elevation field of view, solves the occlusion problem existing in traditional large-field-of-view laser radars, and can achieve a large pitch field of view of -30° to +30° while suppressing total reflection of the optical surface. It not only improves the performance of the laser radar, but also makes it more suitable for use in scenarios that require high-precision, large-range measurements, such as self-driving cars, drone navigation, terrain mapping, and other fields. Furthermore, by precisely controlling the position and angle of each optical element, the design provides greater flexibility and measurement accuracy.

[0033] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1A schematic structural diagram of a scanning module provided by an embodiment of the present application from a viewing angle is shown;

[0036] Figure 2 A schematic diagram showing the principle of a scanning module provided in an embodiment of the present application is shown;

[0037] Figure 3 A schematic diagram showing the results of Experiment 1 provided in an embodiment of the present application is shown;

[0038] Figure 4 A schematic diagram showing the results of Experiment 2 provided in an embodiment of the present application is shown;

[0039] Figure 5 A schematic diagram showing the results of Experiment 3 provided in the embodiments of the present application is shown.

[0040] Description of main component symbols:

[0041] 100-reflection drive element; 200-first reflection optical element; 210-reflection surface; 300-refractive optical element; 310-exit surface; 320-incident surface; 400-refractive drive element; 500-third reflection optical element; 600-filtering optical element; 700-focusing optical element; 800-detector; 900-second reflection optical element; 1000-second collimator; 1100-folding mirror; 1200-first collimator; 1300-light-transmitting cover; 1400-base; 1500-laser. DETAILED DESCRIPTION

[0042] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0043] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. In contrast, when an element is referred to as being "directly on" another element, there is no intermediate element. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0044] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0045] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of the template are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0047] In related technologies, with the development of LiDAR technology, LiDAR scanning methods are varied. In the field of three-dimensional space scanning, the demand for LiDAR can be summarized as large field of view (FOV) and high precision. Large field of view mainly refers to a horizontal field of view approaching 360° and a vertical field of view of 60° or more; high precision refers to the relative and absolute accuracy of the radar's ranging, which is generally required to be at the sub-centimeter (i.e. millimeter) level.

[0048] Large field of view LiDAR is a type of LiDAR. Usually, due to the limited structure, the elevation and pitch angles of LiDAR products are partially blocked. In order to ensure that the field of view is not blocked, the LiDAR is made into an asymmetric elevation and pitch angle system, which limits the application scenarios. For example, it cannot be widely used in the surveying and mapping industry.

[0049] As shown in FIGS. 1 and 2 , in order to solve the above technical problems, an embodiment of the present application provides a scanning module, which includes a refractive optical element 300, a refractive driving element 400, a first reflective optical element 200 and a reflective driving element 100, wherein the refractive driving element 400 is connected to the refractive optical element 300, and the refractive driving element 400 is used to drive the refractive optical element 300 to rotate, wherein the rotation axis of the refractive optical element 300 is parallel to the first direction, and the refractive optical element 300 is used to receive and refract a light beam incident along the first direction, and the exit surface 310 and the incident surface 320 of the refractive optical element 300 are parallel to the first direction. 0, one end of the first reflective optical element 200 that is close to each other is arranged to be tilted towards each other; the reflection driving element 100 is connected to the first reflective optical element 200, the reflection driving element is used to drive the first reflective optical element 200 to rotate, the rotation axis of the first reflective optical element 200 is arranged parallel to the first direction, the first reflective optical element 200 is used to receive and reflect the light beam refracted by the refractive optical element 300, and the angle between the reflection surface 210 of the first reflective optical element 200 and the rotation axis of the first reflective optical element 200 is 45°; wherein, the refractive driving element 400 and the reflection driving element 100 are arranged at intervals in the first direction.

[0050] In these embodiments, the present application aims to solve the limitations of the large field of view laser radar in structural design, especially the problem of partial occlusion of the pitch field of view angle. By providing a scanning module and laser radar with symmetrical pitch field of view angle characteristics, it is helpful to expand its scope of application, including more extensive application in surveying and mapping industries, etc.

[0051] The two components of the refractive optical element 300 and the refractive driving element 400 work together, wherein the refractive driving element 400 is responsible for driving the refractive optical element 300 to rotate. The rotation axis of the refractive optical element 300 is parallel to the first direction of incidence of the light beam, which means that the element can receive the light beam coming along the first direction and refract it. The specific setting between the exit surface 310 and the incident surface 320 (the ends close to each other are deflected towards each other) helps to achieve the required beam path adjustment. In other words, the light beam is incident on the refractive optical element 300 along the first direction, and is refracted after passing through the refractive optical element 300, changing the propagation path of the light beam. The setting of the deflection towards each other between the exit surface 310 and the incident surface 320 helps to achieve a specific angle of light beam steering, ensuring that the light beam can be correctly directed to the next component.

[0052] The first reflective optical element 200 is connected to the reflective driving element 100 and drives the first reflective optical element 200 to rotate, so that the first reflective optical element 200 rotates around the rotation axis of the first reflective optical element 200. Similarly, the rotation axis of the first reflective optical element 200 is also parallel to the first direction. The function of the first reflective optical element 200 is to receive the light beam coming out of the refractive optical element 300 and reflect it out. The design of maintaining a 45° angle between the reflective surface 210 and the rotation axis ensures that the light beam can be accurately redirected. In other words, the light beam processed by the refractive optical element 300 will be received by the first reflective optical element 200 and reflected out at an angle of 45°. This 45° angle design ensures that the light beam can propagate in a predetermined direction, thereby covering a larger field of view.

[0053] The refraction driving element 400 and the reflection driving element 100 are arranged at intervals in the first direction. Such a layout may be to ensure that the movements of the two will not interfere with each other and can complete the tasks independently.

[0054] For example, in practical applications, the first direction is a vertical direction. Furthermore, the rotation axis of the first reflective optical element 200 and the rotation axis of the refractive optical element 300 are arranged to coincide with each other.

[0055] Therefore, through the above design, the scanning module achieves symmetry in the pitch field of view, solves the occlusion problem existing in traditional large-field-of-view laser radars, and can achieve a large field of view of -30° to +30° in pitch while suppressing total reflection of the optical surface. It not only improves the performance of the laser radar, but also makes it more suitable for use in scenarios that require high-precision, large-range measurements, such as self-driving cars, drone navigation, terrain mapping, and other fields. Furthermore, by precisely controlling the position and angle of each optical component, the design provides greater flexibility and measurement accuracy.

[0056] As shown in Figures 1 and 2, in some embodiments, the scanning module also includes a focusing optical element 700, at least one second reflecting optical element 900 and a detector 800, the refractive optical element 300 is located between the focusing optical element 700 and the first reflecting optical element 200, the focusing optical element 700 is used to receive and focus the return light beam propagating along the first direction; at least one second reflecting optical element 900 is used to receive and reflect the return light beam after being focused by the focusing optical element 700; the detector 800 is used to receive the return light beam after being reflected by the second reflecting optical element 900.

[0057] In these embodiments, the focusing optical element 700 is located between the refractive optical element 300 and the first reflective optical element 200. The focusing optical element 700 is used to receive and focus the return light beam propagating along the first direction. In other words, the focusing optical element 700 not only processes the emitted light beam, but also processes the return light beam reflected from the target object, ensuring that the return light beam is effectively collected and concentrated.

[0058] At least one second reflective optical element 900 receives and reflects the return light beam after being focused by the focusing optical element 700. That is, there may be multiple such elements to guide the light beam to the final destination, i.e., the detector 800. The use of multiple reflective elements can achieve a more complex optical path design, help optimize the beam path, and adjust the direction of the light beam to adapt to different installation space requirements.

[0059] For example, in this embodiment, the number of the second reflecting optical element 900 is 1. Of course, in other embodiments, according to actual installation scenarios, the number of the second reflecting optical elements 900 may also be 2, 3, 4, 5, 6, 7 or 8, etc.

[0060] The detector 800 receives the return light beam reflected by the second reflective optical element 900 , and the detector 800 converts the optical signal of the received return light beam into an electrical signal, thereby completing the acquisition of environmental information.

[0061] To facilitate understanding of this application, the system workflow is provided as follows:

[0062] Transmitting stage: the laser radar transmits a light beam through the above-mentioned refractive optical element 300 and the first reflective optical element 200. After refraction and reflection, the light beam is directed toward the target area at a predetermined angle and direction.

[0063] Receiving stage: When the light beam encounters an object and is reflected back, a return light beam is formed, which is first captured by the focusing optical element 700 and focused into a smaller area. Subsequently, the return light beam is received by at least one second reflective optical element 900 and reflected again, and finally reaches the detector 800.

[0064] Data processing: After the detector 800 receives the reflected return light beam, it converts it into an electrical signal, and then analyzes it to obtain information about the target object such as distance and shape.

[0065] Obviously, the application of focusing optical element 700 improves the collection efficiency of the return beam, allowing the system to more accurately measure the distance and size of the target. Through the design of multi-level reflective optical elements, the system can better adapt to various complex application scenarios, such as narrow spaces or situations requiring special angle illumination.

[0066] It should be noted that the reflected return light beam is parallel to the outgoing light beam, and follows the same path, passing through the first reflective optical element 200, the refractive optical element 300, the focusing optical element 700, and at least one second reflective optical element 900, and finally hits the detector 800. Since the outgoing light beam is small, the projection area of ​​the first reflective optical element 200 on the filter is small, so in addition to the return light beam reflected by the first reflective optical element 200, other return light will pass through the filter, enter the focusing optical element 700, and then pass through at least one second reflective optical element 900 to reflect to the detector 800. The return light beam reflected by the first reflective optical element 200 will go against the optical path toward the laser 1500, and finally dissipate and be absorbed by the light-absorbing material on the structure, and will not be received by the laser sensor. This part of the return light accounts for a limited proportion of the total return light.

[0067] As shown in Figures 1 and 2, in some embodiments, the scanning module also includes a laser 1500, at least one third reflecting optical element 500, and at least one collimating optical element. The laser 1500 is used to emit the light beam; the at least one third reflecting optical element 500 is used to receive and reflect the light beam emitted by the laser, so that the reflected light beam propagates along the first direction; the at least one collimating optical element is used to shrink the divergence angle of the light beam; wherein, the at least one third reflecting optical element 500 is located between the focusing optical element 700 and the refractive optical element 300, and the laser 1500 and the detector 800 are sequentially arranged on the peripheral side of the focusing optical element 700.

[0068] In these embodiments, the structure of the scanning module becomes more complex and more comprehensive in functionality, and by introducing a laser 1500, at least one third reflecting optical element 500, and at least one collimating optical element, the system is able to emit and process light beams more efficiently.

[0069] The laser 1500 is used as a light source to emit an original light beam. The laser 1500 and the detector 800 are arranged on the periphery of the focusing optical element 700, which can make the scanning module and the laser radar using the scanning module smaller in size.

[0070] For example, the laser 1500 can provide a laser beam with a certain divergence angle. The laser 1500 can be an edge-emitting laser, which is usually divided into a fast axis and a slow axis, with a fast axis divergence angle half width of about 25° and a slow axis divergence angle half width of about 10°; it can also be a surface-emitting laser, with a symmetrical divergence angle, usually with a half width of about 20°.

[0071] At least one third reflecting optical element 500 receives and reflects the light beam emitted by the laser 1500, ensuring that the reflected light beam propagates along the first direction. At least one third reflecting optical element 500 is located between the focusing optical element 700 and the refractive optical element 300, and at least one third reflecting optical element 500 is located on the propagation path of the light beam, that is, guiding the light beam emitted from the laser 1500 into the subsequent optical processing path.

[0072] For example, in this embodiment, the number of the third reflecting optical elements 500 is 2. Of course, in other embodiments, the number of the third reflecting optical elements 500 may be 1, 3, 4, 5, 6, 7 or 8, etc., according to actual installation scenarios.

[0073] At least one collimating optical element is used to shrink the divergence angle of the light beam so that the emitted light beam is as parallel as possible to improve the measurement accuracy and distance, and reduce the area of ​​the blocking filter for the subsequent first emission optical element to cooperate with the detector 800. It is usually located after the laser 1500 and before or after the third reflective optical element 500, depending on the design requirements.

[0074] For example, in this embodiment, the number of collimating optical elements is 2, and the 2 collimating optical elements and the 2 third reflecting optical elements 500 are alternately arranged in sequence, so that the light beam emitted by the laser 1500 located on the side of the refractive optical element 300 can enter the bottom of the refractive optical element 300 and enter along the first direction. Of course, in other embodiments, according to the actual installation scenario, the number of collimating optical elements can be 1, 3, 4, 5, 6, 7 or 8, etc.

[0075] To facilitate understanding of this application, the system workflow is provided as follows:

[0076] Emission phase: The laser 1500 generates a light beam and emits the light beam. The light beam is received and reflected by at least one third reflective optical element 500, and its propagation direction is adjusted so that it propagates along the first direction. The collimating optical element processes the light beam to reduce its divergence angle and ensure that the light beam is emitted to the target area as parallel as possible. The collimated light beam continues to propagate forward, and is processed by the refractive optical element 300 and the first reflective optical element 200 in turn, and finally emitted at a predetermined angle and direction.

[0077] Receiving stage: The returning light beam is first captured by the focusing optical element 700 and focused into a smaller area. The focused light beam is then received by at least one second reflecting optical element 900 and reflected again, and finally reaches the detector 800 to complete the information collection.

[0078] Obviously, through the collimating optical element, the divergence of the light beam can be effectively reduced, so that targets at a long distance can also be clearly detected, enhancing the detection range and accuracy of the system. The position arrangement of the third reflective optical element 500 makes the optical path more compact and efficient, which helps to reduce the volume of the overall device while maintaining good performance. It should be noted that the laser 1500 and the detector 800 are arranged in sequence on the peripheral side of the focusing optical element 700. Such a layout not only saves space, but also simplifies the optical path and reduces the possibility of signal loss.

[0079] In addition, the test results are provided as follows:

[0080] Experiment 1: Simulation of the laser radar. The rotation speed of the first reflective optical element is 6000r / min, the rotation speed of the refractive optical element 300 is 5400r / min, and the 0.1s spot trajectory on the barrel wall is as follows: Figure 3 shown.

[0081] Experiment 2: Simulation of the laser radar. The rotation speed of the first reflective optical element is 6000r / min, the rotation speed of the refractive optical element 300 is 5400r / min, and the 0.2s spot trajectory on the barrel wall is as follows: Figure 4 shown.

[0082] Test 3: Simulate the laser radar with the first reflective optical element rotating at 6000r / min and the refractive optical element 300 rotating at 5400r / min. The 1s spot trajectory on the barrel wall is as follows: Figure 5 shown.

[0083] In some embodiments, the scanning module further includes a filtering optical element 600 , which is disposed between the third reflecting optical element 500 and the focusing optical element 700 , and is used to filter out ambient light in a return light beam propagating to the focusing optical element 700 .

[0084] In these embodiments, the introduction of the filter optical element 600 further enhances the function of the scanning module, especially the processing of the return beam. The element is specifically used to filter out the ambient light in the return beam propagating to the focusing optical element 700, thereby improving the signal-to-noise ratio and measurement accuracy of the system.

[0085] The filter optical element 600 is disposed between the third reflective optical element 500 and the focusing optical element 700. This means that the filter optical element 600 is located on a critical path in the optical path for receiving and processing the return light beam. The main task of the filter optical element 600 is to filter out non-target light sources (i.e., ambient light) in the light beam reflected from the target object. This includes natural light, artificial lighting, and other light sources that may interfere with the normal operation of the laser radar.

[0086] By effectively removing unwanted light, the filtering optical element 600 ensures that the light beam reaching the detector 800 consists primarily of light emitted by the lidar and reflected by the target, greatly reducing noise and improving signal quality. A higher signal-to-noise ratio means more accurate distance measurements and better image quality, which is especially important for applications that require high-resolution data, such as perception systems for self-driving cars or precision mapping.

[0087] Among them, the emission stage of the present application remains unchanged, and the emission of high-quality light beams continues to be completed through the laser 1500, the third reflective optical element 500 and the collimating optical element. A key step is added to the receiving stage: the returned light beam first passes through the third reflective optical element 500, and then enters the filtering optical element 600. The filtering optical element 600 filters out the ambient light and only allows light with a wavelength emitted by the laser radar to pass through. The filtered light beam is then captured by the focusing optical element 700 and focused into a smaller area. The focused light beam is then received and reflected by the second reflecting optical element 900, and finally reaches the detector 800.

[0088] Obviously, under complex lighting conditions, the filter optical element 600 can effectively reduce the interference of ambient light on the system, so that the laser radar can work stably even in daytime or strong light environment. By optimizing the quality of the received return light beam, the system can achieve higher-precision distance measurement and target recognition. It is suitable for more diverse application scenarios, especially outdoors or in situations with strong background light interference, such as urban traffic monitoring, drone navigation, outdoor mapping, etc.

[0089] The filtering optical element 600 is disposed between the third reflecting optical element 500 and the focusing optical element 700, which does not significantly increase the volume of the system while ensuring the effectiveness and simplicity of the optical path.

[0090] For example, in the present application, the filter optical element 600 is configured as a filter. Of course, in other embodiments, the filter optical element 600 can also be configured as an interference filter, a tunable filter, a polarization filter, or the like.

[0091] As shown in FIG. 1 and FIG. 2 , in some embodiments, the refractive optical element 300 includes a wedge-shaped mirror.

[0092] In these embodiments, the refractive optical element 300 is a wedge mirror, which is a transparent optical element with an inclined surface that can be used to change the direction of a light beam without changing its focusing characteristics. The wedge mirror is composed of two parallel or non-parallel pieces of glass or other transparent materials, two of which are inclined, namely the incident surface 320 and the exit surface 310. When the light beam passes through the wedge mirror, due to the existence of its inclined surface, the light beam will be deflected and the propagation direction will be changed. The deflection angle depends on the incident angle and the wedge angle of the wedge mirror.

[0093] Unlike prisms, wedge mirrors do not cause significant changes in the focus position of the light beam, which means that the beam path can be changed without destroying the imaging quality. Wedge mirrors can be used to deflect the transmitted light beam or to redirect the received return light beam, thus simplifying the optical path of the system.

[0094] In the emission stage in the scanning module: the light beam emitted by the laser 1500 is collimated, first reflected by the third reflective optical element 500, and propagates along the first direction. The light beam then enters the wedge mirror, and according to the angle setting of the wedge mirror, the light beam will be deflected at a specific angle to ensure that it is emitted to the target area along the predetermined path.

[0095] Receiving stage: The returned light beam passes through the wedge mirror again and is redirected to ensure that it can accurately reach the subsequent optical components, such as the filter optical element 600, the focusing optical element 700, etc. This bidirectional operation capability makes the wedge mirror an indispensable part of the scanning module, which helps to achieve efficient beam management and precise target positioning.

[0096] Since the wedge mirror can change the beam path without affecting the image quality, it helps to design a more compact system layout. Compared with traditional rotating mirrors, the wedge mirror can achieve a wide range of beam steering through small angle adjustments, reducing the need for complex mechanical movements and improving the reliability and life of the system.

[0097] Exemplarily, the wedge-shaped mirror is trapezoidal. For the emission light path, the light beam enters from the incident surface 320 with a large slope and exits from the exit surface 310 with a small slope. For the receiving light path, the light beam enters from the exit surface 310 with a small slope and exits from the incident surface 320 with a large slope.

[0098] As shown in FIG. 1 and FIG. 2 , in some embodiments, the first reflective optical element 200 includes a first reflective prism.

[0099] In these embodiments, the first reflective optical element 200 is a first reflective prism, which is an optical element that changes the beam path by using total internal reflection or a coated reflective surface 210. The application of a reflective prism in a laser radar scanning module can provide more precise and stable beam control while simplifying the mechanical design of the system.

[0100] The first reflecting prism is usually made of glass or other transparent materials and has one or more reflecting surfaces 210. These reflecting surfaces 210 can be specially coated to enhance the reflection efficiency, or they can rely on total internal reflection. When the light beam enters the prism, it will be reflected on one or more internal reflecting surfaces 210, thereby changing the propagation direction. By carefully designing the angle and shape of the prism, the light beam can be turned at a specific angle. High-quality reflecting prisms can provide a reflectivity close to 100%, ensuring almost no light loss.

[0101] Of course, in other embodiments, the first reflective optical element 200 may also be configured as a plane reflective mirror, a multi-faceted reflective prism, etc.

[0102] As shown in FIG. 1 and FIG. 2 , in some embodiments, the second reflecting optical element 900 includes a second reflecting prism.

[0103] In these embodiments, the second reflective optical element 900 uses a second reflective prism, and this design choice brings significant advantages to the laser radar scanning module. The second reflective prism changes the beam path through its internal total internal reflection or coated reflective surface 210, providing high-precision and stable beam control.

[0104] The second reflecting prism is usually made of glass or other transparent materials and has one or more reflecting surfaces. These reflecting surfaces can be specially coated to enhance the reflection efficiency, or they can rely on total internal reflection. When the returning light beam enters the second reflecting prism, it will be reflected on one or more internal reflecting surfaces, thereby changing the propagation direction. By configuring the angle and shape of the prism, beam steering at a specific angle can be achieved. In the receiving stage in the scanning module: The returning light beam first passes through the filtering optical element 600 to remove ambient light interference. Then, the light beam enters the second reflecting prism, where the light beam is precisely redirected to ensure that it can accurately reach subsequent optical components, such as the focusing optical element 700. The light beam adjusted by the second reflecting prism is then captured by the focusing optical element 700 and focused into a smaller area. Finally, the focused light beam is received by the detector 800 to complete the information collection.

[0105] As shown in FIG. 1 and FIG. 2 , in some embodiments, the third reflecting optical element 500 includes a third reflecting prism.

[0106] In these embodiments, the third reflective optical element 500 uses a third reflective prism, which brings significant advantages to the laser radar scanning module. The third reflective prism changes the beam path through total internal reflection or a coated reflective surface inside it, providing high-precision and stable beam control.

[0107] The third reflecting prism is usually made of glass or other transparent materials and has one or more reflecting surfaces. These reflecting surfaces may be specially coated to enhance the reflection efficiency, or they may rely on total internal reflection. When the light beam emitted from the laser 1500 enters the third reflecting prism, it will be reflected on one or more reflecting surfaces inside, thereby changing the propagation direction. By carefully designing the angle and shape of the prism, beam steering at a specific angle can be achieved.

[0108] In the emission phase of the scanning module: the light beam emitted by the laser 1500 is first collimated by the collimating optical element. The collimated light beam is received by the third reflecting prism, reflected inside it, and emitted at a predetermined angle and direction to ensure that the light beam propagates in the first direction. This precise beam steering helps to ensure that the emitted light beam can accurately cover the target area. Receiving phase: the returning light beam passes through the third reflecting prism again, where the light beam is redirected to ensure that it can accurately reach subsequent optical components, such as the filtering optical element 600, the focusing optical element 700, etc. The bidirectional operation capability of the third reflecting prism allows efficient beam management and precise target positioning.

[0109] The stable reflection angle provided by the third reflective prism helps improve the accuracy of the emitted beam and ensures that the beam can accurately cover the target area. Compared with traditional rotating reflectors, the reflective prism can achieve beam steering through a fixed structure, reducing the need for complex mechanical movements and improving the reliability and life of the system. Since the reflective prism can change the beam path without affecting the imaging quality, it helps to design a more compact system layout.

[0110] As shown in FIG. 1 and FIG. 2 , in some embodiments, the focusing optical element 700 includes a receiving lens.

[0111] In these embodiments, the focusing optical element 700 uses a receiving lens, which brings significant advantages to the laser radar scanning module. The main function of the receiving lens is to effectively focus the returning light beam onto the detector 800, thereby improving the signal-to-noise ratio and measurement accuracy of the system.

[0112] The receiving lens is usually composed of one or more carefully designed lenses made of glass or other transparent materials, which can be a single lens or a combination of multiple lenses. When the light beam reflected from the target object enters the receiving lens, the receiving lens will re-converge these scattered light rays to form a more concentrated light spot, which is finally projected onto the detector 800. A high-quality receiving lens can provide good focusing performance, ensuring that the return light beam is captured as concentratedly as possible to reduce energy loss. The multi-piece combination lens design can effectively correct a variety of aberrations (such as spherical aberration, chromatic aberration, etc.) and improve imaging quality. According to application requirements, different types of lens materials can be selected to adapt to different wavelength ranges to ensure optimal performance.

[0113] In the receiving stage of the scanning module: The returned light beam first passes through the filtering optical element 600 to remove the interference of ambient light. Then, the light beam enters the third reflecting prism, where the light beam is redirected to ensure that it can accurately reach the receiving lens. The receiving lens focuses the returned light beam to form a smaller light spot and projects it onto the detector 800 to complete the information collection.

[0114] Obviously, by effectively focusing the return beam, the receiving lens can significantly increase the signal strength received by the detector 800, thereby improving the signal-to-noise ratio of the system. Good focusing performance helps to improve the spatial resolution of the system, making the distance measurement more accurate. By concentrating the beam in a small area of ​​the detector 800, the receiving lens can help reduce the background noise from the surrounding environment.

[0115] For example, according to the requirements of different application scenarios, specific lens materials and coatings can be selected to optimize performance at different wavelengths.

[0116] Furthermore, there is an additional advantage of using a receiving lens: the receiving lens can achieve efficient beam management in a compact space, simplifying the overall optical path design of the system. Compared with other complex focusing mechanisms, the design of the receiving lens is simpler and more reliable, reducing the use of mechanical components and improving the stability of the system. Certain types of receiving lenses (such as aspherical lenses) can support a larger field of view and are suitable for wide-area scanning applications.

[0117] As shown in FIG. 1 and FIG. 2 , in some embodiments, the collimating optical element includes a collimating mirror.

[0118] In some embodiments, the collimating optical element uses a collimating mirror, which brings significant advantages to the laser radar scanning module. The main function of the collimating mirror is to convert the divergent beam emitted from the laser 1500 into a parallel beam, thereby ensuring that the beam maintains high energy density and directionality when propagating over long distances.

[0119] The collimator is usually composed of one or more carefully designed lenses, which can be a single lens or a combination of multiple lenses. When the divergent light beam emitted from the laser 1500 enters the collimator, the lens will rearrange these light rays to form a beam that is as parallel as possible and reduce the divergence angle of the light beam. A high-quality collimator can provide good collimation performance, ensure that the emitted light beam has a minimum divergence angle, and maintain the concentration of the light beam over a long distance. The multi-lens combination design can effectively correct various aberrations (such as spherical aberration, coma, etc.) and improve the quality of the beam.

[0120] In the emission stage in the scanning module: the divergent light beam emitted by the laser 1500 first passes through the collimator. The collimator converts the divergent light beam into a parallel light beam, ensuring that the light beam maintains a high energy density and direction during propagation. The collimated light beam is then received by the third reflecting prism, reflected inside it, and emitted at a predetermined angle and direction, ensuring that the light beam propagates along the first direction.

[0121] Obviously, by reducing the divergence angle of the light beam, the collimator can ensure that the light beam can still maintain a high energy density when propagating over a long distance, thereby improving the measurement accuracy of the system. The collimated light beam can maintain a strong signal strength at a longer distance, extending the detection range of the system. The collimator helps control the spot size reaching the target surface, ensuring measurement consistency at different distances. In addition, by improving the directionality of the light beam, the interference of other light sources in the environment is reduced, and the signal-to-noise ratio is improved.

[0122] For example, there are two collimators in the present application, and the two collimators are respectively a first collimator 1200 and a second collimator 1000. The laser 1500 is an edge-emitting laser. The first-stage collimator can constrain the laser beam with a large divergence angle emitted by the fast axis of the edge-emitting laser to a laser beam with a smaller divergence angle. Of course, if the laser 1500 is a surface-emitting laser 1500, then the first-stage collimator is a spherical lens.

[0123] The second-stage collimator constrains the laser beam with a large divergence angle emitted by the fast axis of the edge-emitting laser 1500 into a laser beam with a smaller divergence angle. Of course, if the laser 1500 is a surface-emitting laser 1500, the second-stage collimator is a spherical lens.

[0124] In the laser emission optical path, the first-stage collimator and the second-stage collimator can appropriately place reflectors according to actual conditions, mainly the need for light path folding. For example, in this implementation, a folding mirror 1100 is placed between the first-stage collimator and the second-stage collimator to fold the light path by 90 degrees and reduce the volume of the system. Then, a third reflective optical element 500 is placed to fold the light path by 90 degrees and make it incident on the center of the refractive optical element 300.

[0125] As shown in FIG. 1 and FIG. 2 , in some embodiments, the slope of the exit surface 310 is smaller than the slope of the incident surface 320 .

[0126] In these embodiments, the slope of the exit surface 310 of the refractive optical element 300 is less than the slope of the incident surface 320. This design choice has a specific impact on the beam path and performance in the LiDAR scanning module.

[0127] The slope of the exit surface 310 is smaller than that of the incident surface 320, so that there is a certain slope difference between the incident surface 320 and the exit surface 310 of the refractive optical element 300 (such as a wedge mirror), wherein the slope of the exit surface 310 is smaller, while the slope of the incident surface 320 is larger. This will affect the refraction angle of the light beam when it passes through the element, thereby changing the propagation direction and characteristics of the light beam.

[0128] Incident light beam: When the light beam is incident on the refractive optical element 300 from the first direction, the light beam will first undergo a significant refraction, changing its propagation direction, due to the large slope of the incident surface 320. After the first refraction, the light beam propagates inside the element and eventually reaches the exit surface 310 with a smaller slope.

[0129] Outgoing light beam: Since the slope of the exit surface 310 is relatively small, the refraction angle of the light beam when leaving the element is relatively small, which helps to maintain the directionality and energy concentration of the light beam.

[0130] By adjusting the inclination of the incident surface 320 and the exit surface 310, the steering angle of the light beam can be more accurately controlled to ensure that the light beam propagates along the expected path. A smaller inclination of the exit surface 310 helps to reduce the additional divergence of the light beam when it is emitted and maintain a high energy density, which is particularly important when propagating over long distances. Obviously, by optimizing the beam path, the system can obtain more accurate distance measurement and higher spatial resolution.

[0131] As shown in FIG. 1 and FIG. 2 , in some embodiments, the scanning module further includes a weight element, the refractive optical element 300 is formed with a thick end and a thin end, and the weight element is disposed on the thin end.

[0132] In these embodiments, the problem of uneven mass distribution caused by the asymmetry of the refractive optical element 300 (such as a wedge-shaped mirror) is addressed to ensure the mechanical balance and stability of the system.

[0133] The refractive optical element 300 (e.g., wedge mirror) is usually thicker at one end (thick end) and thinner at the other end (thin end). In order to balance the uneven mass distribution, a weight element is installed at the thin end. The main purpose of the weight element is to balance the mass distribution of the entire element by increasing the mass of the thin end, ensuring stability during rotation and reducing vibration.

[0134] When the refractive optical element 300 rotates, if it is not balanced, it will vibrate or shake due to uneven mass distribution, which will not only affect the precise control of the light beam, but also cause mechanical wear and shorten the service life. By adding a counterweight element at the thin end, the dynamic balance during the rotation process can be significantly improved, making the system run more smoothly and improving the accuracy and reliability of the light beam steering.

[0135] Illustratively, in this embodiment, the weight element is configured as a weight block.

[0136] As shown in FIG. 1 and FIG. 2 , in some embodiments, the refractive drive element 400 includes a refractive drive motor, the main shaft of the refractive drive motor is set as a hollow shaft, the axis of the hollow shaft coincides with the rotation axis of the refractive optical element 300; wherein the refractive optical element 300 is set in the hollow shaft.

[0137] In these embodiments, the refractive drive motor is used to drive the refractive optical element 300 (such as a wedge mirror) to rotate to achieve precise control of the beam path. The main shaft of the refractive drive motor adopts a hollow shaft design to allow other components or light beams to pass through its center. The axis of the hollow shaft completely coincides with the rotation axis of the refractive optical element 300, ensuring precise alignment between the two. The refractive optical element 300 is placed inside the hollow shaft, and its rotation axis is consistent with the axis of the hollow shaft, which ensures that the refractive optical element 300 maintains a stable center position during rotation.

[0138] Due to the presence of the hollow shaft, the light beam can enter and leave the refractive optical element 300 through the hollow shaft without being blocked by the motor or other mechanical components, thereby achieving a compact light path layout.

[0139] Obviously, the hollow shaft design makes the mechanical structure of the entire system more compact, saves space, and simplifies the optical path arrangement. The light beam can pass directly through the hollow shaft, avoiding contact with the motor housing or other mechanical parts, reducing unnecessary reflections or scattering, and improving the beam quality.

[0140] Furthermore, the hollow shaft provides better mechanical support, reduces vibration and shaking during rotation, and improves the overall stability of the system. Since the refractive optical element 300 is located inside the hollow shaft, it can be inspected or replaced without disassembling the motor, simplifying the maintenance process.

[0141] Exemplarily, the refraction drive motor is configured as a hollow shaft motor. Of course, this can also be achieved by replacing the main shaft of the refraction drive motor with a hollow shaft.

[0142] Exemplarily, the wedge-shaped mirror is a cylindrical mirror, and the two end surfaces of the wedge-shaped mirror are the incident surface 320 and the exit surface 310 respectively.

[0143] The wedge mirror will refract the light beam emitted from the inside on its outer surface, so that the laser forms an angle θ with the incident light when it is emitted. As the wedge mirror rotates, the laser will produce a solid angle of 2θ, that is, a field of view of 2θ in the vertical direction.

[0144] Exemplarily, the angle θ is 10°, 20°, 30°, 40°, 50°, etc.

[0145] As shown in FIG. 1 and FIG. 2 , in some embodiments, the reflection drive element 100 includes a reflection drive motor, a main shaft of the reflection drive motor is connected to the first reflection optical element 200 , and an axis of the main shaft of the reflection drive motor is arranged parallel to the first direction.

[0146] In these embodiments, the reflection drive motor is used to drive the first reflection optical element 200 to rotate to achieve precise control of the beam path. The main shaft of the reflection drive motor is directly connected to the first reflection optical element 200, ensuring a rigid connection between the two, so that the reflection optical element can rotate synchronously with the motor. The main shaft axis of the reflection drive motor is parallel to the first direction, which means that when the light beam propagates along the first direction, the reflection optical element can rotate around an axis parallel to the propagation direction of the light beam.

[0147] The reflective optical element is fixed to the main shaft of the reflective drive motor through its back or side, ensuring that its rotation axis remains parallel to the first direction of light beam propagation. Since the main shaft axis of the reflective drive motor is parallel to the first direction, the reflective optical element can adjust the angle of the light beam by rotating without changing the propagation direction of the light beam.

[0148] To ensure that the reflective optical element rotates at an accurate angle, an encoder or other position feedback device may be added to the reflective drive motor.

[0149] Exemplarily, the first reflective optical element 200 is shaped as a racetrack-type column, which can achieve dynamic balance and low wind resistance.

[0150] As shown in Figures 1 and 2, in some embodiments, the present application also provides a laser radar, which includes a scanning module, a base 1400 and a light-transmitting cover 1300 as in any of the above embodiments, the light-transmitting cover 1300 is covered on the scanning module, the light-transmitting cover 1300 and the base 1400 form a sealed cavity, the scanning module is arranged in the sealed cavity, and the light-transmitting cover 1300 is configured to only transmit light beams.

[0151] In these embodiments, the base 1400 provides mechanical support to ensure stable installation of the scanning module. The base 1400 cooperates with the light-transmitting cover 1300 to form a sealed cavity to protect the internal components from the external environment. The light-transmitting cover 1300 is placed on the scanning module to protect it while allowing the light beam to pass through. The light-transmitting cover 1300 and the base 1400 form a sealed cavity to prevent external pollutants such as dust and moisture from entering, keeping the interior clean and dry. It is configured to only transmit light beams, that is, it has selective transmission characteristics, which can effectively block unnecessary light (such as ambient light), reduce interference, and improve the signal-to-noise ratio.

[0152] In other words, the sealed cavity effectively isolates the influence of the external environment, protects the internal precision optical and electronic components from dust, moisture and other contaminants, and prolongs the service life of the equipment. The selective transmission characteristics of the light-transmitting cover 1300 can effectively block ambient light and other unnecessary light, reduce background noise, and improve the signal-to-noise ratio and measurement accuracy of the system.

[0153] In all examples shown and described herein, any specific values ​​should be interpreted as merely exemplary and not as limiting, and thus other examples of the exemplary embodiments may have different values.

[0154] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0155] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application.

Claims

1. A scanning module, characterized in that: The scanning module comprises: a refractive optical element and a refractive driving element, wherein the refractive driving element is connected to the refractive optical element, the refractive driving element is used to drive the refractive optical element to rotate, the rotation axis of the refractive optical element is parallel to a first direction, the refractive optical element is used to receive and refract a light beam incident along the first direction, and the ends of the exit surface and the incident surface of the refractive optical element that are close to each other are arranged to be tilted toward each other; a first reflective optical element and a reflective driving element, wherein the reflective driving element is connected to the first reflective optical element, the reflective driving element is used to drive the first reflective optical element to rotate, the rotation axis of the first reflective optical element is arranged parallel to the first direction, the first reflective optical element is used to receive and reflect the light beam refracted by the refractive optical element, and the angle between the reflective surface of the first reflective optical element and the rotation axis of the first reflective optical element is 45°; wherein the refractive driving element and the reflective driving element are arranged at intervals in the first direction; The slope of the exit surface is smaller than the slope of the incident surface; The scanning module also includes: a focusing optical element, wherein the refractive optical element is located between the focusing optical element and the first reflecting optical element, and the focusing optical element is used to receive and focus the return light beam propagating along the first direction; at least one second reflecting optical element, the at least one second reflecting optical element being used to receive and reflect the returning light beam focused by the focusing optical element; a detector, the detector being used to receive the return light beam reflected by the second reflective optical element; The scanning module also includes: a laser, the laser being used to emit the light beam; at least one third reflecting optical element, the at least one third reflecting optical element being used to receive and reflect the light beam emitted by the laser, so that the reflected light beam propagates along the first direction; At least one collimating optical element, wherein the at least one collimating optical element is used to shrink the divergence angle of the light beam; wherein at least one of the third reflecting optical elements is located between the focusing optical element and the refractive optical element, and the laser and the detector are sequentially arranged on the peripheral side of the focusing optical element; The refractive drive element comprises a refractive drive motor, the main shaft of the refractive drive motor is set as a hollow shaft, the axis of the hollow shaft coincides with the rotation axis of the refractive optical element; wherein the refractive optical element is set in the hollow shaft.

2. The scanning module according to claim 1, characterized in that: The scanning module also includes: A filtering optical element is disposed between the third reflecting optical element and the focusing optical element, and is used for filtering out ambient light in the return light beam propagating to the focusing optical element.

3. The scanning module according to claim 2, characterized in that: The refractive optical element comprises a wedge-shaped mirror; and / or, the first reflecting optical element comprises a first reflecting prism; and / or, the second reflecting optical element comprises a second reflecting prism; and / or, the third reflecting optical element comprises a third reflecting prism; and / or, the focusing optical element comprises a receiving lens; And / or, the collimating optical element comprises a collimating mirror.

4. The scanning module according to claim 1, characterized in that: The scanning module further includes a weight element, the refractive optical element is formed with a thick end and a thin end, and the weight element is arranged on the thin end.

5. The scanning module according to claim 1, characterized in that: The reflection drive element includes a reflection drive motor, a main shaft of the reflection drive motor is connected to the first reflection optical element, and an axis of the main shaft of the reflection drive motor is arranged parallel to the first direction.

6. A laser radar, characterized in that: The laser radar comprises: The scanning module according to any one of claims 1 to 5; A light-transmitting cover is disposed on the scanning module and is configured to only transmit the light beam.

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