Receiving module and laser radar

Abstract

The invention provides a receiving module and a laser radar, and relates to the technical field of laser detection. The receiving module comprises a receiving piece, a diffusion piece and at least one detection piece; the receiving part has a receiving area; the detection piece is arranged in the receiving area and is electrically connected with the receiving piece; the diffusion piece is arranged on one side, back to the receiving piece, of the detection piece, at least covers the edge of the receiving area and is used for diffusing the light. According to the receiving module, the diffusion piece is additionally arranged in front of the light filtering piece, so that the incident light can be diffused in a large-angle range, the brightness distribution of an original light source becomes smooth, the effective luminous flux of the incident light entering a detection piece at an edge large view field angle is effectively improved, and the detection signal intensity of an edge view field channel is improved. On the basis, the close-range detection capability of the laser radar is improved, and the view blind area is smaller. In addition, signals of all channels of the laser radar are more uniform, and the detection precision is higher.

Description

Technical Field

[0001] The present invention relates to the technical field of laser detection, and particularly to a receiving module and a lidar. Background Art

[0002] In current lidars, in order to meet a certain detection distance and avoid the problem of reduced light flux caused by the emission component blocking the reflected light in the coaxial optical system, an off-axis optical system design is often adopted, that is, the optical axis of the outgoing light and the optical axis of the incident light deviate by a certain distance to ensure the light input of the system.

[0003] However, the off-axis optical system has a field of view blind area: at a position relatively close to the lidar, since the optical axis of the outgoing light and the optical axis of the incident light do not coincide, and the size of the detector is limited (such as the size of a typical photodiode is 500 microns or 230 microns, etc.), the outgoing light may not be completely incident on the detector after being reflected by an object. As a result, the signal detected by the lidar will be severely attenuated at close range, and in severe cases, the lidar may not detect close-range objects at all. This attenuation phenomenon of the close-range detection signal is particularly obvious in the edge vertical field of view, resulting in poor signal in the close-range edge field of view of the lidar.

[0004] In addition, for the channels in the edge field of view, the reflected light cannot be completely incident on the detector, resulting in uneven signals in each channel of the lidar and poor detection accuracy. Summary of the Invention

[0005] In order to solve the problems of poor signal and poor detection accuracy in the close-range edge field of view of the existing off-axis lidar, one of the purposes of the present invention is to provide a receiving module.

[0006] The present invention provides the following technical solutions:

[0007] A receiving module, comprising:

[0008] A receiving member having a receiving area;

[0009] At least one detecting member disposed in the receiving area and electrically connected to the receiving member; and

[0010] A diffusing member disposed on a side of the detecting member facing away from the receiving member and at least covering an edge of the receiving area, the diffusing member being configured to diffuse light.

[0011] As a further optional solution to the receiving module, the receiving area is arranged in a strip shape, and the diffusing member at least covers both ends of the receiving area along the length direction.

[0012] As a further optional solution for the receiving module, a plurality of detecting elements are provided, and the plurality of detecting elements are arranged along the length direction of the receiving area.

[0013] As a further optional solution for the receiving module, the diffusing element covers the receiving area.

[0014] As a further optional solution for the receiving module, the diffusing element includes a transparent substrate, and at least one surface of the transparent substrate is provided as a frosted surface.

[0015] As a further optional solution for the receiving module, the surfaces of the transparent substrate on the side facing the detecting element and on the side facing away from the detecting element are both provided as frosted surfaces.

[0016] As a further optional solution for the receiving module, the receiving module further includes a filter element, the filter element is arranged on the side of the detecting element facing away from the receiving element, and covers the receiving area;

[0017] The diffusing element is arranged on the side of the filter element facing away from the detecting element.

[0018] Another object of the present invention is to provide a lidar.

[0019] The present invention provides the following technical solutions:

[0020] A lidar includes a transmitting module, a collimating module, and the above-mentioned receiving module;

[0021] The transmitting module and the receiving module are arranged side by side.

[0022] As a further optional solution for the lidar, the collimating module is simultaneously located on the outgoing light path of the transmitting module and the incoming light path of the receiving module.

[0023] As a further optional solution for the lidar, the lidar further includes a fixed seat and a rotating seat, the rotating seat is rotatably arranged on the fixed seat, and the transmitting module, the collimating module, and the receiving module are all arranged on the rotating seat.

[0024] The embodiments of the present invention have the following beneficial effects:

[0025] When the above-mentioned receiving module works, the incident light passes through the diffuser and then irradiates on the detector in the receiving area, and is sensed by the detector. During this process, the diffuser can diffuse the incident light within a large angle range, making the luminance distribution of the original light source smoother. Since the diffuser covers at least the edge of the receiving area, it can effectively increase the effective luminous flux of the incident light entering the detector at a large field of view angle at the edge, and improve the detection signal intensity of the edge field of view channel. On this basis, the short-range detection ability of the lidar is improved, and the blind spot of the field of view is smaller. In addition, the signals of each channel of the lidar are more uniform, and the detection accuracy is higher.

[0026] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following specifically gives preferred embodiments and, in conjunction with the accompanying drawings, makes the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0028] Figure 1 Shows a schematic diagram of the overall structure of a receiving module provided by an embodiment of the present invention;

[0029] Figure 2 Shows a front view of a receiving module provided by an embodiment of the present invention;

[0030] Figure 3 Shows a schematic diagram of the structure of a detector in a receiving module provided by an embodiment of the present invention;

[0031] Figure 4 Shows an effect diagram of a diffuser for simulating an edge field of view channel;

[0032] Figure 5 Shows a light intensity distribution diagram of the edge field of view channel after adding a diffuser;

[0033] Figure 6 Shows a schematic diagram of the overall structure of a receiving module provided by another embodiment of the present invention;

[0034] Figure 7 Shows a schematic diagram of the overall structure of a lidar provided by an embodiment of the present invention;

[0035] Figure 8 Shows a schematic diagram of the structure of a rotating base in a lidar provided by an embodiment of the present invention.

[0036] MAIN ELEMENT SYMBOL DESCRIPTION:

[0037] 100 - Receiving module; 110 - Receiver; 111 - Receiving area; 112 - Bracket; 120 - Diffuser; 130 - Detector; 140 - Filter; 150 - First mirror; 200 - Transmitting module; 210 - Laser; 220 - Second mirror; 300 - Collimation module; 400 - Fixed base; 410 - Base; 411 - Brushless DC torque motor; 420 - Outer shell; 430 - Top cover; 500 - Rotating base; 510 - Rotating shaft. Detailed implementation manner

[0038] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals indicate the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0039] It should be noted that when an element is referred to as "fixed to" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. On the contrary, 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 only for the purpose of illustration.

[0040] In the present invention, unless otherwise clearly defined and limited, the terms "installed", "connected", "connected", "fixed" and other terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, the meaning of "a plurality" is two or more unless otherwise clearly specifically defined.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terms used in the specification of the template herein are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0043] Embodiment

[0044] Please refer to Figures 1 to 3 simultaneously. This embodiment provides a receiving module 100, which is applied to a lidar, especially suitable for an off-axis lidar. The receiving module 100 includes a receiver 110, a diffuser 120, and at least one detector 130.

[0045] Among them, the receiver 110 has a receiving area 111 for receiving incident light reflected from the surface of the detection target.

[0046] The detector 130 is arranged in the receiving area 111, can sense the incident light and generate a detection signal. At the same time, the detector 130 is electrically connected to the receiver 110 and transmits the detection signal to the receiver 110.

[0047] In addition, the diffuser 120 is arranged on the side of the detector 130 facing away from the receiver 110 and at least covers the edge of the receiving area 111. The diffuser 120 is used to diffuse light.

[0048] When the above-mentioned receiving module 100 works, the incident light passes through the diffuser 120 and then irradiates on the detector 130 in the receiving area 111 and is sensed by the detector 130. During this process, the diffuser 120 can diffuse the incident light within a large angle range, making the brightness distribution of the original light source smoother. Since the diffuser 120 at least covers the edge of the receiving area 111, the effective light flux of the incident light entering the detector 130 at a large field of view angle at the edge can be effectively increased, and the detection signal intensity of the edge field of view channel can be improved. On this basis, the short-distance detection ability of the lidar is improved, and the blind area of the field of view is smaller. In addition, the signals of each channel of the lidar are more uniform and the detection accuracy is higher.

[0049] Please refer to Figure 4 and Figure 5 simultaneously. The figure shows the effect of the simulated edge field of view channel after adding the diffuser 120. Among them, a suitable diffuser 120 can generally increase the detection signal intensity of the edge field of view to 130% - 150% of the original signal.

[0050] Optionally, the receiver 110 is a PCB board, and the receiving area 111 is located on one side of the receiver 110.

[0051] Optionally, the detecting element 130 is a signal detector, which can be an Avalanche Photodiode (APD) or a more sensitive Silicon photomultiplier (SiPM).

[0052] In some embodiments, the receiving area 111 is arranged in a strip shape. At this time, the diffusing element 120 at least covering the edge of the receiving area 111 means that the diffusing element 120 at least covers both ends of the receiving area 111 along the length direction.

[0053] Optionally, the receiving element 110 is a rectangular plate, and the receiving area 111 is located on one side of the receiving element 110 along the width direction and is arranged along the length direction of the receiving element 110.

[0054] Please refer to again Figure 1 and Figure 3 , in some specific embodiments, there are two diffusing elements 120. One diffusing element 120 covers one end of the receiving area 111 along the length direction, and the other diffusing element 120 covers the other end of the receiving area 111 along the length direction, which can effectively solve problems such as poor signal in the edge field of view in the short-distance area of the off-axis lidar and uneven signals in each channel, resulting in poor detection accuracy of the off-axis lidar.

[0055] Please refer to Figure 6 , in some other specific embodiments, in order to pursue the practicality and reliability of special application scenarios, for example, paying attention to the signal uniformity and detection accuracy in the short-distance area of the lidar and having high requirements for the performance of the lidar in target detection, tracking, and data processing, the diffusing element 120 can also cover the entire receiving area 111.

[0056] Please refer to again Figure 3 , further, a plurality of detecting elements 130 are provided, and the plurality of detecting elements 130 are arranged along the length direction of the receiving area 111.

[0057] Exemplarily, the number of the detecting elements 130 is sixteen, and the sixteen detecting elements 130 are arranged in a row along the length direction of the receiving area 111.

[0058] Specifically, the diffusing element 120 includes a transparent matrix through which incident light can pass, and at least one surface of the transparent matrix is set as a frosted surface.

[0059] During use, the diffusing element 120 diffuses the incident light through the frosted surface.

[0060] In some embodiments, the surface of the transparent matrix on the side facing away from the detecting element 130 is set as a frosted surface, and the surface of the transparent matrix on the side facing the detecting element 130 is set as a smooth surface.

[0061] In some other embodiments, the surfaces of the transparent substrate facing the detecting member 130 and facing away from the detecting member 130 are both set as frosted surfaces.

[0062] In some specific embodiments, the material of the transparent substrate is glass, and the frosted surface is formed by grinding with sand grains.

[0063] It can be understood that, according to actual requirements, the glass can be ground to different grades to produce different degrees of scattering. The finer the grinding, the higher the smoothness and transmittance of the diffusing member 120. On the contrary, the rougher the grinding, the greater the scattering generated by the diffusing member 120 and the lower the transmittance.

[0064] In some other specific embodiments, the material of the transparent substrate can also be quartz, plexiglass, etc.

[0065] Please refer to again Figure 1 and Figure 3 , in some embodiments, the above receiving module 100 further includes a filter member 140. The filter member 140 is disposed on the side of the detecting member 130 facing away from the receiving member 110 and covers the receiving area 111, and is used to filter the ambient light irradiating on the receiving area 111 and reduce the interference of the ambient light on the detecting signal generated by the detecting member 130.

[0066] Correspondingly, the diffusing member 120 is disposed on the side of the filter member 140 facing away from the detecting member 130.

[0067] Specifically, a bracket 112 is disposed on the receiving member 110, and the bracket 112 is disposed around the receiving area 111. The detecting member 130 disposed on the receiving member 110 is located inside the bracket 112, and the height of the detecting member 130 is less than the height of the bracket 112. At the same time, the filter member 140 is disposed on the bracket 112 and covers the entire receiving area 111.

[0068] Optionally, the filter member 140 adopts a filter.

[0069] In some embodiments, the above receiving module 100 further includes a first reflector 150 (refer to Figure 8 ).

[0070] The incident light reflected from the surface of the detection target first irradiates on the first reflector 150, is reflected by the first reflector 150 to the diffusing member 120 and the filter, and is finally sensed by the detecting member 130.

[0071] Setting the first reflector 150 can adjust the optical path of the incident light, making the structure of the receiving module 100 more compact, and thus facilitating the reduction of the volume of the lidar.

[0072] In summary, by adding the diffuser 120 in front of the filter 140, the above receiving module 100 can diffuse the incident light within a large angle range, making the luminance distribution of the original light source smoother, effectively increasing the effective light flux of the incident light entering the detector 130 at a large field of view angle at the edge, and increasing the detection signal intensity of the edge field of view channel. On this basis, the close-range detection ability of the lidar is improved, and the blind area of the field of view is smaller. In addition, the signals of each channel of the lidar are more uniform, and the detection accuracy is higher.

[0073] Please also refer to Figure 7 and Figure 8 , this embodiment also provides a lidar, specifically an off-axis lidar, which includes a transmitting module 200, a collimating module 300, and the above receiving module 100.

[0074] During use, the laser emitted by the transmitting module 200 exits through the collimating module 300, irradiates on the detection target and is reflected. The light reflected from the surface of the detection target enters the receiving module 100 through the collimating module 300 and is received by the receiving module 100 to complete the detection of the detection target.

[0075] Among them, the transmitting module 200 and the receiving module 100 are arranged side by side, so that the optical axes of the emitted light and the incident light do not coincide, in order to ensure the light input amount of the receiving module 100.

[0076] Specifically, the transmitting module 200 is composed of a laser 210 and a second reflector 220.

[0077] During use, the laser emitted by the laser 210 irradiates on the second reflector 220, is reflected by the second reflector 220 to the collimating module 300, and then exits and irradiates on the detection target.

[0078] Similar to the first reflector 150, the second reflector 220 can adjust the optical path of the emitted light, making the structure of the transmitting module 200 more compact, which is beneficial to reducing the volume of the lidar.

[0079] In some specific embodiments, the first reflector 150 reflects the incident light in the direction away from the transmitting module 200, and the second reflector 220 reflects the emitted light in the direction away from the receiving module 100. On this basis, structures such as the receiver 110 in the receiving module 100 and the laser 210 in the transmitting module 200 are respectively arranged on both sides of the entire lidar, making full use of the space on both sides of the lidar, and at the same time reducing the size of the lidar in the optical axis direction, making the structure of the lidar more compact, which is beneficial to the miniaturization of the lidar.

[0080] Optionally, the laser 210 can be an edge-emitting laser (EEL) or a vertical-cavity surface-emitting laser (VCSEL), depending on the actual requirements.

[0081] Optionally, the collimation module 300 can use a single-piece aspherical mirror or a combination of multiple lenses.

[0082] Furthermore, the collimation module 300 is located on the outgoing optical path of the emission module 200 and the incoming optical path of the receiving module 100 at the same time.

[0083] At this time, the emission module 200 and the receiving module 100 share a collimation module 300, which can effectively save the mold opening cost of the lens.

[0084] In some embodiments, the above lidar is an off-axis mechanical multi-line lidar, which has the advantages of multi-dimensional scanning and high resolution. In addition, the off-axis mechanical multi-line lidar can rotate mechanically and has a large field of view of 360° horizontally, and is applicable to various fields, including autonomous driving, robot navigation, and building surveying, etc.

[0085] Specifically, the above lidar further includes a fixed base 400 and a rotating base 500. The rotating base 500 is rotatably arranged on the fixed base 400, and the emission module 200, the collimation module 300, and the receiving module 100 are all arranged on the rotating base 500.

[0086] During use, the rotating base 500 is driven by other structures to rotate, thereby driving the emission module 200, the collimation module 300, and the receiving module 100 to rotate synchronously, and can detect targets within a horizontal range of 360°.

[0087] In some specific embodiments, the fixed base 400 is composed of a base 410, a housing 420, and a top cover 430. The bottom end of the housing 420 is connected to the base 410, and the top end is connected to the top cover 430, and the base 410, the housing 420, and the top cover 430 enclose a receiving space.

[0088] Correspondingly, the rotating base 500 is located in this receiving space, and a rotating shaft 510 is provided on the rotating base 500. The bottom end of the rotating shaft 510 is rotationally matched with the base 410, and the top end is rotationally matched with the top cover 430.

[0089] In addition, a brushless DC torque motor 411 is also provided on the base 410 to drive the rotation of the rotating shaft 510, thereby driving the entire rotating base 500 to rotate.

[0090] In summary, by adding the diffuser 120 to the receiving module 100, the above lidar can diffuse the incident light within a large angle range, making the luminance distribution of the original light source smoother, effectively increasing the effective luminous flux of the incident light entering the detector 130 at the large field of view angles at the edge, and increasing the detection signal intensity of the edge field of view channels. Therefore, the short-range detection ability of the above lidar is improved, the blind area of the field of view is smaller, the signals of each channel are more uniform, the detection accuracy is higher, and it meets the development trend of miniaturization, lightweight and high performance at the same time.

[0091] In all examples shown and described here, any specific values should be construed as merely exemplary, not as limitations. Therefore, other examples of the exemplary embodiments may have different values.

[0092] It should be noted that like reference numerals and letters denote like items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0093] The above-described embodiments merely represent several implementation manners of the present invention. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A receiving module, characterized in that, Comprising: A receiving member having a receiving area; At least one detecting member disposed in the receiving area and electrically connected to the receiving member; And A diffusing member disposed on a side of the detecting member facing away from the receiving member and at least covering an edge of the receiving area, the diffusing member being configured to diffuse light.

2. The receiving module according to claim 1, wherein The receiving area is arranged in a long strip shape, and the diffusing member at least covers two ends of the receiving area along the length direction.

3. The receiving module according to claim 2, wherein A plurality of the detecting members are provided, and the plurality of detecting members are arranged along the length direction of the receiving area.

4. The receiving module according to claim 1, wherein The diffusing member covers the receiving area.

5. The receiving module according to any one of claims 1-4, characterized in that, The diffusing member includes a transparent substrate, and at least one surface of the transparent substrate is provided as a frosted surface.

6. The receiving module according to claim 5, wherein Surfaces of the transparent substrate facing the detecting member side and the side facing away from the detecting member are both provided as frosted surfaces.

7. The receiving module according to any one of claims 1-4, characterized in that, The receiving module further includes a light filtering member disposed on a side of the detecting member facing away from the receiving member and covering the receiving area; The diffusing member is disposed on a side of the light filtering member facing away from the detecting member.

8. A lidar, characterized in that, Comprising a transmitting module, a collimating module, and the receiving module according to any one of claims 1-7; The transmitting module and the receiving module are arranged side by side.

9. The lidar according to claim 8, wherein, The collimating module is simultaneously located on an outgoing light path of the transmitting module and an incident light path of the receiving module.

10. The lidar according to claim 8, wherein, The lidar further includes a fixed seat and a rotating seat, the rotating seat is rotatably disposed on the fixed seat, and the transmitting module, the collimating module, and the receiving module are all disposed on the rotating seat.

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