LiDAR

Abstract

This invention discloses a lidar, comprising: a housing, a bracket disposed within the housing, and a viewing window disposed on the front side of the housing; a galvanometer module, installed within the housing and fixedly connected to the bracket, the galvanometer module including a MEMS galvanometer facing the viewing window; a laser transceiver module, installed within the housing and disposed below the galvanometer module; and a reflection module, installed within the housing and disposed in front of the laser transceiver module, the reflection module including a reflector facing the galvanometer module and the laser transceiver module; a laser beam emitted by the laser transceiver module is reflected by the reflector to the MEMS galvanometer, the MEMS galvanometer converts the single-line laser beam into a multi-line laser beam and projects it to the outside through the viewing window. This invention provides good support strength and installation rigidity for the galvanometer module through the bracket, reducing or even avoiding resonance. The galvanometer module can have a larger size, reflecting more laser beams, effectively improving the accuracy of surface contour recognition of target objects.

Description

Technical Field

[0001] This invention relates to the field of radar technology, and in particular to a lidar. Background Technology

[0002] LiDAR is a radar system that uses laser beams to detect the distance, orientation, speed, and other characteristics of a target object. The concept was first proposed in the 1960s. In recent years, with the booming development of the autonomous driving market (including autonomous vehicles, AGVs, UAVs, etc.), the demand for LiDAR has been increasing.

[0003] With technological advancements, the application of MEMS (Micro-Electro-Mechanical System) galvanometers as laser beam scanning elements in lidar has become a new trend in lidar development. MEMS galvanometers are micromirrors fabricated using MEMS technology. Their operating mode is primarily resonant, offering advantages over traditional mechanical optical scanning mirrors, such as lighter weight, smaller size, higher oscillation frequency, and the absence of rotating parts. However, limited by the overall structure and size of lidar systems, MEMS galvanometers can reflect fewer laser beams, resulting in lower accuracy in recognizing the surface contours of target objects. Summary of the Invention

[0004] In view of this, a lidar that can effectively improve the recognition of the surface contour of a target object is provided.

[0005] A lidar system includes: a housing with a bracket inside, and a viewing window on the front side of the housing; a galvanometer module installed inside the housing and fixedly connected to the bracket, the galvanometer module including a MEMS galvanometer facing the viewing window; a laser transceiver module installed inside the housing and positioned below the galvanometer module; and a reflection module installed inside the housing and positioned in front of the laser transceiver module, the reflection module including a reflector facing the galvanometer module and the laser transceiver module; a laser beam emitted by the laser transceiver module is reflected by the reflector to the MEMS galvanometer, the MEMS galvanometer converts the single-line laser beam into a multi-line laser beam and projects it to the outside through the viewing window.

[0006] In some embodiments, the bracket includes two side plates spaced apart from each other, a top plate connected between the tops of the two side plates, and a mounting plate connected between the two side plates and the top plate. The mounting plate is inclined relative to the side plates and the top plate, and the galvanometer module is fixedly connected to the mounting plate.

[0007] In some embodiments, a main control circuit board is also fixedly connected to the mounting plate. The main control circuit board and the galvanometer module are respectively fixed to the front and rear surfaces of the mounting plate and are electrically connected.

[0008] In some embodiments, the laser transceiver module includes a transceiver body and an LD circuit board connected by an optical fiber. The LD circuit board is fixedly connected to the main control circuit board and located above the transceiver body. The transceiver body is provided with an upwardly tilted optical fiber interface.

[0009] In some embodiments, the laser transceiver module further includes an APD circuit board, which is mounted on the transceiver body.

[0010] In some embodiments, the thickness of the mounting plate is greater than the thickness of the side plate and the top plate, and triangular ribs are provided between the mounting plate and the side plate.

[0011] In some embodiments, the mounting plate is provided with an opening for mounting the galvanometer module, and the mounting plate is provided with a reinforcing rib at the bottom of the opening.

[0012] In some embodiments, the bottom of the side plate is bent to form a fixing plate, and the fixing plate is fixedly connected to the housing; the thickness of the fixing plate is greater than the thickness of the side plate and the top plate, and side ribs are provided between the fixing plate and the side plate.

[0013] In some embodiments, at least one of the top plate, side plate, and mounting plate has a perforated hole.

[0014] In some embodiments, the reflection module further includes a frame for mounting the reflector, the reflector convexly forming a first connecting portion, the outer surface of the first connecting portion being a convex spherical surface; the frame includes a second connecting portion, the second connecting portion being concavely forming a receiving groove to receive the first connecting portion, the groove wall of the receiving groove being a concave spherical surface.

[0015] Compared to existing technologies, the lidar of this invention provides good support strength and installation rigidity for the galvanometer module through the bracket, reducing or even avoiding resonance. The galvanometer module can be larger and reflect more laser beams. It can not only accurately detect the position of the target object and monitor its movement speed, but also effectively improve the accuracy of the surface contour recognition of the target object. Moreover, the overall structure is compact and has a high space utilization rate. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of an embodiment of the lidar of the present invention.

[0017] Figure 2 for Figure 1 Another perspective view.

[0018] Figure 3 for Figure 1 The diagram shows the structure of a lidar without its housing.

[0019] Figure 4 for Figure 3 Another perspective view.

[0020] Figure 5 This is a schematic diagram of the assembly of the laser transceiver module and the reflection module on the lidar base of the present invention.

[0021] Figure 6 This is a schematic diagram of the laser transceiver module.

[0022] Figure 7 This is a cross-sectional view of the reflection module.

[0023] Figure 8 This is a schematic diagram of the assembly of the galvanometer module and the bracket of the lidar of the present invention.

[0024] Figure 9 This is a schematic diagram of the support structure.

[0025] Explanation of icon numbers:

[0026] 10. Housing 12. Base 14. Cover 14. Window 141. Aviation plug adapter plate 143. Aviation plug interface 145. Bracket 16. Side plate 161. Side rib 162. Top plate 163. Triangular rib 164. Mounting plate 165. Opening 166. Fixing plate 167. Reinforcing rib 168. Hole 169. Fastener 18;

[0027] Laser transceiver module 20, LD circuit board 22, transceiver body 24, fiber optic interface 25, APD circuit board 26, fiber optic cable 28;

[0028] Reflection module 30, mirror frame 32, second connecting part 321, groove wall 323, perforation 325, reflector 34, first connecting part 341, outer surface 343, mounting hole 345, connector 36, gasket 38;

[0029] 40 galvanometer module, 42 MEMS galvanometer, 44 outer frame. Detailed Implementation

[0030] To facilitate understanding of the present invention, a more comprehensive description will be given below with reference to the accompanying drawings. One or more embodiments of the present invention are exemplarily shown in the drawings to provide a more accurate and thorough understanding of the disclosed technical solutions. However, it should be understood that the present invention can be implemented in many different forms and is not limited to the embodiments described below.

[0031] In the accompanying drawings of this invention, the same or similar reference numerals correspond to the same or similar components. In the description of this invention, it should be understood that if terms such as "upper," "lower," "left," and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0032] This invention provides a lidar, which is preferably applied in fields such as surveying, meteorological monitoring, security, and autonomous driving. Figure 1-4 The image shows a specific embodiment of the lidar of the present invention. The lidar includes a housing 10 and a laser transceiver module 20, a reflection module 30 and a galvanometer module 40 disposed within the housing 10.

[0033] The housing 10 includes a base 12 and a cover 14 covering the base 12, together forming a sealed space for mounting the laser transceiver module 20, the reflection module 30, the galvanometer module 40, etc. A viewing window 141 is provided on the front of the cover 14. The laser beam emitted by the laser transceiver module 20 is directed towards an external target object through the viewing window 141. The laser beam reflected by the target object enters the housing 10 through the viewing window 141 and is received by the laser transceiver module 20. Preferably, the viewing window 141 is glued to the cover 14 to achieve a sealed connection. An aviation connector adapter plate 143 is provided on the back of the cover 14, and an aviation connector interface 145 is formed on the aviation connector adapter plate 143 for electrical connection between the laser radar of this invention and other devices. Preferably, the sealing rating of the aviation connector interface 145 is not lower than IP68. O-rings are provided between the aviation plug adapter plate 143 and the cover 14, and between the cover 14 and the base 12, so that the whole machine has a sealing and waterproof function and ensures electrical safety.

[0034] A bracket 16 is fixedly connected to the base 12. A galvanometer module 40 is mounted on the bracket 16. A laser transceiver module 20 and a reflection module 30 are mounted on the base 12. The laser transceiver module 20 is located below the galvanometer module 40, while the reflection module 30 is positioned near the front of the base 12 and faces both the laser transceiver module 20 and the galvanometer module 40. The laser transceiver module 20 is used to transmit and receive laser beams. The transmitted laser beam first strikes the reflection module 30, and then, under the reflection of the reflection module 30, it strikes the galvanometer module 40. The galvanometer module 40 converts the single-line laser beam into a multi-line laser beam, which is then directed towards an external target object through a viewing window 141. According to the principle of optical path reversibility, the multi-line laser beam reflected back from the target object passes through the viewing window 141 and strikes the galvanometer module 40, where it is converted into a single-line laser beam and emitted towards the reflection module 30. Finally, it is reflected back to the laser transceiver module 20 by the reflection module 30.

[0035] Please also refer to Figure 8 and Figure 9 The bracket 16 is preferably an integral structure, including two side plates 161 arranged at relative intervals, a top plate 163 connected between the tops of the two side plates 161, and a mounting plate 165 arranged at an inclination relative to the side plates 161 and the top plate 163.

[0036] Two side plates 161 are vertically arranged, and their bottoms are bent to form fixing plates 167. The fixing plates 167 and the base 12 have corresponding connecting holes. During assembly, the fixing plates 167 are stacked on the base 12. Fixing components 18, such as screws and pins, pass through the connecting holes of the fixing plates 167 and are screwed or tightly fitted into the connecting holes of the base 12, thus fixing the bracket 16 to the base 12. Preferably, the thickness of the fixing plate 167 is greater than the thickness of the side plates 161 and the top plate 163. In one specific embodiment, the thickness of the side plates 161 is 2mm and the thickness of the fixing plate 167 is 3mm, which can effectively increase the strength of the fixing plate 167, improve the stability of the connection between the bracket 16 and the base 12, and reduce resonance. Preferably, a side rib 162 is formed between the fixing plate 167 and the side plates 161, further increasing the overall strength of the bracket 16. The outer edge of the side rib 162 is flush with the outer edge of the fixing plate 167, without increasing the overall width of the bracket 16.

[0037] Mounting plate 165 extends downward and backward from top plate 163, with its two sides connected to two side plates 161 respectively. Mounting plate 165, top plate 163, and side plates 161 together form the mounting space of galvanometer module 40. Galvanometer module 40 includes MEMS galvanometer 42 and an outer frame 44 surrounding MEMS galvanometer 42. MEMS galvanometer 42 can vibrate within outer frame 44 to achieve conversion between single-line laser beam and multi-line laser beam, enabling left-right and up-down scanning of target objects. In this embodiment, mounting plate 165 has an opening 166 in the center for mounting galvanometer module 40, and mounting plate 165 has connection holes at the edge of opening 166. Correspondingly, outer frame 44 of galvanometer module 40 has connection holes. During assembly, fasteners 18, such as screws and pins, pass through the connection holes of mounting plate 165 and are screwed or tightly fitted into the connection holes of outer frame 44, thus fixing galvanometer module 40 to mounting plate 165.

[0038] In this embodiment, a main control circuit board 50 is also provided on the mounting plate 165. The main control circuit board 50 is fixedly connected to the mounting plate 165 by fasteners 18, such as screws and pins. The main control circuit board 50 is electrically connected to various electronic components, including the laser transceiver module 20 and the galvanometer module 40, to control the operation of the entire lidar and to calculate the outline, distance, orientation, and speed of the target object based on the signals transmitted and received by the laser beam. Preferably, the thickness of the mounting plate 165 is greater than the thickness of the side plate 161 and the top plate 163. In a specific embodiment, the thickness of the mounting plate 165 is 3mm, which can provide better support strength and installation rigidity, so that the galvanometer module 40 and the main control circuit board 50, which are respectively fixed to the front and rear surfaces of the mounting plate 165, do not resonate with external excitation vibration conditions. Preferably, a triangular rib 164 is formed between the mounting plate 165 and the side plate 161, and a reinforcing rib 168 is formed at the bottom of the opening 166 of the mounting plate 165, further increasing the overall strength of the bracket 16 and reducing the amplitude.

[0039] The lidar of this invention features a bracket 16 within its housing 10 to mount a galvanometer module 40. The bracket 16, through its special thickness design and the inclusion of side ribs 162, triangular ribs 164, and reinforcing ribs 168, provides sufficient support strength and mounting rigidity, allowing the MEMS galvanometer 42 of the galvanometer module 40 to have a larger size, preferably at the centimeter level. This creates a sufficiently large reflective area, reflecting more laser beams and more accurately identifying the surface contours of target objects. Simultaneously, the bracket 16 arranges the galvanometer module 40 and the laser transceiver module 20 vertically, effectively utilizing the internal space of the housing 10, resulting in a more compact overall structure and smaller overall size. Furthermore, the bracket 16 mounts the main control circuit board 50, facilitating connection and wiring, and improving the modularity of the lidar unit. Preferably, the bracket 16 has perforated holes 169 on its top plate 163, side plates 161, and mounting plate 165 to reduce overall weight.

[0040] Please also refer to Figure 5 and Figure 6 The laser transceiver module 20 includes an LD (Laser Diode) circuit board 22, a transceiver body 24, and an APD (Avalanche Photo Diode) circuit board 26.

[0041] Multiple laser diodes (LDs) are mounted on the LD circuit board 22. These LDs serve as the light source for the laser transceiver module 20 and are connected to the transceiver body 24 via optical fiber 28. The transceiver body 24 is fixed to the base 12 by fasteners 18, such as screws or pins. In the illustrated embodiment, there are multiple transceiver bodies 24 (e.g., four), and the number of LD circuit boards 22 is half the number of transceiver bodies 24. Each LD circuit board 22 provides a light source to two transceiver bodies 24 simultaneously. Multiple optical deactivation circuit boards 26 are also present, each mounted on one transceiver body 24. The receiving optical path employs a sealed design, unaffected by stray light interference. The optical deactivation circuit board 26 converts the optical signal from the laser beam received by the transceiver body 24 into an electrical signal. It utilizes the avalanche multiplication effect of APD carriers to amplify the photoelectric signal, improving detection sensitivity.

[0042] Each transceiver unit 24 has a fiber optic interface 25 on its side for connecting to the fiber optic cable 28. The fiber optic interface 25 and the APD circuit board 26 are located on opposite sides of the transceiver unit 24, facilitating component installation and electrical connection. In the illustrated embodiment, the LD circuit board 22 is fixedly connected to the rear surface of the main control circuit board 50 via fasteners 18, such as screws and pins, located above the transceiver unit 24. The fiber optic interface 25 is inclined upward relative to the vertical direction, which can reduce the increase in the overall depth of the lidar of this invention due to the bending radius requirement of the fiber optic cable 28 (usually the bending radius is at least 30mm), making the overall structure more compact. In addition, the fiber optic cable 28 is designed to be arranged upward to connect to the LD circuit board 22. Using the main control circuit board 50 to install and fix the LD circuit board 22 can make full use of the overall space, reduce the number of fixing structural components for the LD circuit board 22, and make the internal modularity of the invention better. It is more independent of the housing 10 and easy to disassemble and assemble.

[0043] It should be understood that the number of LD circuit boards 22, transceiver bodies 24, and APD circuit boards 26 in the laser transceiver module 20 can vary according to design requirements. For example, each LD circuit board 22 may provide a light source for one transceiver body 24, and this is not limited to a specific embodiment.

[0044] Please also refer to Figure 5 and Figure 7 The reflection module 30 includes a frame 32 and a reflector 34 mounted on the frame 32. The frame 32 is fixed to the base 12 by fasteners 18, such as screws or pins. The reflector 34 faces the light-emitting surface of the transceiver 24 and the MEMS galvanometer 42, forming an angle with both, allowing the laser beam to be redirected and propagated between the transceiver 24 and the MEMS galvanometer 42. Preferably, the number of reflection modules 30 is the same as the number of transceiver 24, with each reflection module 30 corresponding to one transceiver 24. In the illustrated embodiment, the reflection modules 30 are distributed along an arc, with the galvanometer module 40 located at the center of the arc. The laser beam emitted by each transceiver 24 is reflected by the reflector 34 of the corresponding reflection module 30 and concentrated towards the MEMS galvanometer 42, where it is then converted into a multi-line laser beam and directed towards the target object.

[0045] A first connecting portion 341 is formed by the outward protrusion of the mirror 34 facing the frame 32. The first connecting portion 341 is spherical, and its outer surface 343 is a convex spherical surface. The frame 32 has a second connecting portion 321, and the side of the second connecting portion 321 facing the mirror 34 is recessed to form a receiving groove for accommodating the first connecting portion 341. The receiving groove is spherical, and its groove wall 323 is a concave spherical surface, which mates with the outer surface 343 of the first connecting portion 341 to form a rotatable connection. This allows the mirror 34 to rotate in any direction relative to the frame 32, correcting the angle of the mirror 34, compensating for part tolerances and assembly errors, and ensuring that the reflected laser beam is within the receiving range of the MEMS galvanometer 42. In some embodiments, after the mirror 34 is corrected, the first connecting portion 341 and the second connecting portion 321 are bonded and fixed by adhesive, so that the mirror 34 can always maintain the corrected angle during subsequent use.

[0046] In this embodiment, a mounting hole 345 is formed in the center of the first connecting portion 341, and the axis of the mounting hole 345 coincides with the center line of the outer surface 343 of the first connecting portion 341. A through hole 325 is formed in the center of the second connecting portion 321, the through hole 325 communicates with the receiving groove, and the axis of the through hole 325 coincides with the center line of the groove wall 323 of the receiving groove. During assembly, the connector 36 passes through the through hole 325 of the second connecting portion 321 and the receiving groove, and is then inserted and fixed into the mounting hole 345 of the first connecting portion 341. In some embodiments, the connector 36 can be a screw, pin, rivet, etc., and is screwed or tightly fitted into the mounting hole 345. Preferably, the diameter of the through hole 325 is much larger than the outer diameter of the connector 36, and the connector 36 and the hole wall of the through hole 325 are radially spaced apart, allowing the connector 36 to swing within the through hole 325, so that the reflector 34 can rotate relative to the mirror frame 32 for angle correction.

[0047] Preferably, the reflective module 30 further includes a gasket 38, which is preferably made of a wear-resistant material and is fitted onto the rod of the connector 36 and sandwiched between the head end of the connector 36 and the second connecting portion 321. The inner diameter of the gasket 38 is slightly larger than the diameter of the rod of the connector 36, allowing the rod of the connector 36 to pass through and have some room for movement; the outer diameter of the gasket 38 is larger than the diameter of the through hole 325, so that it can completely cover the through hole 325 and cover the inner edge of the second connecting portion 321. Preferably, the side of the second connecting part 321 facing the gasket 38 is a convex spherical surface, and the side of the gasket 38 facing the second connecting part 321 is a concave spherical surface. The curvature of the two is the same, which allows the second connecting part 321 and the gasket 38 to fit tightly and rotate relative to each other, further facilitating the angle adjustment of the reflector 34. Moreover, after the angle is adjusted, the axis of the connector 36 and the center line of the outer surface 343 of the first connecting part 341 still remain in the same state. The connector 36 will not wobble in the mounting hole 345, so that the connector 36 is subjected to balanced force and will not break.

[0048] The lidar of this invention uses a bracket 16 to mount a galvanometer module 40. A laser transceiver module 20 is positioned below the galvanometer module 40, and a reflector module 30 is positioned near the front of the housing 10, facing both the laser transceiver module 20 and the galvanometer module 40. This results in a compact structure and high space utilization. Furthermore, the bracket 16 provides excellent support strength and installation rigidity for the galvanometer module 40, reducing or even eliminating resonance. The galvanometer module 40 can be larger, reflecting more laser beams. This allows the lidar to not only accurately detect the position and speed of target objects but also effectively improve the accuracy of surface contour recognition and perform 3D modeling of the external environment. In summary, the lidar of this invention has a simple and compact overall structure, superior performance, and is applicable to various fields. In particular, it can provide precise technical support for autonomous driving and has broad application prospects.

[0049] It should be noted that the present invention is not limited to the above-described embodiments. Based on the inventive spirit of the present invention, those skilled in the art can make other changes, and these changes made in accordance with the inventive spirit of the present invention should be included within the scope of protection claimed by the present invention.

Claims

1. A lidar, characterized in that, include: A housing (10) is provided with a bracket (16) inside the housing (10), and a viewing window (141) is provided on the front side of the housing (10); A galvanometer module (40) is installed inside the housing (10) and fixedly connected to the bracket (16). The galvanometer module (40) includes a MEMS galvanometer (42) facing the viewing window (141). The bracket (16) includes two side plates (161) spaced apart from each other, a top plate (163) connected between the tops of the two side plates (161), and a mounting plate (165) connected between the two side plates (161) and the top plate (163). The galvanometer module (40) is fixedly connected to the housing (10). Mounting plate (165); the thickness of mounting plate (165) is greater than the thickness of side plate (161) and top plate (163), and triangular ribs (164) are provided between mounting plate (165) and side plate (161); the bottom of side plate (161) is bent to form a fixing plate (167), and the fixing plate (167) is fixedly connected to the shell (10); the thickness of fixing plate (167) is greater than the thickness of side plate (161) and top plate (163), and side ribs (162) are provided between fixing plate (167) and side plate (161); A laser transceiver module (20) is installed inside the housing (10) and positioned below the galvanometer module (40); A reflection module (30) is installed inside the housing (10) and disposed on the front side of the laser transceiver module (20). The reflection module (30) includes a reflector (34), which is disposed facing the galvanometer module (40) and the laser transceiver module (20). The laser beam emitted by the laser transceiver module (20) is reflected by the reflector (34) to the MEMS galvanometer (42), which converts the single-line laser beam into a multi-line laser beam and projects it to the outside through the window (141).

2. The lidar as described in claim 1, characterized in that, The mounting plate (165) is inclined relative to the side plate (161) and the top plate (163).

3. The lidar as described in claim 2, characterized in that, The mounting plate (165) is also fixedly connected to a main control circuit board (50). The main control circuit board (50) and the galvanometer module (40) are respectively fixed on the front and rear surfaces of the mounting plate (165) and are electrically connected.

4. The lidar as described in claim 3, characterized in that, The laser transceiver module (20) includes a transceiver body (24) and an LD circuit board (22) connected by an optical fiber (28). The LD circuit board (22) is fixedly connected to the main control circuit board (50) and located above the transceiver body (24). The transceiver body (24) is provided with an upwardly tilted optical fiber interface (25).

5. The lidar as described in claim 4, characterized in that, The laser transceiver module also includes an APD circuit board (26), which is mounted on the transceiver body (24).

6. The lidar as described in claim 1, characterized in that, The mounting plate (165) is provided with an opening (166) for mounting the galvanometer module (40), and the mounting plate (165) is provided with a reinforcing rib (168) at the bottom of the opening (166).

7. The lidar as described in any one of claims 2-5, characterized in that, At least one of the top plate (163), side plate (161) and mounting plate (165) has a perforation (169).

8. The lidar as described in any one of claims 1-5, characterized in that, The reflection module (30) further includes a frame (32) for mounting the reflector (34). The reflector (34) protrudes to form a first connecting part (341), and the outer surface (343) of the first connecting part (341) is a convex spherical surface. The frame (32) includes a second connecting part (321), and the second connecting part (321) is recessed to form a receiving groove to receive the first connecting part (341). The groove wall (323) of the receiving groove is a concave spherical surface.

Images