Large-viewing-angle laser radar scanning device based on 360-degree rotation

Abstract

The utility model discloses a large-viewing-angle laser radar scanning device based on 360-degree rotation. The large-viewing-angle laser radar scanning device comprises an outer shell, a rotating support, a base, an optical prism, a transmitting assembly and a receiving assembly, the rotating support is a rectangular support jointly defined by two side plates, a top plate and a bottom plate, a first cylindrical shaft is installed on the top plate, and a second cylindrical shaft is installed on the bottom plate. The upper end of the first cylindrical shaft is rotationally connected with the top of the outer shell, and the lower end of the second cylindrical shaft is rotationally connected with the base. A rotating shaft is horizontally mounted in the rotating bracket, and the optical prism is coaxially fixed on the rotating shaft; the transmitting assembly comprises a first convex lens, a first plane mirror and at least one transmitting module; the receiving assembly comprises a second convex lens, a second plane mirror and at least one receiving module. According to the utility model, a horizontal and vertical double-shaft rotation structure is adopted, the expansion of a radar scanning visual angle is ensured, and the cost is reduced at the same time.

Description

Technical Field

[0001] The utility model belongs to the technical field of lidar, and relates to a large-view lidar scanning device based on 360° rotation. Background Technique

[0002] Lidar technology is the product of the combination of laser technology and radar technology. Lidar has a wide range of applications in many fields such as the military, aerospace, and geographic mapping. In the field of driverless cars, lidar plays a core role as the eyes of driverless cars and can effectively detect complex environments in a high-speed environment.

[0003] Most current driverless cars adopt a mechanical rotation scanning scheme. The so-called mechanical lidar means that the lidar module rotates as a whole to achieve one-dimensional to two-dimensional scanning. Multiple beams of lasers are arranged vertically to form multiple planes, and multiple planes scan simultaneously to achieve a dynamic three-dimensional scanning effect. The lasers in the vertical direction are arranged at an angle and emit in different directions to form multiple scanning lines to achieve vertical angle coverage. Limited by manufacturing processes, mechanical rotation lidar requires high-precision assembly. Currently, lidars have problems such as high cost, complex assembly processes, and inability to linearly increase the number of laser lines. Because as the number of arranged laser beams increases, the process requirements for laser alignment increase exponentially. At the same time, the single-axis overall rotation scheme is not conducive to the requirements of large field-of-view scanning of the lidar, which poses a high challenge for the future entry of lidar into vehicle-grade products. Therefore, it is necessary to develop a lidar scanning structure that can increase the radar scanning angle of view, improve the scanning efficiency, and reduce the process cost.

[0004] Conventional lidars and their scanning structures mainly include at least 1 emission module and 1 reception module. The emission module is fixed on the base of the lidar; the emission module emits laser light to a beam splitter module through a mirror module. The beam splitter DOE (diffractive optical element) divides the point laser into a point array; the mirror module and the beam splitter module are fixed on an independent rotating base, and the rotating base is driven by a motor at the bottom; the reception module is located at the bottom of the motor to receive the reflected laser light. After adopting the above conventional scanning structure scheme, the lidar can achieve efficient two-dimensional scanning, making the resolution of the lidar higher and the scanning speed faster. However, for more and more detailed usage scenarios, the two-dimensional scanning using such a scanning structure has limitations, such as being unable to rotate horizontally by 360° and having too small a vertical field of view (≤20°). Content of the Utility Model

[0005] The purpose of the utility model is to propose a large-view lidar scanning device based on 360° rotation to solve the defects of the existing lidar and its scanning structure, such as single-direction 360° rotation scanning and too small a vertical rotation field of view.

[0006] To achieve the above object, the utility model adopts the following technical solutions to solve the problem:

[0007] A large-angle lidar scanning device based on 360° rotation includes a housing and a rotating bracket, a base, an optical prism, a transmitting component, and a receiving component installed inside the housing;

[0008] The rotating bracket is a rectangular bracket surrounded by two side plates, a top plate, and a bottom plate. A first cylindrical shaft is vertically and fixedly installed at the center of the upper surface of the top plate, and a second cylindrical shaft is vertically and fixedly installed at the center of the lower surface of the bottom plate. The central axes of the first cylindrical shaft and the second cylindrical shaft are located on the same axis; the upper end of the first cylindrical shaft is rotatably connected to the top of the housing, and the lower end of the second cylindrical shaft is rotatably connected to the base; the first cylindrical shaft or the second cylindrical shaft is driven by a driving motor and can rotate around its own central axis, thereby driving the entire rotating bracket to rotate horizontally around the axis;

[0009] A rotating shaft is horizontally installed inside the rotating bracket, and both ends of the rotating shaft are rotatably installed in through holes correspondingly opened in the two side plates of the rotating bracket. The optical prism is coaxially fixed on the rotating shaft, and the optical prism is driven by a motor to rotate around the central axis of the rotating shaft;

[0010] The transmitting component includes a first convex lens, a first plane mirror, and at least one transmitting module; the receiving component includes a second convex lens, a second plane mirror, and at least one receiving module; the first convex lens and the second convex lens are symmetrically installed on the left and right sides inside the rotating bracket below the optical prism, and both are located on one side of the vertical section where the central axis of the optical prism is located; the first plane mirror and the second plane mirror are installed on the bottom plate of the rotating bracket and are respectively located directly below the first convex lens and the second convex lens. The mirror surfaces of the first plane mirror and the second plane mirror are both inclined upward; the transmitting module and the receiving module are respectively fixedly installed on one side of the mirror surfaces of the first plane mirror and the second plane mirror and are at the same height as the center of the reflecting mirror.

[0011] Further, a wireless power receiving coil is installed on the lower surface of the bottom plate of the rotating bracket, and the wireless power receiving coil sleevs the upper end of the second cylindrical shaft. A wireless power transmitting coil corresponding to the wireless power receiving coil is installed on the upper surface of the base, and the wireless power transmitting coil sleevs the lower end of the second cylindrical shaft. The wireless power receiving coil is connected to the motor of the optical prism.

[0012] Further, both ends of the rotating shaft are rotatably installed in the through holes of the corresponding side plates through bearings.

[0013] Further, the upper end of the first cylindrical shaft is rotatably connected to the top of the outer housing through a bearing, and the lower end of the second cylindrical shaft is rotatably connected to the base through a bearing.

[0014] Further, a counterbore is formed in the middle of the base, and the lower end of the second cylindrical shaft is located in the counterbore and is rotatably connected through a bearing.

[0015] Further, the four corners of the base are fixedly installed and supported on the bottom plate of the outer housing through screws.

[0016] Further, the middle part of the second cylindrical shaft is a gear shaft, and a driving gear meshing with it is arranged on one side of the gear shaft. The driving gear is driven to rotate by a driving motor, and the driving motor drives the driving gear to drive the second cylindrical shaft to rotate around its own central axis, thereby driving the rotating bracket to rotate.

[0017] Further, the optical prism is a wide-angle four-prism.

[0018] Further, the transmitting module adopts an LD laser emitter.

[0019] Further, the receiving module adopts an APD laser receiver.

[0020] Compared with the prior art, the present utility model has the following technical effects:

[0021] The device of the present utility model adopts a horizontal + vertical double-axis rotation structure, which ensures the expansion of the radar scanning angle of view. Through the 360° rotation of the rotating bracket around the axis in the horizontal direction and the 360° rotation of the optical prism in the vertical direction, the 360° rotation of the lidar scanning device in two dimensions is realized, so that the maximum field of view angle (45°) in the vertical direction can be achieved while the horizontal rotation is realized. Especially for the vertical viewing angle, the single laser is split into multiple lasers through the four-prism, which reduces the process requirements for aligning multiple transmitting modules and can increase the scanning resolution at the same time. The cost of a single four-prism is also lower than the cost of stacking multiple transmitting modules, which improves the scanning efficiency of the lidar and reduces the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is the axial view structural schematic diagram of the 360° rotation-based large-view-angle lidar scanning device of the present utility model;

[0023] Figure 2 is the front view structural schematic diagram of the 360° rotation-based large-view-angle lidar scanning device of the present utility model;

[0024] Figure 3 is of the present utility model Figure 2 A-A sectional schematic diagram;

[0025] Figure 4 This is a top view of the large-angle lidar scanning device based on 360° rotation of the present utility model.

[0026] The meanings of the reference numerals in the figure are as follows:

[0027] 1. Rotating bracket, 2. Base, 3. Optical prism;

[0028] 1-1. Side plate, 1-2. Top plate, 1-3. Bottom plate, 1-4. First cylindrical shaft, 1-5. Second cylindrical shaft;

[0029] 4-1. First convex lens, 4-2. First plane mirror, 4-3. Transmitting module, 5-1. Second convex lens, 5-2. Second plane mirror, 5-3. Receiving module.

[0030] The present utility model will be further explained below in conjunction with the accompanying drawings and specific embodiments. Specific Embodiments

[0031] As Figures 1 to 4 shown, the large-angle lidar scanning device based on 360° rotation given by the present utility model includes an outer housing, and a rotating bracket 1, a base 2, an optical prism 3, a transmitting assembly and a receiving assembly installed in the outer housing.

[0032] The rotating bracket 1 is a rectangular bracket jointly formed by two side plates 1-1, a top plate 1-2 and a bottom plate 1-3. A first cylindrical shaft 1-4 is vertically and fixedly installed at the center of the upper surface of the top plate 1-2, and a second cylindrical shaft 1-5 is vertically and fixedly installed at the center of the lower surface of the bottom plate 1-3. The central axes of the first cylindrical shaft 1-4 and the second cylindrical shaft 1-5 are located on the same axis; the upper end of the first cylindrical shaft 1-4 is rotatably connected to the top of the outer housing, and the lower end of the second cylindrical shaft 1-5 is rotatably connected to the base, so that the first cylindrical shaft 1-4 and the second cylindrical shaft 1-5 jointly form a virtual first rotation axis. The first cylindrical shaft 1-4 or the second cylindrical shaft 1-5 is driven by a driving motor and can rotate around its own central axis, thereby driving the entire rotating bracket 1 to rotate horizontally around the axis.

[0033] Preferably, the upper end of the first cylindrical shaft 1-4 is rotatably connected to the top of the outer housing through a bearing, and the lower end of the second cylindrical shaft 1-5 is rotatably connected to the base through a bearing. Preferably, a counterbore is formed in the middle of the base 2, and the lower end of the second cylindrical shaft 1-5 is located in the counterbore and is rotatably connected through a bearing. The four corners of the base 2 are fixedly installed and supported on the bottom plate of the outer housing by screws.

[0034] Preferably, the middle part of the second cylindrical shaft 1-5 is a gear shaft (i.e., a circle of teeth is evenly arranged along the circumferential direction on the outer wall of the middle part of the second cylindrical shaft), and a driving gear meshing with it is arranged on one side of the gear shaft. The driving gear is driven by a driving motor to rotate. The driving motor drives the driving gear to drive the second cylindrical shaft to rotate around its own central axis. Since the upper end of the first cylindrical shaft 1-4 is rotatably connected to the top of the outer housing and the lower end of the second cylindrical shaft 1-5 is rotatably connected to the base, the second cylindrical shaft 1-5 is driven by the driving gear to rotate, thereby driving the rotating bracket 1 above it to rotate.

[0035] A rotating shaft is horizontally installed in the rotating bracket 1. The two ends of the rotating shaft are respectively rotatably installed in the through holes correspondingly opened in the two side plates 1-1 of the rotating bracket 1 (preferably, the two ends of the rotating shaft are rotatably installed in the through holes of the corresponding side plates 1-1 through bearings). The optical prism 3 is coaxially fixed on the rotating shaft. The optical prism 3 is driven by a motor to rotate around the central axis of the rotating shaft. Specifically, the output shaft of the motor is coaxially fixedly connected to the rotating shaft, and the motor drives the rotating shaft to rotate to drive the optical prism 3 to rotate. Preferably, a wireless power receiving coil is installed on the lower surface of the bottom plate 1-3 of the rotating bracket 1, and the upper end of the second cylindrical shaft 1-5 is sleeved therein. A wireless power transmitting coil corresponding to the wireless power receiving coil is installed on the upper surface of the base 2, and the lower end of the second cylindrical shaft 1-5 is sleeved therein. The wireless power receiving coil is connected to the optical prism 3 through a motor to realize power supply to the motor.

[0036] The transmitting assembly includes a first convex lens 4-1, a first plane mirror 4-2 and at least one transmitting module 4-3; the receiving assembly includes a second convex lens 5-1, a second plane mirror 5-2 and at least one receiving module 5-3; the first convex lens 4-1 and the second convex lens are symmetrically installed on the left and right in the rotating bracket 1 below the optical prism 3, and both are located on one side of the vertical section where the central axis of the optical prism 3 is located; the first plane mirror 4-2 and the second plane mirror 5-2 are installed on the bottom plate 1-3 of the rotating bracket 1 and are respectively located directly below the first convex lens 4-1 and the second convex lens 5-1. The mirror surfaces of the first plane mirror 4-2 and the second plane mirror 5-2 are both inclined upward (preferably 45°); the transmitting module 4-3 and the receiving module 5-3 are respectively fixedly installed on one side of the mirror surfaces of the first plane mirror 4-2 and the second plane mirror 5-2 through brackets and are at the same height as the center of the reflecting mirror. According to the design of the above technical solution, the laser beam emitted by the transmitting module 4-3 is reflected by the first plane mirror 4-2 and then incident on the optical prism 3 through the first convex lens 4-1, and is reflected by the optical prism 3 onto the measurement target. After the beam reflected by the measurement target returns to the optical prism 3, it is reflected by the optical prism 3 to the second convex lens 5-1, and then reflected by the second plane mirror 5-2 to the receiving module 5-3.

[0037] Preferably, the optical prism 3 is a wide-angle four-prism.

[0038] Preferably, the transmitting module 4-3 uses an LD laser emitter.

[0039] Preferably, the receiving module 5-3 uses an APD laser receiver.

[0040] The working principle of the present utility model is as follows:

[0041] To achieve a 360° horizontal rotation and expand the vertical field of view angle, the device of the present utility model adopts a horizontal + vertical two-axis rotation structure. Through the 360° rotation of the rotating bracket 1 around the axis in the horizontal direction and the 360° rotation of the optical prism 3 in the vertical direction, a 360° rotation of the lidar scanning device in two dimensions is realized, so that the maximum field of view angle (45°) in the vertical direction can be achieved while the horizontal rotation is realized.

[0042] The device of the present utility model is a typical laser ranging and scanning system, and its working principle is based on the emission, reflection, reception and signal conversion of laser. The infrared laser emitted by the transmitting module 4-3 is reflected by the first plane mirror 4-2 and enters the first convex lens 4-1 for focusing. Then it is reflected by the optical prism 3 (quadrilateral prism). Because the quadrilateral prism rotates 360° in two dimensions, by controlling the rotation angle and speed, the precise movement of the laser within a 45° range in the vertical direction can be achieved. There is a proportional relationship between this movement angle and speed and the rotation of the prism, allowing precise control of the laser pointing; when the laser beam hits the target object, part of the laser is reflected to the quadrilateral prism, and then reflected vertically by the quadrilateral prism and enters the second convex lens 5-1 for focusing again. Then it is reflected by the second plane mirror 5-2 and changes from the vertical state to the horizontal state, so as to be received by the receiving module 5-3, and the optical signal is converted into an electrical signal again. By controlling the emission and reception of the laser, the precise positioning and measurement of the target object can be realized. In addition, the electrical signal received by the receiving module 5-3 can then be further processed and analyzed to obtain the required measurement data or other functions such as feature recognition of the target object.

Claims

1. A large-angle lidar scanning device based on 360° rotation, including an outer housing, characterized in that, It also includes a rotating bracket (1), a base (2), an optical prism (3), a transmitting component, and a receiving component installed inside the housing. The rotating bracket (1) is a rectangular bracket jointly formed by two side plates (1-1), a top plate (1-2), and a bottom plate (1-3). At the center of the upper surface of the top plate (1-2), a first cylindrical shaft (1-4) is vertically and fixedly installed. At the center of the lower surface of the bottom plate (1-3), a second cylindrical shaft (1-5) is vertically and fixedly installed. The central axes of the first cylindrical shaft (1-4) and the second cylindrical shaft (1-5) are on the same axis. The upper end of the first cylindrical shaft (1-4) is rotatably connected to the top of the housing, and the lower end of the second cylindrical shaft (1-5) is rotatably connected to the base. The first cylindrical shaft (1-4) or the second cylindrical shaft (1-5) is driven by a driving motor and can rotate around its own central axis, thereby driving the entire rotating bracket (1) to rotate horizontally around the axis. A rotating shaft is horizontally installed inside the rotating bracket (1). The two ends of the rotating shaft are respectively rotatably installed in through holes correspondingly opened in the two side plates (1-1) of the rotating bracket (1). The optical prism (3) is coaxially fixed on the rotating shaft, and the optical prism (3) is driven by a motor to rotate around the central axis of the rotating shaft. The transmitting component includes a first convex lens (4-1), a first plane mirror (4-2), and at least one transmitting module (4-3). The receiving component includes a second convex lens (5-1), a second plane mirror (5-2), and at least one receiving module (5-3). The first convex lens (4-1) and the second convex lens are symmetrically installed on the left and right in the rotating bracket (1) below the optical prism (3), and both are located on one side of the vertical section where the central axis of the optical prism (3) is located. The first plane mirror (4-2) and the second plane mirror (5-2) are installed on the bottom plate (1-3) of the rotating bracket (1) and are respectively located directly below the first convex lens (4-1) and the second convex lens (5-1). The mirror surfaces of the first plane mirror (4-2) and the second plane mirror (5-2) are both inclined upward. The transmitting module (4-3) and the receiving module (5-3) are respectively fixedly installed on one side of the mirror surfaces of the first plane mirror (4-2) and the second plane mirror (5-2) through brackets, and their heights are flush with the center of the reflecting mirror.

2. The 360° rotation-based large-view lidar scanning device according to claim 1, wherein A wireless power receiving coil is installed on the lower surface of the bottom plate (1-3) of the rotating bracket (1), and the upper end of the second cylindrical shaft (1-5) is sleeved inside the wireless power receiving coil. A wireless power transmitting coil corresponding to the wireless power receiving coil is installed on the upper surface of the base (2), and the lower end of the second cylindrical shaft (1-5) is sleeved inside the wireless power transmitting coil. The wireless power receiving coil is connected to the motor of the optical prism (3).

3. The 360° rotation-based large-view lidar scanning device according to claim 1, wherein Both ends of the rotating shaft are rotatably installed in the through holes of the corresponding side plates (1-1) through bearings.

4. The 360° rotation-based large-view lidar scanning device according to claim 1, wherein The upper end of the first cylindrical shaft (1-4) is rotatably connected to the top of the housing through a bearing, and the lower end of the second cylindrical shaft (1-5) is rotatably connected to the base through a bearing.

5. The 360°-rotating large-view-angle lidar scanning device according to claim 4, characterized in that, A counterbore is formed in the middle of the base (2), and the lower end of the second cylindrical shaft (1-5) is located in the counterbore and is rotatably connected through a bearing.

6. The 360° rotation-based large viewing angle lidar scanning device according to claim 1, wherein The four corners of the base (2) are fixedly installed and supported on the bottom plate of the outer housing through screws.

7. The 360° rotation-based large viewing angle lidar scanning device according to claim 1, characterized in that The middle part of the second cylindrical shaft (1-5) is a gear shaft, and a driving gear meshing with it is arranged on one side of the gear shaft. The driving gear is driven by a driving motor to rotate. The driving motor drives the driving gear to drive the second cylindrical shaft to rotate around its own central axis, thereby driving the rotating bracket (1) to rotate.

8. The 360° rotation-based large viewing angle lidar scanning device according to claim 1, wherein The optical prism (3) is a wide-angle four-prism.

9. The 360° rotation-based large viewing angle lidar scanning device according to claim 1, wherein The emission module (4-3) uses an LD laser emitter.

10. The 360° rotation-based large viewing angle lidar scanning device according to claim 1, characterized in that, The receiving module (5-3) uses an APD laser receiver.

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