Three-dimensional laser scanner

Abstract

The invention relates to a three-dimensional laser scanner, which comprises a base, a main scanning shaft driving motor, a main scanning assembly and a laser emitting and receiving assembly, and is characterized in that the main scanning assembly and the laser emitting and receiving assembly are oppositely mounted on the base; the main scanning shaft driving motor is arranged in the base, is in driving connection with the main scanning assembly and / or the laser emitting and receiving assembly, and drives the main scanning assembly and / or the laser emitting and receiving assembly to rotate along the main scanning shaft; the main scanning assembly comprises a reflective mirror and a secondary scanning shaft driving motor, and the secondary scanning shaft driving motor drives the reflective mirror to rotate along a secondary scanning shaft; the main scanning shaft and the secondary scanning shaft are not parallel and not orthogonal, and a laser transmitting and receiving optical axis of the laser transmitting and receiving assembly is parallel to the main scanning shaft or the secondary scanning shaft. Compared with the prior art, the scanning period of the single laser is fully utilized, and the angle and distance data of the scanning area along the upper and lower parts of angles of the scanner mounting plane can be obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of laser scanners, and in particular to a three-dimensional laser scanner. Background Art

[0002] In recent years, with the rapid development of lidar technology, there have been many three-dimensional laser scanners, but they generally still have structural and traditional scanning structure limitations.

[0003] For example, the 3D scanning mechanism disclosed in Chinese patent application CN202011596543.6 uses a single-laser 3D laser scanner. However, due to the orthogonal movement of the secondary scanning axis, the latitudinal direction differs from the actual requirements of application scenarios such as robot obstacle avoidance, making it difficult to fully utilize the scanning range in the latitudinal direction. 3D laser scanners using multiple lasers only scan along the primary scanning axis, and the number of measured latitudes along the secondary scanning axis is determined by the number of lasers, resulting in a latitudinal scanning dead zone. Summary of the Invention

[0004] The purpose of the present invention is to provide a three-dimensional laser scanner to overcome the defect of the above-mentioned prior art that it is difficult to fully utilize the scanning range in the latitudinal direction.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A three-dimensional laser scanner comprises a base, a main scanning axis drive motor, a main scanning assembly, and a laser emitting and receiving component, wherein the main scanning assembly and the laser emitting and receiving component are relatively mounted on the base;

[0007] The main scanning axis drive motor is disposed in the base and is drivingly connected to the main scanning assembly and / or the laser emitting and receiving assembly to drive the main scanning assembly and / or the laser emitting and receiving assembly to rotate along the main scanning axis;

[0008] The main scanning assembly includes a reflecting mirror and a secondary scanning axis driving motor, and the secondary scanning axis driving motor drives the reflecting mirror to rotate along the secondary scanning axis;

[0009] The main scanning axis is not parallel or orthogonal to the secondary scanning axis, and the main and secondary scanning axes rotate at different speeds. The laser emitting and receiving optical axes of the laser emitting and receiving components are parallel to the main scanning axis or the secondary scanning axis.

[0010] As a preferred technical solution, the main scanning axis and the secondary scanning axis form an angle α∈(0°, 45°).

[0011] As a preferred technical solution, the angle β∈(0°, 90°) is formed between the reflecting mirror surface of the reflector and the secondary scanning axis.

[0012] As a preferred technical solution, the laser emitting and receiving assembly includes a coaxially arranged laser receiving optoelectronic device, a laser receiving objective lens, a laser and a laser emitting objective lens.

[0013] As an optimal technical solution, the emitting end of the laser is facing the reflector; the laser emitting objective lens is arranged on the side of the laser close to the reflector; the laser receiving objective lens is arranged on the outside of the laser emitting objective lens, and the optical axes of the laser emitting objective lens and the laser receiving objective lens are parallel; the laser receiving photoelectric device is arranged on the side of the laser away from the reflector.

[0014] As a preferred technical solution, the laser emitting and receiving components are mounted on the base and are driven by the main scanning axis drive motor; the three-dimensional laser scanner also includes a rotating bracket driven by the main scanning axis drive motor, and the main scanning assembly is mounted on an end of the rotating bracket away from the base and arranged opposite to the laser emitting and receiving components;

[0015] The main scanning axis driving motor drives the laser emitting and receiving components and the main scanning assembly to rotate along the main scanning axis simultaneously or separately.

[0016] As an optimal technical solution, when the optical axis of the laser emitting objective lens is parallel to the main scanning axis, the base and the laser emitting and receiving components are fixed during scanning; the main scanning axis drive motor drives the main scanning assembly to rotate and scan around the main scanning axis, and at the same time, the secondary scanning axis drive motor drives the reflector to rotate around the secondary scanning axis to complete three-dimensional scanning.

[0017] As an optimal technical solution, when the optical axis of the laser emitting objective lens is parallel to the secondary scanning axis, the base is fixed during scanning; the main scanning axis motor drives the main scanning assembly and the laser emitting and receiving components to rotate and scan around the main scanning axis, and at the same time, the secondary scanning axis drive motor drives the reflector to rotate around the secondary scanning axis to complete three-dimensional scanning.

[0018] As a preferred technical solution, the main scanning assembly is installed in the base and is drivingly connected to the main scanning axis drive motor;

[0019] The three-dimensional laser scanner further comprises a mounting bracket fixedly connected to the base, and the laser emitting and receiving components are arranged at one end of the mounting bracket away from the base and arranged opposite to the main scanning assembly.

[0020] As an optimal technical solution, the laser emitting objective lenses of the laser emitting and receiving components are adjusted to be parallel to the main scanning axis or the secondary scanning axis during scanning; the main scanning axis driving motor drives the main scanning assembly to rotate and scan along the main scanning axis; the secondary scanning axis driving motor drives the reflector to rotate along the rotating secondary scanning axis to complete three-dimensional scanning.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The 3D scanner proposed in this invention utilizes a dual-scanning-axis scanning method, employing two non-parallel and non-orthogonal scanning axes. A secondary scanning axis rotates around the primary scanning axis, while a plane mirror rotates around the secondary scanning axis. Because the primary and secondary scanning axes, as well as the reflective surface of the reflector, each form a specific angle. When the primary and secondary scanning axes rotate at different speeds, the scanning light axis refracted by the reflector will scan along the upper and lower angles of the scanner's mounting plane, obtaining a dense point cloud within the specified scanning area. This dual-scanning-axis scanning method fully utilizes the scanning range in the latitudinal direction, allowing a single laser scanner to obtain angular and distance data for the scanning area along the upper and lower angles of the scanner's mounting plane. This also addresses the potential obstruction issues encountered during horizontal scanning to a certain extent. The present invention fully utilizes the scanning cycle of a single laser, maximizing the utilization of all scans by keeping the entire scanning range within the desired angle through mechanical design without significantly increasing the scanning frequency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the structure of one embodiment of the present invention in which the optical axis of the laser emission objective lens is parallel to the main scanning axis;

[0024] Figure 2 This is a schematic diagram of the structure of one embodiment of the present invention in which the optical axis of the laser emission objective lens is parallel to the secondary scanning axis;

[0025] Figure 3 A three-dimensional schematic diagram of a situation in which the optical axis of the laser emission objective lens is parallel to the main scanning axis in one embodiment of the present invention;

[0026] Figure 4 Schematic diagram of scanning angles when the optical axis of the laser emission objective lens is parallel to the main scanning axis in one embodiment of the present invention; 4a) the main scanning axis is oriented toward θ = 0°, 4b) the secondary scanning axis is oriented toward γ = 0°;

[0027] Figure 5 A schematic diagram of a three-dimensional scanning range in one embodiment of the present invention;

[0028] Figure 6 FIG1 is a schematic diagram of dense scan lines obtained within 0.5 seconds at a set scan frequency and rotation speed in one embodiment of the present invention;

[0029] Figure 7 A structural cross-sectional view of another embodiment of the present invention;

[0030] Figure 8 A structural perspective diagram of another embodiment of the present invention;

[0031] The numbers in the figure are as follows: 1. Main scanning axis, 2. Secondary scanning axis, 3. Reflector, 4. Base, 5. Main scanning axis drive motor, 6. Secondary scanning axis drive motor, 7. Laser receiving photoelectric device, 8. Laser receiving objective lens, 9. Laser, 10. Laser emitting objective lens, 11. 3D laser scanner, 12. 3D scanning range, 13. 3D scanning range cross section. DETAILED DESCRIPTION

[0032] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0033] Example 1

[0034] A three-dimensional laser scanner is provided on a base 4 of the three-dimensional laser scanner. A main scanning axis driving motor 5 and a main scanning assembly and a laser emitting and receiving component are arranged relatively thereto.

[0035] The main scanning assembly includes a secondary scanning axis drive motor 6 and a reflector 3. The rotational axis of the secondary scanning axis drive motor 6 (i.e., the secondary scanning axis 2) forms an angle α with the rotational axis of the main scanning axis drive motor 5 (i.e., the main scanning axis 1). The output end of the secondary scanning axis drive motor 6 drives the reflector 3, and the reflective surface of the reflector 3 forms an angle β with the rotational axis of the secondary scanning axis drive motor 6 (i.e., the secondary scanning axis 2).

[0036] Furthermore, in the present invention, the main scanning axis 1 and the secondary scanning axis 2 form an angle α∈(0°, 45°), and the reflecting mirror surface of the reflector 3 and the secondary scanning axis 2 form an angle β∈(0°, 90°).

[0037] The laser emitting and receiving assembly includes a coaxially arranged laser receiving optoelectronic device 7, a laser receiving objective lens 8, a laser 9 and a laser emitting objective lens 10, wherein the emitting end of the laser 9 faces the reflector 3, the laser emitting objective lens 10 is arranged on the side of the laser 9 close to the reflector 3, and the laser receiving objective lens 8 is arranged on the outside of the laser emitting objective lens 10, and the optical axes of the laser emitting objective lens 10 and the laser receiving objective lens 8 are parallel. The laser receiving objective lens 8 adopts a convex lens, and the laser receiving optoelectronic device 7 is arranged at the focal length of the laser receiving objective lens 8 on the side opposite to the laser 9 and the reflector 3.

[0038] Furthermore, the optical axes of the laser emitting objective lens 10 and the laser receiving objective lens 8 are parallel, and both are parallel to the main scanning axis 1 or parallel to the sub-scanning axis 2 .

[0039] In this embodiment, the laser emitting and receiving assembly is mounted on a base 4 and is drivably connected to a main scanning axis drive motor 5. The orientation of the laser emitting and receiving optical axes of the laser emitting and receiving assembly is adjustable. The main scanning axis drive motor 5 is also drivably connected to a rotating bracket. The main scanning assembly is mounted above the base 4 via the rotating bracket and is positioned opposite the laser emitting and receiving assembly. The main scanning axis drive motor 5 can simultaneously or independently drive the laser emitting and receiving assembly and the main scanning assembly to rotate along the main scanning axis 1.

[0040] like Figure 1 The figure shows the situation where the optical axis of the laser emitting objective lens 8 is parallel to the main scanning axis 1. At this time, the base 4 and the laser emitting and receiving components are fixed during scanning; the main scanning axis drive motor 5 drives the main scanning assembly to rotate around the main scanning axis 1 for scanning, and at the same time, the secondary scanning axis drive motor 6 drives the reflector 3 to rotate around the secondary scanning axis 2 to complete three-dimensional scanning.

[0041] like Figure 2 The figure shows the situation where the optical axis of the laser emitting objective lens 8 is parallel to the secondary scanning axis 2. At this time, the base 4 is fixed during scanning; the main scanning axis motor 5 drives the main scanning assembly and the laser emitting and receiving components to rotate and scan around the main scanning axis 1, and at the same time, the secondary scanning axis drive motor 6 drives the reflector 3 to rotate around the secondary scanning axis 2 to complete three-dimensional scanning.

[0042] The main feature of the present invention is that the main scanning axis 1 and the secondary scanning axis 2 are not parallel and not orthogonal; further, the dual scanning axis scanning form with the angle α∈(0°, 45°) between the main scanning axis 1 and the secondary scanning axis 2 does not rely on the specific implementation structure shown in the above embodiments.

[0043] The following shows the scanning mode and scanning range calculation when the laser emission lens is parallel to the main scanning axis 1. Figure 3 The scanning angle θ of the main scanning axis 1 and the scanning angle γ of the secondary scanning axis 2 are shown, where θ, γ∈[0°,360°).

[0044] like Figure 4 As shown in a, when the main scanning axis 1 is oriented toward θ = 0° and the secondary scanning axis 2 is oriented toward γ = 0°, the scanning direction of the 3D laser scanner is toward the upper right, and the angle between the scanning direction and the horizontal plane (the plane orthogonal to the main scanning axis) is u = 90° + 2α - 2β; Figure 4 As shown in Figure 2b, when the primary scanning axis 1 is oriented toward θ = 180° and the secondary scanning axis 2 is oriented toward γ = 180°, the scanning direction is downward and right, and the angle between the scanning direction and the horizontal plane (the plane perpendicular to the primary scanning axis) is v = 2α + 2β - 90°. The calculation method is the same for the case where the optical axis of the laser emission objective lens is parallel to the primary scanning axis 1.

[0045] From the above process, we can obtain u + v = 4 * α. That is, the angle α between the main scanning axis 1 and the secondary scanning axis 2 determines the angular range of the vertical scan, and the angle β between the reflector 3 and the secondary scanning axis 2 determines the center direction of the vertical scan. By constraining α∈(0°, 45°), β∈(0°, 90°), u∈(0°, 90°), and v∈(0°, 45°), we can calculate the α and β values ​​required for different vertical scan ranges. By further considering structural interference and optical path design, we can further determine the α and β values ​​of the final product.

[0046] like Figure 5 As shown, in this embodiment, α=12.5°, β=48° are selected to obtain a scanning range of u=19°, v=31°, where 11 is a three-dimensional laser scanner, 12 is a three-dimensional scanning range, and 13 is a cross-section of the three-dimensional scanning range.

[0047] In actual scanning, given the main scanning axis rotation speed p and the secondary scanning axis scanning speed q, the angle at time t can be obtained by rotating the scanning line along the secondary scanning axis by an angle p*t, and then rotating the main scanning axis by an angle q*t. The specific formula is as follows, where the unit vector of the scanning direction is obtained.

[0048]

[0049] Set the scanning frequency to 100kHz, the main scanning axis rotation speed to 40rps, and the sub-scanning axis rotation speed to 17rps. Dense scanning lines around the periphery can be obtained within 0.5 seconds. Figure 6 As shown, it can be seen that through the device and scanning method of the present invention, all scans can be run within the desired angle through mechanical structure design without significantly increasing the scanning frequency, thereby maximizing the utilization of all scans.

[0050] Example 2

[0051] As another embodiment of the present invention, Figure 7 、 8 As shown, another configuration of the three-dimensional laser scanner of the present invention. Its main features are the same as those in Example 1, that is, they all include a main scanning axis 1, a secondary scanning axis 2, a reflector 3, a base 4, a main scanning axis drive motor 5, and a secondary scanning axis drive motor 6. The main scanning axis 1 and the secondary scanning axis 3 form an angle α∈(0°, 45°), and the reflector 3 and the secondary scanning axis 2 form an angle β∈(0°, 90°). The laser emitting and receiving components include: a laser receiving photoelectric device 7, a laser receiving objective lens 8, a laser 9, and a laser emitting objective lens 10. The optical axes of the laser emitting objective lens 10 and the laser receiving objective lens 8 are parallel. The main scanning axis 1 and the secondary scanning axis 2 are not parallel and not orthogonal, and a dual scanning axis scanning form is adopted in which the main scanning axis 1 and the secondary scanning axis 3 form an angle α∈(0°, 45°).

[0052] The difference between this embodiment and embodiment 1 is that in this embodiment, the main scanning assembly is installed in the base 4 and is connected to the main scanning axis drive motor 5, while the laser emitting and receiving components are arranged above the base 4 relative to the main scanning assembly via a mounting bracket fixed to the base 4. The rotation axes of the main scanning axis drive motor 5 and the secondary scanning axis drive motor 6, that is, the main scanning axis 1 and the secondary scanning axis 2, are neither parallel nor orthogonal. During scanning, the laser emitting objective lens 10 of the laser emitting and receiving components is adjusted to be parallel to the main scanning axis 1 or the secondary scanning axis 2 respectively; the main scanning assembly is driven by the main scanning axis drive motor 5 to rotate and scan along the main scanning axis 1; and the reflector 3 is driven by the secondary scanning axis drive motor 6 to rotate along the rotating secondary scanning axis 2 to complete the scanning.

[0053] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

Claims

1. A three-dimensional laser scanner, characterized in that: It comprises a base (4), a main scanning axis driving motor (5), a main scanning assembly and a laser emitting and receiving component, wherein the main scanning assembly and the laser emitting and receiving component are relatively mounted on the base (4); The main scanning axis driving motor (5) is arranged in the base (4) and is drivingly connected to the main scanning assembly and / or the laser emitting and receiving component to drive the main scanning assembly and / or the laser emitting and receiving component to rotate along the main scanning axis (1); The main scanning assembly comprises a reflective mirror (3) and a secondary scanning axis drive motor (6), wherein the secondary scanning axis drive motor (6) drives the reflective mirror (3) to rotate along the secondary scanning axis (2); The main scanning axis (1) and the secondary scanning axis (2) are not parallel or orthogonal, and the main and secondary scanning axes have different rotation speeds. The laser emitting and receiving optical axes of the laser emitting and receiving components are parallel to the main scanning axis (1) or the secondary scanning axis (2).

2. A three-dimensional laser scanner according to claim 1, characterized in that: The main scanning axis (1) and the secondary scanning axis (2) form an included angle α∈(0°, 45°).

3. The three-dimensional laser scanner according to claim 1, characterized in that: The angle β∈(0°, 90°) formed between the reflecting mirror surface of the reflecting mirror (3) and the secondary scanning axis (2) is .

4. The three-dimensional laser scanner according to claim 1, characterized in that: The laser emitting and receiving assembly comprises a coaxially arranged laser receiving photoelectric device (7), a laser receiving objective lens (8), a laser (9) and a laser emitting objective lens (10).

5. The three-dimensional laser scanner according to claim 4, characterized in that: The emitting end of the laser (9) faces the reflector (3); the laser emitting objective lens (10) is arranged on a side of the laser (9) close to the reflector (3); the laser receiving objective lens (8) is arranged outside the laser emitting objective lens (10), and the optical axes of the laser emitting objective lens (10) and the laser receiving objective lens (8) are parallel; and the laser receiving photoelectric device (7) is arranged on a side of the laser (9) away from the reflector (3).

6. The three-dimensional laser scanner according to claim 1, characterized in that: The laser emitting and receiving components are mounted on a base (4) and are drivably connected to a main scanning axis drive motor (5); the three-dimensional laser scanner further comprises a rotating bracket drivably connected to the main scanning axis drive motor (5); the main scanning assembly is mounted on an end of the rotating bracket away from the base (4) and is arranged opposite to the laser emitting and receiving components; The main scanning axis driving motor (5) drives the laser emitting and receiving components and the main scanning assembly to rotate along the main scanning axis (1) simultaneously or separately.

7. The three-dimensional laser scanner according to claim 6, characterized in that: When the optical axis of the laser emitting objective lens (8) is parallel to the main scanning axis (1), the base (4) and the laser emitting and receiving components are fixed during scanning; the main scanning axis driving motor (5) drives the main scanning assembly to rotate around the main scanning axis (1) for scanning, and at the same time, the secondary scanning axis driving motor (6) drives the reflector (3) to rotate around the secondary scanning axis (2), thereby completing three-dimensional scanning.

8. The three-dimensional laser scanner according to claim 6, characterized in that: When the optical axis of the laser emitting objective lens (8) is parallel to the secondary scanning axis (2), the base (4) remains stationary during scanning; the main scanning axis motor (5) drives the main scanning assembly and the laser emitting and receiving components to rotate and scan around the main scanning axis (1), while the secondary scanning axis drive motor (6) drives the reflector (3) to rotate around the secondary scanning axis (2), thereby completing three-dimensional scanning.

9. The three-dimensional laser scanner according to claim 1, characterized in that: The main scanning assembly is installed in the base (4) and is drivingly connected to the main scanning axis driving motor (5); The three-dimensional laser scanner further comprises a mounting bracket fixedly connected to the base (4); the laser emitting and receiving components are arranged at an end of the mounting bracket away from the base (4) and arranged opposite to the main scanning assembly.

10. The three-dimensional laser scanner according to claim 9, characterized in that: During scanning, the laser emitting objective lenses (10) of the laser emitting and receiving components are respectively adjusted to be parallel to the main scanning axis (1) or the secondary scanning axis (2); the main scanning assembly is driven by the main scanning axis driving motor (5) to rotate and scan along the main scanning axis (1); and the reflective mirror (3) is driven by the secondary scanning axis driving motor (6) to rotate along the rotating secondary scanning axis (2), thereby completing three-dimensional scanning.

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