Transmitting module, scanning module, optical system and laser radar

Abstract

The utility model provides a transmitting module, a scanning module, an optical system and a laser radar, and relates to the technical field of laser ranging. The transmitting module comprises a plurality of optical fiber lasers, a first concave lens and a first convex lens, the plurality of optical fiber lasers are used for transmitting laser beams, and the first concave lens and the first convex lens are sequentially arranged on a propagation path of the laser beams. The scanning module comprises a first wedge-shaped prism and a second wedge-shaped prism which are rotatably arranged, and the rotating speed of the first wedge-shaped prism is larger than that of the second wedge-shaped prism. The optical system comprises a receiving module, the transmitting module and the scanning module. When the optical system is applied to the laser radar, due to the fact that the laser beam is higher in power, smaller in divergence angle, more concentrated in energy and high in scanning precision, the laser radar is higher in resolution ratio and longer in surveying and mapping distance, and the target of ultra-long-distance high-precision surveying and mapping can be achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of laser ranging, and in particular to a transmitting module, a scanning module, an optical system and a laser radar. Background Art

[0002] Most of the existing lidars use multiple EELs (Edge-Emitting Lasers) or VCSLEs (Vertical-Cavity Surface-Emitting Lasers) arranged in a linear array as the laser source, and use multiple small and medium-sized lenses as the emission collimation and receiving convergence system. At the same time, a prism and galvanometer, galvanometer and galvanometer, and micro-galvanometer scanning method are used to achieve two-dimensional scanning, and finally a linear array APD (Avalanche Photo Diode) or a linear array SiPM (Silicon photomultiplier) is used to realize echo signal reception.

[0003] However, this type of lidar can only perform short-range mapping and has low resolution. Utility Model Content

[0004] In order to solve the problem that the existing laser radar can only perform short-range mapping and has low resolution, one of the purposes of the utility model is to provide a transmitting module.

[0005] The utility model provides the following technical solutions:

[0006] A transmitting module comprises a fiber laser, a first concave lens and a first convex lens. The fiber laser is provided in plurality and each of the fiber lasers is used to transmit a laser beam. The first concave lens and the first convex lens are sequentially arranged on a propagation path of the laser beam.

[0007] As a further optional solution for the emission module, the first concave lens is a moon-shaped concave lens, the concave surface of the first concave lens faces the first convex lens, and the first convex lens is a double convex lens.

[0008] As a further optional solution for the emission module, the concave surface of the first concave lens is fitted with the convex surface of the first convex lens facing the first concave lens, and the first concave lens is bonded to the first convex lens.

[0009] Another object of the present invention is to provide a scanning module.

[0010] The utility model provides the following technical solutions:

[0011] A scanning module comprises a first wedge-shaped prism and a second wedge-shaped prism which are rotatably arranged, wherein the rotation speed of the first wedge-shaped prism is greater than the rotation speed of the second wedge-shaped prism.

[0012] As a further optional solution for the scanning module, the rotation speed of the first wedge-shaped prism is 1400-5800 r / min, and the rotation speed of the second wedge-shaped prism is 180-540 r / min.

[0013] Another object of the utility model is to provide an optical system.

[0014] The utility model provides the following technical solutions:

[0015] An optical system comprises a receiving module, the transmitting module and the scanning module.

[0016] As a further optional scheme for the optical system, the receiving module includes a second convex lens, a third convex lens, a second concave lens and a fourth convex lens, and the second convex lens, the third convex lens, the second concave lens and the fourth convex lens are arranged in sequence on the propagation path of the reflected light beam of the laser beam.

[0017] As a further optional solution for the optical system, the second convex lens and the third convex lens are both plano-convex lenses, and the plane of the second convex lens is arranged opposite to the plane of the third convex lens.

[0018] As a further optional solution for the optical system, the plane of the second convex lens is fitted with the plane of the third convex lens, and the second convex lens is bonded to the third convex lens.

[0019] As a further optional solution for the optical system, the second concave lens is a double concave lens, and the fourth convex lens is a double convex lens.

[0020] As a further optional scheme for the optical system, the transmitting module also includes a first reflector and a second reflector, the first convex lens, the first reflector and the second reflector are arranged in sequence on the propagation path of the laser beam, and the second reflector is located between the scanning module and the receiving module.

[0021] Another object of the present utility model is to provide a laser radar.

[0022] The utility model provides the following technical solutions:

[0023] A laser radar comprises the above optical system.

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

[0025] In the above optical system, the transmitting module adopts a fiber laser as the laser source, making full use of the characteristics of high power and concentrated energy of the laser beam emitted by the fiber laser, and cooperates with the first concave lens and the first convex lens arranged in sequence to collimate the laser beam, thereby forming a nearly circular Gaussian spot, which has the advantages of high power, very small divergence angle and concentrated energy.

[0026] The collimated laser beam passes through the scanning module to scan the surveying area. Since the rotation speed of the first wedge-shaped prism in the scanning module is greater than that of the second wedge-shaped prism, a petal-shaped scanning path is formed, so a limited number of laser beams can be used to achieve sufficient scanning accuracy. During the scanning process, the reflected light beam passes through the scanning module and irradiates the receiving module, which receives the echo signal.

[0027] When the above optical system is applied to LiDAR, due to the higher power, smaller divergence angle, more concentrated energy and high scanning accuracy of the laser beam, the LiDAR has higher resolution and longer mapping distance, and can achieve the goal of high-precision mapping at ultra-long distances.

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 A schematic diagram of the overall structure of an optical system provided by an embodiment of the utility model is shown;

[0031] Figure 2 A front view of an optical system provided by an embodiment of the utility model is shown;

[0032] Figure 3 An optical path diagram of an emission module provided by an embodiment of the utility model is shown;

[0033] Figure 4 A schematic diagram of a scanning path of a scanning module provided by an embodiment of the utility model is shown;

[0034] Figure 5 The optical path diagram of a receiving module in an optical system provided by an embodiment of the utility model is shown.

[0035] Description of main component symbols:

[0036] 100-transmitting module; 110-fiber laser; 120-first concave lens; 130-first convex lens; 140-first reflector; 150-second reflector; 200-scanning module; 210-first wedge-shaped prism; 220-second wedge-shaped prism; 300-receiving module; 310-second convex lens; 320-third convex lens; 330-second concave lens; 340-fourth convex lens; 350-filter; 360-photodetector. DETAILED DESCRIPTION

[0037] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0038] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. In contrast, when an element is referred to as being "directly on" another element, there is no intermediate element. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0039] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of the template herein are only for the purpose of describing specific embodiments 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.

[0042] In some embodiments, please refer to Figure 1 and Figure 2 , this embodiment provides a transmitting module 100, which is applied to the optical system of a laser radar.

[0043] Please combine Figure 3 Specifically, the emission module 100 includes a fiber laser 110 , a first concave lens 120 and a first convex lens 130 .

[0044] There are multiple fiber lasers 110, and each of the multiple fiber lasers 110 is used to emit a laser beam. Accordingly, the first concave lens 120 and the first convex lens 130 are sequentially arranged on the propagation path of the laser beam.

[0045] In the above optical system, the transmitting module 100 adopts the fiber laser 110 as the laser source, making full use of the characteristics of high power and concentrated energy of the laser beam emitted by the fiber laser 110, and cooperates with the first concave lens 120 and the first convex lens 130 arranged in sequence to collimate the laser beam, so as to form a nearly circular Gaussian spot, which has the advantages of high power, very small divergence angle and concentrated energy.

[0046] Because the laser beam has higher power, smaller divergence angle, and more concentrated energy, the lidar has higher resolution and longer mapping distance, and can achieve the goal of high-precision mapping over ultra-long distances.

[0047] In some embodiments, the number of the fiber lasers 110 is eight, and the wavelength of the laser beam emitted by the fiber laser 110 is 1550 nm.

[0048] The emission module 100 using multiple fiber lasers 110 is small in size and has a more compact structure, making it easy to assemble and carry.

[0049] In contrast, existing lidars use linear array EEL or linear array VCSLE as laser sources, which have large structural dimensions and are inconvenient to assemble and carry.

[0050] In some embodiments, the first concave lens 120 is a meniscus lens. The concave surface of the first concave lens 120 faces the first convex lens 130, and the convex surface of the first concave lens 120 faces the fiber laser 110. In addition, the first convex lens 130 is a biconvex lens.

[0051] Furthermore, the concave surface of the first concave lens 120 is bonded to the convex surface of the first convex lens 130 facing the first concave lens 120 , and the first concave lens 120 and the first convex lens 130 are bonded and fixed to form a double cemented lens.

[0052] In some embodiments, please refer to Figure 1 and Figure 2 This embodiment also provides a scanning module 200, which is applied to the optical system of laser radar.

[0053] Specifically, the scanning module 200 includes a first wedge-shaped prism 210 and a second wedge-shaped prism 220 that are rotatably disposed.

[0054] The rotation speed of the first wedge-shaped prism 210 is greater than the rotation speed of the second wedge-shaped prism 220 .

[0055] Please combine Figure 4 When in use, the collimated laser beam passes through the scanning module 200 to scan the surveying area. Since the rotation speed of the first wedge-shaped prism 210 in the scanning module 200 is greater than the rotation speed of the second wedge-shaped prism 220, a petal-shaped scanning path is formed, so a limited number of laser beams can be used to achieve sufficient scanning accuracy, and the resolution of the laser radar can also be improved, and the surveying distance of the laser radar can be increased, which is conducive to achieving the goal of ultra-long-distance high-precision surveying.

[0056] Exemplarily, the first wedge-shaped prism 210 and the second wedge-shaped prism 220 are rotated separately to realize a quasi-circular scanning area of ​​40° horizontally and 40° vertically.

[0057] Compared with the conventional scanning method using a galvanometer, the scanning module 200 has sufficient scanning time, a petal-shaped scanning path, a point cloud that covers the entire field of view, and a higher resolution.

[0058] In addition, by controlling the rotation speed ratio of the first wedge-shaped prism 210 and the second wedge-shaped prism 220 , different scanning forms can be achieved.

[0059] In some specific implementations, the rotation speed of the first wedge-shaped prism is 1400-5800 r / min, and the rotation speed of the second wedge-shaped prism is 180-540 r / min.

[0060] Optionally, the rotation speed of the first wedge prism may be 1400 r / min, 3000 r / min, 5800 r / min or any value between 1400-5800 r / min.

[0061] Optionally, the rotation speed of the second wedge prism can be 180 r / min, 300 r / min, 540 r / min or any value between 180-540 r / min.

[0062] In some embodiments, please refer to Figure 1 and Figure 2 This embodiment also provides an optical system applied to laser radar, and the optical system is composed of a receiving module 300, the above-mentioned transmitting module 100 and the above-mentioned scanning module 200.

[0063] When in use, the laser beam emitted by the transmitting module 100 is oriented by the scanning module 200 to scan the surveying area, and the reflected light beam during the scanning process passes through the scanning module 200 and then irradiates the receiving module 300, which receives the echo signal.

[0064] See also Figure 5 Specifically, the receiving module 300 is composed of a second convex lens 310, a third convex lens 320, a second concave lens 330, a fourth convex lens 340, a filter 350 and a photodetector 360, and the second convex lens 310, the third convex lens 320, the second concave lens 330, the fourth convex lens 340, the filter 350 and the photodetector 360 are sequentially arranged on the propagation path of the reflected light beam of the laser beam.

[0065] When in use, the second convex lens 310, the third convex lens 320, the second concave lens 330 and the fourth convex lens 340 arranged in sequence can converge the reflected light beams of each laser beam. Subsequently, the filter 350 filters out stray light of other bands to improve the signal-to-noise ratio of the entire optical system, thereby increasing the ranging capability. Finally, each reflected light beam converges at different positions of the photodetector 360, and the photodetector 360 receives the echo signal.

[0066] Compared with the existing laser radar that uses multiple small and medium-sized lenses as the receiving and converging system, the above-mentioned receiving module 300 uses a large-aperture second convex lens 310, a third convex lens 320, a second concave lens 330 and a fourth convex lens 340, which can simultaneously receive the reflected light beams of each laser beam, and can receive stronger echo signals, which also improves the surveying distance.

[0067] In addition, although the apertures of the second convex lens 310, the third convex lens 320, the second concave lens 330 and the fourth convex lens 340 are larger than those of small and medium-sized lenses, their number is smaller, making the overall structure of the receiving module 300 smaller, which is conducive to reducing the volume of the entire optical system.

[0068] In some embodiments, the second convex lens 310 and the third convex lens 320 are both plano-convex lenses. The plane of the second convex lens 310 is arranged opposite to the plane of the third convex lens 320 , the convex surface of the second convex lens 310 faces the scanning module 200 , and the convex surface of the third convex lens 320 faces the second concave lens 330 .

[0069] Furthermore, the plane of the second convex lens 310 is aligned with the plane of the third convex lens 320, and the second convex lens 310 and the third convex lens 320 are bonded and fixed to form a double cemented lens.

[0070] In some embodiments, the second concave lens 330 is a bi-concave lens, and the fourth convex lens 340 is a bi-convex lens.

[0071] Please refer again Figure 1 and Figure 2 Furthermore, the transmitting module 100 also includes a first reflector 140 and a second reflector 150 .

[0072] The first concave lens 120 , the first convex lens 130 , the first reflector 140 and the second reflector 150 are sequentially arranged on the propagation path of the laser beam, and the second reflector 150 is located between the scanning module 200 and the receiving module 300 .

[0073] When in use, the laser beam emitted by the fiber laser 110 is collimated by the first concave lens 120 and the first convex lens 130 and then irradiated on the first reflector 140, and then reflected by the first reflector 140 to the second reflector 150, and then reflected by the second reflector 150 to the scanning module 200. The scanning module 200 adjusts the direction of the laser beam to scan the surveying area.

[0074] At the same time, the reflected light beam in the scanning process passes through the scanning module 200 in the opposite direction and irradiates the receiving module 300 , and the receiving module 300 receives the echo signal.

[0075] Therefore, the first reflector 140 and the second reflector 150 are provided so that the transmitting module 100 and the receiving module 300 can scan the module 200 together, thereby making the arrangement of the optical system compact and the overall structure small in volume, thereby achieving miniaturization and lightness of the structure.

[0076] In some specific embodiments, the first concave lens 120, the first convex lens 130 and the first reflector 140 are arranged along a first direction, which is shown as the X direction in the figure, and the fiber laser 110 emits a laser beam along the X direction. In addition, the receiving module 300 and the scanning module 200 are also arranged along the X direction.

[0077] At this time, the reflection surface of the first reflection mirror 140 forms an angle of 45° with the X direction, and the reflection surface of the second reflection mirror 150 is parallel to the reflection surface of the first reflection mirror 140 .

[0078] In summary, the above optical system uses the fiber laser 110 as a laser source, uses the first concave lens 120 and the first convex lens 130 to collimate the laser beam emitted by the fiber laser 110, uses the first wedge prism 210 and the second wedge prism 220 as the scanning module 200, and uses the large-aperture second convex lens 310, the third convex lens 320, the second concave lens 330 and the fourth convex lens 340 to simultaneously receive the reflected light beams of each laser beam.

[0079] Among them, the laser beam emitted by the fiber laser 110 has high power and concentrated energy. After being collimated by the first concave lens 120 and the first convex lens 130, a nearly circular Gaussian spot can be formed. In other words, the collimated laser beam has high power, a very small divergence angle, and concentrated energy. Even if it is irradiated on an object at a distance, the reflected light beam reflected to the receiving module 300 has sufficiently high energy. At the same time, the receiving module 300 uses a large-aperture lens, which can receive a stronger echo signal. Therefore, the surveying and mapping distance of the above optical system is greatly improved.

[0080] In addition, the divergence angle of the collimated laser beam is very small, and combined with the petal-shaped scanning path of the first wedge-shaped prism 210 and the second wedge-shaped prism 220, the scanning accuracy is higher, so that the resolution of the above optical system is greatly improved.

[0081] In short, the above optical system overcomes the defects of existing laser radar that it can only perform close-range mapping and has low resolution, while also having the advantage of a compact structure.

[0082] This embodiment also provides a laser radar, including the above-mentioned optical system, which can achieve high-precision mapping over ultra-long distances.

[0083] In all examples shown and described herein, any specific values ​​should be interpreted as merely exemplary and not as limiting, and thus other examples of the exemplary embodiments may have different values.

[0084] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0085] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A transmitting module, characterized in that: It comprises a fiber laser, a first concave lens and a first convex lens. There are a plurality of fiber lasers, each of which is used to emit a laser beam. The first concave lens and the first convex lens are sequentially arranged on a propagation path of the laser beam.

2. The transmitting module according to claim 1, characterized in that: The first concave lens is a meniscus lens, the concave surface of the first concave lens faces the first convex lens, and the first convex lens is a biconvex lens.

3. The transmitting module according to claim 2, characterized in that: The concave surface of the first concave lens is bonded to the convex surface of the first convex lens facing the first concave lens, and the first concave lens is bonded to the first convex lens.

4. A scanning module, characterized in that: The invention comprises a first wedge-shaped prism and a second wedge-shaped prism which are rotatably arranged, wherein the rotation speed of the first wedge-shaped prism is greater than the rotation speed of the second wedge-shaped prism; The rotation speed of the first wedge-shaped prism is 1400-5800 r / min, and the rotation speed of the second wedge-shaped prism is 180-540 r / min.

5. An optical system, characterized in that: It comprises a receiving module, the transmitting module described in claim 1, 2 or 3, and the scanning module described in claim 4.

6. The optical system according to claim 5, characterized in that The receiving module includes a second convex lens, a third convex lens, a second concave lens and a fourth convex lens, and the second convex lens, the third convex lens, the second concave lens and the fourth convex lens are sequentially arranged on the propagation path of the reflected light beam of the laser beam.

7. The optical system according to claim 6, characterized in that The second convex lens and the third convex lens are both plano-convex lenses, and the plane of the second convex lens is arranged opposite to the plane of the third convex lens.

8. The optical system according to claim 7, characterized in that The plane of the second convex lens is in contact with the plane of the third convex lens, and the second convex lens is bonded to the third convex lens.

9. The optical system according to claim 6, characterized in that The second concave lens is a biconcave lens, and the fourth convex lens is a biconvex lens.

10. The optical system according to any one of claims 5 to 9, characterized in that: The transmitting module also includes a first reflector and a second reflector. The first convex lens, the first reflector and the second reflector are sequentially arranged on the propagation path of the laser beam, and the second reflector is located between the scanning module and the receiving module.

11. A laser radar, characterized in that: An optical system comprising any one of claims 5-10.

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