CN114814791A

CN114814791A - Laser radar

Info

Publication number: CN114814791A
Application number: CN202210611079.6A
Authority: CN
Inventors: 谢双伟; 龚田; 赵晨行
Original assignee: Suzhou Ruixin Microsystem Technology Co ltd
Current assignee: Suzhou Ruixin Microsystem Technology Co ltd
Priority date: 2022-05-31
Filing date: 2022-05-31
Publication date: 2022-07-29

Abstract

The invention discloses a laser radar.A first micro-vibration mirror reflects light emitted by a transmitting component to a first reflection element, the first reflection element reflects the light to a second micro-vibration mirror, the second micro-vibration mirror reflects the light to enable the light to be emitted to the outside, the second micro-vibration mirror reflects light returned from the outside to a second reflection element, and the second reflection element reflects the returned light to enable the returned light to be incident to a receiving component. The reflection light propagation direction of the micro-vibration mirror is changed by swinging either one of the first micro-vibration mirror and the second micro-vibration mirror, so that the two-dimensional scanning of the light emitted by the laser radar is realized. The second micro-vibration mirror can be a one-dimensional vibration mirror, and can receive more light returned by the outside through the second micro-vibration mirror with a larger transmitting surface, so that the light energy received by the laser radar can be improved.

Description

Laser radar

Technical Field

The invention relates to the field of optical systems, in particular to a laser radar.

Background

In a laser radar, a Micro-Electro-Mechanical System (MEMS) is applied, that is, a Micro galvanometer is used to rapidly scan a target area in two dimensions. For the scheme of realizing two-dimensional scanning by adopting a two-dimensional micro-vibration mirror, the scheme is limited by the current technological level, the two-dimensional micro-vibration mirror is difficult to be large-sized, the small size of the micro-vibration mirror has little influence on laser radar emitted light, but greatly influences the received return light, and the size of the received return light energy is directly determined by the area of the micro-vibration mirror; in addition, in some laser radars, because the reflector is arranged in the receiving light path, the light energy received by the receiving detector is also low; the weak energy of the return light received by the laser radar results in a low signal-to-noise ratio, is easily disturbed, and allows a short detection distance.

Disclosure of Invention

The invention provides a laser radar, which can receive light returned from the outside and can receive more light returned from the outside and can improve the received light energy by arranging a micro-vibration mirror used for receiving the light returned from the outside and making the returned light incident to a receiving component to have a larger reflection surface.

In order to achieve the purpose, the invention provides the following technical scheme:

a laser radar comprises a transmitting assembly, a first micro-vibration mirror, a second micro-vibration mirror, a first reflecting element, a second reflecting element and a receiving assembly, wherein the first micro-vibration mirror is used for reflecting light emitted by the transmitting assembly to the first reflecting element, the first reflecting element is used for reflecting the light to the second micro-vibration mirror, the second micro-vibration mirror is used for reflecting the light to enable the light to be emitted to the outside and reflecting the light returned from the outside to the second reflecting element, and the second reflecting element is used for reflecting returning light to enable the returning light to be incident to the receiving assembly;

and either one of the first micro-vibration mirror and the second micro-vibration mirror changes the reflected light propagation direction of the micro-vibration mirror through swinging, so that the two-dimensional scanning of the light emitted by the laser radar is realized.

Preferably, the reflecting surface of the second micro-galvanometer is larger than the reflecting surface of the first micro-galvanometer.

Preferably, the size of the first reflecting element is determined according to the size of the reflecting surface of the first micro-galvanometer, the rotation angle of the first micro-galvanometer and the relative position of the first micro-galvanometer and/or the size of the second reflecting element is determined according to the size of the reflecting surface of the second micro-galvanometer, the rotation angle of the second micro-galvanometer and the relative position of the second micro-galvanometer.

Preferably, the area of the first reflection element is larger than the area of the reflection surface of the first micro-galvanometer, and/or the area of the second reflection element is larger than the area of the reflection surface of the second micro-galvanometer.

Preferably, the first reflective element and the second reflective element are arranged in tandem, and the second reflective element is located on a side of the first reflective element away from the second micro-galvanometer.

Preferably, the first reflecting element and the second reflecting element are arranged in parallel, and the first reflecting element is closer to the first micro-mirror than the second reflecting element.

Preferably, the first reflective element and the second reflective element are the same reflective element.

Preferably, the reflecting surface of the first reflecting element is a plane, a concave surface or a convex surface, and the reflecting surface of the second reflecting element is a plane, a concave surface or a convex surface.

Preferably, the receiving assembly comprises a converging assembly and an array of optoelectronic devices, the converging assembly being configured to converge the received light to any optoelectronic device of the array of optoelectronic devices.

Preferably, the receiving assembly comprises a converging assembly, a reflecting element array and a photoelectric device, the converging assembly is used for converging the received light to the reflecting element array, and any reflecting element of the reflecting element array is used for reflecting the light to the photoelectric device.

In the laser radar according to the present invention, the first micro oscillating mirror reflects the light emitted from the emitting module to the first reflecting element, the first reflecting element reflects the light to the second micro oscillating mirror, the second micro oscillating mirror reflects the light to emit the light to the outside, the second micro oscillating mirror reflects the light returning from the outside to the second reflecting element, and the second reflecting element reflects the returning light to make the returning light enter the receiving module. The reflection light propagation direction of the micro-vibration mirror is changed by swinging either one of the first micro-vibration mirror and the second micro-vibration mirror, so that the two-dimensional scanning of the light emitted by the laser radar is realized. The second micro-vibration mirror can be a one-dimensional vibration mirror, and can receive more light returned from the outside by setting the second micro-vibration mirror with a larger reflecting surface, so that the light energy received by the laser radar can be improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic diagram of a laser radar according to an embodiment of the present invention;

fig. 2 is a schematic diagram of a lidar according to another embodiment of the present invention;

fig. 3 is a schematic diagram of a lidar according to another embodiment of the present invention;

fig. 4 is a schematic diagram of a lidar according to another embodiment of the present invention;

fig. 5 is a schematic diagram of a receiving assembly according to an embodiment of the invention.

Reference numerals in the drawings of the specification include:

a transmitting component-100, a first micro-galvanometer-101, a second micro-galvanometer-102 and a receiving component-105;

a first reflective element-103, a second reflective element-104, a third reflective element-106;

a first focusing assembly-107, an array of reflective elements-108, a reflective element-109, and an optoelectronic device-110. A second convergence assembly-111.

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present invention, the technical solution in the embodiment of the present invention will be clearly and completely described below with reference to the drawings in the embodiment of the present invention, and it is obvious that the described embodiment is only a part of the embodiment of the present invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, shall fall within the protection scope of the present invention.

The present embodiment provides a laser radar, and referring to fig. 1, fig. 1 is a schematic diagram of a laser radar provided in an embodiment, as shown in the figure, the laser radar includes a transmitting assembly 100, a first micro-vibration mirror 101, a second micro-vibration mirror 102, a first reflection element 103, a second reflection element 104, and a receiving assembly 105, where the first micro-vibration mirror 101 is configured to reflect light emitted by the transmitting assembly 100 to the first reflection element 103, the first reflection element 103 is configured to reflect light to the second micro-vibration mirror 102, the second micro-vibration mirror 102 is configured to reflect light to emit light to the outside, and reflect light returning from the outside to the second reflection element 104, and the second reflection element 104 is configured to reflect returning light to make returning light enter the receiving assembly 105;

either one of the first micro oscillating mirror 101 and the second micro oscillating mirror 102 changes the reflected light propagation direction of the micro oscillating mirror through swinging, so that the light emitted by the laser radar is scanned in two dimensions.

Either one of the first micro-galvanometer 101 and the second micro-galvanometer 102 can swing, and the transmission direction of the reflected light emitted by the micro-galvanometer is changed by swinging; the first micro-vibration mirror 101 and the second micro-vibration mirror 102 swing to change the propagation direction of light emitted by the laser radar and realize two-dimensional scanning of the light emitted by the laser radar. Reference is made to fig. 1. In fig. 1, a solid line with an arrow indicates a traveling direction of light emitted by the emission member 100, and a dotted line with an arrow indicates a traveling direction of light returned from the outside. In the laser radar of this embodiment, the second micro-vibration mirror 102 can be a one-dimensional vibration mirror, the one-dimensional vibration mirror can achieve a larger size, and the second micro-vibration mirror 102 having a larger reflection surface is provided to receive more light returned from the outside, so that the light energy received by the laser radar can be improved, the reduction of the signal-to-noise ratio or the interference of the light energy easily can be avoided, and the increase of the detection distance can be facilitated.

Preferably, the size of the reflection surface of the first micro-galvanometer 101 is sufficient to enable all the light emitted by the emitting assembly 100 to enter the first reflecting element 103, so as to ensure the emitting efficiency of the laser radar. In this requirement, the first micro-galvanometer 101 is preferably as small as possible, so that the laser radar has a small structure.

Preferably, the position of the first reflecting element 103 relative to the first micro-galvanometer 101 and the size of the first reflecting element 103 are such that the reflected light from the first micro-galvanometer 101 in different directions can be incident on the first reflecting element 103 during the oscillation of the first micro-galvanometer 101, and the first reflecting element 103 can reflect all the reflected light from the first micro-galvanometer 101 in different directions to the second micro-galvanometer 102. In practical applications, the size of the first reflective element 103 can be determined by combining the size of the reflective surface of the first micro-galvanometer 101, the rotation angle of the first micro-galvanometer 101, and the relative position of the two. The area of the first reflective element 103 is larger than the area of the reflective surface of the first micro-mirror 101, so that light in different directions of the first micro-mirror 101 can be reflected, and the first reflective element 103 needs to be prevented from being too large in structure.

Preferably, the position of the second micro-galvanometer 102 relative to the first reflecting element 103 and the size of the reflecting surface of the second micro-galvanometer 102 are such that the reflected light from the first reflecting element 103 in different directions can be incident on the second micro-galvanometer 102 during the swinging of the first micro-galvanometer 101 and the second micro-galvanometer 102. Preferably, the reflecting surface of the second micro-galvanometer 102 is larger than the reflecting surface of the first micro-galvanometer 101, and the size of the reflecting surface of the second micro-galvanometer 102 determines the amount of energy of the received return light because the second micro-galvanometer 102 collects the return light from the outside. Therefore, by providing the second micro-galvanometer 102 having a large reflection surface, it is possible to receive a large amount of light returned from the outside.

The position of the second reflecting element 104 relative to the second micro-galvanometer 102 and the size of the second reflecting element 104 are determined to ensure that the reflected light emitted from the second micro-galvanometer 102 in different directions can be incident on the second reflecting element 104 during the swinging process of the second micro-galvanometer 102. In practical applications, the size of the second reflective element 104 can be determined by combining the size of the reflective surface of the second micro-galvanometer 102, the rotation angle of the second micro-galvanometer 102, and the relative position of the two. The area of the second reflective element 104 may be larger than the reflective surface area of the second micro-galvanometer 102, so that during the oscillation of the second micro-galvanometer 102, the second reflective element 104 may receive the reflected light from the second micro-galvanometer 102 in different directions, and the reflected light from the second micro-galvanometer 102 in different directions can be collected to the receiving assembly 105.

In this embodiment, the arrangement of the first micro-galvanometer 101, the first reflecting element 103, the second micro-galvanometer 102, and the second reflecting element 104 is not particularly limited, and it is preferable that the laser radar has a simple and compact structure on the premise of satisfying light propagation. As an alternative, the first micro-galvanometer 101 and the second micro-galvanometer 102 may be arranged in parallel, the first reflecting element 103 and the second reflecting element 104 may be arranged in front and behind, and the second reflecting element 104 is located on the side of the first reflecting element 103 away from the second micro-galvanometer 102. As can be exemplarily seen in fig. 1, the first reflective element 103 is disposed opposite to the first micro-galvanometer 101 and the second micro-galvanometer 102, and the second reflective element 104 is disposed on a side of the first reflective element 103 away from the second micro-galvanometer 102. Wherein the angles of the first reflective element 103 and the second reflective element 104 are different. The angle of the first reflective element 103 refers to the angle of the normal of the first reflective element 103 with respect to a preset direction. The angle of the second reflective element 104 refers to the angle of the normal to the second reflective element 104 relative to a predetermined direction. In this configuration, the transmitter module 100 and the receiver module 105 may be disposed on opposite sides.

Alternatively, the angles of the first reflective element 103 and the second reflective element 104 may be the same or nearly the same. Referring to fig. 2, fig. 2 is a schematic diagram of a laser radar according to another exemplary embodiment, where as shown in the figure, a first micro-galvanometer 101 and a second micro-galvanometer 102 are arranged in parallel, a first reflective element 103 is arranged opposite to the first micro-galvanometer 101 and the second micro-galvanometer 102, and a second reflective element 104 is located on a side of the first reflective element 103 away from the second micro-galvanometer 102. Wherein the angles of the first reflective element 103 and the second reflective element 104 are approximately the same. In this configuration, the transmitting module 100 and the receiving module 105 can be disposed on the same side, which is advantageous for making the lidar compact.

As still another alternative, the first micro galvanometer 101 and the second micro galvanometer 102 may be arranged in parallel, with the first reflective element 103 and the second reflective element 104 arranged in parallel. Referring to fig. 3, fig. 3 is a schematic diagram of a lidar according to another embodiment, where a first micro-galvanometer 101 and a second micro-galvanometer 102 are arranged in parallel, a first reflective element 103 and a second reflective element 104 are arranged in parallel, the first reflective element 103 is closer to the first micro-galvanometer 101 than the second reflective element 104, and the second reflective element 104 is closer to the second micro-galvanometer 102. The angle of the first reflective element 103 and the angle of the second reflective element 104 may be set according to the propagation path of the light, and the angles of the first reflective element 103 and the second reflective element 104 may be the same or different.

Alternatively, in this embodiment, the first reflective element 103 and the second reflective element 104 may be the same reflective element. Referring to fig. 4, fig. 4 is a schematic diagram of a laser radar according to another embodiment, in which a first micro-galvanometer 101 and a second micro-galvanometer 102 are arranged in parallel, a third reflective element 106 is arranged opposite to the first micro-galvanometer 101 and the second micro-galvanometer 102, and a reflected light from the first micro-galvanometer 101 is incident on the third reflective element 106 and reflected to the second micro-galvanometer 102; the return light collected by the second micro-galvanometer 102 is incident on the third reflecting element 106, and is reflected by the third reflecting element 106 to the receiving unit 105.

In the present embodiment, the transmitting module 100 and the receiving module 105 are arranged according to the propagation path of the light, and as shown in fig. 3 or fig. 4, the receiving module 105 may be arranged in the space between the first micro-galvanometer 101 and the second micro-galvanometer 102.

In practical applications, the first micro-galvanometer 101, the first reflecting element 103, the second micro-galvanometer 102 and the second reflecting element 104 may be arranged according to the requirements of the arrangement position of the transmitting assembly 100 and the receiving assembly 105 or the requirements of the optical structure or the structural size of the laser radar.

Alternatively in each of the above embodiments, the reflective surface of the first reflective element 103 may be a plane, a concave surface, or a convex surface. The reflective surface of the second reflective element 104 may be planar, concave, or convex. The reflecting surface of the first reflecting element 103 is a plane, which helps to maintain the collimation of the emitted light and helps to ensure the transmitting efficiency of the laser radar. The concave surface of the second reflecting element 104 can converge the light returning from the second micro galvanometer 102 from the outside to the receiving component 105, which helps to reduce the volume of the receiving component 105.

Preferably, in each of the above embodiments, the first reflective element 103 or the second reflective element 104 may be plated with a high reflective film, and the corresponding wavelength of the high reflective film is matched with the wavelength of the light emitted from the emitting assembly 100, so as to improve the reflectivity, which is helpful for improving the transmitting and receiving optical efficiency of the laser radar.

In the above embodiments, the first micro-galvanometer 101 may be a one-dimensional micro-galvanometer, and the second micro-galvanometer 102 may be a one-dimensional micro-galvanometer, so that the light emitted by the laser radar is scanned in two dimensions by the swing of the first micro-galvanometer 101 and the swing of the second micro-galvanometer 102. For example, the first galvanometer 101 may be oscillated about one single axis, such as about the X-axis, and the second galvanometer 102 may be oscillated about another single axis, such as about the Y-axis, with the axes being perpendicular or approximately perpendicular.

Optionally, in each of the above embodiments, the emitting assembly 100 may include a light source and a collimating assembly for collimating light emitted from the light source. In this embodiment, the optical structure of the collimating component is not limited, and the collimating component may include, but is not limited to, a convex lens, a plano-convex lens, a concave lens, a plano-concave lens, a spherical mirror, or an aspherical mirror. The light source may be, but is not limited to, an Edge-Emitting Laser (EEL) or an array, a Vertical-Cavity Surface-Emitting Laser (VCSEL) or an array, or a fiber Laser and an array thereof divided by an optical device.

Alternatively, the receiving assembly 105 may include a converging assembly for converging received light to any one of an array of optoelectronic devices and an array of optoelectronic devices. In this embodiment, the optical structure of the converging assembly is not limited, and the received light can be converged to the optoelectronic device array. The converging component may include, but is not limited to, a convex lens, a plano-convex lens, a concave lens, a plano-concave lens, a spherical mirror, or an aspherical mirror.

Any photoelectric device of the photoelectric device array can correspond to a swing angle of the first micro-galvanometer 101 or the second micro-galvanometer 102, so that light emitted corresponding to the swing angle can be converged to the corresponding photoelectric device after returning through the outside correspondingly.

Alternatively, the receiving assembly 105 may include a converging assembly for converging received light to the array of reflective elements, any reflective element of the array of reflective elements for reflecting light to the optoelectronic device, and an optoelectronic device. In this embodiment, the optical structure of the converging component is not limited, and the received light can be converged. Any one of the reflective elements of the reflective element array may correspond to a swing angle of the first micro-galvanometer 101 or the second micro-galvanometer 102, so that light emitted corresponding to the swing angle and returning through the outside may be converged to the corresponding reflective element. Referring to fig. 5, fig. 5 is a schematic view of a receiving assembly of an embodiment, as shown in the first focusing assembly 107, the received light is focused to the reflective element array 108, and any reflective element 109 of the reflective element array 108 is used for reflecting the light out to make the light incident on the optoelectronic device 110. A second concentrating element 111 may preferably be disposed between the array of reflective elements 108 and the optoelectronic device 110, the second concentrating element 111 being for concentrating light reflected by the array of reflective elements 108 onto the optoelectronic device 110. Alternatively, the array of reflective elements 108 may be, but is not limited to, an array of digital micro-mirrors.

Optionally, in each of the above embodiments, the optoelectronic device may be, but is not limited to, an Avalanche Photodiode (APD), a Silicon photomultiplier (SiPM), or a Single-Photon detector (SPAD).

The laser radar provided by the invention is described in detail above. The principles and embodiments of the present invention are explained herein using specific examples, which are presented only to assist in understanding the method and its core concepts. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.

Claims

1. A laser radar is characterized by comprising a transmitting assembly, a first micro vibrating mirror, a second micro vibrating mirror, a first reflecting element, a second reflecting element and a receiving assembly, wherein the first micro vibrating mirror is used for reflecting light emitted by the transmitting assembly to the first reflecting element, the first reflecting element is used for reflecting the light to the second micro vibrating mirror, the second micro vibrating mirror is used for reflecting the light to enable the light to be emitted to the outside and reflecting the light returned from the outside to the second reflecting element, and the second reflecting element is used for reflecting returning light to enable the returning light to be incident to the receiving assembly;

2. The lidar of claim 1, wherein a reflective surface of the second micro-galvanometer is larger than a reflective surface of the first micro-galvanometer.

3. The lidar of claim 1, wherein the first reflective element is sized according to a size of a reflective surface of the first galvanometer, a rotation angle of the first galvanometer, and a relative position of the first and/or the second reflective element is sized according to a size of a reflective surface of the second galvanometer, a rotation angle of the second galvanometer, and a relative position of the second and/or the second galvanometer.

4. Lidar according to claim 1, wherein the area of the first reflective element is larger than the area of the reflective surface of the first micro-mirror and/or the area of the second reflective element is larger than the area of the reflective surface of the second micro-mirror.

5. The lidar of claim 1, wherein the first reflective element and the second reflective element are arranged in tandem, the second reflective element being on a side of the first reflective element remote from the second microresonator mirror.

6. The lidar of claim 1, wherein the first reflective element and the second reflective element are arranged in parallel, the first reflective element being closer to the first microresonator than the second reflective element.

7. The lidar of claim 1, wherein the first reflective element and the second reflective element are the same reflective element.

8. The lidar of claim 1, wherein the reflective surface of the first reflective element is planar, concave, or convex and the reflective surface of the second reflective element is planar, concave, or convex.

9. Lidar according to any of claims 1 to 8, wherein the receiving assembly comprises a converging assembly and an array of optoelectronic devices, the converging assembly being adapted to converge the received light to any of the optoelectronic devices of the array of optoelectronic devices.

10. The lidar of any of claims 1-8, wherein the receiving assembly comprises a converging assembly, an array of reflective elements, and an optoelectronic device, the converging assembly configured to converge the received light to the array of reflective elements, any reflective element of the array of reflective elements configured to reflect the light to the optoelectronic device.