CN218896188U

CN218896188U - Receiving and transmitting device of single-line laser radar

Info

Publication number: CN218896188U
Application number: CN202222449688.4U
Authority: CN
Inventors: 朱天凤; 徐彬; 袁山山; 王丽; 罗海燕
Original assignee: Jiangxi Shangke Jixing Optoelectronic Technology Co ltd
Current assignee: Jiangxi Shangke Jixing Optoelectronic Technology Co ltd
Priority date: 2022-09-16
Filing date: 2022-09-16
Publication date: 2023-04-21
Anticipated expiration: 2032-09-16

Abstract

The utility model relates to a receiving and transmitting device of a single-line laser radar, which comprises a light emitting unit, a receiving unit and a scanning unit, wherein the light emitting unit comprises a laser, a ball column lens and a first aspheric mirror which are sequentially arranged with an optical axis, the receiving unit comprises a special reflecting mirror, a second aspheric mirror and a sensor, the special reflecting mirror is arranged on an optical path of the light emitting unit in a backward inclined mode, a light passing hole is formed in the middle position of the special reflecting mirror, the lower surface of the special reflecting mirror is a reflecting surface, the second aspheric mirror and the sensor are sequentially arranged on a reflecting optical path of the lower surface of the special reflecting mirror, the light emitting unit and the receiving unit share the optical axis through the special reflecting mirror to form a light receiving and transmitting coaxial optical path, and the scanning unit comprises a rotary reflecting mirror which is arranged on the optical path of the light emitting unit in an inclined mode. The utility model uses the special reflector, reduces the light beam loss and improves the receiving and transmitting efficiency and the measuring range on the basis of not increasing the cost.

Description

Receiving and transmitting device of single-line laser radar

Technical Field

The utility model relates to a receiving and transmitting device of a single-line laser radar, and belongs to the technical field of laser measurement.

Background

Laser ranging is a relatively common ranging method at present, and laser radars comprise single-line laser radars and multi-line laser radars. The single-line laser radar realizes the scanning of targets by mechanical rotation, and the scanning angles are 270 degrees, 360 degrees and the like. Single-line lidar generally uses two optical structures, one of which is a coaxial transceiving structure and the other of which is a different coaxial transceiving structure. Because the optical structure of the transceiver is more beneficial to the miniaturization of the structure, the blind area is relatively small, and therefore, most of single-line laser radars adopt the structure form of the transceiver.

Fig. 1 is a schematic diagram of a common optical path of a transceiver. The laser 1-1, the lens 1-2 and the semi-reflective and semi-transparent lens 1-3 form a light-emitting unit, the lens 1-4 and the sensor 1-5 form a light-receiving unit, and the lens 1-6 is the target. After the laser light emitted by the laser 1-1 is collimated by the lens 1-2, a laser beam 1-7 with a smaller divergence angle is obtained. While the laser beam passes through the half mirror 1-3, part of the laser beam passes through the mirror, and the other part of the laser beam 1-8 is reflected elsewhere. The laser beam 1-9 reflected by the target 1-6, a part of which is reflected by the half mirror 1-3 into the focusing lens 1-4 and finally into the sensor 1-5. Some of the reflected light 1-9 also directly passes through the half-reflecting half-transmitting lens, namely the laser beam 1-10. It can be seen that the half-reflecting half-transmitting mirror in the structure can consume a part of light beams when the light beams pass through, which is not beneficial to improving the receiving and transmitting efficiency.

The coaxial mode of receiving and transmitting has a certain blind area although the blind area is relatively smaller. A typical transceive coaxial radar has almost no signal light back to the receiving device due to the blockage of the transmitting device by light diffusely reflected from the target within a target distance Lei Daxiao of 300 mm. In order to increase the measurement range of the radar, it is necessary to reduce the measurement blind area.

There are also some studies in the prior art to reduce the blind measurement area, for example, in the utility model of the grant publication CN 211061696U, by distributing two sets of laser transmitting modules on two sides of the laser receiving module, to reduce the blind area at the near end of the lidar system. The disadvantage of this approach is that two sets of transmit light paths are required, increasing cost.

Disclosure of Invention

The technical problem to be solved by the utility model is to provide the receiving and transmitting device of the single-line laser radar, which can realize the coaxial receiving and transmitting of the optical path, reduce the light beam loss and improve the receiving and transmitting efficiency.

In order to solve the problems, the utility model adopts the following technical scheme:

the receiving and transmitting device of the single-line laser radar comprises a light emitting unit, a receiving unit and a scanning unit, wherein the light emitting unit comprises a laser, a ball column lens and a first aspheric mirror which are sequentially arranged with an optical axis, the receiving unit comprises a special reflecting mirror, a second aspheric mirror and a sensor,

the special reflecting mirror is arranged on the light path of the transmitting unit in a backward tilting way, the middle position of the special reflecting mirror is provided with a light-passing hole, the lower surface of the special reflecting mirror is a reflecting surface, the second aspheric mirror and the sensor are sequentially arranged on the reflecting light path of the lower surface of the special reflecting mirror, the light-emitting unit and the receiving unit share the optical axis through the special lens to form a light path with a coaxial receiving and transmitting function,

the scanning unit comprises a rotating mirror controlled by a motor, and the rotating mirror is obliquely arranged on the light path of the light-emitting unit.

Further, the special reflecting mirror and the rotary reflecting mirror form an included angle of 45 degrees with the light path of the transmitting unit.

Further, an extension part is arranged at the top of the special reflecting mirror, and a high reflection film is plated on the lower surface of the extension part, so that part of diffuse reflection light can be reflected into the receiving unit.

Further, an elbow is fixedly arranged on the reflecting surface of the rotary reflecting mirror, one end of the elbow is used for passing through the collimated incident laser beam, and the other end of the elbow is used for passing through the collimated laser beam reflected by the rotary reflecting mirror.

Further, the aperture of the light passing hole is not smaller than the diameter of the laser beam collimated by the first aspheric mirror.

The working principle of the utility model is that the spherical cylindrical lens carries out fast axis compression on laser emitted by the laser, then the laser is collimated by the first aspheric mirror, and the collimated light beam passes through the light passing hole of the special reflector and reaches the rotary reflector. The rotary reflecting mirror can rotate 360 degrees under the control of a motor, and reflects laser to a target for scanning. The laser reflected from the surface of the target object enters the lower surface of the special reflector after being reflected by the rotary reflector, and enters the second aspheric mirror after being reflected, and finally the laser is converged into the sensor. The photoelectric sensor can convert the optical signal into a current signal and output the current signal, and finally the electric signal is input into the CPU, and the distance between surrounding objects is calculated according to an optical time flight method, so that the scanning of the surrounding environment is completed.

The light passing hole of the special reflecting mirror does not influence the transmission of the collimated light. The special reflector is used for replacing the half-reflecting half-lens with the coaxial receiving and transmitting function, so that the loss of each time of laser passing through the half-reflecting half-lens is reduced, and the receiving and transmitting efficiency is improved; the lower surface of the extension part of the special reflector is plated with a high reflection film, so that diffuse reflection light rays with the target at 50-300mm can be reflected into the receiving unit; the bent pipe is fixed on the rotary reflecting mirror, so that stray light can be reduced.

In summary, compared with the prior art, the utility model has the beneficial effects that:

1. the utility model uses the special reflector to replace the half-reflecting half-lens with coaxial receiving and transmitting, reduces the loss of each time the laser passes through the half-reflecting half-lens, improves the receiving and transmitting efficiency, reduces the light beam loss on the basis of not increasing the cost, and improves the receiving and transmitting efficiency.

2. According to the utility model, the side face blind area of the laser radar can be reduced and the measuring range can be increased by arranging the extension part of the special reflector, and the extension part of the special reflector does not occupy the position of the light-transmitting light path and does not reduce the light receiving efficiency.

Drawings

Fig. 1 is a schematic diagram of a common optical path of a transceiver in the prior art.

Fig. 2 is a schematic structural diagram of an embodiment of the present utility model.

Fig. 3 is a schematic structural diagram of a special reflector according to the present utility model.

Fig. 4 is a schematic view of an optical path for reducing a dead zone according to an embodiment of the present utility model.

Fig. 5 is a schematic diagram showing connection between a rotary mirror and a motor according to the present utility model.

Detailed Description

The utility model is described in further detail below with reference to the drawings and the specific examples. The objects, technical solutions and advantages of the present utility model will become more apparent from the following description. It should be noted that the described embodiments are preferred embodiments of the utility model, and not all embodiments.

Referring to fig. 2, a transceiver of a single-line laser radar includes a light emitting unit, a receiving unit and a scanning unit, wherein the light emitting unit includes a laser 1, a ball lens 2 and a first aspherical mirror 3 which are sequentially arranged with an optical axis, and the receiving unit includes a special reflecting mirror 4, a second aspherical mirror 6 and a sensor 7.

Referring to fig. 3, the special reflector 4 is disposed on the optical path of the emission unit in a backward inclined manner by 45 °, and a light-passing hole 4-2 is formed in the middle of the special reflector 4, and the aperture is 5mm for passing the collimated laser 11. The aperture of the light passing hole 4-2 is not smaller than the diameter of the laser beam collimated by the first aspheric mirror 3.

The lower surface of the special reflecting mirror 4 is a reflecting surface for reflecting the signal light 12 coming back from the target. The second aspheric mirror 6 and the sensor 7 are sequentially arranged on a reflection light path on the lower surface of the special reflecting mirror, and the light emitting unit and the receiving unit share an optical axis through the special lens 4 to form a light path with coaxial receiving and transmitting. The scanning unit comprises a rotating mirror 5 controlled by a motor 13 as shown in fig. 5, the rotating mirror 5 being arranged obliquely on the light path of the lighting unit at an angle of 45 ° to the light path. The back of the rotary mirror 5 is connected to a motor shaft 13 a. An elbow pipe 8 is fixedly arranged on the reflecting surface of the rotary reflecting mirror 5, one end of the elbow pipe is used for passing through the collimated incident laser beam, and the other end of the elbow pipe is used for passing through the collimated laser beam reflected by the rotary reflecting mirror 5. The included angle between the bent pipe 8 and the mirror surface of the rotary reflecting mirror 5 is 45.

The scanning unit is mounted in a window 9 and the light emitting unit and the receiving unit are arranged in a housing 10.

The laser 1 is a semiconductor laser, the divergence angle of the fast axis is larger, and the first spherical cylindrical lens 2 is used for compressing the fast axis beam once, and then collimating the laser beam through the aspherical mirror to obtain the laser beam 11. The collimated laser beam 11 passes through the light-passing hole 4-2 of the special mirror 4 and is incident on the rotating mirror 5. The surface of the rotary reflecting mirror 5 is provided with a reflecting layer, so that most of laser can be reflected, and meanwhile, the rotary reflecting mirror is controlled by the motor 13 and can rotate by 360 degrees, so that the emitted laser can irradiate surrounding objects. The arrangement of the bent pipe can play a role in reducing stray light.

Referring to fig. 3 and 4, an extension portion 4-1 is disposed at the top of the special reflector 4, a reflective film is coated on the lower surface of the extension portion 4-1, the reflective angle is smaller than that of the special reflector 4, and the diffuse reflection light 14 with the target at 50-300mm can be reflected into the receiving unit. The extension 4-1 is a part of a special reflector, and does not occupy the position of the light-transmitting path, and does not reduce the efficiency of light receiving.

The above description is merely illustrative of the preferred embodiments of the present utility model and is not intended to limit the scope of the present utility model, and it is obvious that any person skilled in the art can easily think of alternatives or modifications based on the above embodiments to obtain other embodiments, which are all covered by the scope of the present utility model.

Claims

1. A receiving and transmitting device of a single-line laser radar is characterized in that:

comprises a light-emitting unit, a receiving unit and a scanning unit, wherein the light-emitting unit comprises a laser, a ball column lens and a first aspheric mirror which are sequentially arranged with an optical axis, the receiving unit comprises a special reflecting mirror, a second aspheric mirror and a sensor,

2. The single-wire lidar transmitting-receiving device according to claim 1, wherein:

the special reflecting mirror and the rotary reflecting mirror form an included angle of 45 degrees with the light path of the transmitting unit.

3. The single-wire lidar transmitting-receiving device according to claim 1 or 2, wherein:

the top of the special reflector is provided with an extension part, and the lower surface of the extension part is plated with a high reflection film, so that part of diffuse reflection light can be reflected into the receiving unit.

4. The single-wire lidar transmitting-receiving device according to claim 1 or 2, wherein:

and an elbow is fixedly arranged on the reflecting surface of the rotary reflecting mirror, one end of the elbow is used for passing through the collimated incident laser beam, and the other end of the elbow is used for passing through the collimated laser beam reflected by the rotary reflecting mirror.

5. The single-wire lidar transmitting-receiving device according to claim 1, wherein:

the aperture of the light passing hole is not smaller than the diameter of the laser beam collimated by the first aspheric mirror.