CN114545368A

CN114545368A - Laser radar

Info

Publication number: CN114545368A
Application number: CN202210217968.4A
Authority: CN
Inventors: 刘立福; 冯洪亮; 胡小波
Original assignee: LeiShen Intelligent System Co Ltd
Current assignee: LeiShen Intelligent System Co Ltd
Priority date: 2022-03-07
Filing date: 2022-03-07
Publication date: 2022-05-27

Abstract

The invention relates to the technical field of radar detection, and particularly discloses a laser radar. The transmitting module of the laser radar transmits laser beams to a target object, the receiving module receives laser beams reflected by the target, the optical path module adjusts the paths of the laser beams transmitted to the target object and the laser beams reflected by the target object, the rotatable prism group is arranged in the optical path module to realize surface array detection of the target object, and the speed reducing mechanism is arranged between the driving motor and the prism to reduce the rotation speed of the prism, further reduce the scanning speed, increase the output torque of the driving motor, realize stable work of the laser radar in a vibration environment, avoid jitter of a cloud point image and improve the detection precision. The resonant frequency of the vibration mirror group in the light path module is not less than 1000HZ, and the laser radar is ensured to have stable and more laser beams under the condition of low rotating speed of the prism through the matching of the rotating speed of the prism and the laser radar so as to obtain more point cloud number.

Description

Laser radar

Technical Field

The invention relates to the technical field of radar detection, in particular to a laser radar.

Background

In the prior art, the transmitting module, the optical module and the receiving module of the mechanical rotating laser radar are all fixed on an outer rotor of a motor of the mechanical rotating laser radar, the moment of inertia is large, and the point cloud pattern jumping distortion is easily caused if the speed is not stable in a vibration environment.

Therefore, it is desirable to provide a lidar to solve the above technical problems.

Disclosure of Invention

The invention aims to provide a laser radar which can work stably in a vibration environment and realize area array detection of a target.

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

a lidar comprising:

the transmitting module is used for transmitting laser beams to a target object;

the receiving module is used for receiving the laser beam reflected by the target;

the optical path module is used for adjusting the paths of laser beams emitted to a target object and laser beams reflected by a target, the optical path module comprises a prism group, the prism group comprises a prism and a driving motor for driving the prism to rotate, a speed reducing mechanism is arranged between the driving motor and the prism, and the speed reducing mechanism is used for reducing the rotating speed of the prism; the resonance frequency of the vibration mirror group is not less than 1000 HZ.

As a preferable technical solution of the laser radar, the driving motor is a brushless motor, an input end of the speed reducing mechanism is in driving connection with an output shaft of the brushless motor, and an output end of the speed reducing mechanism is connected with the prism and can drive the prism to rotate.

As an optimal technical scheme of the laser radar, the outer side of the brushless motor is rotatably sleeved with a rotating shaft, the prism sleeve is arranged outside the rotating shaft and fixedly connected with the rotating shaft, and the output end of the speed reducing mechanism is connected with the rotating shaft and can drive the rotating shaft to rotate.

As a preferable aspect of the laser radar, the deceleration mechanism includes:

the sun gear is in driving connection with an output shaft of the brushless motor;

the N planetary gears are respectively meshed with the sun gear, and the planetary gears are rotatably arranged on the brushless motor; n is a positive integer;

an internal gear as an output, the planetary gear meshing with teeth on an inner circle of the internal gear.

As a preferable technical solution of the laser radar, the prism assembly further includes a speed detection component for detecting a rotational speed of the prism.

As a preferable technical solution of the laser radar, the galvanometer group includes a metal galvanometer piece, and the metal galvanometer piece can realize resonance at a frequency of not less than 1000 HZ.

As a preferable technical solution of the above laser radar, the optical path module further includes a reflecting mirror, and the reflecting mirror is disposed on a front side of the mirror group in a direction of emitting the laser beam to the target object.

As a preferable technical solution of the laser radar, the material of the metal galvanometer plate is 65Mn, and the thickness of the metal galvanometer plate is 0.15mm to 0.28 mm.

As a preferred technical solution of the above laser radar, the receiving module includes a first receiving group and a second receiving group that are coaxially disposed in sequence along the direction of the laser beam reflected by the target, the first receiving group is disposed at the rear side of the optical path module in the direction of the laser beam reflected by the target, the first receiving group is configured to collect the laser beam, and the second receiving group is configured to receive the laser beam.

As an above-mentioned laser radar's a preferred technical scheme, the emission module includes laser generator transmitting terminal, laser generator transmitting terminal set up in first receiving group with between the second receiving group, just the second receiving group laser generator transmitting terminal with the coaxial setting of first receiving group, the laser line beam of laser generator transmitting terminal transmission is worn to establish first receiving group is launched extremely the light path module.

As a preferred technical scheme of the laser radar, two emission ends of the laser generators are arranged on two sides of the prism group, and each emission end of the laser generator is correspondingly provided with a first receiving group, a second receiving group and a vibration mirror group.

The invention has the beneficial effects that:

the transmitting module of the laser radar transmits laser beams to a target object, the receiving module receives laser beams reflected by the target, the optical path module adjusts the paths of the laser beams transmitted to the target object and the laser beams reflected by the target object, the rotatable prism group is arranged in the optical path module to realize surface array detection of the target object, and the speed reducing mechanism is arranged between the driving motor and the prism to reduce the rotation speed of the prism, further reduce the scanning speed, increase the output torque of the driving motor, realize stable work of the laser radar in a vibration environment, avoid jitter of a cloud point image and improve the detection precision. Meanwhile, the resonant frequency of the vibration mirror group in the light path module is not less than 1000HZ, and the laser radar is ensured to have stable and more laser beams under the condition of low rotating speed of the prism through the matching of the resonant frequency and the rotating speed of the prism, so that more point clouds can be obtained.

Drawings

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

fig. 2 is a schematic structural diagram of a prism assembly provided in an embodiment of the present invention.

In the figure:

1. a fixing plate; 5. a control module;

21. a laser generator transmitting end;

31. a first reception group; 32. a second reception group;

41. a prism; 42. a drive motor; 431. a sun gear; 432. a planetary gear; 433. an internal gear; 44. a rotating shaft; 45. a first rotating bearing; 46. a fixed seat; 47. a second rotary bearing; 481. a metal code disc; 482. a photosensor; 49. a vibrating mirror group; 410. a mirror.

Detailed Description

In order to make the technical problems solved, technical solutions adopted and technical effects achieved by the present invention clearer, the technical solutions of the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

To among the prior art, the transmission module, optical module and the receiving module of mechanical type rotation laser radar all fix on mechanical type rotation laser radar's motor outer rotor, and inertia is bigger, under the vibrations environment, if speed is unstable, then easily arouses the problem of point cloud picture distortion of beating, and this embodiment provides a laser radar in order to solve above-mentioned technical problem.

Specifically, as shown in fig. 1 and fig. 2, the laser radar provided by the present embodiment includes a transmitting module, a receiving module, and an optical path module. The transmitting module is used for transmitting laser beams to a target object, and the receiving module is used for receiving the laser beams reflected by the target. The light path module is used for adjusting the path of the laser beam emitted to the target object and the path of the laser beam reflected by the target. The optical path module comprises a prism group and a vibrating mirror group 49, the prism group comprises a prism 41 and a driving motor 42 for driving the prism 41 to rotate, a speed reducing mechanism is arranged between the driving motor 42 and the prism 41, and the speed reducing mechanism is used for reducing the rotating speed of the prism 41; the resonant frequency of the oscillator group 49 is not less than 1000 HZ.

The laser radar that this embodiment provided sets up rotatable prism group in order to realize the face array and survey the target in the light path module, and sets up reduction gears between driving motor 42 and prism 41, has reduced prism 41's slew velocity, and then has reduced the speed of scanning to driving motor 42's output torque has been increased, has realized that laser radar can stable work in vibrations environment, avoids some cloud pictures to have the shake, has improved the precision of surveying. Meanwhile, the resonant frequency of the galvanometer group 49 in the optical path module is not less than 1000HZ, and the laser radar is ensured to have stable and more laser beams under the condition of low rotating speed of the prism 41 by matching with the rotating speed of the prism 41 so as to obtain more point clouds.

Laser radar still includes fixed plate 1, and transmission module, receiving module and light path module are all installed on fixed plate 1.

The prism 41 may be a quadrangular prism, a pentagonal prism, a hexagonal prism, etc., and is not particularly limited herein.

In the present embodiment, the driving motor 42 is preferably a brushless motor, and the brushless motor is mounted on the fixed plate 1. The input end of the speed reducing mechanism is in driving connection with the output shaft of the brushless motor, and the output end of the speed reducing mechanism is connected with the prism 41 and can drive the prism 41 to rotate. Compared with a stepping motor used in the prior art, the brushless motor has no vibration, cannot jump when rotating, further cannot cause point cloud picture shaking, is small in size, does not occupy space, and reduces production cost. In other embodiments, the driving motor 42 may also be a servo motor or a torque servo motor, which can realize low-speed and stable rotation for scanning, but the volume of the lidar is larger than that of a brushless motor, and the lidar can be designed according to actual use requirements.

In order to further reduce the volume of the laser radar and improve the compactness of the laser radar, in this embodiment, the structural characteristic of the brushless motor is utilized, the rotating shaft 44 is rotatably sleeved outside the brushless motor, the prism 41 is sleeved outside the rotating shaft 44 and is fixedly connected with the rotating shaft 44, and the output end of the speed reducing mechanism is connected with the rotating shaft 44 and can drive the rotating shaft 44 to rotate. The brushless motor drives the speed reducing mechanism, and the speed reducing mechanism drives the rotating shaft 44 to rotate relative to the brushless motor, so as to drive the prism 41 to rotate.

The rotating shaft 44 is preferably connected with the brushless motor through the first rotating bearing 45, the first rotating bearing 45 is sleeved outside the brushless motor, the inner ring of the first rotating bearing 45 is connected with the brushless motor, and the inner ring of the first rotating bearing 45 is connected with the rotating shaft 44. The number of the first rotating bearings 45 is set according to the size of the brushless motor and the rotating shaft 44 to improve the stability of the rotation of the rotating shaft 44.

In the present embodiment, the speed reducing mechanism is a planetary gear structure, and specifically includes a sun gear 431, the sun gear 431 is in driving connection with the output shaft of the brushless motor, the sun gear 431 is engaged with N planetary gears 432 along its circumferential direction, N is a positive integer. The brushless motor is used as a mounting carrier, and the N planetary gears 432 are rotatably mounted on the brushless motor. The reduction mechanism further includes an internal gear 433, and the planetary gear 432 is meshed with teeth on an inner circle of the internal gear 433. The internal gear 433 serves as an output end, and specifically, a side surface of the internal gear 433 is connected to an upper end surface of the rotating shaft 44. The brushless motor drives the sun gear 431 to rotate, and the sun gear 431 rotates to drive the planet gear 432 to rotate around the axis of the planet gear, so that the internal gear 433 is driven to rotate to drive the rotating shaft 44 to rotate. The speed reducing mechanism has good structure compactness and reduces the volume of the laser radar. In other embodiments, the speed reducing mechanism may also be a gear set structure to reduce the transmission ratio and reduce the rotation speed, and is not limited specifically herein.

In order to facilitate the installation of the planetary gear 432, the fixing seat 46 is installed on the upper end face of the brushless motor, the fixing seat 46 is provided with an upright post, the planetary gear 432 is rotatably connected with the upright post through the second rotating bearing 47, and the output shaft of the brushless motor penetrates through the fixing seat 46 to be connected with the sun gear 431.

In this embodiment, the prism assembly further includes a speed detection component for detecting the rotation speed of the prism 41, so as to control the rotation speed of the prism 41 within a reasonable range, and make the laser radar operate stably.

Further, the speed detecting assembly provided by the present embodiment includes a metal code wheel 481, the metal code wheel 481 is fixedly installed on the upper end surface of the rotating shaft 44, and the metal code wheel 481 rotates with the rotating shaft 44. A photoelectric sensor 482 is provided on one side of the prism 41, and the photoelectric sensor 482 cooperates with the metal code wheel 481 to detect the rotational speed of the prism 41 and also to recognize the angle of rotation of the prism 41.

The photosensor 482 is preferably a correlation photosensor, and the metal code wheel 481 is disposed between an emitting end and a receiving end of the correlation photosensor. A bracket is provided on the fixing plate 1, and the photoelectric sensor 482 is mounted on the bracket.

In other embodiments, an encoder or other detection sensor may be disposed on the driving motor 42 to detect the rotation speed of the prism 41, which is not limited in detail herein.

The galvanometer group 49 provided by the embodiment includes a metal galvanometer plate, and the metal galvanometer plate can realize resonance with a frequency not less than 1000 HZ. The metal vibrating mirror is adopted in the embodiment, so that the problem that the number of target points for detection of the electromagnetic vibrating mirror in the prior art is small is solved, and the problems that a silicon substrate resonant vibrating mirror is thin, hard and brittle, sensitive to vibration, easy to damage by vibration and high in cost are solved. The metal vibration lens adopted by the embodiment has the inherent frequency, and is a characteristic of the metal vibration lens, the metal vibration lens is not easy to damage and interfere in a vibration environment, can stably work, and is low in cost.

This embodiment adopts the metal lens that shakes to realize the laser radar that economic feasibility and ability area array detected the target, but except adopting the metal material, other unknown and can reach the material of same effect also are in the protection scope of this application.

The material and thickness of the metal vibrating lens determine the resonance of the metal vibrating lens, the thickness is small, the resonance frequency cannot be achieved, the thickness is large, the resonance angle cannot meet the requirement, and the field angle is reduced. Therefore, the metal vibrating piece can determine the thickness of the metal vibrating piece according to the material of the metal vibrating piece. Usually, the resonance angle of the metal vibrating lens is 25 degrees as the best, and the service life of the metal vibrating lens is prolonged.

In this embodiment, the material of the metal vibrating plate is preferably 65Mn (spring steel), the thickness of the metal vibrating plate is 0.15mm to 0.28mm, so as to realize resonance at a frequency of not less than 1000HZ, and both the mechanical angle realized by the metal vibrating plate and the pressure that can be borne can meet the use requirements. The metal vibration lens in the embodiment is 65Mn, and compared with a vibration lens made of titanium alloy which can realize resonance with frequency of not less than 1000Hz, the cost of the vibration lens is greatly reduced. More preferably, the material of the metal galvanometer plate is 65Mn, and the thickness of the metal galvanometer plate is preferably 0.2mm or 0.25 mm.

The vibrating mirror group 49 further includes vibrating mirror reflectors, coils, angle detectors, and the like, which are prior art and will not be described in detail herein.

The optical path module further includes a reflector 410, the reflector 410 is disposed at the front side of the vibration mirror group 49 along the direction of emitting the laser beam to the target object, and the reflector 410 and the vibration mirror group 49 cooperate to adjust the path of the laser beam, so that the emitted laser beam is incident on the prism 41, or the returned laser beam is received by the receiving module. The mounting positions and mounting angles of the mirror group 49 and the reflecting mirror 410 are not particularly limited, and are set according to adjustment of an actual optical path.

The receiving module is used for receiving the laser beam reflected by the target, in this embodiment, the receiving module includes a first receiving group 31 and a second receiving group 32 which are sequentially and coaxially arranged along the direction of the laser beam reflected by the target, the first receiving group 31 is arranged at the rear side of the light path module along the direction of the laser beam reflected by the target, the first receiving group 31 is used for converging the laser beam, and the second receiving group 32 is used for receiving and processing the laser beam, so as to achieve the purpose of detecting the target by surface scanning.

The emission module includes laser generator transmitting terminal 21, and laser generator transmitting terminal 21 sets up and receives between group 32 in first receiving group 31 and second, and the second receives and organizes 32, laser generator transmitting terminal 21 and the coaxial setting of first receiving group 31, and the laser line beam of laser generator transmitting terminal 21 transmission wears to establish first receiving group 31 and launches to the light path module. Specifically, the first receiving set 31 is provided with a through hole for allowing the laser emitted from the emitting end 21 of the laser generator to penetrate through the first receiving set 31 and emit the laser to the optical path module.

The laser radar that this embodiment provided still includes control module group 5, and control module group 5 installs on fixed plate 1, and transmission module group, receiving module group and light path module all are connected with control module group 5 electricity.

In order to increase the number of scanning points and enlarge the scanning area to improve the accuracy of the detection target, in this embodiment, two laser generator emission ends 21 are provided, the two laser generator emission ends 21 are disposed at two sides of the prism group, and each laser generator emission end 21 is correspondingly provided with a first receiving group 31, a second receiving group 32 and a vibrating mirror group 49.

The emission module comprises a laser generator, the laser generator is provided with two laser generator emission ends 21, and the laser generator is electrically connected with the control module 5.

When using the laser radar that this embodiment provided, the laser beam of emission module transmission passes through the light path module and launches to the target object on, then the light beam of target object reflection returns through the former way of light path module and is received by receiving module, and prism 41 constantly rotates at laser radar detection's in-process to realize face array detection target object, and prism 41 rotational speed is low, avoids some cloud pictures to have the shake, has improved the precision of surveying.

Further, the laser emitted by the emitting module penetrates through the first receiving group 31 and is emitted to the reflecting mirror 410, and is reflected to the vibrating mirror group 49 through the reflecting mirror 410, the vibrating mirror group 49 realizes scanning at a vertical angle, the laser is emitted to the prism group after passing through the vibrating mirror group 49, the prism 41 rotates to realize large-angle scanning in a horizontal direction, and the laser is emitted to a target object after passing through the prism 41. The light beam reflected from the target object returns in the original path, and enters the second receiving group 32 after being converged by the first receiving group 31, and the second receiving group 32 receives and processes the laser beam, so that the purpose of detecting the target object by surface scanning is achieved.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A lidar, comprising:

the laser beam path adjusting device comprises a light path module, a laser beam adjusting module and a laser beam adjusting module, wherein the light path module is used for adjusting a path of a laser beam emitted to a target object and receiving the laser beam reflected by the target object and comprises a prism group and a vibration mirror group (49), the prism group comprises a prism (41) and a driving motor (42) for driving the prism (41) to rotate, a speed reducing mechanism is arranged between the driving motor (42) and the prism (41), and the speed reducing mechanism is used for reducing the rotating speed of the prism (41); the resonance frequency of the vibration mirror group (49) is not less than 1000 HZ.

2. Lidar according to claim 1, wherein the driving motor (42) is a brushless motor, an input end of the speed reduction mechanism is in driving connection with an output shaft of the brushless motor, and an output end of the speed reduction mechanism is connected with the prism (41) and can drive the prism (41) to rotate.

3. The lidar of claim 2, wherein a rotating shaft (44) is rotatably sleeved outside the brushless motor, the prism (41) is sleeved outside the rotating shaft (44) and is fixedly connected with the rotating shaft (44), and an output end of the speed reduction mechanism is connected with the rotating shaft (44) and can drive the rotating shaft (44) to rotate.

4. The lidar of claim 2 or 3, wherein the deceleration mechanism comprises:

a sun gear (431) drivingly connected to an output shaft of the brushless motor;

n planetary gears (432) respectively meshed with the sun gear (431), wherein the planetary gears (432) are rotatably mounted on the brushless motor; n is a positive integer;

internal gear (433), internal gear (433) are as the output, planetary gear (432) with tooth meshing on the internal circle of internal gear (433).

5. Lidar according to claim 1, wherein said prism assembly further comprises a speed detection assembly for detecting a rotational speed of said prism (41).

6. Lidar according to claim 1, 2, 3 or 5, wherein said galvanometer group (49) comprises a galvanometer metal plate capable of realizing a resonance at a frequency of not less than 1000 HZ.

7. The lidar of claim 6, wherein the optical path module further comprises a mirror (410), the mirror (410) being disposed on a front side of the mirror group (49) in a direction of emitting the laser beam toward the target object.

8. The lidar of claim 6, wherein the galvanometer plate is 65Mn thick, and the thickness of the galvanometer plate is 0.15mm to 0.28 mm.

9. The lidar of claim 1, 2, 3, 5, 7 or 8, wherein the receiving module comprises a first receiving group (31) and a second receiving group (32) sequentially and coaxially arranged along the direction of the laser beam reflected by the target, the first receiving group (31) is arranged at the rear side of the optical path module along the direction of the laser beam reflected by the target, the first receiving group (31) is used for converging the laser beam, and the second receiving group (32) is used for receiving the laser beam.

10. The lidar of claim 9, wherein the transmitting module comprises a laser generator transmitting end (21), the laser generator transmitting end (21) is disposed between the first receiving group (31) and the second receiving group (32), the laser generator transmitting end (21) and the first receiving group (31) are coaxially disposed, and a laser beam emitted from the laser generator transmitting end (21) penetrates through the first receiving group (31) and is transmitted to the optical path module.

11. Lidar according to claim 10, wherein said laser generator emitting ends (21) are provided in two, two said laser generator emitting ends (21) are disposed on both sides of said prism group, and each said laser generator emitting end (21) is provided with said first receiving group (31), said second receiving group (32) and said vibrating mirror group (49) respectively.