CN221303564U

CN221303564U - Laser radar optical system based on four-side turning mirror

Info

Publication number: CN221303564U
Application number: CN202322919755.9U
Authority: CN
Inventors: 刘岳飞; 王向永; 祁高进
Original assignee: Changzhou Xingyu Automotive Lighting Systems Co Ltd
Current assignee: Changzhou Xingyu Automotive Lighting Systems Co Ltd
Filing date: 2023-10-31
Publication date: 2024-07-09
Anticipated expiration: 2033-10-31

Abstract

The utility model discloses a laser radar optical system based on a four-sided rotating mirror, which comprises a transmitting module, a four-sided rotating mirror and a receiving module; the emitting module comprises a first reflecting mirror, a second reflecting mirror, a first collimating lens, a second collimating lens, a third collimating lens and an LD array, wherein a first light beam emitted by the LD array sequentially passes through the first collimating lens, the second collimating lens, the first reflecting mirror, the third collimating lens and the second reflecting mirror and then is emitted to the four-side rotating mirror; the receiving module comprises a receiver array, a first receiving lens, a second receiving lens, a third receiving lens and a third reflecting mirror, and the second light beam reflected by the four-side rotating mirror sequentially passes through the first receiving lens, the third reflecting mirror, the second receiving lens and the third receiving lens and then is incident on the receiver array. The utility model provides a four-side rotating mirror-based laser radar optical system, which ensures enough resolution and overall efficiency and effectively compresses the volume of the system.

Description

Laser radar optical system based on four-side turning mirror

Technical Field

The utility model relates to a four-side turning mirror-based laser radar optical system.

Background

The laser radar is an advanced detection device which utilizes the reflection of a target to emit a laser beam, receives and processes the reflected light through a receiving system to obtain the characteristic quantities of the target such as the spatial position, the speed and the like, and is widely applied to the fields of intelligent driving, topographic exploration, intelligent robots and the like due to the advantages of high spatial modeling characteristic, high resolution, interference resistance, small volume, light weight and the like.

The laser radar generally comprises a transmitting system, a scanning system, a receiving system and a digital processing system, the existing scheme mostly adopts a transceiving coaxial mode, the transmitted light and the received light are positioned on the same axis, the transmitted light returns along the original path of a transmitting path and enters the receiving system from a bypass, the mode is compact in layout and high in space utilization rate, but the overall efficiency is generally not high due to the central shielding. For example:

The application publication number is CN113093149A, and a rotating mirror device and a laser radar are disclosed, wherein the transmitting end and the receiving end are designed in a layered manner, so that the overall height of the laser radar is greatly increased while the light efficiency is ensured.

In the scanning laser radar disclosed in the application publication No. CN115685144A, a reflecting mirror at the transmitting end is positioned at the center of a receiving light path, a receiving light beam enters a receiving system through a reflecting mirror bypass, and the light efficiency at the receiving end is low, so that the overall efficiency is low.

In the application publication CN113589256a, the transmitting end and the receiving end are located on the same side, but in order to reduce the aperture of the turning mirror, the resolution of the laser radar is very limited.

In summary, in the existing solutions, the overall efficiency, volume, and resolution are mutually restricted, and a more excellent architecture is needed to achieve a small volume while ensuring sufficient resolution and overall efficiency.

Disclosure of Invention

The technical problem to be solved by the utility model is to overcome the defects of the prior art, provide a four-side turning mirror-based laser radar optical system, ensure enough resolution and overall efficiency and effectively compress the volume of the system.

In order to solve the technical problems, the technical scheme of the utility model is as follows:

A laser radar optical system based on four-side turning mirrors comprises a transmitting module, four-side turning mirrors and a receiving module;

The emitting module comprises a first reflecting mirror, a second reflecting mirror, a first collimating lens, a second collimating lens, a third collimating lens and an LD array, wherein a first light beam emitted by the LD array sequentially passes through the first collimating lens, the second collimating lens, the first reflecting mirror, the third collimating lens and the second reflecting mirror and then is emitted to the four-side rotating mirror;

the receiving module comprises a receiver array, a first receiving lens, a second receiving lens, a third receiving lens and a third reflecting mirror, and the second light beam reflected by the four-side rotating mirror sequentially passes through the first receiving lens, the third reflecting mirror, the second receiving lens and the third receiving lens and then is incident on the receiver array.

Further, the first collimating lens, the second collimating lens and the third collimating lens are all plano-convex lenses.

Further, the focal lengths of the first collimating lens, the second collimating lens and the third collimating lens are 75 mm-110 mm.

Further, the total optical length of the first collimating lens, the second collimating lens and the third collimating lens is 90-154 mm.

Further, the plane of the first collimating lens is opposite to the LD array, the convex surface of the first collimating lens is opposite to the convex surface of the second collimating lens, the plane of the second collimating lens is opposite to the first reflecting mirror, the first reflecting mirror is opposite to the plane of the third collimating lens, the convex surface of the third collimating lens is opposite to the second reflecting mirror, and the second reflecting mirror is opposite to the four-side rotating mirror.

Further, the first receiving lens, the second receiving lens and the third receiving lens are all plano-convex lenses.

Further, the focal lengths of the first receiving lens, the second receiving lens and the third receiving lens are 37.5 mm-100 mm.

Further, the total optical length of the first receiving lens, the second receiving lens and the third receiving lens is 90 mm-154 mm.

Further, the convex surface of the first receiving lens is opposite to the four-sided rotating mirror, the plane of the first receiving lens is opposite to the third reflecting mirror, the third reflecting mirror is opposite to the convex surface of the second receiving lens, the plane of the second receiving lens is opposite to the convex surface of the third receiving lens, and the plane of the third receiving lens is opposite to the receiver array.

Further, the light transmission aperture of the four-side turning mirror is 45 x 45mm ²～75*75mm².

By adopting the technical scheme, the transmitting module and the receiving module are separated at two sides of the four-sided rotating mirror, the optical axes of the transmitting module and the receiving module are ensured to be coaxial by utilizing the four-sided rotating mirror, the blocking problem generated by the reflecting mirror when receiving and transmitting the same side is avoided, and the overall efficiency is effectively improved. The transmitting module and the receiving module adopt a folding optical system, so that the whole volume is fully compressed.

Drawings

FIG. 1 is a front view of a four-sided turning mirror based lidar optical system of the present utility model;

FIG. 2 is a system architecture diagram of a four-sided turning mirror based lidar optical system of the present utility model;

FIG. 3 is a diagram of a central area probe optical path of the present utility model;

FIG. 4 is a diagram of an edge area detection light path according to the present utility model;

fig. 5 is a system architecture diagram of another embodiment of the present utility model.

Detailed Description

In order that the utility model may be more readily understood, a more particular description of the utility model will be rendered by reference to specific embodiments that are illustrated in the appended drawings.

As shown in fig. 1, the present embodiment provides a four-sided turning mirror-based laser radar optical system, which includes a transmitting module 8, a four-sided turning mirror 9, and a receiving module 10.

As shown in fig. 2, the emitting module 8 includes a first reflecting mirror 1, a second reflecting mirror 7, a first collimating lens 21, a second collimating lens 22, a third collimating lens 23 and an LD array 3, and the first light beam L1 emitted by the LD array 3 sequentially passes through the first collimating lens 21, the second collimating lens 22, the first reflecting mirror 1, the third collimating lens 23 and the second reflecting mirror 7 and then exits onto the four-sided rotating mirror 9.

As shown in fig. 2, the receiving module 10 includes a receiver array 4, a first receiving lens 51, a second receiving lens 52, a third receiving lens 53 and a third reflecting mirror 6, and the second light beam L2 reflected by the four-sided turning mirror 9 sequentially passes through the first receiving lens 51, the third reflecting mirror 6, the second receiving lens 52 and the third receiving lens 53 and then is incident on the receiver array 4.

As shown in fig. 2, the first collimating lens 21, the second collimating lens 22 and the third collimating lens 23 of the present embodiment are all plano-convex lenses, the focal lengths are all 75mm to 110mm, and the total optical lengths are all 90mm to 154mm. In this focal length range, the laser emitted from the LD array 3 can be collimated into a small divergence angle beam of 0.1 ° to 0.3 °, so that the beams emitted from adjacent LD arrays 3 do not overlap with each other, and the detection result is affected. The system diaphragm of the collimating lens group is arranged on the second reflecting mirror 7, so that the aperture of the rotating mirror is smaller, and the light efficiency of the collimating system can reach more than 80 percent.

As shown in fig. 2, in this embodiment, the plane of the first collimating lens 21 is opposite to the LD array 3, the convex surface of the first collimating lens 21 is opposite to the convex surface of the second collimating lens 22, the plane of the second collimating lens 22 is opposite to the first reflecting mirror 1, the first reflecting mirror 1 is opposite to the plane of the third collimating lens 23, the convex surface of the third collimating lens 23 is opposite to the second reflecting mirror 7, and the second reflecting mirror 7 is opposite to the four-sided turning mirror 9.

As shown in fig. 2, the first receiving lens 51, the second receiving lens 52 and the third receiving lens 53 of the present embodiment are all plano-convex lenses, the focal lengths are all 37.5mm to 100mm, and the optical total lengths are all 90mm to 154mm. Within this focal length range, the layout of the LD array 3 and the receiver array 4 can be made to be the most compact, and the overall volume can be reduced. The total optical length is between 90mm and 154mm, and the length range can be matched with the emitting end, so that the overall layout is compact. The F number is between 0.8 and 1.2, so that the light energy reflected by the rotating mirror can be fully utilized and converged on the detector, and the overall efficiency is improved.

As shown in fig. 2, the convex surface of the first receiving lens 51 is disposed opposite to the four-sided turning mirror 9, the plane of the first receiving lens 51 is disposed opposite to the third reflecting mirror 6, the third reflecting mirror 6 is disposed opposite to the convex surface of the second receiving lens 52, the plane of the second receiving lens 52 is disposed opposite to the convex surface of the third receiving lens 53, and the plane of the third receiving lens 53 is disposed opposite to the receiver array 4.

As shown in fig. 2, the aperture of the four-sided turning mirror 9 in this embodiment is 45×45mm ²～75*75mm², and this aperture can make the light efficiency of the emitting module reach more than 80%, and at the same time, the receiving module can collect enough reflected light.

As shown in FIG. 2, the light paths of the receiving module 8 and the receiving module 10 are respectively provided with a reflecting mirror, so that the overall structure size is minimum, the space utilization rate is highest, and the overall structure of the system is 160-230 mm long, 90-150 mm wide and 45-75 mm high.

As shown in fig. 2, the transmitting module 8 and the receiving module 10 are disposed at two sides of the four-sided turning mirror 9, and the included angles between the reflecting surfaces of the four-sided turning mirror 9 are 90±0.1°, so that the transmitting and receiving beams can be kept coaxial when the turning mirror rotates.

As shown in fig. 2, the incident optical axis of the receiving module 10 deviates from the horizontal direction by an angle of ±0.5° as shown by the dotted line portion of fig. 1, so as to compensate the angle rotated by the rotating mirror during the time of flight when measuring the remote target, and the corresponding third mirror 6 also deflects by ±0.5°.

As shown in fig. 1, in the narrow side direction of the LD array 3 and the receiver array 4, the collimator lens group and the lens of the receiving lens group are subjected to trimming processing, so that the system volume can be reduced without losing the light efficiency.

In addition, as shown in fig. 5, when the focal length of the emitting module 8 is small, the size of the emitting module 8 can be made small, and the emitting module 8 can be directly disposed on the side of the four-sided turning mirror 9.

The working principle of the utility model is as follows:

As shown in fig. 1 to 3, laser light emitted by the LD array 3 is collimated into a small-angle light beam L1 through three collimating lenses, a first reflecting mirror 1 is arranged between a second collimating lens 22 and a third collimating lens 23 to realize the first refraction of the emergent light beam, a second reflecting mirror 7 is arranged on the path of the emergent light beam to reflect the emergent light beam onto a four-sided rotating mirror 9, a reflection increasing film is plated on the surface of the rotating mirror, when the rotating mirror rotates rapidly, the emergent light beam scans horizontally, a light beam L2 reflected by a target is reflected by an adjacent rotating mirror to enter a receiving module, and as the dihedral angle of the reflecting surface of the four-sided rotating mirror is 90 degrees, the transmitting module and the receiving module can be placed oppositely, and the transmitting and receiving light beams can be kept coaxial all the time.

The incident light is converged on the light sensitive surface of the receiver array 4 through the first receiving lens 51, the second receiving lens 52 and the third receiving lens 53, photoelectric conversion is realized, and the target space position is calculated according to the receiver position, the turning mirror angle, the flight time of laser and the like, so that a point cloud image of the surrounding environment is formed. A third reflecting mirror 6 is arranged between the first receiving lens 51 and the second receiving lens 52, so that the receiving light path is turned over, and the whole system is tightly arranged.

The technical problems, technical solutions and advantageous effects solved by the present utility model have been further described in detail in the above-described embodiments, and it should be understood that the above-described embodiments are only illustrative of the present utility model and are not intended to limit the present utility model, and any modifications, equivalent substitutions, improvements, etc. within the spirit and principle of the present utility model should be included in the scope of protection of the present utility model.

Claims

1. The laser radar optical system based on the four-sided rotating mirror is characterized by comprising a transmitting module (8), the four-sided rotating mirror (9) and a receiving module (10);

The emitting module (8) comprises a first reflecting mirror (1), a second reflecting mirror (7), a first collimating lens (21), a second collimating lens (22), a third collimating lens (23) and an LD array (3), wherein a first light beam (L1) emitted by the LD array (3) sequentially passes through the first collimating lens (21), the second collimating lens (22), the first reflecting mirror (1), the third collimating lens (23) and the second reflecting mirror (7) and then is emitted to the four-side rotating mirror (9);

The receiving module (10) comprises a receiver array (4), a first receiving lens (51), a second receiving lens (52), a third receiving lens (53) and a third reflecting mirror (6), and the second light beam (L2) reflected by the four-side rotating mirror (9) sequentially passes through the first receiving lens (51), the third reflecting mirror (6), the second receiving lens (52) and the third receiving lens (53) and then is incident on the receiver array (4).

2. The four-sided turning mirror based lidar optical system of claim 1, wherein: the first collimating lens (21), the second collimating lens (22) and the third collimating lens (23) are all plano-convex lenses.

3. The four-sided turning mirror based lidar optical system according to claim 2, wherein: the focal lengths of the first collimating lens (21), the second collimating lens (22) and the third collimating lens (23) are 75-110 mm.

4. The four-sided turning mirror based lidar optical system according to claim 2, wherein: the total optical length of the first collimating lens (21), the second collimating lens (22) and the third collimating lens (23) is 90-154 mm.

5. The four-sided turning mirror based lidar optical system according to claim 2, wherein: the plane of first collimating lens (21) is set up with LD array (3) relatively, the convex surface of first collimating lens (21) is set up with the convex surface of second collimating lens (22) relatively, the plane of second collimating lens (22) is set up with first speculum (1) relatively, the plane of first speculum (1) and third collimating lens (23) sets up relatively, the convex surface of third collimating lens (23) is set up with second speculum (7) relatively, second speculum (7) set up with four sides turning mirror (9) relatively.

6. The four-sided turning mirror based lidar optical system of claim 1, wherein: the first receiving lens (51), the second receiving lens (52) and the third receiving lens (53) are all plano-convex lenses.

7. The four-sided turning mirror based lidar optical system of claim 6, wherein: the focal lengths of the first receiving lens (51), the second receiving lens (52) and the third receiving lens (53) are 37.5 mm-100 mm.

8. The four-sided turning mirror based lidar optical system of claim 6, wherein: the total optical length of the first receiving lens (51), the second receiving lens (52) and the third receiving lens (53) is 90-154 mm.

9. The four-sided turning mirror based lidar optical system of claim 6, wherein: the convex surface of the first receiving lens (51) is opposite to the four-side rotating mirror (9), the plane of the first receiving lens (51) is opposite to the third reflecting mirror (6), the third reflecting mirror (6) is opposite to the convex surface of the second receiving lens (52), the plane of the second receiving lens (52) is opposite to the convex surface of the third receiving lens (53), and the plane of the third receiving lens (53) is opposite to the receiver array (4).

10. The four-sided turning mirror based lidar optical system of claim 1, wherein: the light-transmitting aperture of the four-side rotating mirror (9) is 45mm ²～75*75mm².