CN208255403U - Laser radar optical system - Google Patents

Abstract

The laser radar optical system provided by the utility model adopts a transmitting end, a receiving end, a collimating lens group, a correction mirror and an optical window; The window is emitted, and shoots to the measured target; the echo beam returned by the measured target is incident from the optical window, and enters the receiving end through the collimating lens group and the correcting mirror; among them, the focal length of the laser radar optical system in the horizontal direction is the same as The focal length in the vertical direction is the same. By adopting a correcting mirror that can be used to adjust the focal length of the outgoing beam and the echo beam in a specific direction, it is avoided that the outgoing beam emitted from the laser radar optical system and the echo beam received by the receiving end of the laser radar optical system are in the horizontal direction. The problem of inconsistency with the focal length in the vertical direction avoids aberrations and improves detection capabilities.

Description

LiDAR Optical System

technical field

The utility model relates to laser application technology, in particular to a laser radar optical system.

Background technique

Lidar emits a laser beam to the target area and receives the laser echo beam reflected from the target area, and obtains the three-dimensional information of the space to be measured according to the flight time of the laser beam. Because lidar has the advantages of high resolution, high measurement accuracy, and strong anti-interference ability, it is widely used in fields such as unmanned driving and has become an indispensable sensor in these fields. The laser radar optical system is the "eye" of the laser radar, and its quality directly affects the measurement accuracy and detection ability of the laser.

The existing laser radar optical system is composed of optical parts such as optical windows, collimation systems, and laser sources. function of other parts.

However, in order to meet the scanning requirements and aesthetic requirements of lidar, the shape of the optical window is generally cylindrical or curved, which will cause the beam passing through itself to be diffused in one direction, which causes the outgoing beam to pass through the optical window. The focal lengths in the horizontal and vertical directions of the window are different, forming aberrations. Such aberration will reduce the optical energy density of the outgoing beam in the direction of diffusion when the outgoing beam reaches the space to be measured, and the energy of the received echo beam will also decrease accordingly, making it inaccurate to obtain the three-dimensional information of the space to be measured , which in turn causes a decline in the detection capability of the entire lidar.

Utility model content

In order to solve the problems existing in the prior art that the optical energy density decreases and the laser radar detection ability decreases due to the diffusion of the collimated laser beam passing through the optical window, the utility model provides a laser radar optical system.

The utility model provides a laser radar optical system, comprising:

Transmitter, receiver, collimator lens group, correction mirror and optical window;

The emitting end is used to generate an outgoing light beam, and the outgoing light beam is emitted from the optical window through the collimating lens group and the correcting mirror, and then directed to the measured target;

The echo beam returned by the measured object is incident from the optical window, passes through the collimating lens group and the correcting mirror, and enters the receiving end;

Wherein, the focal length of the lidar optical system in the horizontal direction is the same as that in the vertical direction.

In this embodiment, a correcting mirror is provided, and the diopter of the correcting mirror matches the diopter of the optical window. The focal length is the same as the focal length in the vertical direction, thereby avoiding the problem of inconsistency in the horizontal and vertical focal lengths of the outgoing beam emitted from the laser radar optical system and the echo beam received by the receiving end of the laser radar optical system , thereby avoiding aberrations and improving detection capabilities.

In one of the optional implementation manners, the focal length f _H in the horizontal direction and the focal length f _V in the vertical direction of the lidar optical system are calculated according to formula (1):

Wherein, said Q _1,H is the diopter of the optical window in the horizontal direction, said Q _1,V is the diopter of the optical window in the vertical direction, and said Q _2,H is the diopter of the collimating lens group in the horizontal direction The diopter in the direction, the Q _{2, V} is the diopter of the collimator lens group in the vertical direction, the Q _{3, H} is the diopter of the correcting mirror in the horizontal direction, and the Q _{3, V} is the diopter of the collimator lens group in the vertical direction. The diopter _of the correcting mirror in the vertical direction, the d12 is the distance between the optical window and the collimating lens group, and the _d23 is the distance between the collimating lens group and the correcting mirror spacing between.

In this embodiment, the focal length of the laser radar optical system can be determined according to the diopter of the optical window, the collimating lens group and the correcting mirror, and the distance between each element, so as to realize the adjustment of the laser radar optical system in the horizontal direction and The focal length adjustment in the vertical direction improves the detection capability of the entire lidar optical system.

In one of the optional implementation manners, the focal length of the lidar optical system in the horizontal direction is the same as the focal length in the vertical direction, including:

Determine the diopter of the correction mirror in the horizontal direction and the vertical direction according to the diopter of the optical window in the horizontal direction and the vertical direction, so that the diopter of the laser radar optical system in the horizontal direction is the same as that in the vertical direction The diopters in the vertical direction are the same.

In this embodiment, the diopter of the correction mirror in the horizontal direction and the vertical direction is determined and adjusted according to the diopter of the optical window in the horizontal direction and the vertical direction, so that the diopter of the laser radar optical system in the horizontal direction is the same as The diopter in the vertical direction is the same, thereby ensuring that the diopter of the lidar optical system in the horizontal direction is the same as the focal length in the vertical direction, and the aberrations are accurately and effectively compensated.

In one optional implementation manner, the collimating lens group includes at least one positive lens and at least one negative lens.

In this embodiment, the collimating lens group may include multiple lenses, which may specifically be composed of at least one positive lens and at least one negative lens. Compared with a single-lens collimating lens, the collimating lens group using multiple lenses It can more effectively collimate the outgoing beam and the echo beam, further reduce the aberration of the beam in the horizontal direction and the vertical direction, and improve the detection capability of the laser radar optical system.

In one of the optional implementation manners, the correction mirror is a lens.

In one of the optional implementation manners, the correction mirror is a cylindrical mirror.

In one of the optional implementation manners, the correction mirror is a reflection mirror.

In the above embodiment, according to the type of light beam and the design requirements of the optical path, the correcting mirror can specifically adopt a lens structure or a reflective mirror. By adopting this method, the correcting mirror that matches the demand can be further determined according to the specific design requirements. Effectively compensates for aberrations.

In one of the optional implementation manners, when the correcting mirror is a lens, the correcting mirror is interspersed between the lenses of the collimating lens group.

In this embodiment, if the correcting mirror is a lens, the correcting mirror can be placed between the lenses of the collimating lens group, or it can be placed on an optical path other than the collimating lens group.

In one of the optional implementation manners, the lidar optical system further includes: a light splitting element;

The light splitting element is used to change the transmission direction of the echo light beam and/or the outgoing light beam.

In this embodiment, by setting the light splitting element, the transmission direction of the outgoing beam or echo beam can be redirected, so that the distance between the components in the laser radar optical system is relatively compact, reducing the cost of the laser radar optical system. volume.

In one of the optional implementation manners, the lidar optical system further includes: a processing unit;

The processing unit is respectively connected with the transmitting end and the receiving end, and is used for determining the information of the measured target according to the outgoing light beam and the echo light beam.

In this embodiment, by setting the processing unit respectively connected to the transmitting end and the receiving end, so that the processing unit obtains the optical information of the outgoing beam and the echo beam, and calculates and processes the optical information to obtain the measured target information.

The laser radar optical system provided by the utility model adopts a transmitting end, a receiving end, a collimating lens group, a correction mirror and an optical window; The window is emitted and directed to the measured target; the echo beam returned by the measured target is incident from the optical window, and enters the receiving end through the collimating lens group and the correcting mirror; wherein, the beam presents the first deflection through the correcting mirror, and the beam A second deflection with the opposite direction and the same angle as the first deflection is presented through the optical window. By adopting a correcting mirror that can be used to adjust the focal length of the outgoing beam and the echo beam in a specific direction, it is avoided that the outgoing beam emitted from the laser radar optical system and the echo beam received by the receiving end of the laser radar optical system are in the horizontal direction. The problem of inconsistency with the focal length in the vertical direction avoids aberrations and improves detection capabilities.

Description of drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the disclosure and together with the description serve to explain the principles of the disclosure.

Fig. 1 is a schematic structural diagram of a lidar optical system provided by Embodiment 1 of the present invention;

Fig. 2 is a schematic diagram of spot changes of a laser radar optical system provided by Embodiment 1 of the present invention;

Fig. 3 is a schematic cross-sectional view in the horizontal direction of the optical path of another laser radar optical system provided by Embodiment 1 of the present invention;

Fig. 4 is a schematic cross-sectional view in the vertical direction of the optical path of another laser radar optical system provided by Embodiment 1 of the present invention;

Fig. 5 is a schematic structural diagram of a lidar optical system provided by Embodiment 2 of the present invention;

Fig. 6 is a schematic cross-sectional view in the horizontal direction of the optical path of another laser radar optical system provided by Embodiment 2 of the present invention;

7 is a schematic cross-sectional view in the vertical direction of the optical path of another laser radar optical system provided by Embodiment 2 of the present invention.

Reference signs:

10-transmitter; 20-receiver;

30-collimating lens group; 40-correcting mirror;

50-optical window; 60-processing module;

70-light splitting element; 800-optical axis.

By means of the above-mentioned drawings, certain embodiments of the present disclosure have been shown and will be described in more detail hereinafter. These drawings and written description are not intended to limit the scope of the disclosed concept in any way, but to illustrate the disclosed concept for those skilled in the art by referring to specific embodiments.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the utility model clearer, the technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model.

Lidar emits a laser beam to the target area and receives the laser echo beam reflected from the target area, and obtains the three-dimensional information of the space to be measured according to the flight time of the laser beam. Because lidar has the advantages of high resolution, high measurement accuracy, and strong anti-interference ability, it is widely used in fields such as unmanned driving and has become an indispensable sensor in these fields. The laser radar optical system is the "eye" of the laser radar, and its quality directly affects the measurement accuracy and detection ability of the laser.

The existing laser radar optical system is composed of optical parts such as optical windows, collimation systems, and laser sources. function of other parts.

However, in order to meet the scanning requirements and aesthetic requirements of lidar, the shape of the optical window is generally cylindrical or curved, which will cause the beam passing through itself to be diffused in one direction, which causes the outgoing beam to pass through the optical window. The focal lengths in the horizontal and vertical directions of the window are different, forming aberrations. Such aberration will reduce the optical energy density of the outgoing beam in the direction of diffusion when the outgoing beam reaches the space to be measured, and the energy of the received echo beam will also decrease accordingly, making it inaccurate to obtain the three-dimensional information of the space to be measured , which in turn causes a decline in the detection capability of the entire lidar.

It should be noted that the exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the accompanying drawings, the same numerals in different drawings refer to the same or similar elements unless otherwise indicated. The implementations described in the following exemplary examples do not represent all implementations consistent with the present disclosure. Rather, they are merely examples of apparatuses and methods consistent with aspects of the present disclosure as recited in the appended claims.

The technical solution of the present utility model and how the technical solution of the present application solves the above-mentioned technical problems will be described in detail below with specific embodiments. The following specific embodiments may be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. Embodiments of the utility model will be described below in conjunction with the accompanying drawings.

FIG. 1 is a schematic structural diagram of a lidar optical system provided by Embodiment 1 of the present invention.

As shown in Figure 1, the laser radar optical system includes: a transmitting end 10, a receiving end 20, a collimating lens group 30, a correction mirror 40 and an optical window 50; wherein, the transmitting end 10 is used to generate an outgoing light beam, and the The outgoing beam passes through the collimating lens group 30 and the correcting mirror 40 and exits from the optical window 50, and shoots to the measured target; the echo beam returned by the measured target is incident from the optical window 50 , enter the receiving end 20 through the collimating lens group 30 and the correcting mirror 40, wherein the focal length of the lidar optical system in the horizontal direction is the same as that in the vertical direction.

Specifically, since the light beam presents a first deflection through the correction mirror, and the light beam presents a second deflection through the optical window, the second deflection is compensated by the first deflection, so that the focal length of the laser radar optical system in the horizontal direction is the same as that in the The focal length in the vertical direction remains the same, wherein, when the second deflection is to converge the beam in the horizontal direction, the first deflection can be to diverge the beam in the horizontal direction, and when the second deflection is to converge the beam in the vertical direction When diverging, the first deflection may diverge the light beam in the horizontal direction.

Wherein, in one of the optional implementation manners, the outgoing light beam and the echo light beam present a first deflection after passing through the correction mirror 40, and the outgoing light beam and the echo light beam pass through the optical window 50 Then a second deflection occurs, and the deflection direction of the first deflection is opposite to that of the second deflection and the deflection angle is the same.

Furthermore, the deflection directions and deflection angles of the first deflection and the second deflection are respectively related to the diopters of the correction mirror 40 and the optical window 50 , which are not limited in this embodiment.

In the technical solution provided by the structure shown in Figure 1, by setting a correcting mirror, the correcting mirror 40 can be used to adjust the focal length of the outgoing beam and the echo beam in a specific direction, thereby avoiding that the outgoing beam emitted from the laser radar optical system And the problem that the focal length of the echo beam received by the receiving end of the laser radar optical system is inconsistent in the horizontal direction and the vertical direction, thereby avoiding aberrations and improving detection capabilities.

It should be noted that, in the first embodiment, the relative positional relationship between the correcting mirror 40 and the collimating lens group 30 can be as shown in FIG. 1 , or other ways can be adopted, which is not limited by the present invention.

In one of the optional implementation manners, the focal length f _H in the horizontal direction and the focal length f _V in the vertical direction of the lidar optical system are calculated according to formula (1):

Wherein, said Q _1,H is the diopter of the optical window in the horizontal direction, said Q _1,V is the diopter of the optical window in the vertical direction, and said Q _2,H is the diopter of the collimating lens group in the horizontal direction The diopter in the direction, the Q _{2, V} is the diopter of the collimator lens group in the vertical direction, the Q _{3, H} is the diopter of the correcting mirror in the horizontal direction, and the Q _{3, V} is the diopter of the collimator lens group in the vertical direction. The diopter _of the correcting mirror in the vertical direction, the d12 is the distance between the optical window and the collimating lens group, and the _d23 is the distance between the collimating lens group and the correcting mirror spacing between.

In this embodiment, the focal length of the laser radar optical system can be determined according to the diopter of the optical window, the collimating lens group and the correcting mirror, and the distance between each element, so as to realize the adjustment of the laser radar optical system in the horizontal direction and The focal length adjustment in the vertical direction improves the detection capability of the entire lidar optical system.

In an optional implementation manner, the focal length of the lidar optical system in the horizontal direction is the same as the focal length in the vertical direction, including: according to the diopters of the optical window in the horizontal direction and the vertical direction Determine the diopter of the correction mirror in the horizontal direction and the vertical direction, so that the diopter of the laser radar optical system in the horizontal direction is the same as that in the vertical direction.

Further, in this embodiment, taking the diopter Q1,H=0 of the optical lens in the horizontal direction as an example, there are two achievable ways when f _H =f _V is satisfied:

The diopter of one of the corrective lenses can be expressed as:

In this embodiment, both the optical window and the corrective mirror have zero diopters in the horizontal direction.

The diopter of another corrective lens can be expressed as:

In this embodiment, the optical window has zero diopters in the horizontal direction and the corrective mirror has zero diopters in the vertical direction.

In this embodiment, the diopter of the correction mirror in the horizontal direction and the vertical direction is determined and adjusted according to the diopter of the optical window in the horizontal direction and the vertical direction, so that the diopter of the laser radar optical system in the horizontal direction is the same as The diopter in the vertical direction is the same, thereby ensuring that the diopter of the lidar optical system in the horizontal direction is the same as the focal length in the vertical direction, and the aberrations are accurately and effectively compensated.

In order to further illustrate the solution of the first embodiment, FIG. 2 is a schematic diagram of light spot changes of a lidar optical system provided by the first embodiment of the present invention. The schematic diagram of spot change shown in FIG. 2 is illustrated by taking the optical window 50 to diffuse the outgoing beam in the horizontal direction, and the correcting mirror 40 to correct the outgoing beam and the echo beam in the horizontal direction as an example.

As shown in FIG. 2 , L in FIG. 2 represents the observation position, f ₀ is the focal length of the laser radar optical system after adding the correction mirror 40, and f _H is the focal length of the laser radar optical system without the correction mirror 40 in the horizontal direction.

The first row is the observed spot shape change without the correcting mirror 40: when L<f ₀ , the converged spot is relatively large, and the horizontal direction is larger than the vertical direction. When L=f ₀ , the converging spot is the smallest in the vertical direction, but still large in the horizontal direction. When f ₀ <L<f _H , the spot size of the converged light spot in the vertical direction and the horizontal direction is basically equal, but the overall size of the light spot is larger. When L=f _H , the converging spot converges the least in the horizontal direction, but is still very large in the vertical direction. When L>f _H , the converged spot becomes larger, and the vertical direction is larger than the horizontal direction.

The second line observes the change of the shape of the light spot after adding the correcting mirror 40. Compared with the light spot in the first line, when L gradually increases from less than _f0 until it is greater than _fH , the light spot changes in the horizontal and vertical directions The changes in the direction are basically consistent, and there will be no situation where the convergence point of the light spot in a certain direction is very large, that is to say, the convergence situation of the light spot in the horizontal direction and the vertical direction is always consistent. At the same time, it is obvious that when L=f ₀ , the light spot converges to the minimum in the horizontal direction and the vertical direction at the same time, and the receiving end can be placed at this position and detect or detect the converged light spot at this position to obtain the measured target information.

In order to further illustrate the laser radar optical system provided in the first embodiment, Fig. 3 is a schematic cross-sectional view of the optical path of another laser radar optical system provided in the first embodiment of the present utility model in the horizontal direction, and Fig. 4 is a schematic diagram of the implementation of the present utility model. Example 1 provides a schematic cross-sectional view of the optical path of another laser radar optical system in the vertical direction.

As shown in Figures 3 and 4, the laser radar optical system includes: a transmitting end, a receiving end, a collimating lens group 30, a correction mirror 40 and an optical window 50; wherein, the transmitting end is used to generate an outgoing light beam, and the The outgoing beam passes through the collimating lens group 30 and the correcting mirror 40 and exits from the optical window 50, and shoots to the measured target; the echo beam returned by the measured target is incident from the optical window 50 , entering the receiving end through the collimating lens group 30 and the correcting mirror 40, wherein the light beam presents a first deflection after passing through the correcting mirror, and the light beam presents a direction opposite to the first deflection direction and A second deflection of the same angle. Wherein, as shown in Figure 3, the collimating lens group 30 and the correcting mirror 40 can be arranged in pairs, that is, a group of collimating lens groups 30 and a correcting mirror 40 are set for the outgoing beam, and a set of collimating lens is also set for the echo beam. Straight lens group 30 and a corrective mirror 40. Wherein, since the receiving end and the transmitting end are generally arranged in parallel along the horizontal plane, their optical paths on the vertical plane will overlap.

In addition, the collimating lens group 30 includes at least one positive lens and at least one negative lens. Specifically, the collimating lens group 30 may include multiple lenses, which may be composed of at least one positive lens and at least one negative lens. Compared with a single-lens collimating lens, the collimating lens group 30 using multiple lenses can A more effective collimation effect is performed on the outgoing beam and the echo beam, further reducing the aberration of the beam in the horizontal or vertical direction, and improving the detection capability of the laser radar optical system.

In addition, according to the type of light beam and the design requirements of the optical path, in this application, the correction mirror can specifically adopt a lens structure, a mirror, or a combination of a lens and a mirror. In addition, the correction mirror can also use a cylindrical surface mirror.

In Fig. 3 and Fig. 4, in order to cooperate with the optical path design, the correcting mirror 40 is set as a lens, and in an optional embodiment, the correcting mirror 40 can be arranged on the optical path other than the collimating lens group 30, such as being arranged on The collimating lens group 30 is close to the optical path of the emitting end or the receiving end side (as shown in Figure 3 ), or is arranged on the optical path of the collimating lens group 30 away from the emitting end or the receiving end side, and of course, the correction mirror 40 also It can be interspersed between the positive lens and the negative lens of the collimating lens group 30 , and the present invention is not limited thereto.

At the same time, optionally, when the correcting mirror 40 is a lens, the correcting mirror 40 may also be a cylindrical mirror, wherein the side of the correcting mirror 40 close to the transmitting end or the receiving end is a convex surface of the cylindrical mirror. In this embodiment, if the correcting mirror 40 is a lens, the correcting mirror 40 can adopt a cylindrical mirror structure, wherein in order to compensate the optical window 50, the side of the correcting mirror 40 close to the emitting end or the emitting end can be set as a cylindrical surface The convex surface of the mirror adjusts the focal length of the beam only in a specific direction.

Further, in the light path shown in Fig. 3 and Fig. 4, the section of the front surface of the optical window 50 in the vertical direction is a plane, that is, the optical window 50 does not work on the light beam in the vertical direction (as 4); the section of the front surface of the optical window 50 in the horizontal direction is an arc surface, that is, the optical window 50 plays a divergent effect on the outgoing beam and the echo beam in the horizontal direction (as shown in Figure 3) . Based on this, the cross section of the correction mirror 40 on the side surface near the focal length point is a convex cylindrical surface (as shown in Figure 3 ), and the cross section in the vertical direction is a plane (as shown in Figure 4 ), The correction mirror 40 converges the light beam in the horizontal direction. Therefore, the correcting mirror 40 can effectively compensate for the divergence effect of the optical window 50 on the outgoing light beam and the echo light beam, so that the focal points of the outgoing light beam in the vertical direction and the horizontal direction are better coincident.

The laser radar optical system provided by Embodiment 1 of the utility model adopts a transmitting end, a receiving end, a collimating lens group, a correction mirror and an optical window; The mirror emits from the optical window and shoots to the measured target; the echo beam returned by the measured target is incident from the optical window, and enters the receiving end through the collimating lens group and the correcting mirror; among them, the laser radar optical system is in the horizontal direction The focal length of is the same as the focal length in the vertical direction. By adopting a correcting mirror that can be used to adjust the focal length of the outgoing beam and the echo beam in a specific direction, it is avoided that the outgoing beam emitted from the laser radar optical system and the echo beam received by the receiving end of the laser radar optical system are in the horizontal direction. The problem of inconsistency with the focal length in the vertical direction avoids aberrations and improves detection capabilities.

Furthermore, in order to better describe the laser radar optical system provided in this embodiment, on the basis of the embodiment shown in Figure 1, Embodiment 2 of the present utility model provides a laser radar optical system, which is similar to that shown in Figure 1 Similar in structure, the laser radar optical system in Embodiment 2 includes: a transmitting end 10, a receiving end 20, a collimating lens group 30, a correcting mirror 40 and an optical window 50; wherein, the transmitting end 10 is used to generate an outgoing light beam , the outgoing light beam exits the optical window 50 through the collimating lens group 30 and the correcting mirror 40, and shoots to the measured target; the echo beam returned by the measured target passes through the optical window The film 50 is incident, and enters the receiving end 20 through the collimating lens group 30 and the correcting mirror 40, wherein the focal length of the laser radar optical system in the horizontal direction is the same as that in the vertical direction.

Different from the first embodiment, the lidar optical system in the second embodiment further includes: a light splitting element 70 , and/or, a processing module 80 .

Specifically, the lidar optical system may further include: a light splitting element 70 .

The light splitting element 70 is used to change the transmission direction of the light beam, so that when the overall space of the laser radar optical system is limited, the transmission direction of the echo beam changes through the light splitting element 70 and is incident on the receiving end 20 accurately, and/or , the transmission direction of the outgoing light beam is changed through the light splitting element 70 and accurately exits from the optical window 50 .

In addition, optionally, the laser radar optical system further includes: a processing unit 60; the processing unit 60 is respectively connected to the transmitting end 10 and the receiving end 20, and is used to The light beam determines information about the measured object. In this embodiment, by setting the processing unit 60 respectively connected to the transmitting end 10 and the receiving end 20, so that the processing unit 60 obtains the optical information of the outgoing beam and the echo beam, and calculates and processes the optical information to obtain information about the target being measured.

In order to further illustrate the laser radar optical system in the second embodiment, FIG. 5 is a schematic structural diagram of a laser radar optical system provided in the second embodiment of the present invention. Wherein, FIG. 5 shows the light transmission directions of the outgoing light beam and the return light beam in the laser radar optical system.

Specifically, in the structure shown in FIG. 5 , based on the material and coating properties of the light splitting element 70 , it does not change the transmission direction of the outgoing beam, but only changes the transmission direction of the echo beam.

In addition, the position and number of the light splitting elements 70 can be set according to the actual situation, and according to the different positions and numbers of the light splitting elements 70, the optical path in the laser radar optical system will also change accordingly. That is to say, in other structures, the light splitting element 70 can also be used to change the transmission direction of the outgoing beam without changing the transmission direction of the echo beam; or, two light splitting elements 70 are used to change the transmission direction of the outgoing light beam and the echo beam respectively. direction of transmission. In this embodiment, by providing the light splitting element 70, the transmission direction of the outgoing light beam and/or the echo light beam can be redirected, so that the distance between the components in the laser radar optical system is relatively compact, reducing The volume of the lidar optical system.

Further, Fig. 6 is a schematic cross-sectional view in the horizontal direction of the optical path of another laser radar optical system provided by the second embodiment of the utility model; Fig. 7 is another laser radar optical system provided by the second embodiment of the utility model The cross-sectional schematic diagram of the optical path in the vertical direction.

In order to compensate the divergence effect of the optical window 50 on the beam in a specific direction, the correcting mirror 40 is configured as a reflective mirror, and a correcting mirror 40 can be configured for the outgoing beam and the return beam respectively. Further, when the correcting mirror 40 is a reflecting mirror, the reflective surface of the correcting mirror 40 can be set as a concave surface, so as to only adjust the focal length of the light beam in a specific direction, and realize the function of compensating the optical window.

Taking the optical path in the structure shown in Fig. 6 and Fig. 7 as an example, aiming at the outgoing light beam and echo light beam being diverged in the horizontal direction when passing through the optical window 50, a group of collimating lens groups 30 and a correction lens group 30 can be respectively arranged. Mirror 40 and a light splitting element 70, wherein the collimating lens group 30 is composed of a positive lens and a negative lens, the correcting mirror 40 is a reflecting mirror, and the light splitting element 70 is a total reflection mirror to realize compensation to the light beam. Wherein, since the receiving end and the transmitting end are generally arranged in parallel along the horizontal plane, their optical paths on the vertical plane will overlap.

Specifically, the cross section of the front surface of the optical window 50 in the vertical direction is a plane (as shown in FIG. 7 ), that is, the optical window 50 has no effect on the echo beam and the emission beam in the vertical direction; The section of the front surface of the window 50 in the horizontal direction is an arc surface (as shown in FIG. 6 ), that is, the optical window 50 diverges the echo beam and the emission beam in the horizontal direction. Based on this, the cross section of the reflective surface of the correction mirror 40 in the present embodiment two is a concave surface (as shown in Figure 6 ) on the horizontal line, and the cross section in the vertical direction is a plane (as shown in Figure 7 ). The direction plays a converging role. Therefore, the correction mirror 40 can effectively compensate for the divergence of the echo beam and the emission beam due to the optical window 50 , so that the focal points of the echo beam and the emission beam in the vertical direction and the horizontal direction are better coincident.

Further, the outgoing light beam is compensated by the correcting mirror 40, and the transmission direction of the light splitting element 70 is changed in sequence, and then enters the collimating lens group 30, and the collimated outgoing light beam will exit from the optical window 50 and be transmitted to the During the echo process of the measured target, the echo beam incident from the optical window 50 is focused by the collimator lens group 30, and then the transmission direction of the echo beam is changed by the spectroscopic element 70, so that the echo beam The wave beam hits the reflective surface of the rectifying mirror 40 and is compensated, and the compensated echo beam is finally reflected to the receiving end. It should be noted that the relative position of the correcting mirror 40 and the light splitting element 70 may be as shown in FIG. 6 or 7 , or may be set according to the actual situation, and the relative position is not limited in this embodiment.

Optionally, the collimator lens group 30 in the above embodiment includes at least one positive lens and at least one negative lens. Specifically, the collimating lens group 30 may include multiple lenses, which may be composed of at least one positive lens and at least one negative lens. Compared with a single-lens collimating lens, the collimating lens group 30 using multiple lenses can A more effective collimation effect is performed on the outgoing beam and the echo beam, further reducing the aberration of the beam in the horizontal or vertical direction, and improving the detection capability of the laser radar optical system.

The laser radar optical system provided by the second embodiment of the utility model adopts a transmitting end, a receiving end, a collimating lens group, a correction mirror and an optical window; The mirror emits from the optical window and shoots to the measured target; the echo beam returned by the measured target is incident from the optical window, and enters the receiving end through the collimating lens group and the correcting mirror; among them, the laser radar optical system is in the horizontal direction The focal length of is the same as the focal length in the vertical direction. By adopting a correcting mirror that can be used to adjust the focal length of the outgoing beam and the echo beam in a specific direction, it is avoided that the outgoing beam emitted from the laser radar optical system and the echo beam received by the receiving end of the laser radar optical system are in the horizontal direction. The problem of inconsistency with the focal length in the vertical direction avoids aberrations and improves detection capabilities.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present utility model, and are not intended to limit it; although the present utility model has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand : It is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements to some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions depart from the various embodiments of the present invention Scope of technical solutions.

Claims (10)

1. A laser radar optical system is characterized in that, comprising: a transmitting end, a receiving end, a collimating lens group, a correction mirror and an optical window; The emitting end is used to generate an outgoing light beam, and the outgoing light beam is emitted from the optical window through the collimating lens group and the correcting mirror, and then directed to the measured target; The echo beam returned by the measured object is incident from the optical window, passes through the collimating lens group and the correcting mirror, and enters the receiving end; Wherein, the focal length of the lidar optical system in the horizontal direction is the same as that in the vertical direction. 2. laser radar optical system according to claim 1, is characterized in that, also comprises: calculate described laser radar optical system according to formula (1) focal length f _H in horizontal direction and the focal length f in vertical direction _V : Wherein, said Q _1,H is the diopter of the optical window in the horizontal direction, said Q _1,V is the diopter of the optical window in the vertical direction, and said Q _2,H is the diopter of the collimating lens group in the horizontal direction The diopter in the direction, the Q _{2, V} is the diopter of the collimator lens group in the vertical direction, the Q _{3, H} is the diopter of the correcting mirror in the horizontal direction, and the Q _{3, V} is the diopter of the collimator lens group in the vertical direction. The diopter _of the correcting mirror in the vertical direction, the d12 is the distance between the optical window and the collimating lens group, and the _d23 is the distance between the collimating lens group and the correcting mirror spacing between. 3. The laser radar optical system according to claim 2, wherein the focal length of the laser radar optical system in the horizontal direction is the same as the focal length in the vertical direction, comprising: Determine the diopter of the correction mirror in the horizontal direction and the vertical direction according to the diopter of the optical window in the horizontal direction and the vertical direction, so that the diopter of the laser radar optical system in the horizontal direction is the same as that in the vertical direction The diopters in the vertical direction are the same. 4. The lidar optical system according to claim 1, wherein the collimating lens group comprises at least one positive lens and at least one negative lens. 5. The lidar optical system according to claim 4, wherein the correction mirror is a lens. 6 . The lidar optical system according to claim 5 , wherein when the correcting mirror is a lens, the correcting mirror is inserted between the lenses of the collimating lens group. 7. The lidar optical system according to claim 4, wherein the correction mirror is a cylindrical mirror. 8. The lidar optical system according to claim 4, wherein the correcting mirror is a reflecting mirror. 9. The lidar optical system according to any one of claims 1-8, further comprising: a light splitting element; The light splitting element is used to change the transmission direction of the echo light beam and/or the outgoing light beam. 10. The lidar optical system according to any one of claims 1-8, further comprising: a processing unit; The processing unit is respectively connected with the transmitting end and the receiving end, and is used for determining the information of the measured target according to the outgoing light beam and the echo light beam.