Laser radar transmitting and receiving device and laser radar

Abstract

The invention relates to the technical field of optical detection, and provides a laser radar transmitting and receiving device and a laser radar, the laser radar transmitting and receiving device comprises a transmitting lens group, a first receiving lens group and a second receiving lens group, the transmitting lens group is used for shaping a laser beam and transmitting the shaped laser beam outwards; the first receiving lens group is used for receiving laser echoes, the second receiving lens group is used for receiving the laser echoes, and the entrance pupil diameter of the second receiving lens group is larger than that of the first receiving lens group. Thus, the first receiving lens group can receive and converge short-distance laser echoes at a large angle, the second receiving lens group can receive and converge long-distance laser echoes, and compared with a traditional laser radar transmitting device, the laser radar transmitting device has the advantages of being large in short-distance ranging view field, long in partial view field ranging distance, small in blind area and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of optical detection, and particularly to a lidar transceiver device and a lidar. Background Art

[0002] A lidar is a device that detects parameters of a target object by emitting laser beams. Its working principle is as follows: emit a laser beam (i.e., the transmitted signal) towards the target object, then compare the received echo signal reflected from the target with the transmitted signal, and after appropriate processing, relevant parameters of the target object can be obtained, such as: parameters of the target object's distance, azimuth, altitude, speed, attitude, shape, etc.

[0003] The lidar transceiver device includes a transmitting lens group and a receiving lens group. The transmitting lens group is used to shape the laser beam generated by the laser and emit the shaped laser beam outward. The receiving lens group is used to receive the laser echo reflected by the target object. However, the existing lidar transceiver device has the technical problem of a large blind area and is difficult to achieve a long detection distance. Summary of the Invention

[0004] The purpose of the present invention is to provide a lidar transceiver device and a lidar, aiming to solve the technical problem of the large blind area existing in the existing lidar transceiver device.

[0005] In a first aspect, the present application provides a lidar transceiver device, which includes:

[0006] A transmitting lens group, which is used to shape the laser beam and emit the shaped laser beam outward;

[0007] A first receiving lens group, which is used to receive the laser echo, and the first receiving lens group and the transmitting lens group are arranged substantially parallel;

[0008] A second receiving lens group, which is used to receive the laser echo, and the second receiving lens group and the transmitting lens group are arranged substantially parallel, and the entrance pupil diameter of the second receiving lens group is larger than the entrance pupil diameter of the first receiving lens group.

[0009] In one embodiment, the lidar transceiver device satisfies the following mathematical relationship: 2.8 < ENPD2 / ENPD1 < 5.5; where ENPD1 is the entrance pupil diameter of the first receiving lens group, and ENPD2 is the entrance pupil diameter of the second receiving lens group.

[0010] In one embodiment, the lidar transceiver device satisfies the following mathematical relationship: 2.5 < FOV1 / FOV2 < 4.9; where FOV1 is the maximum field of view angle of the first receiving lens group, and FOV2 is the maximum field of view angle of the second receiving lens group.

[0011] In one embodiment, the lidar transceiver device satisfies the following mathematical relationship: 2.2 < EFL2 / EFL1 < 4; where EFL1 is the paraxial focal length of the first receiving lens group, and EFL2 is the paraxial focal length of the second receiving lens group.

[0012] In one embodiment, the optical parameters of the transmitting lens group and / or the first receiving lens group satisfy the following conditions: the maximum field of view angle is greater than 85° and less than 110°.

[0013] In one embodiment, the optical parameters of the transmitting lens group and / or the first receiving lens group satisfy the following conditions: the paraxial focal length is greater than 20 mm and less than 25 mm.

[0014] In one embodiment, the optical parameters of the transmitting lens group and / or the first receiving lens group satisfy the following conditions: the back focal length is greater than 2.35 mm and less than 4.5 mm.

[0015] In one embodiment, the optical parameters of the transmitting lens group and / or the first receiving lens group satisfy the following conditions: the entrance pupil diameter is greater than 7 mm and less than 13 mm.

[0016] In one embodiment, the transmitting lens group and / or the first receiving lens group includes: a first lens, a second lens, a third lens, and a fourth lens that are sequentially arranged at intervals along the optical axis from the object plane to the image plane; the first lens has a negative refractive power, the second lens has a positive refractive power, the third lens has a positive refractive power, and the fourth lens has a positive refractive power.

[0017] In one embodiment, the side of the first lens close to the object plane is concave, and the side of the first lens close to the image plane is convex.

[0018] In one embodiment, the side of the second lens close to the object plane is concave, and the side of the first lens close to the image plane is convex.

[0019] In one embodiment, the side of the third lens close to the object plane is convex, and the side of the first lens close to the image plane is convex.

[0020] In one embodiment, the side of the fourth lens close to the object plane is convex, and the side of the first lens close to the image plane is flat.

[0021] In one embodiment, the following mathematical relationship is also satisfied: 1.5 < n1 < 1.6, where n1 is the refractive index of the first lens at a wavelength of 905 nm.

[0022] In one embodiment, the following mathematical relationship is also satisfied: 2.0 < n2 < 2.1, where n2 is the refractive index of the second lens at a wavelength of 905 nm.

[0023] In one embodiment, the following mathematical relationship is also satisfied: 1.5 < n3 < 1.6, where n3 is the refractive index of the third lens at a wavelength of 905 nm.

[0024] In one embodiment, the following mathematical relationship is also satisfied: 1.8 < n4 < 1.9, where n4 is the refractive index of the fourth lens at a wavelength of 905 nm.

[0025] In one embodiment, the optical parameters of the second receiving lens group satisfy the following conditions: 24° < FOV2 < 36°, where FOV2 is the maximum field of view angle of the second receiving lens group.

[0026] In one embodiment, the optical parameters of the second receiving lens group satisfy the following conditions: 56 mm < EFL2 < 80 mm, where EFL2 is the paraxial focal length of the second receiving lens group.

[0027] In one embodiment, the optical parameters of the second receiving lens group satisfy the following conditions: 47 mm < BFL2 < 70 mm, where BFL2 is the back focal length of the second receiving lens group.

[0028] In one embodiment, the optical parameters of the second receiving lens group satisfy the following conditions: 20 mm < ENPD2 < 39 mm, where ENPD2 is the entrance pupil diameter of the second receiving lens group.

[0029] In one embodiment, the second receiving lens group includes a fifth lens, a sixth lens, and a seventh lens that are sequentially spaced along the optical axis from the object plane to the image plane; the fifth lens has a positive refractive power; the sixth lens has a negative refractive power; the seventh lens has a positive refractive power.

[0030] In one embodiment, the side of the fifth lens close to the object plane is convex, and the side of the fifth lens close to the image plane is concave.

[0031] In one embodiment, the side of the sixth lens close to the object plane is concave, and the side of the sixth lens close to the image plane is concave.

[0032] In one embodiment, the side of the seventh lens close to the object surface is a toroidal surface, and the side of the seventh lens close to the image surface is a convex surface.

[0033] In one embodiment, the following mathematical relationship is further satisfied: 1.5 < n5 < 1.6, where n5 is the refractive index of the fifth lens at a wavelength of 905 nm.

[0034] In one embodiment, the following mathematical relationship is further satisfied: 2.0 < n6 < 2.1, where n6 is the refractive index of the sixth lens at a wavelength of 905 nm.

[0035] In one embodiment, the following mathematical relationship is further satisfied: 1.5 < n7 < 1.6, where n7 is the refractive index of the seventh lens at a wavelength of 905 nm.

[0036] In one embodiment, the optical axis of the emission lens group and the optical axis of the first receiving lens group are parallel to each other, and the included angle between the optical axis of the second receiving lens group and the optical axis of the emission lens group is between -30° and 30°.

[0037] In one embodiment, at least one of the emission lens group, the first receiving lens group, and the second receiving lens group is a non-reflective optical lens group.

[0038] In one embodiment, the total length of the emission lens group, the first receiving lens group, and the second receiving lens group is less than 70 mm.

[0039] In one embodiment, the second receiving lens group is located on the side of the first receiving lens group away from the emission lens group.

[0040] In one embodiment, the lidar transceiver device further includes a light blocking member, and the light blocking member is located between the emission lens group and the first receiving lens group.

[0041] In a second aspect, the present application provides a lidar, and the lidar includes the lidar transceiver device according to any one of the above.

[0042] The beneficial effects of the lidar transceiver device and the lidar provided by the present invention are as follows: The transmitting lens group, the first receiving lens group, and the second receiving lens group are arranged substantially parallel, and emit laser beams or receive laser echoes in the same or approximately the same direction. The transmitting lens group is used to shape the laser beam and emit the shaped laser beam outward. After the laser beam is reflected by the target object, a laser echo is formed, which is received by the first receiving lens group and the second receiving lens group respectively to detect the target object. The entrance pupil diameter of the second receiving lens group is larger than that of the first receiving lens group. The first receiving lens group can receive and converge the laser echoes at close range, and the second receiving lens group can receive and converge the laser echoes at long range, improving the return of the long-range laser echo to the lidar transceiver device, solving the technical problem of large blind areas existing in the existing lidar transceiver devices. Compared with the traditional lidar transmitting device, it can measure distances both at close range and at long range, and has characteristics such as small blind areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0044] Figure 1 Structural schematic diagram of the lidar transceiver device provided by the embodiment of the present invention;

[0045] Figure 2 Distribution diagram of the transmitting lens group, the first receiving lens group, and the second receiving lens group provided by the embodiment;

[0046] Figure 3 Structural schematic diagram of the transmitting lens group and / or the first receiving lens group provided by the embodiment;

[0047] Figure 4 Structural schematic diagram of the second receiving lens group provided by the embodiment;

[0048] Figure 5 A side view of the transmitting lens group, the first receiving lens group, and the second receiving lens group provided by the embodiment;

[0049] Figure 6 Another side view of the transmitting lens group, the first receiving lens group, and the second receiving lens group provided by the embodiment;

[0050] Figure 7 Field curvature and distortion diagram of the first receiving lens group provided by the embodiment;

[0051] Figure 8The spot diagram of the first receiving lens group provided for the embodiment;

[0052] Figure 9 The field curvature and distortion diagram of the second receiving lens group provided for the embodiment;

[0053] Figure 10 The spot diagram of the second receiving lens group provided for the embodiment.

[0054] Among them, the reference numerals in the figures are as follows:

[0055] 11. Emitting lens group; 12. First receiving lens group; 13. Second receiving lens group; 14. Filter cover; 15. Light blocking member;

[0056] 110. First lens; 111. First side surface; 112. Second side surface;

[0057] 120. Second lens; 121. Third side surface; 122. Fourth side surface;

[0058] 130. Third lens; 131. Fifth side surface; 132. Sixth side surface;

[0059] 140. Fourth lens; 141. Seventh side surface; 142. Eighth side surface;

[0060] 150. Fifth lens; 151. Ninth side surface; 152. Tenth side surface;

[0061] 160. Sixth lens; 161. Eleventh side surface; 162. Twelfth side surface;

[0062] 170. Seventh lens; 171. Thirteenth side surface; 172. Fourteenth side surface. Detailed implementation manners

[0063] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions from beginning to end. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention.

[0064] Referring to "one embodiment" or "embodiment" throughout the specification means that the specific features, structures or characteristics described in connection with the embodiment are included in at least one embodiment of the present application. Therefore, the phrases "in one embodiment" or "in some embodiments" appearing throughout the specification do not all refer to the same embodiment. In addition, in one or more embodiments, the specific features, structures or characteristics can be combined in any suitable manner.

[0065] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0066] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0067] In the present invention, unless otherwise clearly defined and limited, the terms "mounted", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral body; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0068] Embodiment 1

[0069] Please refer to Figure 1 and Figure 2 , the lidar transceiver device provided in this embodiment includes a transmitting lens group 11, a first receiving lens group 12, and a second receiving lens group 13. The transmitting lens group 11 is used to shape the laser beam and emit the shaped laser beam outward. The first receiving lens group 12 is used to receive the laser echo, and the first receiving lens group 12 and the transmitting lens group 11 are arranged substantially parallel. The second receiving lens group 13 is used to receive the laser echo, and the second receiving lens group 13 and the transmitting lens group 11 are arranged substantially parallel. The transmitting lens group 11, the first receiving lens group 12, and the second receiving lens group 13 are arranged substantially parallel, and emit the laser beam or receive the laser echo in the same or substantially the same direction. The angle between the optical axes of the three is between -40° and 40°. The transmitting lens group 11 is used to shape the laser beam and emit the shaped laser beam outward. The laser beam is reflected by the target object to form a laser echo, which is received by the first receiving lens group 12 and the second receiving lens group 13 respectively to detect the target object.

[0070] Among them, the entrance pupil diameter of the second receiving lens group 13 is larger than that of the first receiving lens group 12. The larger the entrance pupil diameter, the more beneficial it is to receive the laser echo from a long distance. In this way, the first receiving lens group 12 can receive and converge the laser echo from a short distance, and the second receiving lens group 13 can receive and converge the laser echo from a long distance, improving the return of the long-distance laser echo to the lidar transceiver device, so that the lidar transceiver device can be used not only for short-distance detection, but also for long-distance detection, which is beneficial to reducing the detection blind area.

[0071] Optionally, the field of view angle of the second receiving lens group 13 is smaller than that of the first receiving lens group 12. The field of view angle is an important factor determining the size of the imaging angle range. Thus, the first receiving lens group 12 improves the short-distance detection angle range, increases the receiving echo angle range of the first receiving lens group 12, and is beneficial to reducing the blind area at the edge position. It can be understood that in other embodiments, according to the actual ranging field of view requirements, through reasonable optical design, it is possible to make the field of view angle of the second receiving lens group 13 equal to or greater than that of the first receiving lens group 12, so as to achieve long-distance large-angle ranging.

[0072] In one embodiment, in combination with Figure 1 , the lidar transceiver device further includes a filter cover 14. The filter cover 14 is arranged on the image side of the transmitting lens group 11, the first receiving lens group 12, and the second receiving lens group 13 to protect the three lens groups.

[0073] Optionally, the filter cover 14 can also transmit the light waveband required by the lidar and filter the light waveband range that is not desired to participate in the detection.

[0074] In one of the embodiments, in combination with Figure 1 and Figure 2 , the second receiving lens group 13 is located on the side of the first receiving lens group 12 away from the transmitting lens group 11, so that the optical axes of the first receiving lens group 12 and the transmitting lens group 11 are as close as possible, which is beneficial to making the radiation areas of the first receiving lens group 12 and the transmitting lens group 11 coincide as much as possible.

[0075] Specifically, the field of view angles of the first receiving lens group 12 and the transmitting lens group 11 are the same. Since their optical axes are basically parallel and adjacent to each other, their field of view angles are basically coincident. The laser beams emitted by the transmitting lens group 11 within its field of view angle are basically received by the first receiving lens group 12 with the same field of view angle, reducing the blind area of the lidar transceiver device and making full use of the field of view angles of the first receiving lens group 12 and the transmitting lens group 11. This avoids using a first receiving lens group 12 with a larger field of view angle and also avoids missing the laser echoes reflected back at close range. Optionally, the optical axis of the first receiving lens group 12 is parallel to the optical axis of the transmitting lens group 11, and the distance between the optical axis of the first receiving lens group 12 and the optical axis of the transmitting lens group 11 is 1 / 2 to 2 times the entrance pupil diameter of the first receiving lens group 12.

[0076] In one embodiment, in combination with Figure 2 , the lidar transceiver device further includes a light blocking member 15, and the light blocking member 15 is located between the transmitting lens group 11 and the first receiving lens group 12. The light blocking member 15 separates the transmitting lens group 11 and the first receiving lens group 12, avoiding crosstalk of the light rays of the two, and preventing the laser beams emitted by the transmitting lens group 11 from entering the first receiving lens group 12 without being reflected by the target object, thereby improving the detection accuracy and accuracy.

[0077] Specifically, the transmitting lens group 11 and the first receiving lens group 12 are symmetrically arranged on both sides of the light blocking member 15, ensuring that the optical axes of the transmitting lens group 11 and the first receiving lens group 12 are as close as possible, and reducing the near-range blind area of the lidar transceiver device.

[0078] Specifically, the second receiving lens group 13 and the transmitting lens group 11 are located on both sides of the light blocking member 15, and the second receiving lens group 13 is located on the side of the first receiving lens group 12 away from the transmitting lens group 11. Based on this, on the one hand, it avoids the laser beams emitted by the transmitting lens group 11 from entering the second receiving lens group 13 without being reflected by the target object, and on the other hand, it is beneficial for the first receiving lens group 12 to obtain a larger effective detection angle at close range, and it is beneficial for the second receiving lens group 13 to focus on receiving the laser echoes reflected back in parallel at long range.

[0079] In some embodiments, the first receiving lens group 12 and the second receiving lens group 13 are spaced apart. The second receiving lens group 13 can receive the near-range laser echoes outside the field of view angle of the first receiving lens group 12 and the near-range laser echoes partially overlapping with the field of view angle of the first receiving lens group 12. Thus, the first receiving lens group 12 and the second receiving lens group 13 can synchronously complete near-range ranging. Later, through software algorithm processing, the near-range test data is corrected according to the data measured by the first receiving lens group 12, achieving the purpose of reducing the ranging blind area.

[0080] Specifically, the lidar transceiver device further includes a receiving device, which is installed between the first receiving lens group 12 and the second receiving lens group 13 and is optically coupled to the first receiving lens group 12 and the second receiving lens group 13 respectively to receive the laser echo transmitted by the first receiving lens group 12 and the second receiving lens group 13.

[0081] In one embodiment, in combination with Figure 1 , the total lengths of the transmitting lens group 11, the first receiving lens group 12, and the second receiving lens group 13 are all less than 70 mm. Since the transmitting lens group 11, the first receiving lens group 12, and the second receiving lens group 13 are arranged substantially parallel and aligned with each other, the total length of the lidar transceiver device is less than 70 mm, which is beneficial to realizing the miniaturization design of the lidar, thereby expanding the application scenarios of the lidar. It can be installed inside a vehicle with a narrow space. At the same time, it is beneficial to the hidden installation of the lidar, avoiding the lidar being exposed and easily damaged, and improving the service life of the lidar.

[0082] In addition, since the total lengths of the transmitting lens group 11, the first receiving lens group 12, and the second receiving lens group 13 are small, they can be set as non-reflective optical lens groups, which is beneficial to reducing the design difficulty of the optical lens group.

[0083] In one embodiment, in combination with Figure 1 , ENPD1 is the entrance pupil diameter of the first receiving lens group 12, ENPD2 is the entrance pupil diameter of the second receiving lens group 13, and ENPD2 and ENPD1 satisfy the following mathematical relationship: 2.8 < ENPD2 / ENPD1 < 5.5. In this way, the ratio range of ENPD2 / ENPD1 ensures a reasonable detection distance discrimination between the two first receiving lens groups 12 and the second receiving lens group 13.

[0084] If the ratio of ENPD2 / ENPD1 is less than 2.8, the energy returned by the first receiving lens group 12 and the second receiving lens group 13 to the detection device is not very different, which means that the ranging distance capabilities of the first receiving lens group 12 and the second receiving lens group 13 are not very different, and it is not conducive to expanding the ranging distance range. If the ratio of ENPD2 / ENPD1 is greater than 5.5, it means that the value of ENPD1 is too small and the value of ENPD2 is too large. The focal length of the first receiving lens group 12 will be too short and the ranging distance will be too short, which means that it focuses intensively on a target object at a very short distance. Or, the focal length of the second receiving lens group 13 will be too long, the ranging field of view will be small, and at the same time, the design difficulty of the lidar transceiver device is large and the processing cost is high.

[0085] In one embodiment, in combination with Figure 1, FOV1 is the maximum field of view angle of the first receiving lens group 12, FOV2 is the maximum field of view angle of the second receiving lens group 13, and FOV1 and FOV2 satisfy the following mathematical relationship: 2.5 < FOV1 / FOV2 < 4.9. In this way, the ratio range of FOV1 / FOV2 ensures a reasonable field of view angle differentiation between the first receiving lens group 12 and the second receiving lens group 13.

[0086] If the ratio of FOV1 / FOV2 is less than 2.5, the difference in the field of view angles between the first receiving lens group 12 and the second receiving lens group 13 is small, and the field of view angle of the first receiving lens group 12 is not large enough to achieve the purpose of blind area filling, and it is difficult to detect target objects located outside the field of view of the second lens group 13. If the ratio of FOV1 / FOV2 is greater than 4.9, the field of view angle of the first receiving lens group 12 relative to the second receiving lens group 13 will be significantly too large, which means that the field of view angle of the second receiving lens group 13 is too small, resulting in an insufficient field of view for long-distance detection, and only partial information of the target object located at a long distance can be detected, and the complete information of the target object cannot be accurately identified.

[0087] In one embodiment, combined with Figure 1 , EFL1 is the paraxial focal length of the first receiving lens group 12, EFL2 is the paraxial focal length of the second receiving lens group 13, and EFL1 and EFL2 satisfy the following mathematical relationship: 2.2 < EFL2 / EFL1 < 4. In this way, the ratio range of EFL2 / EFL1 ensures an appropriate focal length differentiation between the first receiving lens group 12 and the second receiving lens group 13. The two receiving lens groups can provide complementary focal length ranges, thereby achieving more accurate and flexible object distance detection and imaging effects. This will help optimize the system performance and meet the application requirements.

[0088] If the ratio of EFL2 / EFL1 is less than 2.2, the focal lengths of the two receiving lens groups are close, and the ranging capabilities are basically the same. If the ratio of EFL2 / EFL1 is greater than 4, the focal length of the second receiving lens group 13 relative to the focal length of the first receiving lens group 12 will be significantly larger, the total length of the first receiving lens group 12 is too short or the total length of the second receiving lens group 13 is too long, increasing the design difficulty.

[0089] In one embodiment, combined with Figure 2 and Figure 3 , the optical parameter FOV1 of the first receiving lens group 12 satisfies the following condition: 85° < FOV1 < 110°. Based on this, it is ensured that the first receiving lens group 12 has a wider field of view angle and reduces the field of view blind area at close range.

[0090] In one embodiment, combined with Figure 2 and Figure 3, the optical parameter EFL1 of the first receiving lens group 12 satisfies the following condition: 20 mm < EFL1 < 25 mm. Based on this, it is ensured that the first receiving lens group 12 obtains clear images at close range, improving the close-range detection ability.

[0091] In one embodiment, the back focal length BFL1 of the first receiving lens group 12 satisfies the following condition: 2.35 mm < BFL1 < 4.5 mm. Based on this, the back focal length BFL1 of the first receiving lens group 12 is relatively small, which is beneficial to optimizing the spatial layout, reducing the total length of the first receiving lens group 12, and ensuring the reliable installation and integration of the first receiving lens group 12.

[0092] In one embodiment, the optical parameter ENPD1 of the first receiving lens group 12 satisfies the following condition: 7 mm < ENPD1 < 13 mm. Based on this, it is ensured that the first receiving lens can clearly obtain the laser echo at close range, while avoiding the situation where relatively more light may be truncated or blocked when ENPD1 is less than 7 mm, resulting in a decrease in the energy received by the detection device.

[0093] In some embodiments, combined with Figure 2 and Figure 3 , the maximum field of view angle FOV3 of the emission lens group 11 satisfies the following condition: 85° < FOV3 < 110°, ensuring that the emission lens group 11 has a wider field of view angle and realizing a wide-angle emitted laser beam.

[0094] In some embodiments, combined with Figure 2 and Figure 3 , the paraxial focal length EFL3 of the emission lens group 11 satisfies the following condition: 20 mm < EFL3 < 25 mm. Based on this, it is ensured that the emission lens group 11 has a relatively wide field of view angle, a relatively large depth of field range, and can keep more objects far from the focal plane clear.

[0095] In some embodiments, combined with Figure 2 and Figure 3 , the back focal length BFL3 of the emission lens group 11 satisfies the following condition: 2.35 mm < BFL3 < 4.5 mm. Based on this, the back focal length BFL3 of the emission lens group 11 is relatively small, which is beneficial to optimizing the spatial layout, reducing the total length of the emission lens group 11, and ensuring the reliable installation and integration of the emission lens group 11.

[0096] In some embodiments, combined with Figure 2 and Figure 3 , the entrance pupil diameter ENPD3 of the emission lens group 11 satisfies the following condition: 7 mm < ENPD3 < 13 mm. Based on this, it is ensured that the emission lens group 11 outputs an appropriate light flux and has a suitable size, which is beneficial to the miniaturized design of the emission lens group 11.

[0097] Optionally, the maximum field of view angle, paraxial focal length, back focal length and entrance pupil diameter of the emitting lens group 11 and the first receiving lens group 12 are the same, so that the two can be coaxially arranged, the field of view angles are easily overlapped, blind spots are reduced, coordination is better, and the difficulty of designing optical parameters is reduced.

[0098] In some embodiments, in combination Figure 1 and Figure 3 , the first receiving lens group 12 includes a first lens 110, a second lens 120, a third lens 130 and a fourth lens 140 which are arranged in sequence along the optical axis from the object plane to the image plane. The object plane refers to the side close to the inside of the laser radar, and the image plane is close to the side of the outside of the laser radar. The first lens 110 has a negative refractive power and is used to emit the laser beam, thereby expanding the field of view and reducing the blind spot. The second lens 120 has a positive refractive power, the third lens 130 has a positive refractive power, and the fourth lens 140 has a positive refractive power, which continuously reduces the beam aperture. If only one lens with a positive refractive power is used, the same focusing effect cannot be achieved, and a single lens with a large positive refractive power has a large imaging distortion. The first lens 110 has a negative refractive power and is used to emit the laser beam, so that the laser echo is horizontally converged on the photosensitive surface of the detection device. At the same time, the air gap between adjacent lenses is used to correct aberrations to avoid the problem that the bonding surface is prone to aberrations due to contact bonding between lenses, and the gap between the lenses is conducive to increasing the stroke of the beam and gradually reducing the aperture of the beam.

[0099] As the diameter of the light beam gradually decreases, the diameters of the fourth lens 140, the third lens 130, the second lens 120 and the first lens 110 gradually increase, and the next lens can receive the light beam emitted by the previous lens. Such a design is conducive to the reasonable distribution of the diameter of the lens, which is conducive to maximizing the use of the size of the lens and reducing the diameter of the downstream lens as much as possible, which is conducive to the miniaturization and lightweight design of the first receiving lens group 12.

[0100] Specifically, the intervals between the first lens 110 and the second lens 120 on the center line of the optical axis, the intervals between the second lens 120 and the third lens 130 on the center line of the optical axis, and the intervals between the third lens 130 and the fourth lens 140 on the center line of the optical axis gradually increase. Since the divergence angle of the downstream laser beam is large, it is beneficial to quickly expand the beam aperture.

[0101] Optionally, the distance between the third lens 130 and the fourth lens 140 on the optical axis centerline is 10 to 50 times the distance between the second lens 120 and the third lens 130 on the optical axis centerline. The light beam emitted by the third lens 130 has a smaller divergence angle and requires a large stroke to reduce the aperture.

[0102] In one embodiment, in combination Figure 3, one side of the first lens 110 close to the object surface is concave, and one side close to the image surface is convex, which are both conducive to the diffusion of the light beam. Therefore, the reverse incidence is conducive to quickly reducing the divergence angle of the light beam. Specifically, the first lens 110 has a first side 111 close to the object surface and a second side 112 close to the image surface. The first side 111 is concave, and the second side 112 is convex. The first side 111 and the second side 112 can be either spherical surfaces or aspherical surfaces.

[0103] In one embodiment, combined with Figure 3 , one side of the second lens 120 close to the object surface is concave, and one side of the first lens 110 close to the image surface is convex, so that the second lens 120 has a positive refractive power and the absolute value of the refractive power is small, avoiding excessive deflection of the light beam and generating aberrations, and the light beam remains convergent, which is conducive to further reducing the beam diameter. Specifically, the second lens 120 has a third side 121 close to the object surface and a fourth side 122 close to the image surface. The third side 121 is concave, and the fourth side 122 is convex.

[0104] In one embodiment, combined with Figure 3 , one side of the third lens 130 close to the object surface is convex, and one side of the first lens 110 close to the image surface is convex, so that the third lens 130 has a positive refractive power and the absolute value of the refractive power is relatively large, which can further increase the angle of the light beam. The light beam remains convergent. On the one hand, it is conducive to further reducing the beam diameter, and on the other hand, it avoids excessive deflection. Specifically, the third lens 130 has a fifth side 131 close to the object surface and a sixth side 132 close to the image surface. The fifth side 131 is convex, and the sixth side 132 is convex.

[0105] In one embodiment, combined with Figure 3 , one side of the fourth lens 140 close to the object surface is convex, and one side of the first lens 110 close to the image surface is flat, so that the fourth lens 140 has a positive refractive power to converge the light beam. Specifically, the fourth lens 140 has a seventh side 141 close to the object surface and an eighth side 142 close to the image surface. The seventh side 141 is convex, and the eighth side 142 is flat. The seventh side 141 and the eighth side 142 can be either spherical surfaces or aspherical surfaces.

[0106] In one embodiment, n1 is the refractive index of the first lens 110 at a wavelength of 905 nm, and n1 satisfies the following mathematical relationship: 1.5 < n1 < 1.6. Thus, the first lens 110 belongs to a low-refractive-index lens. Optionally, the refractive index n1 of the first lens 110 is 1.53, 1.55, 1.57, 1.58 or 1.60.

[0107] In one embodiment, n2 is the refractive index of the second lens 120 at a wavelength of 905 nm, and n2 satisfies the following mathematical relationship: 2.0 < n2 < 2.1. In this way, the refractive index n2 of the second lens 120 is relatively high, which can well correct the angular deviation generated by the first lens 110. Optionally, the refractive index n2 of the second lens 120 is 2.0, 2.02, 2.05, 2.08, or 2.1.

[0108] In one embodiment, n3 is the refractive index of the third lens 130 at a wavelength of 905 nm, and n3 satisfies the following mathematical relationship: 1.5 < n3 < 1.6. In this way, the third lens 130 is a low-refractive-index lens. Optionally, the refractive index n3 of the third lens 130 is 1.53, 1.55, 1.57, 1.58, or 1.60.

[0109] In one embodiment, n4 is the refractive index of the fourth lens 140 at a wavelength of 905 nm, and n4 satisfies the following mathematical relationship: 1.8 < n4 < 1.9. In this way, the refractive index n4 of the fourth lens 140 is relatively high, which can well correct the angular deviation generated by the third lens 130. Optionally, the refractive index n4 of the fourth lens 140 is 1.8, 1.82, 1.85, 1.88, or 1.9.

[0110] Specifically, the materials of the first lens 110, the second lens 120, the third lens 130, and the fourth lens 140 can be glass, plastic, or a glass-plastic hybrid material, which is not specifically limited herein.

[0111] In this way, the first receiving lens group 12 is composed of the first lens 110, the second lens 120, the third lens 130, and the fourth lens 140. By reasonable surface shape matching, small aberration can be ensured, the spot passing through the first receiving lens group 12 is clear, has high sharpness, the spot aberration passing through the first receiving lens group 12 is small, and the energy is concentrated within the photosensitive surface of the detection device. Moreover, the optical design with a large field of view can enable the echo signals generated at the edge position to be received by the first receiving lens group 12, ensuring a large ranging field of view.

[0112] In addition, specifically, the first receiving lens group 12 only includes the above four lenses, and the small number of lenses helps to reduce the volume of the optical lens and lower the cost. Combining Figure 7 , for a wavelength of 905 nm, within the range of 0 - 45° field of view angle, the sagittal field curvature of the first receiving lens group 12 is less than or equal to 0.715 mm, the meridional field curvature is less than or equal to 0.153 mm, and the maximum distortion is less than 25%. Combining Figure 8, for a wavelength of 905 nm, the image quality of the first receiving lens group 12 is better, the RMS radius (representing the radius of the central circle containing all the light rays at the reference point) is less than 65 μm, and the GEO radius is less than 150 μm. Specifically, when the object surface is 30°, the RMS radius is the largest, at this time the RMS radius is 63.336 μm, and the GEO radius is 144.497 μm. When the object surface is 20°, the GEO radius is the largest, at this time the RMS radius is 60.251 μm, and the GEO radius is 147.895 μm. When the object surface is 0, the RMS radius and the GEO radius are the smallest, at this time, the RMS radius is 50.529 μm, and the GEO radius is 105.276 μm.

[0113] In some embodiments, referring to Figure 1 and Figure 3 , the emission lens group 11 includes a first lens 110, a second lens 120, a third lens 130, and a fourth lens 140 that are sequentially arranged at intervals along the optical axis from the object surface to the image surface. The first lens 110 has a negative refractive power, the second lens 120 has a positive refractive power, the third lens 130 has a positive refractive power, and the fourth lens 140 has a positive refractive power. The first lens 110 has a negative refractive power for emitting a laser beam, thereby expanding the field of view angle and reducing the blind area. The second lens 120 has a positive refractive power, the third lens 130 has a positive refractive power, and the fourth lens 140 has a positive refractive power, and the divergence angle of the laser beam gradually decreases, so that the finally output laser beam has a relatively small divergence angle and is relatively parallel. If only a lens with a positive refractive power is used, the same focusing effect cannot be achieved, and the imaging distortion of a single lens with a large positive refractive power is large. At the same time, the air gap between adjacent lenses is used to correct aberrations, avoiding the problem that the cemented surface is prone to generate aberrations due to the contact and cementing of the lenses, and the gap between the lenses is conducive to increasing the formation of the light beam and gradually expanding the aperture of the light beam.

[0114] Specifically, in combination with Figure 3, the first lens 110, the second lens 120, the third lens 130, and the fourth lens 140 of the emission lens group 11 can be the same as the above introduction, that is, the emission lens group 11 and the first receiving lens group 12 adopt the same structure, which is conducive to reducing the types of components. For example, the side of the first lens 110 close to the object surface is concave, and the side of the first lens 110 close to the image surface is convex. The side of the second lens 120 close to the object surface is concave, and the side of the first lens 110 close to the image surface is convex. The side of the third lens 130 close to the object surface is convex, and the side of the first lens 110 close to the image surface is convex. The side of the fourth lens 140 close to the object surface is convex, and the side of the first lens 110 close to the image surface is flat, etc., which will not be elaborated one by one here. It should be noted that the laser beam of the emission lens group 11 exits from the first lens 110 to the fourth lens 140, and the beam aperture gradually increases. The laser echo of the first receiving lens group 12 is incident from the fourth lens 140 to the first lens 110, and the beam aperture gradually decreases.

[0115] In this embodiment, the second receiving lens group 13 is a small field of view, long focal length, and large aperture lens group compared with the first receiving lens group 12, which can ensure that the overlapping area of the second receiving lens group 13 and the first receiving lens group 12 has a longer ranging ability; at the same time, the small field of view, long focal length, and large aperture system are beneficial to improving the angular resolution of the radar system.

[0116] In one embodiment, in combination with Figure 1 and Figure 2 , the FOV2 of the second receiving lens group 13 satisfies the following condition: 24° < FOV2 < 36°. Based on this, it is ensured that the second receiving lens group 13 can better focus the echo energy, increase the detection range, and reduce the field of view blind area at a long distance.

[0117] In one embodiment, in combination with Figure 1 and Figure 2 , the EFL2 of the second receiving lens group 13 satisfies the following condition: 56mm < EFL2 < 80mm. Based on this, it is ensured that there is sufficient space for arranging the receiving device.

[0118] In one embodiment, the back focal length BFL2 of the second receiving lens group 13 satisfies the following condition: 47mm < BFL2 < 70mm. Based on this, the back focal length BFL2 of the second receiving lens group 13 is relatively large, which is beneficial to increasing the detection range, enhancing the focusing and collecting ability of light. Moreover, the larger back focal length can reduce the occurrence of distortion and make the long-distance imaging more real and accurate.

[0119] In one embodiment, the ENPD2 of the second receiving lens group 13 satisfies the following condition: 20 mm < ENPD2 < 39 mm. Based on this, the second receiving lens group 13 can receive more echo signals, ensuring a relatively long ranging ability.

[0120] In some embodiments, in combination with Figure 1 and Figure 4 , the second receiving lens group 13 includes a fifth lens 150, a sixth lens 160, and a seventh lens 170 that are sequentially arranged at intervals along the optical axis from the object surface to the image surface. The fifth lens 150 has a positive refractive power, the sixth lens 160 has a negative refractive power, and the seventh lens 170 has a positive refractive power, so as to gradually reduce the aperture of the laser echo, and the sixth lens 160 can correct the light beam of the seventh lens 170 to improve aberration. Based on the above lens arrangement, lens surface shape design, and optical power distribution, the aberration distribution is relatively reasonable, enabling the optical lens to have better image quality.

[0121] In one embodiment, in combination with Figure 4 , the side of the fifth lens 150 close to the object surface is convex, and the side of the fifth lens 150 close to the image surface is concave, both of which are conducive to the convergence of the light beam. Specifically, the fifth lens 150 has a ninth side surface 151 close to the object surface and a tenth side surface 152 close to the image surface. The ninth side surface 151 is convex, and the tenth side surface 152 is concave. The ninth side surface 151 and the tenth side surface 152 can be either spherical surfaces or aspherical surfaces.

[0122] In one embodiment, in combination with Figure 4 , the side of the sixth lens 160 close to the object surface is concave, and the side of the sixth lens 160 close to the image surface is concave, both of which are conducive to the diffusion of the light beam, which is conducive to increasing the divergence angle of the callback light beam, but the light beam still remains in a converging state. Specifically, the sixth lens 160 has an eleventh side surface 161 close to the object surface and a twelfth side surface 162 close to the image surface. The eleventh side surface 161 is concave, and the twelfth side surface 162 is concave.

[0123] In one embodiment, the side of the seventh lens 170 close to the object surface is a toroidal surface, and the side of the seventh lens 170 close to the image surface is convex, both of which are conducive to the convergence of the light beam. Specifically, the seventh lens 170 has a thirteenth side surface 171 close to the object surface and a fourteenth side surface 172 close to the image surface. The thirteenth side surface 171 is a toroidal surface, and the fourteenth side surface 172 is convex. The toroidal surface is used to correct the astigmatism and field curvature caused by the filter cover 14.

[0124] In one embodiment, n5 is the refractive index of the fifth lens 150 at a wavelength of 905 nm, and n5 satisfies the following mathematical relationship: 1.5 < n5 < 1.6. Thus, the fifth lens 150 belongs to a low-refractive-index lens. Optionally, the refractive index n5 of the fifth lens 150 is 1.53, 1.55, 1.57, 1.58, or 1.60.

[0125] In one embodiment, n6 is the refractive index of the sixth lens 160 at a wavelength of 905 nm, and n6 satisfies the following mathematical relationship: 2.0 < n6 < 2.1. Thus, the refractive index n6 of the sixth lens 160 is relatively high, and it can well correct the angular deviation generated by the seventh lens 170. Optionally, the refractive index n6 of the sixth lens 160 is 2.0, 2.02, 2.05, 2.08, or 2.1.

[0126] In one embodiment, n7 is the refractive index of the seventh lens 170 at a wavelength of 905 nm, and n7 satisfies the following mathematical relationship: 1.5 < n7 < 1.6. Thus, the seventh lens 170 belongs to a low-refractive-index lens. Optionally, the refractive index n7 of the seventh lens 170 is 1.53, 1.55, 1.57, 1.58, or 1.60.

[0127] Specifically, the materials of the fifth lens 150, the sixth lens 160, and the seventh lens 170 can be glass, plastic, or a glass-plastic hybrid material, and no specific limitation is made here. Optionally, the second receiving lens group 13 is composed of the fifth lens 150, the sixth lens 160, and the seventh lens 170.

[0128] Combined with Figure 9 , for a wavelength of 905 nm, within the 0 - 45° field of view range, the sagittal field curvature of the second receiving lens group 13 is less than or equal to 0.52 mm, the meridional field curvature is less than or equal to 0.50 mm, and the maximum distortion is less than 1%. Combined with Figure 10 , for a wavelength of 905 nm, the image quality of the second receiving lens group 13 is good, the RMS radius (representing the radius of the central circle containing all rays at the reference point) is less than 45 μm, and the GEO radius is less than 105 μm. Specifically, when the object plane is 16°, the RMS radius is the largest, and at this time, the RMS radius is 44.722 μm and the GEO radius is 98.576 μm. When the object plane is 0, the GEO radius is the largest, and at this time, the RMS radius is 35.092 μm and the GEO radius is 102.455 μm. When the object plane is 8°, the RMS radius is the smallest, and at this time, the RMS radius is 31.264 μm and the GEO radius is 92.600 μm. When the object plane is 12°, the GEO radius is the smallest, and at this time, the RMS radius is 38.698 μm and the GEO radius is 87.337 μm.

[0129] In some embodiments, combined with Figure 5 andFigure 6 The optical axis of the emission lens group 11 and the optical axis of the first receiving lens group 12 are parallel to each other, and the included angle θ between the optical axis of the second receiving lens group 13 and the optical axis of the emission lens group 11 is between -30° and 30°. The included angle θ can be selected as -30°, -20°, -10°, 0, 10°, 20° or 30°.

[0130] Under normal circumstances, the included angle θ is zero, ensuring that the ranging ability of the central field of view is relatively far. The field of view with a relatively far ranging ability is generally the FOV2 of the second receiving lens group 13. During actual use, the included angle θ can be adjusted according to the actual project requirements, and the field of view for long-distance ranging will be adjusted to FOV2 - θ to FOV2 + θ. For example, when the value of θ is 5°, the field of view for long-distance ranging will be adjusted to FOV2 - 5° to FOV2 + 5°.

[0131] Embodiment 2

[0132] The present application also provides a lidar, including any one of the lidar transceiver devices in Embodiment 1. Correspondingly, the lidar receives laser echoes at different distances by means of the first receiving lens group 12 and the second receiving lens group 13, and can not only be used for short-distance detection, but also detect long distances, which is beneficial to reducing the detection blind area.

[0133] In addition, the lidar generally further includes a housing, and the lidar transceiver device is installed in the housing.

[0134] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A lidar transceiver device, characterized in that, the lidar transceiver device includes: a transmitting lens group for shaping a laser beam and emitting the shaped laser beam outward; a first receiving lens group for receiving laser echoes, and the first receiving lens group and the transmitting lens group are arranged substantially parallel; a second receiving lens group for receiving laser echoes, the second receiving lens group and the transmitting lens group are arranged substantially parallel, and the entrance pupil diameter of the second receiving lens group is greater than the entrance pupil diameter of the first receiving lens group.

2. The lidar transceiver device according to claim 1, characterized in that, the lidar transceiver device satisfies the following mathematical relationship: 2.8 < ENPD2 / ENPD1 < 5.5; where ENPD1 is the entrance pupil diameter of the first receiving lens group, and ENPD2 is the entrance pupil diameter of the second receiving lens group.

3. The lidar transceiver device according to claim 1, characterized in that, the lidar transceiver device satisfies the following mathematical relationship: 2.5 < FOV1 / FOV2 < 4.9; where FOV1 is the maximum field of view angle of the first receiving lens group, and FOV2 is the maximum field of view angle of the second receiving lens group.

4. The lidar transceiver device according to claim 1, characterized in that, the lidar transceiver device satisfies the following mathematical relationship: 2.2 < EFL2 / EFL1 < 4; where EFL1 is the paraxial focal length of the first receiving lens group, and EFL2 is the paraxial focal length of the second receiving lens group.

5. The lidar transceiver device according to claim 1, characterized in that, the optical parameters of the transmitting lens group and / or the first receiving lens group satisfy the following conditions: the maximum field of view angle is greater than 85° and less than 110°; the paraxial focal length is greater than 20 mm and less than 25 mm; the back focal length is greater than 2.35 mm and less than 4.5 mm; the entrance pupil diameter is greater than 7 mm and less than 13 mm.

6. The lidar transceiver device according to claim 1, characterized in that, the transmitting lens group and / or the first receiving lens group includes: a first lens, a second lens, a third lens, and a fourth lens sequentially arranged at intervals along the optical axis from the object plane to the image plane; the first lens has a negative refractive power, the second lens has a positive refractive power, the third lens has a positive refractive power, and the fourth lens has a positive refractive power.

7. The lidar transceiver device according to claim 6, characterized in that: the side of the first lens close to the object plane is concave, and the side of the first lens close to the image plane is convex; the side of the second lens close to the object plane is concave, and the side of the first lens close to the image plane is convex; the side of the third lens close to the object plane is convex, and the side of the first lens close to the image plane is convex; the side of the fourth lens close to the object plane is convex, and the side of the first lens close to the image plane is flat.

8. The lidar transceiver device according to claim 6, characterized in that, it also satisfies the following mathematical relationship: 1.5 < n1 < 1.6, where n1 is the refractive index of the first lens at a wavelength of 905 nm; 2.0 < n2 < 2.1, where n2 is the refractive index of the second lens at a wavelength of 905 nm; 1.5 < n3 < 1.6, where n3 is the refractive index of the third lens at a wavelength of 905 nm; 1.8 < n4 < 1.9, where n4 is the refractive index of the fourth lens at a wavelength of 905 nm.

9. The lidar transceiver device according to claim 1, characterized in that, the optical parameters of the second receiving lens group satisfy the following conditions: 24° < FOV2 < 36°, where FOV2 is the maximum field of view angle of the second receiving lens group; 56 mm < EFL2 < 80 mm, where EFL2 is the paraxial focal length of the second receiving lens group; 47 mm < BFL2 < 70 mm, where BFL2 is the back focal length of the second receiving lens group; 20 mm < ENPD2 < 39 mm, where ENPD2 is the entrance pupil diameter of the second receiving lens group.

10. The lidar transceiver device according to claim 1, characterized in that: the second receiving lens group includes a fifth lens, a sixth lens, and a seventh lens that are sequentially spaced along the optical axis from the object plane to the image plane; the fifth lens has a positive refractive power; the sixth lens has a negative refractive power; the seventh lens has a positive refractive power.

11. The lidar transceiver device according to claim 10, characterized in that: the side of the fifth lens close to the object plane is convex, and the side of the fifth lens close to the image plane is concave; the side of the sixth lens close to the object plane is concave, and the side of the sixth lens close to the image plane is concave; the side of the seventh lens close to the object plane is a spherical cylinder, and the side of the seventh lens close to the image plane is convex.

12. The lidar transceiver device according to claim 10, characterized in that, the following mathematical relationship is also satisfied: 1.5 < n5 < 1.6, where n5 is the refractive index of the fifth lens at a wavelength of 905 nm; 2.0 < n6 < 2.1, where n6 is the refractive index of the sixth lens at a wavelength of 905 nm; 1.5 < n7 < 1.6, where n7 is the refractive index of the seventh lens at a wavelength of 905 nm.

13. The lidar transceiver device according to claim 1, characterized in that: the optical axis of the transmitting lens group and the optical axis of the first receiving lens group are parallel to each other, and the angle between the optical axis of the second receiving lens group and the optical axis of the transmitting lens group is between -30° and 30°.

14. The lidar transceiver device according to claim 1, characterized in that, the lidar transceiver device further includes at least one of the following: at least one of the transmitting lens group, the first receiving lens group, and the second receiving lens group is a non-reflective optical lens group; the total lengths of the transmitting lens group, the first receiving lens group, and the second receiving lens group are all less than 70 mm.

15. A lidar, characterized in that, The lidar includes the lidar transceiver device according to any one of claims 1 to 14.

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