Laser radar optical module, laser radar and self-moving device

Abstract

The utility model provides a laser radar optical module, a laser radar and a self-moving device, and relates to the technical field of laser radars. The laser radar optical module comprises a transmitting lens group, a first receiving lens group and a second receiving lens group; the transmitting mirror group is used for receiving a laser beam emitted by the laser light source, deflecting the laser beam and then emitting the laser beam to a target object; the first receiving lens group is used for receiving an echo light beam formed by emission of a target object, collecting the echo light beam and then emitting the echo light beam to the first laser receiver; the second receiving mirror group is used for receiving an echo light beam formed by reflection of the target object, collecting the echo light beam and then emitting the echo light beam to the second laser receiver; wherein the transmitting lens group deflects the laser beam towards the direction of the first receiving lens group. The laser beams are deflected towards the direction of the first receiving lens group through the transmitting lens group, the near-field measurement blind area is reduced, the near-field measurement capability is improved, long-distance measurement is considered in a one-transmitting and two-receiving mode, and the measurement precision of targets at different distances is effectively guaranteed.

Description

Technical Field

[0001] This utility model relates to the field of lidar technology, specifically to a lidar optical module, lidar, and self-moving device. Background Technology

[0002] Most current Time-of-Flight (TOF) optical modules for lidar systems use parallel-axis optical paths. In these paths, the transmitting and receiving mirrors are placed parallel to each other, creating a transmit-receive baseline. This baseline refers to the spatial distance or geometric offset between the transmitter and receiver in the optical system, describing their relative positional relationship along the optical axis. This baseline results in a large near-field blind zone; for example, with an 8mm baseline, the near-field blind zone can reach 20cm. Therefore, triangulation lidar is often used in scenarios with high near-field requirements. However, for long-range measurements, triangulation has extremely low accuracy. Thus, current lidar systems cannot yet achieve both near-range and long-range measurements with equal high precision. Utility Model Content

[0003] In view of the problems existing in the prior art, the present invention provides a lidar optical module, lidar and self-moving device to improve the problem that the existing lidar cannot achieve both long and short distance measurement.

[0004] To achieve the above and other related objectives, the first aspect of this utility model provides a lidar optical module, including a transmitting mirror group, a first receiving mirror group, and a second receiving mirror group; the transmitting mirror group is used to receive a laser beam emitted from a laser source and deflect the laser beam before projecting it onto a target; the first receiving mirror group is used to receive an echo beam reflected from the target and converge the echo beam before projecting it onto a first laser receiver; the second receiving mirror group is used to receive an echo beam reflected from the target and converge the echo beam before projecting it onto a second laser receiver; wherein, the transmitting mirror group deflects the laser beam toward the first receiving mirror group, and the distance between the baseline of the second receiving mirror group and the transmitting mirror group is greater than the distance between the first receiving mirror group and the transmitting mirror group.

[0005] The first receiving mirror group receives the near-field echo beam. The transmitting mirror group deflects the laser beam towards the first receiving mirror group. The angle between the echo beam formed after detecting the target and the first receiving optical axis of the first receiving mirror group is small, increasing the receiving range of the first receiving mirror group at close range, thereby reducing the near-field blind zone and improving near-range ranging capability. The second receiving mirror group receives the long-range echo beam. The distance between the second receiving mirror group and the transmitting mirror group is greater than the distance between the first receiving mirror group and the transmitting mirror group. During long-range measurement, the angle between the long-range echo beam and the second receiving mirror group is small, allowing the second receiving mirror group to deflect the effective signal to the second laser receiver, thus achieving long-range measurement. By deflecting the laser beam towards the first receiving mirror group through the transmitting mirror group, the near-field measurement blind zone is reduced, and the near-field measurement capability is improved. This dual-receiver approach effectively ensures the measurement accuracy of targets at different distances by simultaneously transmitting and receiving the laser beam at a single distance.

[0006] In one embodiment of the present invention, the second receiving mirror group is disposed on the side of the first receiving mirror group away from the transmitting mirror group.

[0007] The transmitting mirror group deflects the laser beam toward the first receiving mirror group. When the second receiving mirror group is located on the side of the first receiving mirror group that is far away from the transmitting mirror group, the laser beam is also deflected toward the second receiving mirror group. Since the second receiving mirror group is farther away from the transmitting mirror group, the second receiving mirror group can receive the echo beam from a farther distance than the first receiving mirror group, thereby improving the long-range ranging capability of the lidar.

[0008] In one embodiment of the present invention, the first receiving mirror group includes a first redirection module, which deflects the echo beam toward the transmitting mirror group.

[0009] The echo beam at close range has a certain angle with the first receiving mirror group. The echo signal is deflected towards the transmitting mirror group by the first redirection module. Even when the incident angle of the echo beam is large, the echo beam can still be emitted to the first laser receiver, maximizing the reception of the echo beam reflected back from close range, reducing the near-field blind zone, and improving the near-field measurement capability.

[0010] In one embodiment of this utility model, the deflection angle of the laser beam by the transmitting mirror group is the same as the deflection angle of the echo beam by the first redirection module, but in the opposite direction.

[0011] The deflection of the laser beam by the reflector group and the deflection of the echo beam by the first redirection module are symmetrical with respect to the baseline. As the distance to the target decreases, the incident angle of the echo beam relative to the first receiving mirror group becomes larger. If the first receiving mirror group still receives the signal in the horizontal direction, then the echo beam returning at a large angle will not be able to reach the limited receiving surface of the first laser receiver. By deflecting the echo beam, the large-angle echo beam returning from a close distance can reach the first laser receiver after being deflected by the first receiving mirror group.

[0012] In one embodiment of this utility model, the first redirection module includes a wedge lens, a freeform lens, or a deflecting lens group.

[0013] The first redirection module can be configured as a wedge lens, a freeform lens that deflects the echo beam toward the direction of the transmitting lens group, or a deflecting lens group that deflects the echo beam toward the direction of the transmitting lens group.

[0014] In one embodiment of the present invention, the first receiving mirror group includes a first beam-gathering module, which is disposed on the side of the first redirection module close to the first laser receiver.

[0015] The first redirection module deflects the received echo beam and sends it to the first beam-gathering module. The first beam-gathering module then gathers the echo beam and sends it to the first laser receiver, making it easier for the first laser receiver to receive echo signals over a wider range.

[0016] In one embodiment of the present invention, the second receiving mirror group includes a second redirection module, which deflects the echo beam toward the transmitting mirror group.

[0017] The second receiving mirror group is responsible for receiving echo signals from a long distance. By deflecting the echo beam through the second redirection module, the receiving range of the second receiving mirror group can be improved, thereby enhancing the ranging capability of the lidar.

[0018] In one embodiment of this utility model, the second redirection module includes a wedge lens, a freeform surface lens, or a deflecting lens group.

[0019] In one embodiment of this utility model, the transmitting mirror group includes a transmitting collimation module and a transmitting redirection module; the transmitting collimation module is used to receive the laser beam emitted by the laser source, collimate it to form a collimated beam, and then emit it; the transmitting redirection module is used to receive the collimated beam and deflect it toward the first receiving mirror group before emitting it.

[0020] By using a transmission collimation module to collimate the laser beam emitted from the laser source and then projecting it as a collimated beam, the quality of the laser beam can be improved. This allows the projected collimated beam to accurately reach the target and return a high-quality echo beam. Furthermore, by using a transmission redirection module to deflect the collimated beam towards the first receiving mirror group, the angle between the echo beam and the first receiving mirror group is reduced, improving the near-field ranging capability of the first receiving mirror group, reducing the near-field ranging blind zone, and effectively enhancing the ranging capability of the lidar.

[0021] In one embodiment of this utility model, the emission redirection module includes a wedge lens, a freeform surface lens, or a deflecting lens group.

[0022] A second aspect of this utility model provides a lidar, comprising a lidar optical module, a laser source, a first laser receiver, and a second laser receiver as described in any of the preceding claims; the laser source is used to emit a laser beam; the first laser receiver is used to receive the echo beam emitted from the first receiving mirror group; and the second laser receiver is used to receive the echo beam emitted from the second receiving mirror group.

[0023] By deflecting the laser beam from the transmitting end toward the first receiving mirror group, the angle between the echo beam and the first receiving mirror group is reduced. This allows the first receiving mirror group to receive echo beams from closer distances, reducing the near-field blind zone and improving near-range ranging capability. By receiving echo beams from farther distances through the second receiving mirror group, the lidar can measure both near and far distances, improving ranging accuracy at both distances.

[0024] A third aspect of this utility model provides a self-moving device, including a device body and the aforementioned lidar, wherein the lidar is disposed on the device body and is used to collect three-dimensional information.

[0025] In combination with existing technologies, the beneficial effects of this utility model are as follows:

[0026] Existing lidar ranging systems mostly use parallel-axis optical designs. The optical baseline between the transmitting and receiving mirror groups results in a large blind zone at close range, leading to inaccurate near-field ranging. Triangulation-based lidar systems have lower accuracy at long distances, thus making it impossible for lidar systems to handle both short and long-range measurements. This invention's lidar optical module includes a transmitting mirror group, a first receiving mirror group, and a second receiving mirror group. The first receiving mirror group receives the near-field echo beam. The transmitting mirror group deflects the laser beam towards the first receiving mirror group. The angle between the echo beam formed after detecting the target and the optical axis of the first receiving mirror group is small, allowing the first receiving mirror group to receive the echo beam from a closer distance, thereby reducing the near-field blind zone and improving near-range ranging capability. The second receiving mirror group receives the long-range echo beam. The distance between the second receiving mirror group and the transmitting mirror group is greater than the distance between the first receiving mirror group and the transmitting mirror group. During long-range measurements, the angle between the long-range echo beam and the second receiving mirror group is small, allowing the second receiving mirror group to deflect the echo beam to a second laser receiver, thus achieving long-range measurement. By deflecting the laser beam towards the first receiving mirror group through the transmitting mirror group, the near-field measurement blind zone is reduced, and the near-field measurement capability is improved. By using a one-transmitter-two-receiver approach, long-distance measurement can also be taken into account, effectively ensuring the measurement accuracy of targets at different distances. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of an exemplary parallel-axis optical design;

[0029] Figure 2 This is a schematic diagram of an exemplary parallel-axis optical receiver;

[0030] Figure 3 This is another exemplary schematic diagram of a parallel-axis optical receiver;

[0031] Figure 4 This is a schematic diagram of an exemplary lidar optical module of this utility model;

[0032] Figure 5 This is a schematic diagram of another exemplary lidar optical module of the present invention.

[0033] Component designation explanation:

[0034] 100, Transmitting mirror group; 110, First incident surface; 120, First exit surface; 200, First receiving mirror group; 210, Second incident surface; 220, Second exit surface; 300, Second receiving mirror group; 310, Third incident surface; 320, Third exit surface; 330, Fourth incident surface; 340, Fourth exit surface; 400, Laser source; 500, First laser receiver; 600, Second laser receiver; 700, Near-range reflecting surface; 800, Far-range reflecting surface. Detailed Implementation

[0035] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. It should also be understood that the terminology used in the embodiments of this utility model is for describing specific implementation schemes and not for limiting the scope of protection of this utility model. Test methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or according to the conditions recommended by the respective manufacturers.

[0036] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise specified in this invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention, as well as the prior art known to those skilled in the art and the description of this invention, may be implemented using any prior art methods, equipment, and materials similar to or equivalent to those in the embodiments of this invention.

[0037] It should be noted that the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity of description and are not intended to limit the scope of implementation of this utility model. Any changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of implementation of this utility model.

[0038] The Time-of-Flight (TOF) method in lidar uses a laser pulse to illuminate a target object and measures the time difference between the pulse's emission and its reflection back to the detector. Since the speed of light in air is constant, the distance between the target object and the lidar can be calculated by multiplying the time difference by the speed of light. Lidar TOF methods are widely used due to their high precision and fast response. Most current lidar TOF optical modules use a parallel-axis optical path, where the transmitting and receiving mirrors are placed parallel to each other. This parallel-axis path, due to the presence of a transmit / receive baseline, results in a relatively large blind zone at close range.

[0039] Please see Figure 1 , Figure 1 This is a schematic diagram of a parallel-axis optical design. In the parallel-axis optical path, the transmitting and receiving mirror groups are placed parallel to each other. The transmitting end emits a laser beam to a reflecting surface, and then the reflecting surface reflects the echo beam, which is received by the receiving end. The incident angle of the echo signal to the receiving module is different at different distances from the reflecting surface; the incident angle of the echo beam from the closer reflecting surface (70°) is greater than that from the farther reflecting surface (80°). Please refer to [link / reference]. Figure 2 , Figure 2 The diagram illustrates the optical path of the echo beam from both near and far-range reflecting surfaces, as it travels through the receiving lens assembly to the laser receiver. At far distances, the echo beam has a smaller angle of incidence relative to the receiving lens, allowing the lens to deflect the effective signal onto the surface of the laser receiver. At near distances, the echo beam's angle relative to the receiving lens assembly is too large, resulting in insufficient deflection angle. Consequently, the echo beam fails to reach the surface of the laser receiver, making distance measurement of the near-range reflecting surface 700 impossible, creating a near-field blind zone. Please refer to [link to relevant documentation]. Figure 3 , Figure 3 The diagram shows the optical path of the echo beam from the reflector at both near and far distances, as it passes through the receiving end lens group to reach the laser receiver. By changing the lens shape and angle, the light deflection angle can be increased, so that the echo beam at near distances can also be deflected into the receiving range. However, with a single lens, the echo beam at far distances will be lost. A comprehensive consideration is needed to make trade-offs, and it is impossible to receive echo beams at both near and far distances.

[0040] Existing technologies using parallel-axis optical paths reduce optical blind spots by compressing the transmit / receive baseline. However, the transmit / receive baseline cannot be infinitely compressed due to current structural manufacturing processes, ranging requirements, and lens size limitations. Referring to currently available LiDARs, the baseline has been compressed to its limit, yet the near-field blind spot remains significant. Therefore, triangulation-based LiDARs are often used in scenarios with high near-field requirements. Triangulation-based LiDAR is a ranging technology based on triangular geometry. It uses a laser emitter to emit a laser beam towards a target object and captures the reflected laser spot through a camera or photodetector. Since the laser emitter, camera or detector, and target object form a triangle, the distance between the target object and the LiDAR can be calculated by measuring the position of the reflected spot on the camera or detector and combining this with the known geometric relationship between the laser emitter and the camera or detector, using triangular geometry principles. However, the accuracy of triangulation-based LiDAR in long-range measurements is far inferior to that of Time-of-Flight (TOF) LiDAR. This results in current LiDARs being unable to simultaneously handle both short and long-range measurements, or in other words, current LiDARs cannot maintain sufficient accuracy in both short and long-range measurements.

[0041] In view of this, this application provides a lidar optical module and lidar. A first receiving mirror group 200 receives the near-field echo beam, and a transmitting mirror group 100 deflects the laser beam towards the first receiving mirror group 200. The angle between the echo beam formed after detecting the target and the first receiving optical axis of the first receiving mirror group 200 is small, allowing the first receiving mirror group 200 to receive echo beams from closer distances, thereby reducing near-field blind spots and improving near-range ranging capability. A second receiving mirror group 300 is used to receive echo beams from longer distances, enabling long-range measurement. By employing a one-transmitter-two-receiver approach, long-range measurement is achieved, effectively ensuring the measurement accuracy of targets at different distances.

[0042] Please see Figure 4 and Figure 5 The first aspect of this utility model provides a lidar optical module, including a transmitting mirror group 100, a first receiving mirror group 200, and a second receiving mirror group 300; the transmitting mirror group 100 is used to receive a laser beam emitted from a laser source 400 and deflect the laser beam before emitting it to a target object; the first receiving mirror group 200 is used to receive an echo beam reflected from the target object and converge the echo beam before emitting it to a first laser receiver 500; the second receiving mirror group 300 is used to converge the echo beam reflected from the target object and emit it to a second laser receiver 600; wherein, the transmitting mirror group 100 deflects the laser beam towards the first receiving mirror group 200, and the distance between the baseline of the second receiving mirror group 300 and the transmitting mirror group 100 is greater than the distance between the first receiving mirror group 200 and the transmitting mirror group 100.

[0043] The first receiving mirror group 200 is used to receive the near-field echo beam. The transmitting mirror group 100 deflects the laser beam towards the first receiving mirror group 200. The angle of incidence of the echo beam formed after detecting the near-range reflecting surface 700 into the first receiving mirror group 200 is small, thus enabling the first receiving mirror group 200 to receive the echo beam from a closer target, thereby reducing the near-field blind zone and improving the near-range ranging capability. The second receiving mirror group 300 is used to receive the echo beam from the far-range reflecting surface 800. The distance between the second receiving mirror group 300 and the transmitting mirror group 100 is greater than the distance between the first receiving mirror group 200 and the transmitting mirror group 100. During long-range measurement, the angle between the echo beam from the far-range reflecting surface 800 and the second receiving mirror group 300 is small, allowing the second receiving mirror group 300 to deflect the echo beam to the second laser receiver 600, thereby achieving the measurement of far-range targets. By deflecting the laser beam towards the first receiving mirror group 200 through the transmitting mirror group 100, the near-field measurement blind zone is reduced and the near-field measurement capability is improved. By using a one-transmitter-two-receiver approach, long-distance measurement can also be taken into account, effectively ensuring the measurement accuracy of targets at different distances.

[0044] Please see Figure 4 and Figure 5 In one embodiment, the transmitting mirror group 100 includes a first incident surface 110 and a first exit surface 120. The laser beam emitted by the laser source 400 enters the transmitting mirror group 100 via the first incident surface 110 and exits via the first exit surface 120. After passing through the transmitting mirror group 100, the laser beam emitted by the laser source 400 is deflected towards the first receiving mirror group 200, thereby reducing the angle between the echo beam reflected from the target and the first receiving mirror group 200, reducing the near-field ranging blind zone, and improving the ranging capability of the lidar. In one embodiment, the transmitting mirror group 100 includes a transmitting collimation module and a transmitting redirection module. The transmitting collimation module receives the laser beam emitted by the laser source 400, collimates it to form a collimated beam, and then emits it. This improves the quality and stability of the laser beam, enabling the emitted collimated beam to accurately reach the target and return a high-quality echo beam. The transmit redirection module is used to deflect the received collimated beam and emit it outwards towards the first receiving mirror group 200, thereby reducing the angle between the echo beam and the first receiving mirror group 200. The first receiving mirror group 200 can receive the echo beam returned by the target at a closer distance, improve the near-field ranging capability of the first receiving mirror group 200, reduce the near-field ranging blind zone, and effectively improve the ranging capability of the lidar.

[0045] In one embodiment, the transmission collimation module is configured as a single aspherical lens. When collimation is achieved using a single aspherical lens, the system cost is low and the assembly and adjustment are simple.

[0046] A single aspherical lens can be either a biconvex single lens or a plano-convex single lens. When the aspherical lens is a biconvex single lens, both its incident and exit surfaces are convex. The focal length is longer in the middle of the lens surface and shorter at the ends of each surface. Biconvex single lenses are mainly used to converge light from point sources or to transmit images to other optical systems. The radii of curvature of its incident and exit surfaces can be equal, giving the lens symmetry, minimizing spherical aberration, and eliminating coma and distortion. Of course, the radii of curvature of the incident and exit surfaces of a biconvex single lens can also be unequal. Alternatively, a single aspherical lens can also be a plano-convex single lens, where one of the incident and exit surfaces is a plane and the other is a convex surface. Specifically, the incident surface can be a plane and the exit surface a convex surface; alternatively, the incident surface can be convex and the exit surface a plane. In this application, the incident surface of the plano-convex single lens is a plane and the exit surface is a convex surface. Of course, the aspherical lens can also be other surface shapes, and is not limited to the above-mentioned biconvex single lens and plano-convex single lens, as long as it enables the system to achieve a collimated beam after shaping.

[0047] In another possible implementation of this application, the transmitting collimation module is configured as a collimating lens group. When collimating with a collimating lens group, it can meet more stringent system size requirements. The collimating lens group may include multiple lenses arranged in sequence to achieve collimation, and the processing accuracy requirements of the lenses themselves are lower than those of a single aspherical lens.

[0048] Of course, as another alternative, the transmitting collimation module can also be configured as a single spherical lens, which can be a biconvex lens or a plano-convex lens. When collimation is achieved using a single spherical lens, the system cost is low and the installation and adjustment are simple. The transmitting collimation module only needs to achieve collimation to form a collimated beam.

[0049] In one embodiment, the emission redirection module is configured as a wedge lens having a wedge-shaped cross-section and a thickness that gradually changes in one direction. When the light beam passes through the wedge lens, it is deflected, thereby changing the direction of light propagation.

[0050] In one embodiment, the wedge lens includes a first plane and a first inclined plane. The collimated beam is perpendicularly incident on the first plane and then deflected out by the first inclined plane in a direction closer to the first receiving lens group 200. This results in a smaller incident angle of the echo beam into the first receiving lens group 200, thereby reducing the near-field blind zone.

[0051] Of course, as some possible approaches, the collimated beam can also enter from the first inclined surface and exit from the first plane.

[0052] In another possible implementation of this application, the emission redirection module is configured as a deflecting lens group. Using a deflecting lens group for collimation can accommodate more stringent system size requirements. The deflecting lens group may include multiple lenses arranged sequentially to deflect the collimated beam, and the machining accuracy requirements of the lenses themselves are lower than those of a single lens.

[0053] Of course, as some alternatives, the transmit redirection module can also be configured as a freeform lens, etc., so that the collimated beam is deflected toward the direction closer to the first receiving mirror group 200.

[0054] In one embodiment, the transmitting lens group 100 is configured as a freeform lens with collimation and deflection capabilities. One side of the freeform lens is a plane, and the other side is an inclined convex surface. Using a freeform lens to achieve collimation and deflection results in low system cost, facilitates the arrangement of the transmitting lens group 100, reduces the size of the optical module, and contributes to the miniaturization of the lidar.

[0055] In another embodiment, the transmitting mirror group 100 is tilted relative to the laser beam emitted by the laser emitter, so that after receiving the laser beam, the transmitting mirror group 100 deflects it towards the first receiving mirror group 200 for emission. The emission angle of the laser beam can be adjusted by adjusting the mounting angle of the transmitting mirror group 100, which facilitates the design and application of the transmitting mirror group 100.

[0056] In one embodiment, the second receiving mirror group 300 is disposed on the side of the first receiving mirror group 200 away from the transmitting mirror group 100. The transmitting mirror group 100 deflects the laser beam toward the first receiving mirror group 200. When the second receiving mirror group 300 is disposed on the side of the first receiving mirror group 200 away from the transmitting mirror group 100, the laser beam is also deflected toward the second receiving mirror group 300, which is more conducive to the second receiving mirror group 300 receiving the echo beam. Since the second receiving mirror group 300 is farther away from the transmitting mirror group 100, the second receiving mirror group 300 can receive the echo beam from a farther distance than the first receiving mirror group 200, thereby improving the long-range ranging capability of the lidar.

[0057] Please see Figure 4 and Figure 5In one embodiment, the first receiving mirror group 200 includes a second incident surface 210 and a second exiting surface 220. The echo beam from the near-field reflecting surface 700 enters the first receiving mirror group 200 via the second incident surface 210 and exits via the second exiting surface 220. There is a certain angle between the echo beam from the near-field reflecting surface 700 and the first receiving mirror group 200. The first receiving mirror group 200 deflects the echo beam toward the transmitting mirror group 100, so that even when the incident angle of the echo beam is large, the echo beam can still be emitted to the first laser receiver 500, maximizing the reception of the echo beam reflected back from the near-field reflecting surface 700 and reducing the near-field blind zone.

[0058] In one embodiment, the first receiving mirror group 200 includes a first redirection module, which deflects the echo beam toward the transmitting mirror group 100. The near-field echo beam has a certain angle with the first receiving mirror group 200. By deflecting the echo beam toward the transmitting mirror group 100 through the first redirection module, even with a large incident angle, the echo beam can still be emitted to the first laser receiver 500, maximizing the reception of the echo beam reflected from the near-field reflecting surface 700, reducing the near-field blind zone, and improving near-field measurement capabilities. Simultaneously, because the echo beam reflected from the far-field reflecting surface 800 will be received by the second receiving mirror group 300, the first redirection module can deflect the echo beam reflected from the near-field reflecting surface 700 at a larger angle, effectively reducing the near-field blind zone.

[0059] In one embodiment, the first redirection module includes a wedge lens, a freeform lens, or a deflecting lens group. The first redirection module can be configured as a wedge lens, a freeform lens that deflects the echo beam toward the direction of the transmitting lens group 100, or a deflecting lens group that deflects the echo beam toward the direction of the transmitting lens group 100, so as to deflect the echo beam toward the transmitting lens group 100.

[0060] In one embodiment, the deflection angle of the laser beam by the transmitting mirror group 100 is the same as, but opposite in direction to, the deflection angle of the echo beam by the first redirection module. The deflection of the laser beam by the transmitting mirror group 100 and the deflection of the echo beam by the first redirection module are symmetrical with respect to the baseline. As the distance to the target object decreases, the angle of incidence of the echo beam from the near-field reflecting surface 700 relative to the first receiving mirror group 200 increases. If the first receiving mirror group 200 still receives the signal in a horizontal direction, the large-angle echo beam will not be able to reach the limited receiving surface of the first laser receiver 500. By deflecting the echo beam, the large-angle echo beam returning from the near field can reach the first laser receiver 500 after being deflected by the first receiving mirror group 200.

[0061] In one embodiment, the first receiving mirror group 200 includes a first beam-receiving module, which is disposed on the side of the first redirection module close to the first laser receiver 500. The first redirection module deflects the received echo beam and then emits it to the first beam-receiving module, which then converges the echo beam and emits it to the first laser receiver 500, thus facilitating the first laser receiver 500 to receive a wider range of echo signals.

[0062] Of course, as an alternative, the first beam-receiving module can also be located on the side of the first redirection module away from the first laser receiver 500.

[0063] The first beam-gathering module can be configured as a single aspherical lens, which can be a biconvex lens or a plano-convex lens. A single aspherical lens system has low cost, is conducive to the arrangement of lens groups, reduces the size of the optical module, and is beneficial to the miniaturization of the lidar. The first beam-gathering module can also be configured as a freeform surface lens to realize the beam-gathering of the echo beam and its output to the first laser receiver 500. The first beam-gathering module can also be configured as a beam-gathering lens group so that the echo beam is gathered and output to the first laser receiver 500.

[0064] Please see Figure 4 In one embodiment, the first redirection module is a freeform lens capable of deflecting and focusing the light beam. One side of the freeform lens is a plane, and the other side is an inclined convex surface. By using a single freeform lens to deflect and focus the echo beam, the number of lenses used is reduced, the size of the lidar optical module is reduced, and this facilitates the miniaturization of the lidar. The echo beam can enter from the plane of the freeform lens and exit from the inclined convex surface to the first laser receiver 500.

[0065] Of course, as an alternative, the echo beam can enter through the convex surface of the freeform lens and exit through the flat surface to the first laser receiver 500.

[0066] Please see Figure 4 In one embodiment, the second receiving mirror group 300 includes a third incident surface 310 and a third exit surface 320. The echo beam formed by the reflection of the far-distance reflecting surface 800 enters the second receiving mirror group 300 through the third incident surface 310 and exits to the second laser receiver 600 through the third exit surface 320. The second receiving mirror group 300 gathers the echo beam formed by the reflection of the far-distance reflecting surface 800 and exits it to the second laser receiver 600, so that the second laser receiver 600 can receive a larger range of echo beams.

[0067] Please see Figure 5In another embodiment, the second receiving mirror group 300 includes a fourth incident surface 330 and a fourth exit surface 340. The echo beam reflected by the far-distance reflecting surface 800 enters the second receiving mirror group 300 via the fourth incident surface 330 and is deflected by the fourth exit surface 340 to the second laser receiver 600. The second receiving mirror group 300 deflects the echo beam reflected by the far-distance reflecting surface 800 toward the direction closer to the transmitting mirror group 100, thereby increasing the receiving range of the second receiving mirror group 300 and thus improving the ranging capability of the lidar.

[0068] In one embodiment, the second receiving mirror group 300 includes a second redirection module, which deflects the echo beam toward the transmitting mirror group 100. The second receiving mirror group 300 is responsible for receiving the echo beam from the far-distance reflecting surface 800. By deflecting the echo beam through the second redirection module, the receiving range of the second receiving mirror group 300 can be increased, thereby improving the ranging capability of the lidar.

[0069] In one embodiment, the second redirection module can be configured as a wedge lens, a freeform lens that deflects the echo beam toward the direction of the transmitting lens group 100, or a deflecting lens group that deflects the echo beam toward the direction of the transmitting lens group 100.

[0070] In one embodiment, the second receiving mirror group 300 includes a second beam-receiving module, which is disposed on the side of the second redirection module close to the second laser receiver 600. The second redirection module deflects the received echo beam and then emits it to the second beam-receiving module, which then converges the echo beam and emits it to the second laser receiver 600, thus facilitating the second laser receiver 600 to receive a wider range of echo signals.

[0071] Of course, as an alternative, the second beam-receiving module can also be located on the side of the second redirection module away from the second laser receiver 600.

[0072] Please see Figure 4 In one embodiment, the second receiving lens group 300 includes an aspherical lens or a spherical lens, wherein the aspherical lens is a plano-convex lens or a biconvex lens, and the spherical lens is a plano-convex lens or a biconvex lens. The second receiving lens group 300 is responsible for receiving echo signals from a long distance. The deflection angle of the echo beam from a long distance does not change much relative to the second receiving lens. Therefore, the second receiving lens group 300 can adopt a parallel-emission lens group, which facilitates the design and assembly of the second receiving lens group 300.

[0073] The second aspect of this utility model provides a lidar, including a lidar optical module as described in any one of the above, a laser source 400, a first laser receiver 500, and a second laser receiver 600; the laser source 400 is used to emit a laser beam; the first laser receiver 500 is used to receive the echo beam emitted from the first receiving mirror group 200; and the second laser receiver 600 is used to receive the echo beam emitted from the second receiving mirror group 300.

[0074] The lidar deflects the laser beam emitted by the laser emitter toward the first receiving mirror group 200, reducing the angle between the echo beam and the first receiving mirror group 200. This allows the first receiving mirror group 200 to receive echo beams from closer ranges, reducing the near-field blind zone and improving near-range ranging capability. The second receiving mirror group 300 receives echo beams from farther ranges, enabling the lidar to perform measurements at both near and far distances, thus improving ranging accuracy at both distances.

[0075] A third aspect of this utility model provides a self-moving device, including a device body and the aforementioned lidar. The lidar is mounted on the device body and is used to collect three-dimensional information. Specifically, the lidar can be installed on the top of the device body or on the side wall of the device body. By configuring the lidar, the self-moving device can improve its ranging capability and near-field ranging accuracy, reduce near-field measurement blind spots, and thus facilitate the planning of the self-moving device's travel path. The self-moving device can be a household appliance such as a robot vacuum cleaner or floor scrubber, a garden tool such as a lawnmower or snowplow, an all-terrain vehicle or car, or other self-moving devices configured with the lidar. The self-moving device also includes other components; please refer to existing self-moving devices, which will not be described in detail here.

[0076] The lidar optical module, lidar, and self-moving device of this invention reduce the near-field blind zone and improve short-range ranging capability, while also taking into account long-range measurement and ensuring ranging accuracy at both short and long distances. Therefore, this invention effectively overcomes some practical problems in the prior art and thus has high utilization value and practical significance.

[0077] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A lidar optical module, characterized in that, include: The transmitting mirror assembly is used to receive the laser beam emitted from the laser source and deflect the laser beam before it is emitted to the target object. The first receiving mirror group is used to receive the echo beam formed by the reflection of the target object, and to converge the echo beam and emit it to the first laser receiver. The second receiving mirror group is used to receive the echo beam formed by the reflection of the target object, and to converge the echo beam and emit it to the second laser receiver. In this configuration, the transmitting mirror group deflects the laser beam toward the first receiving mirror group, and the distance between the second receiving mirror group and the transmitting mirror group is greater than the distance between the first receiving mirror group and the transmitting mirror group.

2. The lidar optical module according to claim 1, characterized in that, The second receiving mirror group is disposed on the side of the first receiving mirror group away from the transmitting mirror group.

3. The lidar optical module according to claim 1, characterized in that, The first receiving mirror group includes a first redirection module, which deflects the echo beam toward the transmitting mirror group.

4. The lidar optical module according to claim 3, characterized in that, The deflection angle of the laser beam by the transmitting mirror group is the same as the deflection angle of the echo beam by the first redirection module, but in the opposite direction.

5. The lidar optical module according to claim 3, characterized in that, The first redirection module includes a wedge lens, a freeform surface lens, or a deflecting lens group.

6. The lidar optical module according to claim 3, characterized in that, The first receiving mirror group includes a first beam-receiving module, which is disposed on the side of the first redirection module close to the first laser receiver.

7. The lidar optical module according to claim 1, characterized in that, The second receiving mirror group includes a second redirection module, which deflects the echo beam toward the transmitting mirror group.

8. The lidar optical module according to claim 7, characterized in that, The second redirection module includes a wedge lens, a freeform lens, or a deflecting lens group.

9. The lidar optical module according to claim 1, characterized in that, The transmitting mirror assembly includes: The transmitting collimation module is used to receive the laser beam emitted by the laser source, collimate it to form a collimated beam, and then emit it. The transmission redirection module is used to receive the collimated beam and deflect it towards the first receiving mirror group before it is emitted.

10. The lidar optical module according to claim 9, characterized in that, The transmission redirection module includes a wedge lens, a freeform surface lens, or a deflecting lens group.

11. A lidar, characterized in that, The laser radar optical module includes any one of claims 1 to 10, and: A laser source used to emit laser beams; The first laser receiver is used to receive the echo beam emitted from the first receiving mirror group; The second laser receiver is used to receive the echo beam emitted from the second receiving mirror group.

12. A self-moving device, characterized in that, The device includes a main body and the lidar as described in claim 11, wherein the lidar is mounted on the main body and is used to collect three-dimensional information.

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