Scanning device and laser radar

Abstract

The utility model discloses a scanning device and a laser radar, and relates to the technical field of laser radars. The scanning device comprises a rotation driving assembly, a support, a reflector and a swing driving assembly. The rotation driving assembly comprises a stator and a rotor, the support is connected to the rotor, and the reflector is rotatably connected to the support. The swing driving assembly comprises a first coil winding and a first magnet, the first coil winding is fixed relative to the position of a stator of the rotation driving assembly, and the first magnet is connected to the reflector so that a magnetic field generated by the first coil winding can drive the reflector to swing relative to the support. The rotation driving assembly and the swing driving assembly are combined to jointly control the posture of the reflecting mirror, and two-dimensional scanning can be achieved only through one reflecting mirror. The scanning device provided by the utility model is simple and compact in structure, is beneficial to realizing miniaturization of equipment, and is relatively low in cost. The laser radar provided by the utility model comprises the scanning device.

Description

Technical Field

[0001] This application relates to the technical field of lidar, and more particularly, to a scanning device and a lidar. Background Art

[0002] The scanning device of a lidar has a significant impact on the radar point cloud effect. The scanning device is expected to achieve a large field of view, high reliability, and low cost. To achieve two-dimensional scanning of a lidar, the scanning devices in the prior art often have a complex structure, poor stability, and it is difficult to miniaturize the device. Summary of the Utility Model

[0003] The objectives of this application include providing a scanning device and a lidar. The structure of the scanning device is simple and compact, with better stability, which is conducive to the miniaturization of the device.

[0004] The embodiments of this application can be implemented as follows:

[0005] In a first aspect, this application provides a scanning device, including:

[0006] A rotation driving component, including a stator and a rotor cooperating with the stator.

[0007] A bracket, connected to the rotor;

[0008] A mirror, rotatably connected to the bracket;

[0009] A swing driving component, including a first coil winding and a first magnet, the first magnet being connected to the mirror so that the magnetic field generated by the first coil winding can drive the mirror to swing relative to the bracket.

[0010] In an optional embodiment, the position of the first coil winding is fixed relative to the stator of the rotation driving component.

[0011] In an optional embodiment, the stator includes a second coil winding, and the rotor includes a second magnet.

[0012] In an optional embodiment, the second coil winding is disposed around the outside of the second magnet.

[0013] In an optional embodiment, the second magnet is a magnetic ring and is disposed around the outside of the first coil winding.

[0014] In an optional embodiment, the first magnet is connected to the end of the mirror close to the first coil winding.

[0015] In an alternative embodiment, the first magnet is a single-pole magnet, and the edge of the mirror is connected to the first magnet along the boundary line between the two magnetic poles of the first magnet.

[0016] In an alternative embodiment, the mirror is a double-sided mirror.

[0017] In an alternative embodiment, the scanning device further includes a first sensor and a second sensor. The first sensor is used to detect the rotational position of the rotor relative to the stator, and the second sensor is used to detect the rotational position of the mirror relative to the bracket.

[0018] In an alternative embodiment, the first sensor and the second sensor are optoelectronic sensors or Hall sensors.

[0019] In an alternative embodiment, an elastic member is provided on the bracket. The mirror has a balanced position relative to the bracket, and the elastic member is used to provide a force for the mirror to rotate towards the balanced position.

[0020] In an alternative embodiment, the rotational axis of the mirror relative to the bracket is perpendicular to the rotational axis of the rotor.

[0021] In an alternative embodiment, the bracket includes a first arm and a second arm provided on the stator. The first arm and the second arm are spaced apart in a direction perpendicular to the rotational axis of the rotor, and opposite sides of the mirror are respectively rotatably connected to the first arm and the second arm.

[0022] In a second aspect, the present application provides a lidar including the scanning device according to any one of the foregoing embodiments.

[0023] The beneficial effects of the embodiments of the present application include, for example:

[0024] The scanning device provided by this application includes a rotation driving assembly, a bracket, a mirror, and a swing driving assembly. The rotation driving assembly includes a stator and a rotor that cooperates with the stator. The bracket is connected to the rotor, and the mirror is rotatably connected to the bracket. The swing driving assembly includes a first coil winding and a first magnet. The first magnet is connected to the mirror so that the magnetic field generated by the first coil winding can drive the mirror to swing relative to the bracket. In the embodiment of this application, the rotation driving assembly can drive the bracket and the mirror to rotate together, thereby realizing scanning in one dimension; and the first coil winding can adjust the deflection angle of the mirror relative to the bracket by changing the magnetic field, thereby realizing scanning in another dimension. Combining the rotation driving assembly and the swing driving assembly to jointly control the attitude of the mirror can realize two-dimensional scanning with only one mirror. The structure of this scanning device can reduce the number of laser transceiver channels and meet high-performance requirements such as long-distance measurement and high resolution at the same time. The structure of the scanning device provided by this application is simple and compact, which is beneficial to the miniaturization of the device and has a low cost.

[0025] The lidar provided by this application includes the above-mentioned scanning device, so it can stably and effectively realize two-dimensional scanning of the lidar at a low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of this application, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of this application, so they should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0027] Figure 1 Schematic diagram of the scanning device in a first perspective view (stator omitted) in an embodiment of this application;

[0028] Figure 2 Schematic diagram of the scanning device in a second perspective view in an embodiment of this application;

[0029] Figure 3 Scanning beams reflected by the mirror at two positions with a 180° difference in rotation angle in an embodiment of this application.

[0030] Reference numerals: 100 - rotation driving assembly; 110 - second coil winding; 120 - second magnet; 200 - swing driving assembly; 210 - first coil winding; 220 - first magnet; 300 - bracket; 310 - first arm; 320 - second arm; 400 - mirror. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are some, but not all, of the embodiments of this application. Components of the embodiments of this application generally described and illustrated in the figures herein can be arranged and designed in a variety of different configurations.

[0032] Therefore, the detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of this application that is claimed, but is merely representative of selected embodiments of this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of this application without creative efforts fall within the scope of protection of this application.

[0033] It should be noted that like reference numerals and letters denote like items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0034] In the description of this application, it should be noted that if terms such as "upper", "lower", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, or the orientations or positional relationships when the utility model product is normally placed, it is only for the convenience of describing this application 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, and thus should not be construed as a limitation of this application.

[0035] In addition, terms such as "first" and "second" are only used for descriptive distinction and should not be construed as indicating or implying relative importance.

[0036] It should be noted that, without conflict, the features in the embodiments of this application can be combined with each other.

[0037] In existing lidars, the scanning devices used to achieve two-dimensional scanning generally have large structural dimensions and poor stability. For example, in the scanning device with a turret structure, the transceiver module rotates together, and wireless or slip rings are required to transmit power and data signals, which have problems such as high cost, large size, complex solutions, poor reliability, and short lifespan. In the 1D+1D scanning method, two fast and slow axis mirrors are required to be responsible for scanning in two dimensions respectively, and finally two-dimensional scanning is completed. In the method of using a rotating mirror for scanning, a special rotating mirror needs to be set up, and two-dimensional pixel coverage is achieved by using a one-dimensional rotating mirror plus transceiver channels arranged in an array in another direction.

[0038] To address the problem of the complex structure of the scanning device in the above related technologies, an embodiment of the present application provides a scanning device that uses only one mirror and achieves two-dimensional scanning through a simple and stable structure, which is conducive to the miniaturization of the device. An embodiment of the present application also provides a lidar including the above scanning device and a scanning method applied to the above lidar.

[0039] Figure 1 Schematic diagram of the scanning device in a first perspective (stator omitted) in an embodiment of the present application; Figure 2 Schematic diagram of the scanning device in a second perspective in an embodiment of the present application. As Figure 1 and Figure 2 shown, the scanning device provided by the embodiment of the present application includes a rotation driving assembly 100, a bracket 300, a mirror 400, and a swing driving assembly 200. The rotation driving assembly 100 includes a stator and a rotor cooperating with the stator. The bracket 300 is connected to the rotor, and the mirror 400 is rotatably connected to the bracket 300. The swing driving assembly 200 includes a first coil winding 210 and a first magnet 220. The first magnet 220 is connected to the mirror 400 so that the magnetic field generated by the first coil winding 210 can drive the mirror 400 to swing relative to the bracket 300. It can be seen that the rotation driving assembly 100 can drive the bracket 300 and the mirror 400 to rotate together, thereby achieving scanning in one dimension; and the first coil winding 210 can adjust the deflection angle of the mirror 400 relative to the bracket 300 by changing the magnetic field, thereby achieving scanning in another dimension. Therefore, the scanning device provided by the embodiment of the present application can achieve two-dimensional scanning only through one mirror 400, and the structure is simple and compact.

[0040] It should be understood that the rotation axis of the rotor and the rotation axis of the mirror 400 relative to the bracket 300 (hereinafter referred to as the rotation axis of the mirror 400) should form at least an angle; optionally, the rotation axis of the rotor and the rotation axis of the mirror 400 are perpendicular to each other; further optionally, the rotation axis of the rotor and the rotation axis of the mirror 400 are perpendicular to each other and intersect, so as to reduce the centrifugal force of the mirror 400 when rotating with the rotor, thereby improving stability. Taking the application in a vehicle-mounted lidar as an example, the rotation driving assembly 100 can drive the bracket 300 and the mirror 400 to rotate in the horizontal direction to achieve horizontal scanning, and the swing driving assembly 200 can drive the mirror 400 to swing in the vertical direction, thereby achieving vertical scanning.

[0041] The first coil winding 210 can be connected to a power source (not shown in the figure) through a wire harness. After being energized, it can generate a magnetic field. This magnetic field acts on the first magnet 220. After the first magnet 220 is subjected to force, it undergoes displacement, driving the mirror 400 to swing to the required angle. The first coil winding 210 can include an iron core and multiple groups of coils wound around the iron core. The strength of the magnetic field can be controlled by the magnitude of the current, and the distribution state of the magnetic field generated by the first coil winding 210 can be adjusted by supplying power to some of the coils. In this embodiment, the position of the first coil winding 210 is fixed relative to the stator, so it will not rotate with the bracket 300, and the wire harness connected to the first coil winding 210 can be kept stable, providing convenience for the wiring design. In other alternative embodiments, the first coil winding 210 can also be fixed to the bracket 300 and the rotor, for example, connected to the rotor or the bracket through a connecting member.

[0042] In this embodiment, the stator includes a second coil winding 110, and the rotor includes a second magnet 120. The second coil winding 110 can be connected to a power source (not shown in the figure) through a wire harness. After being energized, it can generate a magnetic field. This magnetic field acts on the second magnet 120. After the second magnet 120 is subjected to force, it rotates around its own axis, thereby driving the bracket 300 and the mirror 400 to rotate. By adjusting the magnitude of the current in the second coil winding 110, the rotation speed of the second magnet 120 and even the mirror 400 can be controlled. In this embodiment, the second coil winding 110 does not participate in the rotation, which can improve the stability of the circuit.

[0043] Furthermore, the second coil winding 110 is disposed around the outside of the second magnet 120, thus forming a structure similar to an inner-rotor motor. The second magnet 120 is a magnetic ring and is disposed around the outside of the first coil winding 210. Through this arrangement, the first coil winding 210 and the second coil winding 110 can be separated by the second magnet 120, reducing the mutual influence between the two. The first coil winding 210, the second magnet 120, and the second coil winding 110 are generally in the same plane, so that the space inside the second magnet 120 can be utilized to accommodate the first coil winding 210, making the overall structure of the scanning device more compact.

[0044] In this embodiment, the second magnet 120 can be a multi-pole magnetic ring, that is, the second magnet 120 includes multiple pairs of magnetic poles, and each magnetic pole is arranged in sequence around the circumference.

[0045] In alternative embodiments, the relative positions of the stator and the rotor can be reversed. For example, the rotor can be arranged outside the stator, thus forming a structure similar to an outer-rotor motor. In other embodiments, the second coil winding 110 can be used as the rotor and the second magnet 120 as the stator, and a carbon brush can be added to achieve continuous rotation of the second coil winding 110 in the circumferential direction (the specific principle can refer to a brushed motor).

[0046] In the embodiments of the present application, the scanning device may further include a housing, and the first coil winding 210, the second coil winding 110, and the second magnet 120 are located inside the housing. The relative position of the first coil winding 210 and the stator is fixed. The first coil winding 210 and the second coil winding 110 can be fixedly connected to the same fixing component (such as the housing, the base, etc.), or the first coil winding 210 and the second coil winding 110 are fixed by a connecting member, and then one of them is connected to other fixing components.

[0047] In this embodiment, the first coil winding 210, the second magnet 120, and the second coil winding 110 are coaxially arranged and are generally in the same plane. In other embodiments, the position of the first coil winding 210 can be adjusted according to the positions of the mirror 400 and the first magnet 220. For example, when the bracket 300 is relatively high and the mirror 400 is far from the rotor, the first magnet 220 can also be arranged above the second magnet 120 and spaced from the second magnet 120, and is installed and fixed through a connecting component.

[0048] In this embodiment, the bracket 300 includes a first arm 310 and a second arm 320 arranged on the stator. The first arm 310 and the second arm 320 are spaced apart in a direction perpendicular to the rotation axis of the rotor. Opposite sides of the mirror 400 are rotatably connected to the first arm 310 and the second arm 320 respectively. In alternative embodiments, the structure and shape of the bracket 300 can be adjusted as needed.

[0049] Furthermore, the first magnet 220 is connected to the end of the mirror 400 close to the first coil winding 210. As shown in the figure, the mirror 400 is rectangular, and two opposite sides thereof are rotatably connected to the first arm 310 and the second arm 320 respectively, so that the two ends can swing relative to the bracket 300. The end close to the first coil winding 210 is connected to the first magnet 220, so that the first magnet 220 can be as close as possible to the first coil winding 210, and thus is more easily driven by the first coil winding 210.

[0050] In this embodiment, the first magnet 220 is a single-pole magnet, that is, it only includes one N pole and one S pole, and both magnetic poles are semi-circular structures. The first magnet 220 as a whole is a disc structure. The edge of the mirror 400 is connected to the first magnet 220 along the boundary line between the two magnetic poles of the first magnet 220, so that the first coil winding 210 can better provide a force for the first magnet 220 to swing.

[0051] Optionally, the mirror 400 is a double-sided mirror. By setting the mirror 400 to double-sided reflection, during the process that the mirror 400 is driven to rotate one week, the light beam scans two weeks. Figure 3 The scanning light beams reflected by the mirror 400 at two positions with a phase difference of 180° in an embodiment of the present application. As Figure 3 shown, during the process of being driven by the rotor to rotate one week, in a 180° (or close to 180°) stroke, the scanning light beam is reflected by one of the reflecting surfaces of the mirror 400, that is, Figure 3 the scanning light beam A in; and in another 180° (or close to 180°) stroke, the scanning light beam is reflected by the other reflecting surface of the mirror 400, that is, Figure 3 the scanning light beam B in. It can be seen that when the mirror 400 has a certain pitch angle, the scanning light beam A and the scanning light beam B will have different pitch angles, and during the process that the mirror 400 rotates one week, it will scan one week with the scanning light beam A and the scanning light beam B in turn.

[0052] In other optional embodiments, the mirror 400 can also be a single-sided mirror, and by reciprocally rotating the mirror 400 within an angle range of 180° or less, scanning in one direction (such as the horizontal direction) is realized.

[0053] Optionally, an elastic member is provided on the bracket 300. The mirror 400 has an equilibrium position relative to the bracket 300, and the elastic member is used to provide a force for the mirror 400 to rotate towards the equilibrium position. Taking the structure provided in this embodiment as an example, the equilibrium position of the mirror 400 can be the position when the mirror 400 is parallel to the rotation axis of the rotor. By providing the elastic member, when the mirror 400 is at a target position deviating from the equilibrium position, the torques of the driving force of the first coil winding 210, the restoring force of the elastic member, and the gravity on the mirror 400 are balanced, so that the mirror 400 is maintained at the target position. When the mirror 400 deviates from the target position due to the influence of other external factors (such as vibration), the driving force of the first coil winding 210 and the restoring force of the elastic member on the mirror 400 show a trend of increasing and decreasing respectively, and will drive the mirror 400 to return to the target position again. For example, at the target position, the driving force of the first magnet 220 on the first coil winding 210 is a force that makes it deviate further from the equilibrium position, so as to balance the torques of gravity and elastic restoring force. If the mirror 400 swings from the target position towards the equilibrium position due to certain factors, then the driving force of the first magnet 220 on the first coil winding 210 will increase, and the elastic restoring force of the mirror 400 from the elastic member will decrease. Therefore, the resultant force on the mirror 400 will cause it to rotate back to the target position again. Therefore, it can be seen that by providing the elastic member, the mirror 400 can be more stably maintained at the required angle. The elastic member can be an elastic beam, a torsion spring or a spring.

[0054] Further, the scanning device further includes a first sensor (not shown in the figure) and a second sensor (not shown in the figure). The first sensor is used to detect the rotational position of the rotor relative to the stator, and the second sensor is used to detect the rotational position of the mirror 400 relative to the bracket 300. Through the first sensor and the second sensor, the current attitude of the mirror 400 can be monitored, so as to judge the position of the scanning beam, and further judge the position of the detected object. The first sensor and the second sensor are photoelectric sensors (such as reflective photoelectric sensors or transmissive photoelectric sensors) or Hall sensors.

[0055] The lidar (not shown in the figure) provided in the embodiment of the present application includes the above scanning device. In addition, the lidar further includes necessary components such as a transmitting device and a receiving device. The transmitting device is used to emit a beam to the mirror 400 of the scanning device, and the reflected beam is the scanning beam, which is used to detect an object in the target space; the receiving device is used to receive the echo of the scanning beam reflected by the object, so as to judge the distance, azimuth, shape, etc. of the object. The specific detection principle of the lidar can refer to the prior art and will not be elaborated here.

[0056] The embodiment of the present application also provides a scanning method, which is applied to the above lidar. The scanning method includes:

[0057] A detection beam is emitted to the reflector 400 ; the rotation drive assembly 100 is controlled to drive the bracket 300 to rotate; and the magnetic field generated by the first coil winding 210 is changed to adjust the deflection angle of the reflector 400 relative to the bracket 300 .

[0058] While the above steps are being performed, the receiving device can be controlled to receive the echo, and the echo can be analyzed to determine whether an object is detected and the position and shape of the object. The above control steps can be implemented by a controller.

[0059] The step of changing the magnetic field generated by the first coil winding 210 to adjust the deflection angle of the reflector 400 relative to the bracket 300 may specifically include: providing current to different coils in the first coil winding 210 to change the magnetic field generated by the first coil winding 210. In addition, by changing the current in the first coil winding 210, the driving force on the first magnet 220 can be changed, thereby adjusting the deflection angle of the reflector 400.

[0060] In a specific solution for 360° scanning, the rotating driving assembly can be controlled to drive the reflector 400 to rotate continuously in one direction, and the swinging angle (i.e., the inclination angle relative to the bracket 300) of the reflector 400 can be adjusted by the swing driving assembly 200 after each rotation, and the swinging angle of the reflector 400 does not change during the rotation. In this way, two-dimensional scanning within a 360° field of view can be achieved.

[0061] Taking the laser radar mounted on a traffic vehicle as an example, the deflection angle of the reflector in the vertical direction can be precisely controlled through the control algorithm to achieve variable angle scanning, increase the number of scanning lines, and improve the equivalent resolution. Optionally, the vertical angle adjustment of the reflector 400 can be completed in the time gap between the two reflective surfaces of the reflector 400, and the swing angle of the reflector 400 is kept unchanged during the scanning process using one reflective surface.

[0062] The laser radar and scanning method of the embodiment of the present application have the following characteristics:

[0063] 1. No need to superimpose the number of channels, multi-line 2D scanning can be achieved:

[0064] Among them, the number of radar lines: V = N*2*s; - where N is the number of transmitting and receiving channels, and s is the angular scanning order in the vertical direction.

[0065] 2. The relationship between the radar frame rate, line number, and rotor speed of the rotary drive assembly is:

[0066] When the rotor rotates 360°, the radar frame rate F = R / s; R is the rotor speed in Hz, and s is the number of angular steps in the vertical direction.

[0067] 3. It can support line scanning without the influence of image rotation.

[0068] 4. The equivalent number of lines can be dynamically adjusted to achieve adjustable frame rate and number of scanning lines.

[0069] 5. The motion structure is simple and highly reliable, which can reduce the optical path of the radar, thereby reducing the overall size and volume of the radar.

[0070] 6. It can achieve ultra-large field of view scanning. By changing the relative positions of the transmitting device, receiving device, and scanning device, as well as the number of transmitting and receiving devices, different forms such as forward main radar and 360° scanning radar can be achieved.

[0071] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A scanning device, characterized in that: include: A rotation drive assembly includes a stator and a rotor matched with the stator; A bracket connected to the rotor; A reflector rotatably connected to the bracket; The swing drive assembly includes a first coil winding and a first magnet. The first coil winding is fixed relative to the stator of the rotation drive assembly. The first magnet is connected to the reflector so that the magnetic field generated by the first coil winding can drive the reflector to swing relative to the bracket.

2. The scanning device according to claim 1, characterized in that: The first coil winding is fixed in position relative to the stator of the rotary drive assembly.

3. The scanning device according to claim 1, characterized in that: The stator includes a second coil winding and the rotor includes a second magnet.

4. The scanning device according to claim 3, characterized in that: The second coil winding is disposed around the outer side of the second magnet.

5. The scanning device according to claim 4, characterized in that: The second magnet is a magnetic ring and is disposed around the outside of the first coil winding.

6. The scanning device according to any one of claims 1 to 5, characterized in that: The first magnet is connected to an end of the reflector close to the first coil winding.

7. The scanning device according to claim 6, characterized in that: The first magnet is a single-pole magnet, and the edge of the reflector is connected to the first magnet along a boundary line between two magnetic poles of the first magnet.

8. The scanning device according to any one of claims 1 to 5, characterized in that: The reflecting mirror is a double-sided reflecting mirror.

9. The scanning device according to any one of claims 1 to 5, characterized in that: The scanning device further comprises a first sensor and a second sensor, wherein the first sensor is used to detect a rotational position of the rotor relative to the stator, and the second sensor is used to detect a rotational position of the reflector relative to the bracket.

10. The scanning device according to claim 9, characterized in that: The first sensor and the second sensor are photoelectric sensors or Hall sensors.

11. The scanning device according to any one of claims 1 to 5, characterized in that: The bracket is provided with an elastic member, the reflector has a balanced position relative to the bracket, and the elastic member is used to provide a force for the reflector to rotate toward the balanced position.

12. The scanning device according to any one of claims 1 to 5, characterized in that: The reflector is perpendicular to the rotation axis of the bracket and the rotation axis of the rotor.

13. The scanning device according to any one of claims 1 to 5, characterized in that: The bracket includes a first arm and a second arm arranged on the stator, the first arm and the second arm are arranged at intervals in a direction perpendicular to the rotation axis of the rotor, and opposite sides of the reflector are rotatably connected to the first arm and the second arm respectively.

14. A laser radar, characterized in that: A scanning device comprising the scanning device described in any one of claims 1-13.

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