CN114265041A

CN114265041A - Scanning device and scanning method

Info

Publication number: CN114265041A
Application number: CN202111561055.6A
Authority: CN
Inventors: 疏达; 周思雨; 王瑞; 李欣
Original assignee: Benewake Beijing Co Ltd
Current assignee: Benewake Beijing Co Ltd
Priority date: 2021-12-14
Filing date: 2021-12-14
Publication date: 2022-04-01

Abstract

The utility model relates to a scanning device and a scanning method, wherein the device comprises a rotary multi-face prism and at least two receiving and transmitting light path modules; the light beam emitted by the transceiving light path module is reflected by the rotating multi-surface prism and then irradiates a target area, and the echo reflected by the rotating multi-surface prism after being reflected by an object in the target area is received; the rotating multi-face prism is rotationally arranged, and reflects each light beam in the rotating process so as to adjust the direction of the light beam and form a spliced scanning view field; simultaneously, the echo is reflected to the corresponding receiving and transmitting optical path module; wherein, two at least receiving and dispatching light path modules stack the setting along the direction of height of rotatory multiaspect prism. Therefore, by arranging the rotary multi-face prism and the at least two receiving and transmitting light path modules, the scanning view field splicing can be realized so as to realize large view field scanning; simultaneously, with receiving and dispatching optical path module along the direction of height of rotatory multiaspect prism and pile up the setting, can reduce the whole volume of device, when realizing big visual field scanning, realize that the device is miniaturized.

Description

Scanning device and scanning method

Technical Field

The present disclosure relates to the field of optical detection technologies, and in particular, to a scanning apparatus and a scanning method.

Background

The optical detection technology is a technology for detecting an object in a target area by using an optical principle. Among them, the laser radar, also called as optical radar (Light Detection And Ranging), is a short for laser Detection And Ranging system, And is an optical Detection device; the laser radar analyzes information such as the size of reflected energy, the amplitude, the frequency and the phase of a reflection spectrum of the surface of a target object by measuring the propagation distance of a laser beam between a sensor transmitter and the target object, so that accurate three-dimensional structure information of the target object is presented.

With the increasing popularization of the automatic driving technology, the requirement on the scanning view field angle of the laser radar is also increased increasingly. Generally, to achieve large field angle scanning, a field stitching scheme may be employed. In the existing field splicing scheme, different optical paths share the same galvanometer, and a certain included angle is generated on an optical axis between two paths of light receiving and transmitting path modules for splicing so as to realize a larger scanning field angle. However, the phenomenon that the galvanometer structural part shields the field angle at one side is easy to occur in the large-field scanning of the scheme. Meanwhile, in consideration of the background of use of rail crossing and driving devices (e.g., automobiles), the miniaturization of the volume of the lidar system is a trend. However, it is difficult for the existing lidar solutions to satisfy both the requirements of large field angle and small volume.

Disclosure of Invention

To solve the above technical problem or at least partially solve the above technical problem, the present disclosure provides a scanning apparatus and a scanning method.

The embodiment of the disclosure provides a scanning device, which comprises a rotary multi-face prism and at least two receiving and transmitting light path modules;

the light beam emitted by the transceiving light path module irradiates a target area after being reflected by the rotating multi-surface prism, and receives an echo reflected by the rotating multi-surface prism after being reflected by an object in the target area;

the rotary polygon prism is arranged in a rotating mode, and reflects each light beam in the rotating process so as to adjust the direction of the light beam and form a spliced scanning view field; simultaneously reflecting the echo to the corresponding transceiving optical path module;

the at least two receiving and transmitting optical path modules are stacked along the height direction of the rotating multi-face prism.

In some embodiments, the total width of the at least two transceiver optical path modules in the height direction of the rotating polygon prism is equal to or less than the height of the rotating polygon prism.

In some embodiments, the at least two transceiver optical path modules include a first transceiver optical path module and a second transceiver optical path module;

the first transceiving optical path module comprises a first transmitting light source, a first perforated reflector, a first vibrating mirror reflector, a fixed reflector, a first receiving lens and a first receiving device; after a light beam emitted by the first emitting light source passes through the through hole of the first perforated mirror, the light beam is incident on the fixed mirror through the first galvanometer mirror, and the fixed mirror reflects the light beam to the rotating polygon prism; the echo reflected by an object in the target area is reflected to the fixed reflector through the rotating polygon mirror, reflected to the first perforated reflector through the first galvanometer reflector after being reflected, and received by the first receiving device through the first receiving lens after being reflected;

the second transceiving optical path module comprises a second transmitting light source, a second reflector with a hole, a second galvanometer reflector, a second receiving lens and a second receiving device; after the light beam emitted by the second emission light source passes through the through hole of the second perforated reflector, the light beam is reflected to the rotary polygon prism through the second galvanometer reflector; the echo reflected by the object in the target area returns to the rotating polygon prism, is reflected to the second perforated mirror through the second galvanometer mirror after being reflected, and is received by the second receiving device through the second receiving lens after being reflected.

In some embodiments, the first galvanometer mirror and the fixed mirror are arranged along a height direction of the rotating polygon;

and/or the second perforated reflector and the second galvanometer reflector are arranged along the height direction of the rotary polygon prism.

In some embodiments, the first galvanometer mirror and the second galvanometer mirror are respectively located at different height positions in a height direction of the rotating polygon mirror.

In some embodiments, the first galvanometer mirror and the second galvanometer mirror are arranged at a preset included angle.

In some embodiments, the rotating polygon prism is a four-sided prism;

the rotating angle of the rotating polygon prism corresponding to the first transceiving optical path module reaching the maximum field angle is different from the rotating angle of the rotating polygon prism corresponding to the second transceiving optical path module reaching the maximum field angle;

and the maximum field angle reached by the first transceiving optical path module and the maximum field angle reached by the second transceiving optical path module are in angle coincidence.

In some embodiments, the rotational speed of the multi-sided rotating prism is less than or equal to a preset rotational speed;

and/or the number of light beams of the emission light source is greater than or equal to a preset number; wherein the emission light source includes the first emission light source and the second emission light source.

In some embodiments, the power of the first emission light source is greater than or equal to a first preset power, and the power of the second emission light source is greater than or equal to a second preset power.

The embodiment of the disclosure also provides a scanning method, which is implemented by applying any one of the devices; the method comprises the following steps:

acquiring a view field angle, a detection distance and a corresponding resolution of a to-be-scanned view field corresponding to a target area;

determining an operating parameter of the device based on the field of view angle, the detection distance, and the resolution;

and driving the device to scan the target area based on the working parameters.

Compared with the prior art, the technical scheme provided by the embodiment of the disclosure has the following advantages:

in the scanning device and the scanning method provided by the embodiment of the disclosure, the scanning device comprises a rotary polygon prism and at least two receiving and transmitting light path modules, light beams are emitted to the rotary polygon prism through the receiving and transmitting light path modules, and the light beams are reflected in the rotating process of the rotary polygon prism to adjust the directions of the light beams to irradiate a target area so as to form a spliced scanning view field; and the receiving and transmitting optical path module receives the echo reflected by the rotating multi-face prism after being reflected by the object in the target area, so that the large-field scanning is realized, and at least two paths of receiving and transmitting optical path modules are stacked along the height direction of the rotating multi-face prism, so that the whole volume of the scanning device is reduced. Therefore, the scanning device can meet the requirement of miniaturization of the device while meeting the requirement of large-field scanning.

Drawings

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

In order to more clearly illustrate the embodiments or technical solutions in the prior art of the present disclosure, the drawings used in the description of the embodiments or prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive exercise.

Fig. 1 is a schematic perspective view of a scanning device according to an embodiment of the present disclosure.

Fig. 2 is a schematic top view of the scanning apparatus shown in fig. 1.

Fig. 3 is a functional diagram of a rotating polygon mirror in the scanning device shown in fig. 1.

Fig. 4 is a schematic structural diagram of another scanning apparatus provided in the embodiment of the present disclosure.

Fig. 5 is a view field splicing schematic diagram of a scanning device according to an embodiment of the present disclosure.

Fig. 6 is a view field splicing schematic diagram of another scanning device provided in the embodiment of the present disclosure.

Fig. 7 is a schematic diagram of a first state of a scanning device according to an embodiment of the disclosure.

Fig. 8 is a schematic diagram of a second state of the scanning device according to the embodiment of the disclosure.

Fig. 9 is a schematic diagram of a third state of the scanning device according to the embodiment of the disclosure.

Fig. 10 is a schematic diagram of a fourth state of the scanning device according to the embodiment of the disclosure.

Fig. 11 is a schematic flowchart of a scanning method according to an embodiment of the disclosure.

10, a scanning device; 11. rotating the faceted prism; 12. a light path receiving and transmitting module; 121. a first transceiving optical path module; 211. a first emission light source; 212. a first apertured mirror; 213. a first galvanometer mirror; 214. fixing the reflector; 215. a first receiving lens; 216. a first receiving device; 122. a second transceiving optical path module; 221. a second emission light source; 222. a second apertured mirror; 223. a second galvanometer mirror; 224. a second receiving lens; 225. a second receiving device; a1, B1, a2, B2, A3 and B3 respectively denote different light beams; j1 and J2 respectively indicate different galvanometer directions; c1, C2, C11, C12, C21 and C22 respectively indicate different light ray directions; x, Y and Z respectively indicate three mutually perpendicular directions in three-dimensional space.

Detailed Description

In order that the above objects, features and advantages of the present disclosure may be more clearly understood, aspects of the present disclosure will be further described below. It should be noted that the embodiments and features of the embodiments of the present disclosure may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure, but the present disclosure may be practiced in other ways than those described herein; it is to be understood that the embodiments disclosed in the specification are only a few embodiments of the present disclosure, and not all embodiments.

The scanning device and the scanning method provided by the embodiment of the disclosure can be applied to scenes of scanning detection such as automatic driving and auxiliary driving, and large-field scanning is realized through field splicing; simultaneously, pile up the setting on the direction of height along rotatory multiaspect prism through setting up two at least receiving and dispatching light path modules, and the tiling setting of non-bilateral symmetry is favorable to reducing the whole shared space of device, reduces the device volume, satisfies the demand of volume miniaturization.

The scanning device and the scanning method provided by the embodiment of the disclosure are exemplarily described below with reference to fig. 1 to 11.

In some embodiments, as shown in fig. 1 or fig. 2, the scanning device 10 includes a rotating polygon 11 and at least two transceiver optical path modules 12; the light beam emitted by the transceiving light path module 12 is reflected by the rotating multi-surface prism 11 and then irradiates a target area, and receives an echo reflected by the rotating multi-surface prism 11 after being reflected by an object in the target area; the rotating multi-face prism 11 is arranged in a rotating mode, and reflects each light beam in the rotating process so as to adjust the direction of the light beam and form a spliced scanning view field; simultaneously, the echo is reflected to the corresponding receiving and transmitting optical path module 12; wherein, at least two receiving and dispatching optical path modules 12 are stacked along the height direction of the rotating polygon prism 11.

The rotating multi-face prism 11 can rotate, and light beams irradiated on the reflecting face of the rotating multi-face prism are reflected according to different angles in the rotating process to form a spliced scanning view field, so that the requirement of large-angle scanning is met.

Illustratively, on the basis of fig. 1 and fig. 2, as shown in fig. 3, the number of the transceiving optical path modules 12 is two, the horizontal field angle corresponding to one transceiving optical path module is FOV1, the horizontal field angle corresponding to the other transceiving optical path module is FOV2, the rotating polygon prism 11 is a four-sided prism, and the two transceiving optical path modules are asymmetrically arranged with respect to the four-sided prism, so that the prism rotation angles corresponding to the two transceiving optical path modules when reaching the maximum field angle are different, and the field angles overlap when reaching the maximum field angle, so that mutual verification can be performed by using data under the overlapped field angles, thereby ensuring accuracy of field splicing while realizing large field scanning, which will be described in detail later.

It can be understood that a four-sided prism refers to a prism having four sides, including an upper surface, a lower surface, and four sides; and two opposite side surfaces of the four side surfaces are perpendicular to the upper surface and the lower surface, and the other two opposite side surfaces are obliquely arranged relative to the upper surface and the lower surface. In other embodiments, the rotating polygon may also be a prism, a pentaprism or other structure prism, which is not repeated or limited herein.

The light receiving and transmitting module 12 can emit and receive light, and may include a light source, optical lenses (e.g., a lens and a mirror), a receiving device (e.g., a photoelectric conversion device), and the like, which will be described in detail later. The number of the transceiving optical path modules 12 may be two (as shown in fig. 1 or fig. 2), three or more, and may be set based on the requirement of the scanning device, which is not limited herein.

The transmitting-receiving optical path module 12 is stacked along the height direction Z of the rotating polygon prism 11, and for the independent symmetrical arrangement on both sides of the rotating polygon prism 11, the size of the whole scanning device can be reduced, so that the scanning device meets the requirement of volume miniaturization.

In the scanning process, the light beams emitted by the stacked receiving and transmitting light path modules irradiate the target area after being reflected by the rotating multi-face prism, the direction of the light beams changes along with the rotation of the rotating multi-face prism, and the irradiated target area changes along with the change of the light beams, so that a spliced scanning view field is formed, and a larger scanning view field is realized. The light beam is reflected by the object in the target area and then the echo reflected by the rotating multi-surface prism is received by the receiving and transmitting light path module, so that scanning detection is realized.

The scanning device 10 provided by the embodiment of the present disclosure includes a rotating polygon prism 11 and at least two receiving and transmitting optical path modules 12; the light beam emitted by the transceiving light path module 12 is reflected by the rotating multi-surface prism 11 and then irradiates a target area, and receives an echo reflected by the rotating multi-surface prism 11 after being reflected by an object in the target area; the rotating multi-face prism 11 is arranged in a rotating mode, and reflects each light beam in the rotating process so as to adjust the direction of the light beam and form a spliced scanning view field; simultaneously, the echo is reflected to the corresponding receiving and transmitting optical path module 12; wherein, at least two receiving and dispatching optical path modules 12 are stacked along the height direction of the rotating polygon prism 11. Therefore, the requirement of miniaturization of the device volume can be met while large-field scanning is realized; furthermore, the scanning device can be integrally arranged in the automatic driving equipment, so that the integrated installation requirement and the scanning detection requirement of the automatic driving equipment are met.

It will be appreciated that in fig. 1 and 2, the three-dimensional space in which the scanning apparatus 10 is located is illustrated by three mutually perpendicular directions (i.e., X, Y and Z). In other embodiments, the reference space of the scanning device 10 can be shown in other manners, and is not limited herein.

In some embodiments, with continued reference to fig. 1 or fig. 2, the total width of the at least two transceiver optical path modules 12 along the height direction Z of the rotating polygon prism 11 is equal to or less than the height of the rotating polygon prism 11.

The total width of the at least two transceiver optical path modules 12 along the height direction Z of the rotating polygon prism 11 is the distance between the highest point and the lowest point along the height direction Z, and the height of the rotating polygon prism 11 is the height along the height direction Z.

By setting the total width equal to or less than the height of the rotating polygon prism 11, the maximum dimension of the whole scanning device 10 in the height direction Z is the height of the rotating polygon prism 11, and no additional dimension is added due to the arrangement of the transmitting-receiving optical path module 12, so that the overall size of the scanning device is reduced, and the miniaturization design and manufacture of the scanning device are easy to realize.

Illustratively, the total width of the at least two transceiver optical path modules 12 in the height direction Z of the rotating polygon prism 11 is equal to the height of the rotating polygon prism 11; or, the total width of the at least two receiving and transmitting optical path modules 12 along the height direction Z of the rotating polygon prism 11 is smaller than the height of the rotating polygon prism 11, so that the requirement of the device for size miniaturization can be met.

In the embodiment of the present disclosure, only the relative size of the transmitting/receiving optical path module 12 along the height direction Z of the rotating polygon prism 11 and the height of the rotating polygon prism 11 is limited, and the specific physical size is not limited.

In some embodiments, as shown in fig. 4, in the scanning device 10, the at least two transceiver optical path modules 12 include a first transceiver optical path module 121 and a second transceiver optical path module 122; the first transceiving optical path module 121 includes a first transmitting light source 211, a first holed mirror 212, a first galvanometer mirror 213, a fixed mirror 214, a first receiving lens 215, and a first receiving device 216; the second transceiving optical path module 122 includes a second transmitting light source 221, a second perforated mirror 222, a second galvanometer mirror 223, a second receiving lens 224, and a second receiving device 225.

Wherein, after the light beam emitted by the first emitting light source 211 passes through the via hole of the first perforated reflector 212, the light beam is incident on the fixed reflector 214 through the first galvanometer reflector 213, and the fixed reflector 214 reflects the light beam to the rotating polygon 11; the echo reflected by the object in the target region is reflected by the rotating polygon prism 11 to the fixed mirror 214, reflected again by the first galvanometer mirror 213 to the first perforated mirror 212, and reflected again by the first receiving lens 215 to be received by the first receiving device 216.

Wherein, the light beam emitted from the second emission light source 221 passes through the via hole of the second perforated mirror 222, and then is reflected to the rotating polygon prism 11 by the second galvanometer mirror 223; the echo reflected by the object in the target region returns to the rotating polygon prism 11, is reflected by the second galvanometer mirror 223 to the second perforated mirror 222, and is received by the second receiving device 225 through the second receiving lens 224.

Wherein, the motor drives the rotating polygon prism 11 to rotate horizontally at a high speed, thereby realizing angle scanning in the horizontal direction (namely XY direction); the first galvanometer mirror 213 and the second galvanometer mirror 223 may also be driven by a motor to rotate about their axes of rotation, thereby enabling angular scanning in the vertical direction (i.e., the Z direction) and thus scanning of a three-dimensional volume.

Wherein, the emission light source can be a laser light source or other light sources; the light source types of the first emission light source and the second emission light source may be the same or different, and are not limited herein.

In the first transceiving optical path module 121, the first transmitting light source 211 emits one or more collimated laser beams, which pass through a small hole formed in the middle of the first perforated mirror 212 and enter the fixed mirror 241 through the first vibrating mirror 213, and the fixed mirror 214 reflects the laser beams onto the rotating polygon mirror 11 through the turning of the optical path and then irradiates the object to be measured (i.e., the object in the target area); the light returned after being reflected by the object to be measured returns according to the original light path, is reflected to the fixed reflector 214 after passing through the rotating polygon prism 11, is reflected to the first vibrating mirror 213 again and then reflected to the first perforated reflector 212, and the light is converged to the first receiving device 216 through the first receiving lens 215, so that the scanning detection of a path of module, such as ranging, is completed. The second transceiving optical path module 122 is similar to the optical path of the first transceiving optical path module 121, the laser emitted from the second emitting light source 221 passes through a small hole formed in the middle of the second perforated reflector 222, enters the second galvanometer reflector 223, is reflected to the rotating polygon prism 11, is reflected by the object to be measured and returns to the rotating polygon prism 11 again, is reflected and enters the second perforated reflector 222 through the second galvanometer reflector 223, and the reflected light is refracted by the second receiving lens 224 and then completes photoelectric conversion on the second receiving device 225, so as to complete scanning detection of another path of module.

In the light path, the rotating polygon mirror 11, the first galvanometer mirror 213, and the second galvanometer mirror 223 are driven to rotate by a motor, and the fixed mirror 214 is kept stationary, thereby realizing stable three-dimensional scanning.

The optical axes of the first transceiving optical path module 121 and the second transceiving optical path module 122 are coaxial. Specifically, no matter the first transceiving optical path module 121 or the second transceiving optical path module 122, their respective optical transmissions are: the light emitted by the emitting light source and irradiated onto the measured object along the reflectors on the optical axis path, and the light reflected by the measured object and returned back is returned back to the reflector and then to the receiving device through the same path. I.e. both the emitted and the returned light, have the same path without any deviation.

In some embodiments, as shown in FIG. 5, the first galvanometer mirror 213 and the second galvanometer mirror 223 are set at a predetermined angle.

The optical axes of the two light receiving and transmitting path modules in the scanning device have included angles to scan different field angles to complete splicing, so that the increase of the horizontal field angle is realized, and the scanning device meets the requirement of large-field-of-view scanning.

Illustratively, when considering splicing, referring to fig. 5, J1 and J2 represent directions of two galvanometer mirrors respectively, C1 and C2 are two laser emergent rays respectively, C11, C12, C21 and C22 are single-side laser scanning rays respectively, and phi is a galvanometer included angle which is equal to an included angle between optical axes of two transceiving optical path modules. Because the laser emergent ray is vertical to the direction of the galvanometer reflector, the following can be known according to the geometrical relationship:

α=（180°-FOV）/2

FOV = phi (phi is theoretically 0-180 degree)

The scanning angle of the scanning device =2 × FOV =2 × Φ.

In other embodiments, when the number of galvanometer mirrors is N, i.e. as shown in fig. 6, two or more galvanometer mirrors are employed to complete the field stitching: n represents the number of galvanometer mirrors in the scanning device, and 311, 312, … …, 31N-1 and 31N respectively represent N sequentially adjacent galvanometer mirrors; φ 1 represents the angle between the first galvanometer mirror and the second galvanometer mirror, … …, φ N-1 represents the angle between the N-1 st galvanometer mirror and the N-th galvanometer mirror. At this time, the scanning angle of the scanning device can be expressed as:

scanning angle of the scanning device =2 × (Φ 1+ … + Φ N-1), (N ≧ 1, and N is an integer)

Wherein, φ 1, … …, φ N-1 may be equal or unequal, that is, the included angle between each two adjacent galvanometer mirrors may be equal or unequal, and the scanning angle range of 0-360 ° can be realized without limitation.

In the embodiment of the present disclosure, when N =2 is taken, two galvanometer scanning modules (i.e., transceiving optical path modules) are used to complete the field scanning and splicing, and the derivation formula can be known as follows: the two galvanometer scanning modules can theoretically achieve the field angle of 2 multiplied by 180 degrees, namely the field angle of 360 degrees, so that the scanning device can ensure large field scanning.

In some embodiments, continuing on the basis of fig. 1 or fig. 2, with reference to fig. 4, the first galvanometer mirror 213 and the fixed mirror 214 are arranged along the height direction Z of the rotating polygon mirror 11; and/or the second perforated mirror 222 and the second galvanometer mirror are arranged along the height direction Z of the rotating polygon mirror 11.

In combination with the above, while realizing large-field scanning, the two light path receiving and transmitting modules are vertically stacked and arranged along the height direction Z of the rotating multi-surface prism, and the fixed reflector 214 can be introduced into one side of the block to complete light path turning, so as to ensure that light can be emitted normally for scanning; in addition, the size of optical elements such as a prism and a galvanometer is not required to be increased, and the overall size of the scanning device (such as a laser radar whole machine) is reduced, so that the miniaturization requirement is favorably met.

For example, the stacking between the first transceiving optical circuit module 121 and the second transceiving optical circuit module 122, which is detailed in specific optical elements, may include: the first galvanometer mirror 213 and the fixed mirror 214 are arranged in the height direction Z of the rotating polygon mirror 11; and/or the second perforated mirror 222 and the second galvanometer mirror are arranged along the height direction Z of the rotating polygon mirror 11. By the arrangement, the optical elements in the transmitting and receiving optical path modules are longitudinally (namely in the height direction) stacked, so that the whole longitudinal space of the scanning device can be fully utilized, the whole size of the scanning device can be reduced, and the requirement on miniaturization is met.

In some embodiments, with continued reference to fig. 1 and 4, the first galvanometer mirror 213 and the second galvanometer mirror 223 are respectively located at different height positions along the height direction Z of the rotating polygon mirror 11.

Illustratively, taking the orientation shown in fig. 4 as an example, the first galvanometer mirror 213 is located at a higher elevation than the second galvanometer mirror 223. In other embodiments, the first galvanometer mirror 213 may be located at a lower height than the second galvanometer mirror 223, which is not limited herein.

In the embodiment of the present disclosure, two galvanometer mirrors are stacked in the height direction Z of the rotating polygon mirror 11, so that the scanning device can be fully utilized in the longitudinal overall space, the overall size of the scanning device can be reduced, and the miniaturization requirement is satisfied.

It can be understood that the stacking arrangement of the two galvanometer mirrors refers to the stacking arrangement of the motor for moving the driver, and the two mirror surfaces are not stacked in the longitudinal direction, so that independent emitting and receiving of the respective light rays in the two transceiving optical path modules are ensured.

In some embodiments, the rotating faceted prism 11 is a four-sided prism.

In the embodiment of the disclosure, the scanning of the horizontal field angle is completed by rotating the rotating polygon mirror, the horizontal field angle FOV =360 °/mx 2 that can be realized by a single transceiving optical path module is, and M is the number of facets of the mirror. Wherein, because the maximum included angle between the in-plane incident angle and the reflection angle is 180 °, the maximum horizontal scanning angle of a single transceiving optical path module can be 180 °. Based on the formulas in this paragraph, an appropriate faceted prism, such as a four-sided prism, can be provided. Therefore, the rotary polygon mirror 11 has a simple structure, so that the whole structure of the scanning device is simple, and the miniaturization design and manufacture of the scanning device are convenient to realize.

In other embodiments, the rotating polygon mirror 11 may be another polygon mirror, which is not limited herein.

In some embodiments, with reference to fig. 7 to 10, the rotation angle of the rotating polygon prism 11 corresponding to the first transceiving optical path module 121 reaching the maximum field angle is different from the rotation angle of the rotating polygon prism 11 corresponding to the second transceiving optical path module 122 reaching the maximum field angle; in addition, the maximum angle of view reached by the first transceiving optical path module 121 and the maximum angle of view reached by the second transceiving optical path module 122 are angularly overlapped.

Fig. 7 to 10 are top views of the scanning device in different states, respectively, where "different states" can be understood as different angles of rotation of the rotating polygon mirror.

Referring to fig. 7 and 8, the rotating polygon prism 11 rotates about its own center as it rotates, the dotted line 01 is a line passing through the center of the rotating polygon prism and directed straight ahead, and the bold solid lines (i.e., a1, a2, B1, and B2) are paths of light beams (i.e., rays), respectively.

As can be seen from fig. 7 and 8: since the first transmitting/receiving optical path module 121 (right side in the figure) and the second transmitting/receiving optical path module 122 (left side in the figure) are not symmetrical with respect to the chain line 01, when the rotating polygon prism 11 rotates, the scanning angles of the two transmitting/receiving optical path modules are different when the two transmitting/receiving optical path modules correspond to the same rotation angle of the rotating polygon prism 11 (i.e., a1 is different from B1, and a2 is different from B2). For example, a1 and B2 represent light rays emitted from two light path modules to the front, and it can be seen that the rotation angles of the corresponding rotating polygon prisms are different. Namely, the scanning field data of the two light path receiving and transmitting modules are respectively extracted when the rotating polygon prism is at different rotating angles.

Referring to fig. 9 and 10, a3 represents the light beam corresponding to the second transceiving optical path module 122 at the maximum scanning angle, and B3 represents the light beam corresponding to the first transceiving optical path module 121 at the maximum scanning angle. As can be seen from fig. 9 and 10: the scanning light beams A3 and B3 of the two transceiving optical path modules at the maximum scanning angle intersect, namely, the left and right transceiving optical path modules have a field-of-view overlapping region. The overlap region is equivalent to performing two scans, thereby not only increasing the resolution right in front, but also improving the accuracy of the stitching scheme.

In some embodiments, with continued reference to FIG. 4, the rotational speed of the multi-faceted rotating prism 11 is less than or equal to a preset rotational speed; and/or the number of light beams of the emission light source is greater than or equal to a preset number; wherein the emission light source includes a first emission light source 211 and a second emission light source 221.

The rotation of the rotating polygon mirror 11 and the galvanometer mirror may be driven by a motor or other electromagnetic means, but is not limited thereto. The faster the rotational speed of the rotating polygon mirror 11, the lower the resolution of the scanning device 10, when the number of light beam pulses emitted by the light emitting source is fixed. By setting the rotation speed of the polygon mirror 11 to be equal to or less than a preset rotation speed, a higher scanning resolution can be ensured; in particular, a higher horizontal field resolution can be ensured; similarly, by setting the smaller galvanometer reflector, higher vertical field resolution can be ensured.

It can be understood that the preset rotation speed can be set based on the application scenario and the use requirement of the scanning device, and the specific rotation speed value is not limited herein.

At the same time, the resolution of the scanning device is also related to the number of pulses emitted by the emitting light source. In general, the resolution of the rotating polygon mirror can be reduced by reducing the rotational speed of the motor, thereby improving the resolution. However, when the motor speed is extremely low and the resolution is not satisfactory, the resolution requirement can be satisfied by increasing the number of light beams of the emission light source. Specifically, the use of a multi-beam emission light source (e.g., a multi-beam laser), i.e., an increase in the number of pulses, is equivalent to an increase in the number of scanning lines, compared to a single-beam emission light source, thereby improving resolution.

It can be understood that the preset number can be set based on the application scenario and the usage requirement of the scanning device, and is not limited herein.

Illustratively, if only the vertical field resolution needs to be increased, the beams may be arranged in a vertical 1 × q column in the vertical field direction, 1 being 1 beam in the horizontal direction and q being q beams in the vertical direction; if the horizontal field resolution and the vertical field resolution need to be increased simultaneously, the light beams can be arranged in a p × q planar array, wherein p is p beams in the horizontal direction, and q is q beams in the vertical direction. Wherein p and q are both positive integers.

Therefore, at least one of the rotating speed of the rotating polygon prism, the rotating speed of the galvanometer reflector and the number of light beams of the emission light source can be flexibly set based on the requirement of scanning resolution, and the flexible application of the scanning device is realized.

In some embodiments, the power of the first emission light source 211 is greater than or equal to a first preset power and the power of the second emission light source 221 is greater than or equal to a second preset power.

Wherein, the larger the power of the emission light source, the longer the distance that the emergent light beam can propagate. Based on this, by the above arrangement, long-distance scanning can be realized.

Illustratively, the greater the laser power, the further it can measure, according to the lidar ranging equation. Therefore, when the scanning device is used for scanning, the power of an emission light source (such as a laser) can be adjusted according to the distance requirement, the small power is adopted at the near part, the large power is adopted at the far part, namely, the power is flexibly adjusted, and the energy is saved while the accurate scanning is realized.

It can be understood that the maximum power of each emission light source is required to satisfy the requirement of human eye safety.

The first preset power and the second preset power may be equal or different, and are not limited herein.

The scanning device provided by the embodiment of the disclosure is based on a view field splicing scheme, and adopts optical elements such as a rotary multi-surface prism, a galvanometer reflector and the like to carry out scanning splicing, and the optical axis of the light-emitting path module has an included angle, so that 360-degree horizontal view field scanning can be realized. The optical path adjusting device comprises a rotating polygon prism, at least two receiving and transmitting optical path modules, a fixed reflector, a vibrating mirror reflector, a fixed reflector, a light path adjusting module and a light path adjusting module, wherein the at least two receiving and transmitting optical path modules are arranged in a non-bilateral symmetry manner by adjusting the design of the optical path, and are arranged in an up-down stacking manner along the height direction of the rotating polygon prism; compared with a horizontal splicing scheme, the scanning device greatly reduces the size of the whole scanning device, does not have the risk that a structural member shields a large field angle, and is favorable for realizing the design and implementation of a long-distance, large-angle and small-volume scanning device (such as a laser radar).

The scanning device provided by the embodiment of the disclosure solves the problem that the size and the view angle of the whole scanning device are restricted with each other, and can improve the scanning view angle on the premise of not increasing the size and the whole volume of optical elements (such as a rotary polygon mirror, a galvanometer mirror and the like). Furthermore, different scanning resolution requirements can be met by flexibly adjusting the rotating speed and/or the number of the light beams; the power of the emission light source can be adjusted, and different ranging requirements can be met.

On the basis of the foregoing embodiments, an embodiment of the present disclosure further provides a scanning method, which can be executed by applying any one of the scanning apparatuses in the foregoing embodiments, so as to achieve corresponding beneficial effects.

In some embodiments, as shown in fig. 11, the method may include:

s201, obtaining a view field angle, a detection distance and a corresponding resolution of a to-be-scanned view field corresponding to a target area.

The view field angle can comprise a horizontal view field angle and a vertical duration angle, so that a three-dimensional space to be detected is determined. Based on this, the angle of the field of view may be determined based on the size of the target area (i.e., the area to be detected).

Wherein, the detection distance is the distance between the target area and the scanning device, and an appropriate distance range can be determined based on empirical values to improve the scanning detection efficiency.

Wherein, the higher the resolution is, the higher the detection precision is, and the detection resolution can be determined based on the detection precision requirement.

For example, the field angle, the detection distance, and the resolution may be acquired by the scanning device receiving a user operation, or may be acquired automatically by other devices in communication therewith, which is not limited herein.

S202, determining working parameters of the device based on the angle of the field of view, the detection distance and the resolution.

In combination with the above, the view field angle is related to the included angle between the optical axes of the receiving and transmitting optical path modules in the scanning device and the view field angle which can be realized by each of the receiving and transmitting optical path modules; the detection distance is related to the power of a transmitting light source in the scanning device; the resolution is related to the rotational speed of the rotating polygon mirror in the scanning device, the rotational speed of the galvanometer mirror, and the number of light beams of the emission light source.

In this step, the above-mentioned relevant working parameters may be flexibly set based on the view field angle, the detection distance, and the resolution obtained in the foregoing S201, so as to meet the scanning requirement.

And S203, driving the device to scan the target area based on the working parameters.

In conjunction with the above, the scanning device is driven to scan the target area based on the respective operating parameters determined in the foregoing S201.

In the scanning method provided by the embodiment of the disclosure, the working parameters of the scanning device can be flexibly set based on different use requirements, so as to meet the scanning requirements in different scenes.

The scanning device and the scanning method can be applied to large-angle scanning detection in automatic driving, auxiliary driving or other scenes, and the scanning device occupies a small space and is easy to integrate.

It is noted that, in this document, relational terms such as "first" and "second," and the like, may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The foregoing are merely exemplary embodiments of the present disclosure, which enable those skilled in the art to understand or practice the present disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the disclosure. Thus, the present disclosure is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A scanning device is characterized by comprising a rotary multi-surface prism and at least two receiving and transmitting optical path modules;

2. The apparatus of claim 1, wherein the total width of the at least two transmit-receive optical path modules along the height direction of the rotating polygon prism is equal to or less than the height of the rotating polygon prism.

3. The apparatus according to claim 1 or 2, wherein the at least two transceiver optical path modules comprise a first transceiver optical path module and a second transceiver optical path module;

the second transceiving optical path module comprises a second transmitting light source, a second reflector with a hole, a second galvanometer reflector, a second receiving lens and a second receiving device; wherein the light beam emitted by the second emission light source passes through the second aperture-containing reflector

After passing through the hole, the light is reflected to the rotating polygon through the second galvanometer reflector; the echo reflected by the object in the target area returns to the rotating polygon prism, is reflected to the second perforated mirror through the second galvanometer mirror after being reflected, and is received by the second receiving device through the second receiving lens after being reflected.

4. The apparatus of claim 3, wherein the first galvanometer mirror and the fixed mirror are arranged along a height of the rotating polygon;

5. The apparatus of claim 4, wherein the first galvanometer mirror and the second galvanometer mirror are respectively located at different height positions along a height direction of the rotating polygon mirror.

6. The apparatus of claim 3, wherein the first galvanometer mirror and the second galvanometer mirror are set at a predetermined angle.

7. The apparatus of claim 3, wherein the rotating polygon is a four-sided prism;

8. The apparatus of claim 3, wherein the multi-faceted rotating prism has a rotational speed less than or equal to a predetermined rotational speed;

9. The apparatus of claim 3, wherein the power of the first emitting light source is greater than or equal to a first predetermined power, and the power of the second emitting light source is greater than or equal to a second predetermined power.

10. A scanning method, characterized in that it is performed using the apparatus of any one of claims 1-9; the method comprises the following steps:

and driving the device to scan the target area based on the working parameters.