CN110703275A

CN110703275A - Laser radar system and object identification method

Info

Publication number: CN110703275A
Application number: CN201910942983.3A
Authority: CN
Inventors: 罗斯特
Original assignee: Suteng Innovation Technology Co Ltd
Current assignee: Suteng Innovation Technology Co Ltd
Priority date: 2019-09-30
Filing date: 2019-09-30
Publication date: 2020-01-17

Abstract

The present application relates to a laser radar system and an object identification method. The laser radar system includes: a beam emitter for emitting an outgoing beam; a beam receiver for receiving first and second polarized lights in the echo beam, respectively; the echo light beam is a light beam returned after the emergent light beam is reflected by a target object; and the processor is used for comparing the first polarized light and the second polarized light received by the light beam receiver with the emergent light beam and then determining the surface parameters of the target object. By the embodiment of the invention, new identification dimensionality can be added for identifying the target object, so that the target object can be identified more comprehensively.

Description

Laser radar system and object identification method

Technical Field

The present application relates to the field of laser radar technology, and in particular, to a laser radar system and an object recognition method.

Background

Lidar has applications in a number of technical areas, where identification of objects is one of the main applications of lidar. In the related technology, the point cloud data can be monitored through a laser radar, so that the three-dimensional shape of an object is recognized, and a three-dimensional image of the surrounding environment is established; or the reflectivity of the object is obtained by laser radar so that areas of the same reflectivity are marked with the same color.

However, identifying the contour, shape, and position of an object by lidar is not comprehensive enough for identifying the object. It is therefore desirable that additional information be available via lidar to provide more evidence for identifying objects.

Disclosure of Invention

In view of the above, it is necessary to provide a laser radar system and an object identification method capable of obtaining surface parameters of a target object.

In a first aspect, an embodiment of the present invention provides a laser radar system, where the laser radar system includes:

a beam emitter for emitting an outgoing beam;

a beam receiver for receiving first and second polarized lights in the echo beam, respectively; the echo light beam is a light beam returned after the emergent light beam is reflected by the target object;

and the processor is used for comparing the first polarized light and the second polarized light received by the light beam receiver with the emergent light beam and then determining the surface parameters of the target object.

In one embodiment, the optical beam receiver comprises:

the light splitting module is used for splitting the received echo light beam into first polarized light and second polarized light;

the first light beam detection module is used for receiving the first polarized light and generating a first signal;

and the second light beam detection module is used for receiving the second polarized light and generating a second signal.

In one embodiment, the processor is respectively connected with the first beam detection module and the second beam detection module;

and the processor is used for comparing the first signal, the second signal and the signal corresponding to the emergent light beam to determine the surface parameter of the target object.

In one embodiment, the optical beam receiver further comprises:

the first focusing mirror group is used for focusing the first polarized light and then irradiating the first polarized light to the first light beam detection module;

and the second focusing mirror group is used for focusing the second polarized light and then emitting the second polarized light to the second light beam detection module.

In one embodiment, the lidar system further comprises:

and the optical path annular module is used for enabling the emergent light beam emitted by the light beam emitter to pass through, and is also used for deflecting the received echo light beam to emit to the light beam receiver.

In one embodiment, the optical path ring module comprises:

the reflecting mirror is provided with an exit hole, the exit beam exits outwards through the exit hole, and the echo beam is reflected by the reflecting mirror and then emitted to the beam receiver.

In one embodiment, the optical path ring module comprises: the optical system comprises a first light splitting component, an optical rotation component and a second light splitting component;

the first light splitting assembly is used for splitting an emergent light beam emitted by the light beam emitter into an emergent polarized light A and an emergent polarized light B; a polarization rotation component for rotating the polarization direction of the outgoing A-polarized light and the outgoing B-polarized light by 90 degrees; the second light splitting assembly is used for combining the emergent polarized light A and the emergent polarized light B after the polarization direction is rotated by 90 degrees and then emitting the combined emergent polarized light A and B;

the second light splitting component is also used for receiving the echo light beam and splitting the echo light beam into echo P polarized light and echo S polarized light; the optical rotation component is also used for rotating the polarization directions of the echo P polarized light and the echo S polarized light by 0 degree; the first light splitting component is also used for combining the echo P polarized light and the echo S polarized light after the polarization direction is rotated by 0 degree and then emitting the combined light to the light beam receiver.

In one embodiment, the optical path ring module comprises: a circulator, a first collimator and a second collimator;

the circulator comprises a first optical beam interface, a second optical beam interface and a third optical beam interface; an emergent light beam emitted by the light beam emitter enters the circulator through the first light beam interface and is emergent through the second light beam interface; the received echo light beam enters the circulator through the second light beam interface and is emitted to the light beam receiver through the third light beam interface; the first collimator is arranged at the second light beam interface, and the second collimator is arranged between the third light beam interface and the light beam receiver.

In one embodiment, the lidar system further includes a scanner;

and the scanner is used for receiving the emergent light beam passing through the light path annular module and emitting the emergent light beam outwards for scanning, and is also used for receiving the echo light beam, deflecting the echo light beam and transmitting the deflected echo light beam to the light path annular module.

In a second aspect, an embodiment of the present invention provides an object identification method, which is applied to the laser radar system described above, and the method includes:

the light beam emitter emits an emergent light beam;

the light beam receiver receives a first polarized light and a second polarized light in the echo light beam respectively; the echo light beam is a light beam returned after the emergent light beam is reflected by a target object;

and the processor compares the first polarized light and the second polarized light received by the light beam receiver with the emergent light beam and then determines the surface parameters of the target object.

In the laser radar system and the object identification method, the laser radar system comprises a light beam transmitter, a light beam receiver and a processor, wherein the light beam transmitter transmits an emergent light beam; the light beam receiver receives the first polarized light and the second polarized light in the echo light beam respectively; and the processor compares the first polarized light and the second polarized light received by the light beam receiver with the emergent light beam, and then determines the surface parameters of the target object. According to the embodiment of the invention, the first polarized light of the emergent beam and the first polarized light of the echo beam, the second polarized light of the emergent beam and the second polarized light of the echo beam are respectively compared, the variation of the first polarized light and the variation of the second polarized light of the emergent beam and the echo beam are obtained, and the surface parameters of the target object are calculated, wherein the surface parameters can comprise the surface roughness of the target object and the material of the target object, so that a new identification dimension is added for identifying the target object, and the detection efficiency and the accuracy are improved.

Drawings

FIG. 1 is one of schematic diagrams of a lidar system according to an embodiment;

FIG. 2 is a diagram illustrating an exemplary configuration of a light beam receiver;

FIG. 3 is a second schematic diagram of an embodiment of a light beam receiver;

FIG. 4 is a second schematic diagram of an embodiment of a lidar system;

FIG. 5 is a third schematic diagram of an exemplary lidar system;

FIG. 6 is a fourth schematic diagram of an exemplary lidar system;

FIG. 7 is one of the schematic structural diagrams of an optical path ring module according to an embodiment;

FIG. 8 is a second schematic structural diagram of an optical circuit ring module according to an embodiment;

FIG. 9 is a fifth schematic diagram of a lidar system in an embodiment;

FIG. 10 is a sixth schematic diagram of a lidar system in one embodiment;

FIG. 11 is a seventh schematic diagram illustrating a configuration of a lidar system in an embodiment;

FIG. 12 is an eighth schematic block diagram of a lidar system in an embodiment;

FIG. 13 is a flowchart illustrating an object recognition method according to an embodiment.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

In one embodiment, as shown in FIG. 1, a lidar system is provided. The lidar system comprises a beam transmitter 10 for transmitting an outgoing beam; a beam receiver 20 for receiving the first polarized light and the second polarized light in the echo beam, respectively; the echo light beam is a light beam returned after the emergent light beam is reflected by the target object; and the processor 30 is configured to determine the surface parameter of the target object after comparing the first polarized light and the second polarized light received by the light beam receiver with the outgoing light beam.

In the present embodiment, the light beam emitter 10 emits an outgoing light beam toward the target object, as shown by the solid line in fig. 1. The outgoing light beam may be circularly polarized light, including P-polarized light and S-polarized light. Alternatively, the proportion of P-polarized light may be greater than the proportion of S-polarized light, e.g., more than 90% of the outgoing light beam is P-polarized light. The embodiment of the present invention is not limited in detail, and may be set according to actual situations.

The outgoing beam is reflected back to the echo beam after being irradiated to the surface of the target object, and then the echo beam is received by the beam receiver 20, as shown by a dotted line in fig. 1. After the light beam receiver 20 receives the echo light beam, the echo light beam is separated into first polarized light and second polarized light; then, the light beam receiver 20 detects the first polarized light and the second polarized light, respectively, and sends the detection results to the processor 30.

After receiving the detection result, the processor 30 determines the ratio of the first polarized light to the second polarized light according to the detection result, and further determines the surface parameter of the target object according to the ratio of the first polarized light to the second polarized light. The processor 30 compares the first polarized light of the outgoing beam and the first polarized light of the echo beam, the second polarized light of the outgoing beam and the second polarized light of the echo beam, respectively, to obtain the variation of the first polarized light and the second polarized light of the outgoing beam and the echo beam. For example, 90% of the outgoing beam is the first polarized light, 10% of the outgoing beam is the second polarized light, 60% of the returning echo beam from the target object a area is the first polarized light, 40% of the returning echo beam is the second polarized light, and it can be seen that the a area depolarizes 30% of the first polarized light in the outgoing beam to the second polarized light. And 80% of the echo light beams returning from the B area of the target object are the first polarized light, and 20% of the echo light beams are the second polarized light, and then the B area depolarizes 10% of the first polarized light in the incident light beams into the second polarized light.

Since the rougher the surface and the larger the complex refractive index of the material, the larger the depolarization, the corresponding relationship between the surface parameter and the surface roughness may be preset in the processor 30, and after the surface parameter of the target object is obtained, the processor 30 classifies the surface roughness of the target object according to the surface parameter. The processor 30 may also preset a corresponding relationship between the surface parameter and the material, and after obtaining the surface parameter of the target object, the processor 30 classifies the material of the target object according to the surface parameter. Therefore, new identification dimensionality is added for identifying the target object, and the detection efficiency and accuracy are improved.

In practical applications, the light beam transmitter 10, the light beam receiver 20 and the processor 30 may be disposed in a lidar; it is also possible to arrange the beam transmitter 10 and the beam receiver 20 in a lidar and the processor 30 in a terminal, the lidar being connected to the terminal via a network. The embodiment of the present invention is not limited in detail, and may be set according to actual situations.

The laser radar system comprises a light beam transmitter, a light beam receiver and a processor; the light beam emitter emits an emergent light beam; the light beam receiver receives the first polarized light and the second polarized light in the echo light beam respectively; and the processor compares the first polarized light and the second polarized light received by the light beam receiver with the emergent light beam, and then determines the surface parameters of the target object. In the embodiment of the invention, the light beam receiver separates the echo light beam into the first polarized light and the second polarized light, the processor respectively compares the first polarized light of the emergent light beam with the first polarized light of the echo light beam, the second polarized light of the emergent light beam with the second polarized light of the echo light beam to obtain the variation of the first polarized light and the second polarized light of the emergent light beam and the echo light beam, surface parameters are calculated, new identification dimensions are added for identifying the target object, the target object can be identified more comprehensively, and the detection efficiency and the detection accuracy are improved.

In another embodiment, as shown in fig. 2, this embodiment relates to an alternative configuration of the light beam receiver. On the basis of the above-described embodiment shown in fig. 1, the optical beam receiver 20 includes: a light splitting module 21, configured to split the received echo light beam into first polarized light and second polarized light; a first beam detection module 22 for receiving the first polarized light and generating a first signal; and a second beam detection module 23 for receiving the second polarized light and generating a second signal.

In this embodiment, the light beam receiving module 20 may include a light splitting module 21, a first light beam detecting module 22 and a second light beam detecting module 23. The light splitting module 21 receives the echo light beam and splits the echo light beam into a first polarized light and a second polarized light. As shown in fig. 2, the dotted lines with lines represent light of the first polarization and the dotted lines with dots represent light of the second polarization. Alternatively, the spectroscopic module 21 transmits the P-polarized light in the echo beam and deflects the S-polarized light in the echo beam. Optionally, the splitting module 21 includes at least one of a polarization splitting prism, a polarization splitting plate, and a wollaston prism. The embodiment of the present invention is not limited in detail, and may be set according to actual situations.

The beam splitting module 21 splits the echo beam into the first polarized light and the second polarized light, and then the first polarized light is received by the first beam detection module 22 and the second polarized light is received by the second beam detection module 23. After receiving the first polarized light, the first beam detection module 22 generates a first signal according to the first polarized light. After receiving the second polarized light, the second beam detection module 23 generates a second signal according to the second polarized light. The first light beam detection module 22 and the second light beam detection module 23 may be APDs (Avalanche photodiodes), PIN (positive-intrinsic-negative, P-type semiconductor-impurity-N-type semiconductor), single photon receivers SPAD, MPPCs (Silicon photomultipliers), sipms (Silicon photomultipliers), or the like, or may be detectors composed of a single or multiple arrays of the above functional devices. The embodiment of the present invention is not limited in detail, and may be set according to actual situations.

The processor 30 is connected to the first beam detection module 22 and the second beam detection module 23 respectively corresponding to the beam receiving module 20; and the processor 30 is used for comparing the first signal, the second signal and the signal corresponding to the emergent light beam to determine the surface parameter of the target object.

Specifically, after the first beam detection module 22 generates the first signal, the first signal is transmitted to the processing module 30; the second beam detecting module 23 generates a second signal and transmits the second signal to the processing module 30. After receiving the first signal and the second signal, the processing module 30 determines the ratio between the first polarized light and the second polarized light according to the first signal and the second signal, and further determines the surface parameter of the target object according to the ratio between the first polarized light and the second polarized light and the ratio between the first polarized light and the second polarized light in the outgoing light beam. Such as determining the roughness of the target object surface, the complex refractive index of the target object surface, etc.

In one embodiment, as shown in fig. 3, the light beam receiver 20 further includes a first focusing lens group 24 for focusing the first polarized light to the first light beam detecting module 22; and the second focusing lens group 25 is used for focusing the second polarized light and then emitting the second polarized light to the second beam detection module 23.

In this embodiment, a first focusing lens group 24 may be disposed between the light splitting module 21 and the first beam detecting module 22, and the first focusing lens group 24 performs focusing processing on the first polarized light emitted from the light splitting module 21, and then emits the focused first polarized light to the first beam detecting module 22. Similarly, a second focusing lens group 25 may be disposed between the light splitting module 21 and the second beam detecting module 23, and the second focusing lens group 25 focuses the second polarized light emitted from the light splitting module 21 and then emits the focused second polarized light to the second beam detecting module 23. The first focusing lens group 24 and the second focusing lens group 25 focus the polarized light, so that the light beams are converged and then are emitted to the light sensing surface of the light beam detection module, more polarized light can be received by the light beam detection module, signals generated by the light beam detection module are more accurate, the accuracy of the surface parameters determined by the processing module is improved, more first polarized light and more second polarized light are received, the receiving rate of echo light beams is improved, and the distance measuring capability of the laser radar system can be improved.

In one embodiment, as shown in fig. 4, this embodiment relates to an alternative configuration of a lidar system. On the basis of the above-described embodiments shown in fig. 1 to 3, the lidar system further includes an optical path ring module 40 and a scanner 50; and an optical path ring module 40 for passing the outgoing beam emitted from the beam emitter 10 and deflecting the received echo beam to the beam receiver 20. And the scanner 50 is used for receiving the emergent light beam passing through the optical path annular module 40 and emitting the emergent light beam outwards for scanning, and is also used for receiving the echo light beam and deflecting the echo light beam to the optical path annular module 40.

In this embodiment, the light beam emitter 10 generates an outgoing light beam, the light path annular module 40 receives the outgoing light beam, and emits the outgoing light beam to the scanner 50, and the scanner 50 emits the outgoing light beam to the target object. Then, the scanner 50 receives the echo beam returned from the target object and scans the echo beam to the optical path ring module 40. The optical path ring module 40 then deflects the echo beam to the beam receiver 20. The optical path annular module 40 and the scanner 50 may be implemented by various structures, specifically as follows:

referring to configuration one shown in fig. 5, the optical path ring module 40 includes: the reflecting mirror 41 is provided with an exit hole on the reflecting mirror 41, the exit beam exits outwards through the exit hole, and the echo beam is reflected by the reflecting mirror 41 and then emitted to the beam receiver. The scanner 50 includes a galvanometer 51.

Specifically, the outgoing beam generated by the beam transmitter 10 passes through the outgoing hole in the mirror 41 and is incident on the galvanometer 51. Then, the galvanometer 51 vibrates at a preset frequency to scan the outgoing beam onto the target object. The outgoing beam is reflected by the target object and returns an echo beam, and the galvanometer 51 receives the echo beam and reflects the echo beam to the reflecting mirror 41. The mirror 41 reflects the echo beam to the beam receiver 20, so that the beam receiver 20 separates the echo beam into the first polarized light and the second polarized light. Here, the area of the exit aperture of the mirror 41 is less than 50% of the spot area of the echo beam, so that most of the echo beam is received by the beam receiver 20, rather than leaking through the exit aperture to make the beam receiver 20 unable to receive.

Referring to the second structure shown in fig. 6, the optical path ring module 40 includes a first optical splitter component 42, an optical rotator component 43, and a second optical splitter component 44; a first beam splitting assembly 42 for splitting the outgoing beam generated by the beam transmitter 10 into outgoing a-polarized light and outgoing B-polarized light; a polarization rotating member 43 for rotating the polarization directions of the outgoing a-polarized light and the outgoing B-polarized light by 90 °; the second light splitting assembly 44 is used for combining the emergent polarized light A and the emergent polarized light B after the polarization direction is rotated by 90 degrees and then emitting the combined emergent polarized light A and B; the second light splitting assembly 44 is further configured to receive the echo light beam and split the echo light beam into echo a polarized light and echo B polarized light; a rotation assembly 43 for rotating the polarization direction of the echo a polarized light and the echo B polarized light by 0 °; the first light splitting assembly 42 is further configured to combine the echo a polarized light and the echo B polarized light after the polarization direction is rotated by 0 °, and then emit the combined light to the light beam receiver. The scanner includes a galvanometer 52.

Specifically, the description will be given taking an example in which a-polarized light is P-polarized light and B-polarized light is S-polarized light; the beam emitter 10 generates an outgoing beam, the outgoing beam 10 is received by the first beam splitting assembly 42, and then the first beam splitting assembly 42 splits the outgoing beam into outgoing P-polarized light and outgoing S-polarized light. The outgoing P-polarized light and the outgoing S-polarized light then enter the rotation rotator 43, and the rotation rotator 43 rotates the polarization direction of the outgoing P-polarized light by 90 ° and rotates the polarization direction of the outgoing S-polarized light by 90 °. Then, the outgoing P-polarized light and the outgoing S-polarized light whose polarization directions are rotated by 90 ° enter the second light splitting assembly 44, and the second light splitting assembly 44 combines the outgoing P-polarized light and the outgoing S-polarized light whose polarization directions are rotated by 90 ° and emits them. The combined outgoing beam is emitted to the galvanometer 52, and the galvanometer 52 vibrates according to a preset frequency to scan the outgoing beam onto a target object.

The outgoing beam is irradiated to the target object, reflected by the target object, and returns to the echo beam. The galvanometer 52 receives the echo beam and reflects the echo beam to the optical path ring module 40. The second beam splitting assembly 44 of the optical path ring module 40 receives the echo beam and splits the echo beam into echo P-polarized light and echo S-polarized light. Next, the echo P-polarized light and the echo S-polarized light enter the optical rotation unit 43, and the optical rotation unit 43 maintains the polarization directions of the P-polarized light and the S-polarized light, and emits the echo P-polarized light and the echo S-polarized light whose polarization directions are rotated by 0 ° to the first optical splitting unit 42. Then, the first light splitting assembly 42 combines the echo P polarized light and the echo S polarized light of which the polarization directions are rotated by 0 ° and emits the combined light; the echo beam passing through the optical path ring module 40 is received by the beam receiver 20 and separated into the first polarized light and the second polarized light.

In one embodiment, as shown in fig. 7, the first beam splitting assembly 42 includes a first polarizing beam splitter 421 and a first reflecting prism 422; the outgoing light beam enters the first beam splitting assembly 42, is split into outgoing P-polarized light and outgoing S-polarized light by the first polarization beam splitter 421, that is, the transmitted P-polarized light, deflects the S-polarized light to the first reflection prism 422, and is reflected again. Subsequently, both the outgoing P-polarized light and the outgoing S-polarized light enter the optical rotation member 43.

As shown in fig. 7, the optical rotation member 43 includes a magneto-rotation mirror 431 and an optical rotation mirror 432. The magnetic field direction of the magneto-rotation mirror 431 is set to coincide with the incident direction of the outgoing light beam, the outgoing P-polarized light and the outgoing S-polarized light enter the magneto-rotation mirror 431 of the optical rotation member 43, and the magneto-rotation mirror 431 rotates the polarization directions of the outgoing P-polarized light and the outgoing S-polarized light clockwise by 45 ° in the magnetic field direction. Then, the optical rotation mirror 432 further rotates the outgoing P-polarized light and the outgoing S-polarized light, whose polarization directions are rotated by 45 °, clockwise by 45 ° along the incident direction; the emitted P-polarized light passes through the optical rotation member 43 and becomes emitted S-polarized light, and the emitted S-polarized light passes through the optical rotation member 43 and becomes emitted P-polarized light.

As shown in fig. 7, the second beam splitting assembly 44 includes a second polarizing beam splitter 441 and a second reflecting prism 442. The emergent S-polarized light passing through the optical rotation assembly 43 enters the second reflecting prism 442, and is reflected by the second reflecting prism 442 to the second polarizing beam splitter 441, and the second polarizing beam splitter 441 deflects the emergent S-polarized light; the outgoing P-polarized light passing through the optical rotation assembly 43 passes through the second polarization beam splitter 441, and is combined with the outgoing S-polarized light into an outgoing light beam, which is emitted outward.

As shown in fig. 8, the echo light beam is incident on the second beam splitting element 44, and the second polarization beam splitter 441 receives the echo light beam, and the echo P-polarized light in the echo light beam passes through and deflects the echo S-polarized light in the echo light beam. Subsequently, the echo S-polarized light is deflected to the second reflecting prism 442 and then reflected again by the second reflecting prism 442. Then, both the echo P-polarized light and the echo S-polarized light enter the optical rotation member 43.

As shown in fig. 8, the echo P-polarized light and the echo S-polarized light enter the optical rotation mirror 432 of the optical rotation member 43, and the optical rotation mirror 432 rotates the polarization directions of the echo P-polarized light and the echo S-polarized light by 45 ° counterclockwise along the incident direction of the echo light beam. Next, the magneto rotation mirror 431 further rotates the echo P-polarized light and the echo S-polarized light clockwise by 45 ° in the incident direction of the echo light beam, that is, rotates the echo P-polarized light and the echo S-polarized light by 0 °, and keeps the polarization directions unchanged.

As shown in fig. 8, the echo P polarized light and the echo S polarized light passing through the optical rotation assembly 43 enter the first beam splitter assembly 42, the echo P polarized light is reflected by the first reflection prism 422 and then passes through the first polarization beam splitter 421, meanwhile, the first polarization beam splitter 421 deflects the echo S polarized light, and the echo P polarized light and the echo S polarized light are combined into an echo light beam after passing through the first polarization beam splitter 421 and then exit.

In the optical path ring module 40 of the second configuration, the optical path ring module 40 can make all the received echo beams received by the optical beam receiver 20, so that the light quantity of the detected echo beams can be increased compared with the first configuration, thereby improving the detection accuracy.

Referring to the third configuration shown in fig. 9, the optical path ring module 40 includes a fiber circulator 45, a first collimator 46, and a second collimator 47; the fiber optic circulator 45 includes a first optical beam interface, a second optical beam interface, and a third optical beam interface; an outgoing light beam emitted by the light beam emitter 10 enters the circulator 45 through the first light beam interface and exits through the second light beam interface; the received echo light beam enters the circulator 45 through the second light beam interface and is emitted to the light beam receiver 20 through the third light beam interface; the first collimator 46 is arranged at the second beam interface and the second collimator is arranged between the third beam interface and the beam receiver 20. The scanner 50 includes a galvanometer 53.

Specifically, a first light beam interface of the fiber circulator 45 is connected with the light beam emitter 10 through an optical fiber, a second light beam interface of the fiber circulator 45 is connected with the first collimator 46 through an optical fiber, and a third light beam interface of the fiber circulator 45 is connected with the second collimator 47 through an optical fiber. After the light beam emitter 10 generates an outgoing light beam, the outgoing light beam is coupled into the fiber circulator 45 through the first light beam interface and exits from the second light beam interface to the first collimator 46. The first collimator 46 collimates the outgoing beam and directs the outgoing beam to the galvanometer 53. The galvanometer 53 oscillates at a predetermined frequency to scan the outgoing beam onto the target object.

The outgoing beam is irradiated to the target object, reflected by the target object, and returns to the echo beam. The galvanometer 53 receives the echo beam and reflects the echo beam to the first collimator 46. The first collimator 46 then couples the echo beam into the fiber circulator 45 via the second beam interface. The fiber circulator 45 then outputs the echo beam from the third beam interface to the second collimator 47. The second collimator 47 then collimates the echo beam, and transmits the collimated echo beam to the light beam receiver 20, and the light beam receiver 20 separates the echo beam into the first polarized light and the second polarized light.

In the laser radar system, a light beam emitter generates an emergent beam and then emits the emergent beam to a light path annular module, the light path annular module enables the emergent beam to pass through and then emits the emergent beam to a scanner, and the scanner deflects the emergent beam and then emits the emergent beam to a target object; meanwhile, the optical path annular module is also used for receiving the echo light beam received by the scanner, so that the echo light beam is deflected and then emitted to the light beam receiver. The light path annular module can be realized by various structures, and can enable an emergent light beam to pass through and an echo light beam to deflect. The light beam receiver separates and receives the first polarized light and the second polarized light in the echo light beam, the processor compares the first polarized light of the emergent light beam with the first polarized light of the echo light beam, the second polarized light of the emergent light beam with the second polarized light of the echo light beam, the variation of the first polarized light and the second polarized light in the emergent light beam and the echo light beam is obtained, the surface parameter of the target object is calculated, new identification dimensionality is added for identifying the target object, the target object is identified more comprehensively, and the detection efficiency and the accuracy are improved.

Referring to fig. 10, based on the structure of the three optical path ring modules 40, the optical path ring module further includes a reflector 54, where the reflector 54 is used to reflect the outgoing light beam passing through the optical rotation assembly 40 and then transmit the reflected light beam to the vibrating mirror 52, and is also used to receive the echo light beam deflected by the vibrating mirror 52 and then transmit the reflected light beam to the optical path ring module 40. The reflector 54 can fold the emergent light path and the return light path, so as to compress the space occupied by the light paths and reduce the volume of the whole laser radar system.

Referring to fig. 10, based on the structure of the three optical path ring modules 40, the optical beam transmitter 10 may further include a laser source 11 and a collimating lens 12, wherein the collimating lens 12 is located between the laser source 11 and the optical path ring module 40; the collimating lens 12 is configured to collimate the outgoing light beam generated by the laser source 11, and to emit the collimated outgoing light beam to the optical path annular module 40.

In one embodiment, the optical path ring module 40 may not be included, and the outgoing optical path and the return optical path are disposed off-axis. As shown in fig. 11, the lidar system includes a scanner 50, and the scanner 50 may be a galvanometer 55. Specifically, the outgoing beam generated by the beam emitter 10 is emitted to the galvanometer 55, and the galvanometer 55 deflects the outgoing beam and then emits and scans the outgoing beam to the surface of the target object; the return echo beam from the target object is directly received by the beam receiver 20.

The light beam receiver is the same as the light beam receiver described in the previous embodiment, and comprises a light splitting module, a first light beam detection module and a second light beam detection module; the echo light beam received by the light splitting module is split into first polarized light and second polarized light; the first light beam detection module receives the first polarized light and generates a first signal; the second beam detection module receives the second polarized light and generates a second signal. Correspondingly, the processor is respectively connected with the first light beam detection module and the second light beam detection module; the processor compares the first signal, the second signal and the signal corresponding to the emergent beam to determine the surface parameters of the target object. In the embodiment of the invention, the light splitting module has the light splitting function, and the first light beam detection module and the second light beam detection module have the detection function, so that the processor can obtain the surface parameters, a new identification dimension is provided for identifying the object, and the object can be identified more comprehensively.

In one embodiment, as shown in fig. 12, the light beam receiver 20 further includes a collimating lens 26 in front of the incident end; and the collimating lens 26 is used for receiving the echo light beam, collimating the echo light beam, and directing the collimated echo light beam to the light beam receiver 20. The collimating lens 26 is arranged to enable the echo light beam to be emitted to the light splitting module 21 in parallel, so that the echo light beam is evenly emitted to the first light beam detection module 22 and the second light beam detection module 23 after being split by the light splitting module 21, the receiving efficiency of the echo light beam is improved, the accuracy of the light beam detection module is improved, and the accuracy of the processing module in determining the surface parameters of the target object is improved.

In one embodiment, as shown in FIG. 12, the lidar system also includes a mirror 56. The reflector is used for reflecting the outgoing beam generated by the beam transmitter 10 to the vibrating mirror 55, and is also used for receiving the echo beam deflected by the vibrating mirror 55 and reflecting the echo beam to the beam receiver 20. The setting of speculum 56 can fold outgoing light path and echo light path, and the space that the compression light path took reduces the volume of whole laser radar system.

In one embodiment, as shown in FIG. 13, an object identification method is provided. The method is applied to the laser radar system in the embodiment, and specifically comprises the following steps:

the beam emitter emits an outgoing beam, step 401.

Step 402, a light beam receiver respectively receives first polarized light and second polarized light in a echo light beam; the echo light beam is a light beam returned after the emergent light beam is reflected by the target object.

In step 403, the processor compares the first polarized light and the second polarized light received by the light beam receiver with the outgoing light beam, and then determines the surface parameters of the target object.

In this embodiment, the lidar system includes a beam transmitter 10, a beam receiver 20, and a processor 30. The outgoing beam is generated by the beam transmitter 10 and is transmitted to the target object.

The outgoing beam is reflected by the target object to form an echo beam after being irradiated to the target object. The light beam receiver 20 receives the echo light beam and separates the echo light beam into first polarized light and second polarized light; then, the light beam receiver 20 detects the first polarized light and the second polarized light, respectively, and sends the detection results to the processor 30.

The processor 30, after receiving the detection result, determines the ratio between the first polarized light and the second polarized light according to the detection result, and then determines the surface parameter of the target object according to the ratio between the first polarized light and the second polarized light. Specifically, the first polarized light of the emergent beam and the first polarized light of the echo beam, the second polarized light of the emergent beam and the second polarized light of the echo beam are respectively compared to obtain the variation of the first polarized light and the second polarized light of the emergent beam and the echo beam, and the surface parameter of the target object is calculated, wherein the surface parameter may include the surface roughness of the target object and the material of the target object, so that a new identification dimension is added for identifying the target object, and the detection efficiency and the accuracy are improved.

In the object identification method, a light beam transmitter transmits an emergent light beam, and a light beam receiver respectively receives a first polarized light and a second polarized light in a backward light beam; and the processor compares the first polarized light and the second polarized light received by the light beam receiver with the emergent light beam, and then determines the surface parameters of the target object. By the embodiment of the invention, the identification dimensionality of object identification is increased, and the object can be identified more comprehensively.

It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by hardware instructions of a computer program, which can be stored in a non-volatile computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. Any reference to memory, storage, database, or other medium used in the embodiments provided herein may include non-volatile and/or volatile memory, among others. Non-volatile memory can include read-only memory (ROM), Programmable ROM (PROM), Electrically Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), or flash memory. Volatile memory can include Random Access Memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms such as Static RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDRSDRAM), Enhanced SDRAM (ESDRAM), Synchronous Link DRAM (SLDRAM), Rambus Direct RAM (RDRAM), direct bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A lidar system, comprising:

a beam emitter for emitting an outgoing beam;

a beam receiver for receiving first and second polarized lights in the echo beam, respectively; the echo light beam is a light beam returned after the emergent light beam is reflected by a target object;

2. The lidar system of claim 1, wherein the beam receiver comprises:

a light splitting module, configured to split the received echo light beam into the first polarized light and the second polarized light;

3. The lidar system of claim 2, wherein the processor is coupled to the first and second beam detection modules, respectively;

4. The lidar system of claim 2, wherein the beam receiver further comprises:

the first focusing mirror group is used for focusing the first polarized light and then transmitting the first polarized light to the first light beam detection module;

and the second focusing mirror group is used for focusing the second polarized light and then transmitting the second polarized light to the second light beam detection module.

5. The lidar system according to any of claims 1-4, further comprising:

and the light path annular module is used for enabling the emergent light beam emitted by the light beam emitter to pass through, and is also used for deflecting the received echo light beam to emit the received echo light beam to the light beam receiver.

6. The lidar system of claim 5, wherein the optical path ring module comprises:

the reflecting mirror is provided with an emergent hole, the emergent beam is emergent outwards through the emergent hole, and the echo beam is reflected by the reflecting mirror and then is emitted to the beam receiver.

7. The lidar system of claim 5, wherein the optical path ring module comprises:

the optical system comprises a first light splitting component, an optical rotation component and a second light splitting component;

the first light splitting assembly is used for splitting the emergent light beam emitted by the light beam emitter into emergent A polarized light and emergent B polarized light; the optical rotation component is used for rotating the polarization directions of the emergent A polarized light and the emergent B polarized light by 90 degrees; the second light splitting assembly is used for combining the emergent polarized light A and the emergent polarized light B after the polarization direction is rotated by 90 degrees and then emitting the combined emergent polarized light A and B;

the second light splitting component is further used for receiving the echo light beam and splitting the echo light beam into echo A polarized light and echo B polarized light; the optical rotation component is further used for rotating the polarization directions of the echo A polarized light and the echo B polarized light by 0 degree; the first light splitting assembly is further used for combining the echo A polarized light and the echo B polarized light after the polarization direction is rotated by 0 degree and then emitting the combined light to the light beam receiver.

8. The lidar system of claim 5, wherein the optical path ring module comprises: a circulator, a first collimator and a second collimator;

the circulator comprises a first optical beam interface, a second optical beam interface and a third optical beam interface; the emergent light beam emitted by the light beam emitter enters the circulator through the first light beam interface and is emergent through the second light beam interface; the received echo light beam enters the circulator through the second light beam interface and is emitted to the light beam receiver through the third light beam interface; the first collimator is disposed at the second beam interface, and the second collimator is disposed between the third beam interface and the beam receiver.

9. The lidar system of claim 5, wherein the lidar system further comprises a scanner;

the scanner is used for receiving the emergent light beam passing through the light path annular module and emitting the emergent light beam outwards for scanning, and is also used for receiving the echo light beam, deflecting the echo light beam and emitting the deflected echo light beam to the light path annular module.

10. An object recognition method applied to the lidar system according to any one of claims 1 to 9, the method comprising:

the light beam emitter emits an emergent light beam;