Laser radar

Abstract

The embodiment of the invention relates to the technical field of laser detection, and discloses a laser radar. The laser radar comprises a shell module, a transceiving module, a scanning module and a calibration module. The transceiving module is accommodated in the shell module and used for emitting detection light to detect a target object and receiving echo light, and the echo light is formed by reflecting the detection light through the target object. The scanning module is contained in the shell module and comprises a scanning element, the scanning element can rotate relative to the shell module, and the scanning element is used for receiving the detection light and deflecting the detection light so that the detection light can be emitted out of the laser radar. The calibration module is installed on the shell module and comprises a fixing part and a reflecting material layer, and the reflecting material layer is used for reflecting the detection light emitted from the scanning element to form corresponding echo light. According to the laser radar, the current situation that the calibration process is tedious due to the fact that calibration components and calibration scenes outside the laser radar need to be relied on when the scanning angle of the scanning element is recalibrated by the laser radar in the related technology can be improved.

Description

Technical Field

[0001] The present application relates to the field of laser detection technology, and in particular to a laser radar. Background Art

[0002] LiDAR is a radar system that emits laser beams to detect the position, speed and other characteristic quantities of a target. Its working principle is to first emit detection light to the target object, and then receive the echo light reflected from the target. After appropriate processing, relevant information about the target can be obtained, such as target distance, direction, altitude, speed, attitude, and even shape parameters.

[0003] Generally, a laser radar includes a shell, a transceiver module and a scanning module. Among them, the shell is the mounting base of the remaining structures in the laser radar. The transceiver module is used to emit detection light to detect the target object through the detection light, and to receive the echo light formed by the target object reflecting the detection light. The scanning module includes a scanning element that can rotate relative to the shell, such as a micro-electro-mechanical system (MEMS) galvanometer, which is used to receive and deflect the detection light emitted by the transceiver module, thereby continuously changing the emission direction of the detection light to form a specific detection field of view, so as to realize the detection of the target object in the detection field of view; accordingly, the scanning element is also used to receive and deflect the echo light so that the echo light is directed to the transceiver module. Summary of the invention

[0004] In the related technology, the laser radar uses external calibration plates and other components to calibrate the angular position of the scanning element scanning; for example, by placing the calibration plate at different angles in the laser radar detection field of view, the relationship between the feedback signal of the scanning element (such as the feedback voltage signal) and the direction angle of the calibration plate relative to the laser radar (such as the horizontal azimuth or vertical pitch angle) is calibrated, and then the mapping relationship between the feedback signal of the scanning element and the direction angle of the detection light (that is, the direction angle of the scanning element) can be obtained. However, as the working time increases, the feedback sensitivity of the scanning element will change, that is, the feedback signal amplitude under the unit rotation angle of the scanning element will change; if the laser radar still determines the direction angle corresponding to the target object based on the mapping relationship calibrated before leaving the factory, the measured direction angle will be greatly different from the actual direction angle of the target object, which will eventually manifest as a decrease in the control accuracy of the laser radar scanning process in the detection field of view.

[0005] Taking the vehicle-mounted LiDAR as an example, if the sensitivity of the LiDAR changes, the car needs to be driven to a preset calibration scene, or the LiDAR needs to be removed separately and placed in the above calibration scene to recalibrate the scanning angle position of the scanning element. This process relies on external calibration components and calibration scenes. The re-calibration process of the scanning angle of the scanning element is relatively cumbersome and costly.

[0006] The present application aims to provide a laser radar to improve the current situation in related technologies where the laser radar needs to rely on external calibration components and calibration scenes when recalibrating the scanning angle of the scanning element, which leads to a cumbersome calibration process.

[0007] The embodiment of the present application adopts the following ending solution to solve its technical problem: The embodiment of the present application provides a laser radar, including a shell module, a transceiver module, a scanning module and a calibration module. The transceiver module is housed in the shell module, and is used to emit detection light to detect the target object, and receive echo light, which is formed by the detection light being reflected by the target object. The scanning module is housed in the shell module, and includes a scanning element, which can rotate relative to the shell module, and the scanning element is used to receive the detection light and deflect it so that the detection light is emitted outside the laser radar. The calibration module is installed on the shell module, and includes a fixing part and a reflective material layer, the fixing part is fixed to the shell module, the reflective material layer is provided on the surface of the fixing part, and is located in the detection field of view of the laser radar, and the reflective material layer is used to reflect the detection light emitted from the scanning element to form a corresponding echo light.

[0008] In some embodiments, the fixed portion includes a reference area located within the detection field of view of the laser radar, and the reflective material layer is provided on the surface of the reference area; the reference area includes an area where the reflective material layer is not provided, and the reflective material layer has a different reflectivity from the reference area.

[0009] In some embodiments, the reflectivity of the reflective material layer is higher than the reflectivity of the reference area; the reflectivity of the reflective material layer is a first reflectivity value, the reflectivity of the reference area is a second reflectivity value, and the difference between the first reflectivity value and the second reflectivity value is greater than 50%.

[0010] In some embodiments, the reflective material layer has a reflectivity lower than that of the reference area.

[0011] In some embodiments, the laser radar satisfies at least one of the following conditions: a) the reference area is provided with a groove on the side facing the scanning module, and the reflective material layer is provided on the bottom surface of the groove; b) the reference area is provided with a boss on the side facing the scanning module, and the reflective material layer is provided on the top surface of the boss.

[0012] In some embodiments, the reflective material layer forms a reflective mirror surface, and the reflective material layer is configured such that an optical path of the detection light emitted by the scanning module toward the reflective material layer is perpendicular to the reflective material layer.

[0013] In some embodiments, the reflective material layer includes titanium and / or silicon.

[0014] In some embodiments, the housing module includes a base shell and a lens. The base shell defines a receiving cavity and is provided with a window connecting the receiving cavity with the external environment. The lens includes a lens barrel and a lens, the lens barrel is installed at the window and is provided with a mounting hole extending along a first preset direction, the lens is installed in the mounting hole, the lens blocks the window, and the calibration module is installed in the lens barrel. Wherein, the mounting hole includes a first cavity and a second cavity sequentially arranged along the first preset direction, the first cavity is closer to the scanning module than the second cavity, and the edge contour of the first cavity is located within the edge contour of the second cavity when observed along the first preset direction, and the lens includes two lenses, one of which is installed in the first cavity and the other is installed in the second cavity. The fixing portion includes a first part and a second part, the first part is arranged on the bottom wall of the second cavity, and is projected along the first preset direction, the second part extends into the first cavity, and the second part includes the reference area.

[0015] In some embodiments, one of the fixing part and the lens barrel is provided with a plurality of positioning posts, and the other is provided with a plurality of positioning holes, each positioning post corresponds to a positioning hole; each positioning post extends into the corresponding positioning hole to position the fixing part and the lens barrel.

[0016] In some embodiments, the laser radar includes two calibration modules, which are arranged on both sides of the axis of the lens along a second preset direction, and the second preset direction is respectively perpendicular to the first preset direction and the thickness direction of the laser radar; the scanning element includes a two-dimensional galvanometer, and the reflective material layers of the two calibration modules are staggered along the thickness direction.

[0017] Compared with the laser radar in the related art, the laser radar provided in the embodiment of the present application does not need to use calibration elements outside the laser radar when the feedback sensitivity of the scanning element changes, nor does it need to configure the corresponding calibration scene for the laser radar separately. Instead, it can determine the change in scanning angle caused by the change in feedback sensitivity of the scanning element based on the built-in calibration module, so the calibration process is simpler. That is, the laser radar provided in the embodiment of the present application can improve the current situation in which the laser radar in the related art needs to rely on the calibration components and calibration scenes outside the laser radar when recalibrating the scanning angle of the scanning element, which leads to a cumbersome calibration process. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 is a three-dimensional schematic diagram of a laser radar provided in some embodiments of the present application; Figure 2 yes Figure 1 Schematic diagram of the decomposition of the LiDAR; Figure 3 yes Figure 1 A three-dimensional diagram of the medium shot; Figure 4 yes Figure 3 Schematic diagram of the section along the AA line of the middle lens; Figure 5 yes Figure 4 A three-dimensional schematic diagram of the calibration module.

[0020] Description of reference numerals: 1. LiDAR; 100, housing module; 110, base housing; 120, lens; 111, bottom housing; 112, top housing; 1111, bottom wall; 1112, first side wall; 1113, second side wall; 1114, third side wall; 1121, top wall; 1122, fourth side wall; 1123, fifth side wall; 1124, sixth side wall; 121, lens barrel; 122, lens; 1211, mounting hole; 1212, first cavity; 1213, second cavity; 1221, first lens; 1222, second lens; 101, receiving cavity; 102, window; 200, transceiver module; 300, scanning module; 400, calibration module; 410, fixing part; 420, reflective material layer; 411, first part; 412, second part; 4111, positioning hole; 4112, first sink groove; 4121, reference area; 4122, boss. DETAILED DESCRIPTION

[0021] In order to make the objectives, technical solutions and advantages of the present application more clear, the embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0022] When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Instead, they are only examples of devices and methods consistent with some aspects of the present application as detailed in the attached claims.

[0023] In the related technology, the laser radar uses external calibration plates and other components to calibrate the angular position of the scanning element scanning; for example, by placing the calibration plate at different angles in the laser radar detection field of view, the relationship between the feedback signal of the calibrated scanning element (such as the feedback voltage signal) and the direction angle of the calibration plate relative to the laser radar (such as the horizontal azimuth or vertical pitch angle) is calibrated, and then the mapping relationship between the feedback signal of the scanning element and the direction angle of the detection light (that is, the direction angle of the scanning element) can be obtained. However, as the working time increases, the feedback sensitivity of the scanning element will change, that is, the feedback signal amplitude under the unit rotation angle of the scanning element will change; if the laser radar still determines the direction angle corresponding to the target object based on the mapping relationship calibrated before leaving the factory, the measured direction angle will be greatly different from the actual direction angle of the target object, which will eventually manifest as a decrease in the control accuracy of the laser radar scanning process in the detection field of view.

[0024] Taking the vehicle-mounted LiDAR as an example, if the sensitivity of the LiDAR changes, the car needs to be driven to a preset calibration scene, or the LiDAR needs to be removed separately and placed in the above calibration scene to recalibrate the scanning angle position of the scanning element. This process relies on external calibration components and calibration scenes. The re-calibration process of the scanning angle of the scanning element is relatively cumbersome and costly.

[0025] Based on this, an embodiment of the present application provides a laser radar to improve the current situation in the related art where the laser radar needs to rely on calibration components and calibration scenes outside the laser radar when recalibrating the scanning angle of the scanning element, which leads to a cumbersome calibration process.

[0026] See also Figure 1 and Figure 2, which respectively show a stereoscopic schematic diagram and an exploded schematic diagram of a laser radar 1 provided in some embodiments of the present application, wherein the laser radar 1 includes a housing module 100, a transceiver module 200, a scanning module 300 and a calibration module ( Figure 5 ). The transceiver module 200 is housed in the shell module 100, and is used to transmit detection light to detect the target object, and receive echo light; wherein the echo light is formed by the detection light being reflected by the target object. The scanning module 300 is housed in the shell module 100, and includes a scanning element, which can rotate relative to the shell module 100; the scanning element is used to receive the detection light and deflect it so that the detection light is emitted outside the laser radar 1. The calibration module 400 is installed on the shell module 100, and includes a fixing part 410 and a reflective material layer 420. The fixing part 410 is fixed to the shell module 100, and the reflective material layer 420 is arranged on the surface of the fixing part 410 and is located in the detection field of view of the laser radar 1. The reflective material layer 420 is used to reflect the detection light emitted from the scanning element to form a corresponding echo light.

[0027] It should be noted that the "target object" mentioned in this application document means the detection object of the laser radar, which includes but is not limited to: vehicles, pedestrians, buildings, vegetation and ground; the "detection light" mentioned in this application document means the laser beam emitted by the laser radar for detecting the above target objects; the "echo light" mentioned in this application document means the laser beam directed to the laser radar formed by the target object reflecting the above detection light. The target object can be an object other than the laser radar, such as the above-mentioned vehicle, pedestrian, etc., or it can be the above-mentioned calibration module integrated in the laser radar 1. Next, the specific structure of the laser radar 1 is described in detail in conjunction with the drawings.

[0028] For the above-mentioned housing module 100, please refer to Figure 1 and Figure 2 , which is the mounting base for the other components in the laser radar 1, and also constitutes a protective structure for the other components in the laser radar 1. In this embodiment, the housing module 100 includes a base shell 110 and a lens 120. Among them, the base shell 110 is the main part of the housing module 100, which defines a receiving cavity 101 for receiving the above-mentioned transceiver module 200 and the scanning module 300; the base shell 110 is also provided with a window 102 connecting the receiving cavity 101 and the external environment of the laser radar 1, so that the above-mentioned detection light and echo light can enter and exit the laser radar 1. The lens 120 is arranged at the window 102, which is used to perform optical processing on the detection light and the echo light. At the same time, the lens 120 blocks the above-mentioned window 102, thereby realizing the sealing of the base shell 110.

[0029] Regarding the aforementioned base shell 110, please continue to refer to Figure 2The base shell 110 includes a bottom shell 111 and a top shell 112, and the bottom shell 111 and the top shell 112 are connected and fixed along the thickness direction Z of the laser radar 1 to define the above-mentioned receiving chamber 101; wherein, the "thickness direction" described in the present application document means that when the laser radar 1 is installed on a movable device (such as a car), the end close to the mounting surface of the movable device is the bottom, and the end away from the mounting surface is the top, and the thickness direction is a direction determined based on the bottom and the top, such as the direction determined by one of the bottom and the top pointing to the other. The bottom shell 111 includes a bottom wall 1111, a first side wall 1112, a second side wall 1113 and a third side wall 1114. The bottom wall 1111 is generally a flat plate-like structure, and along the first preset direction X shown in the figure, the first side wall 1112 is arranged at one end of the bottom wall 1111; wherein, the first preset direction X is a direction perpendicular to the above-mentioned thickness direction Z. One end of the second side wall 1113 is connected to the first side wall 1112, and the other end extends away from the first side wall 1112 along the first preset direction X, and the height of the first side wall 1112 is smaller than that of the bottom wall 1111 at a position farther away from the first side wall 1112. One end of the third side wall 1114 is connected to the first side wall 1112, and the other end also extends away from the first side wall 1112 along the first preset direction X, and the height of the first side wall 1112 is smaller than that of the bottom wall 1111 at a position farther away from the first side wall 1112; the third side wall 1114 and the second side wall 1113 are arranged opposite to each other along the second preset direction Y shown in the figure, wherein the second preset direction Y is perpendicular to the thickness direction Z and the first preset direction X respectively. The bottom shell 111 does not have a side wall on the side away from the first side wall 1112, so that an opening is formed on this side to facilitate the assembly of the transceiver module 200, the scanning module 300 and the circuit board and other components.

[0030] The top shell 112 includes a top wall 1121, a fourth side wall 1122, a fifth side wall 1123 and a sixth side wall 1124. The top wall 1121 is also generally a flat plate-like structure, and is arranged opposite to the bottom wall 1111 along the thickness direction Z. Along the first preset direction X shown in the figure, the fourth side wall 1122 is arranged at one end of the top wall 1121 away from the first side wall 1112, and the fourth side wall 1122 is arranged opposite to the first side wall 1112 along the first preset direction X. The fourth side wall 1122 fills the open area of ​​the bottom shell 111 to block the area. One end of the fifth side wall 1123 is connected to the fourth side wall 1122, and the other end extends away from the fourth side wall 1122 along the first preset direction X, and the height of the fifth side wall 1123 is smaller than that of the top wall 1121 at a position farther away from the fourth side wall 1122. The fifth side wall 1123 and the second side wall 1113 are complementary fitting structures, and the fifth side wall 1123 and the second side wall 1113 are spliced ​​together to form a side wall of the base shell 110 located between the first side wall 1112 and the fourth side wall 1122. One end of the sixth side wall 1124 is connected to the fourth side wall 1122, and the other end also extends away from the fourth side wall 1122 along the first preset direction X, and the height of the sixth side wall 1124 is smaller at a position farther away from the fourth side wall 1122 than the height of the top wall 1121. The sixth side wall 1124 and the fifth side wall 1123 are arranged opposite to each other along the second preset direction Y shown in the figure, and the sixth side wall 1124 and the third side wall 1114 are complementary fitting structures, and the sixth side wall 1124 and the third side wall 1114 are spliced ​​together to form another side wall of the base shell 110 located between the first side wall 1112 and the fourth side wall 1122. The top shell 112 does not have a side wall on the side away from the fourth side wall 1122, so that an opening is formed on this side; the first side wall 1112 is filled in the opening to block the opening. It should be noted that the "second preset direction" described in the present application document is perpendicular to the first preset direction X; for example, in the present embodiment, the second preset direction Y is a horizontal direction perpendicular to the thickness direction Z and the first preset direction X, respectively. Of course, in other embodiments, the second preset direction Y can also be appropriately changed on this basis, and the present application does not limit this.

[0031] The bottom shell 111 and the top shell 112 are spliced ​​along the thickness direction Z shown in the figure to define the above-mentioned receiving cavity 101. The bottom shell 111 is provided with the above-mentioned window 102 on the first side wall 1112, and the window 102 passes through the first side wall 1112, thereby connecting the above-mentioned receiving cavity 101 with the external environment of the laser radar 1.

[0032] For the aforementioned lens 120, see Figure 3 and Figure 4, which respectively show a three-dimensional schematic diagram of the lens 120 and a cross-sectional schematic diagram along the AA line, wherein the lens 120 includes a lens barrel 121 and a lens 122. The lens barrel 121 is installed at the above-mentioned window 102, and is spaced apart from the above-mentioned scanning module 300 along the above-mentioned first preset direction X, and is provided with a mounting hole 1211 extending along the above-mentioned first preset direction X. The lens 122 is installed in the mounting hole 1211. The lens 120 as a whole blocks the window 102, so that the housing module 100 forms a structure sealed to the outside. In this embodiment, the above-mentioned mounting hole 1211 includes a first cavity 1212 and a second cavity 1213 sequentially arranged along the first preset direction X. Among them, the first cavity 1212 is a cavity close to one side of the receiving cavity 101, one end of which is located in communication with the receiving cavity 101 and communicates with the receiving cavity 101, and the other end extends toward the above-mentioned window 102 or passes through the window 102. The second cavity 1213 is a cavity away from the receiving cavity 101, one end of which is connected to the first cavity 1212, and the other end is located outside the base shell 110; when observed along the first preset direction X, the edge contour of the first cavity 1212 is located within the edge contour of the second cavity 1213, that is, the second cavity 1213 is a larger cavity. The lens 120 includes two lenses 122, which are a first lens 1221 and a second lens 1222; wherein the first lens 1221 is installed in the above-mentioned first cavity 1212, and the second lens 1222 is installed in the second cavity 1213. After being deflected by the scanning module, the detection light generated by the above-mentioned transceiver module 200 passes through the first lens 1221 and the second lens 1222 in sequence to be emitted to the outside of the laser radar 1, and then detects the surrounding environment; that is, the second lens 1222 also constitutes the window piece of the laser radar 1.

[0033] For the above transceiver module 200, please refer to Figure 2, which is accommodated in the accommodating cavity 101 and installed in the housing module 100, for example, the transceiver module 200 can be fixed to the above-mentioned bottom wall 1111. The transceiver module 200 includes a transmitting module and a receiving module. The transmitting module is used to generate detection light, which is used to detect the target object. The transmitting module includes at least one laser. For example, in some embodiments, the transmitting module includes a laser; for example, in other embodiments, the transmitting module includes more than two lasers, and the more than two lasers are arranged according to a preset rule. The receiving module is used to receive the echo light formed by the target object reflecting the detection light, and perform photoelectric conversion to obtain the corresponding electrical signal, so that the signal processing module of the laser radar 1 can obtain the distance, speed and reflectivity of the target object relative to the laser radar 1 based on the above-mentioned electrical signal processing. In some embodiments, the receiving module may include a silicon photomultiplier tube, which has a high dynamic range and can detect echo light signals with relatively weak energy; of course, in other embodiments of the present application, the receiving module may also include other types of photodetectors, as long as it can receive the echo light and complete the photoelectric conversion.

[0034] For the above scanning module 300, please continue to refer to Figure 2, the scanning module 300 is used to scan the detection light emitted by the transceiver module 200 so that the detection light can form a specific detection field of view. In this embodiment, the scanning module 300 includes a scanning element (not shown in the figure), which is used to receive the detection light and deflect it so that the detection light is emitted outside the laser radar. The scanning element can rotate relative to the shell module 100, so that the emission direction of the detection light changes continuously after being reflected by it, so that the above-mentioned detection field of view can be achieved. Optionally, the scanning element can include a two-dimensional galvanometer, such as a two-dimensional MEMS (Micro-Electro-Mechanical System) galvanometer, to achieve two-dimensional scanning. For example, in this embodiment, the two-dimensional galvanometer can rotate around a first rotation axis parallel to the above-mentioned thickness direction Z to achieve a yaw motion along the above-mentioned second preset direction Y; the two-dimensional galvanometer can also rotate around a second rotation axis parallel to the second preset direction Y to achieve a yaw motion along the thickness direction Z shown in the figure. Of course, in other embodiments of the present application, the scanning element may also include other types of scanning devices; for example, in some other embodiments, the scanning element may be a combination of a one-dimensional galvanometer and a multi-faceted rotating mirror. For example, in some other embodiments, the transmitting module may include a linear array of multiple lasers, and the scanning element includes a one-dimensional rotating mirror; this is not limited here one by one, as long as it is ensured that the scanning module 300 can complete the scanning of the detection light, preferably, the above-mentioned two-dimensional scanning solution can be adopted. In addition, the scanning module 300 also includes a scanning drive module, which is connected to the scanning element and is used to drive the scanning element to rotate. In this embodiment, the drive module includes a coil and a magnet. Specifically, the coil is integrated in the above-mentioned two-dimensional galvanometer; the magnet is arranged adjacent to the two-dimensional galvanometer, and the two-dimensional galvanometer is in the magnetic field formed by the magnet; when the coil is energized according to a preset rule, it will rotate under the action of the magnetic field.

[0035] In order to obtain the current scanning direction angle of the two-dimensional galvanometer, the two-dimensional galvanometer can be integrated with a sensor for detecting the direction angle, such as a piezoresistive sensor. Since the direction angles scanned by the two-dimensional galvanometer are different, the feedback voltage signals output by the piezoresistive sensor are also different, so the mapping relationship between the two can be established through the calibration process described above; in this way, during the working process of the laser radar after leaving the factory, the feedback voltage signal output by the piezoresistive sensor can be used to determine the current scanning direction angle of the two-dimensional galvanometer.

[0036] However, as the working time increases, the feedback sensitivity of the scanning element will change, that is, the amplitude of the feedback signal (such as the above-mentioned feedback voltage signal) under the condition of unit rotation angle of the scanning element will change; if the laser radar still determines the direction angle corresponding to the target object based on the mapping relationship calibrated before leaving the factory, the measured direction angle will be significantly different from the actual direction angle of the target object, which will eventually manifest as a decrease in the control accuracy of the laser radar during the scanning process within the detection field of view. To overcome this shortcoming, the laser radar 1 provided in the embodiment of the present application also includes a calibration module 400, and the setting of the calibration module 400 provides a structural basis for the secondary calibration of the scanning element, which is conducive to improving the current situation of the cumbersome secondary calibration process of the laser radar in the related technology.

[0037] For calibration module 400, please refer to Figure 5 , which shows a three-dimensional schematic diagram of the calibration module 400, and combined with Figures 1 to 4 , the calibration module 400 is installed on the shell module 100, and includes a reflective material layer 420 located in the detection field of view of the laser radar 1. The reflective material layer 420 is used to reflect the detection light that is reflected by the scanning module 300 and then directed to the reflective material layer 420 to form a corresponding echo light, so that the laser radar 1 can determine the angular position of the reflective material layer 420 in the detection field of view. Considering that the above-mentioned lens 120 is actually designed and selected based on the detection field of view requirements of the laser radar 1, the calibration module 400 in this embodiment is installed on the above-mentioned lens 120. This setting can easily ensure that the reflective material layer 420 is located in the detection field of view of the laser radar 1. The following is an explanation using this setting as an example; however, it should be understood that in other embodiments of the present application, the calibration module 400 can also be installed on the base shell 110, as long as it has the above-mentioned reflective material layer located in the detection field of view of the laser radar 1.

[0038] Specifically, the calibration module 400 includes a fixing part 410 and the above-mentioned reflective material layer 420; wherein the fixing part 410 includes a reference area 4121 located in the detection field of view of the laser radar, and the reflective material layer 420 is arranged on the surface of the reference area 4121. The fixing part 410 is installed on the bottom wall of the above-mentioned second cavity 1213, and includes a first part 411 located on the bottom wall of the second cavity 1213 and a second part 412 located outside the bottom wall of the second cavity 1213; one end of the second part 412 is connected to the first part 411, and the other end extends to be opposite to the first cavity 1212. More specifically, when the fixing part 410 is projected along the above-mentioned first preset direction X, the first part 411 is located on the bottom wall of the second cavity 1213, and the end of the second part 412 away from the first part 411 is located in the first cavity 1212. The second part 412 includes a reference area 4121 located within the detection field of view of the laser radar 1 , and the reference area 4121 is used to set the above-mentioned reflective material layer 420 , thereby effectively ensuring that the reflective material layer 420 is also located in the detection field of view of the laser radar 1 .

[0039] As for the fixing method of the fixing part 410, it is actually diverse. For example, in some embodiments, the fixing part 410 and the lens barrel 121 can be fixed by bonding. Specifically, the first part 411 is a roughly rectangular plate-shaped structure, which is provided with a plurality of positioning holes 4111; the bottom wall of the second cavity 1213 is provided with a plurality of positioning posts (not shown in the figure), and each positioning post extends into a corresponding positioning hole 4111, thereby realizing the positioning of the fixing part 410 and the lens barrel 121. Preferably, two positioning holes 4111 and two positioning posts can be provided respectively, wherein one positioning hole 4111 is a circular hole and the other positioning hole 4111 is a waist-shaped hole; wherein the width of the waist-shaped hole is equal to the diameter of the positioning post, and the length of the waist-shaped hole is greater than the diameter of the positioning post. One positioning post cooperates with the circular positioning hole 4111, and the other positioning post cooperates with the waist-shaped positioning hole 4111. The setting of the waist-shaped hole can provide a certain redundancy to avoid that it cannot cooperate normally with the corresponding positioning post. A first sink 4112 is provided on one side of the first part 411 facing the bottom wall of the second cavity 1213, and the first sink 4112 can be used to contain glue. Before the fixing part 410 is assembled to the lens barrel 121, glue can be dispensed in the first sink 4112; then, the fixing part 410 is positioned and installed to the bottom wall of the second cavity 1213 based on the positioning hole 4111 and the positioning column; thereafter, the position and posture of the fixing part 410 are appropriately adjusted to the desired state, and the fixing of the fixing part 410 can be completed by waiting for the glue to solidify.

[0040] In some applications, the reference region 4121 includes a region where the reflective material layer 420 is provided (corresponding to Figure 5 black area) and an area without the reflective material layer 420 (corresponding to Figure 54121). The reflectivity of the reflective material layer 420 may be different from that of the reference area 4121. For example, the reflectivity of the reflective material layer 420 may be higher than that of the reference area 4121. This setting is conducive to constructing the neighborhood of the reflective material layer 420 into a reference area 4121 with low reflectivity. The reference area 4121 can block other target objects in the field of view area, prevent other target objects in the field of view area from affecting the detection of the reflective material layer 420, and build a relatively pure detection environment for the reflective material layer 420; while the reflective material layer 420 is located in this area as an object with higher reflectivity, and has a reflectivity difference with the reference area 4121. In this way, the laser radar 1 can more easily identify the reflective material layer 420 when acquiring point cloud data. In some applications, the reflectivity of the reflective material layer may be a first reflectivity value, and the reflectivity of the reference area may be a second reflectivity value, the first reflectivity value is greater than the second reflectivity value, and the difference between the two may be greater than 50%; in this way, the reflective material layer 420 and the reference area 4121 of the fixing portion 410 will have a significant reflectivity difference, which is conducive to better distinguishing the contour of the reflective material layer 420. For example, in some embodiments, the first threshold value may be greater than 80%, such as 85%, 90%, 92%, 95%, etc.; the second threshold value may be less than 30%, such as 25%, 20%, 10%, 5%, etc. It should be noted that the "reflectivity" described in this application document refers to a parameter commonly used in the field of laser radar detection to characterize the reflectivity. Generally, the surface reflectivity of the Kodak whiteboard (calibration whiteboard) is defined as 100%, and the reflectivity of other objects can be obtained by proportional conversion based on it.

[0041] Of course, the reflectivity of the reflective material layer 420 may also be lower than the reflectivity of the reference area 4121. This setting is conducive to constructing the neighborhood of the reflective material layer 420 into a reference area 4121 with high reflectivity. The reference area 4121 can block other target objects in the field of view area, avoid other target objects in the field of view area affecting the detection of the reflective material layer 420, and build a relatively pure detection environment for the reflective material layer 420; while the reflective material layer 420 is located in the area as an object with lower reflectivity, and has a reflectivity difference with the reference area 4121. In this way, the laser radar 1 can more easily identify the reflective material layer 420 when acquiring point cloud data. In some applications, the reflectivity of the reflective material layer can be a first reflectivity value, and the reflectivity of the reference area can be a second reflectivity value, the first reflectivity value is less than the second reflectivity value, and the absolute value of the difference between the two can be greater than 50%; in this way, the reflective material layer 420 and the reference area 4121 of the fixing part 410 will have a significant reflectivity difference, which is conducive to better distinguishing the outline of the reflective material layer 420. For example, in some embodiments, the first threshold value may be less than 30%, such as 25%, 20%, 10%, 5%, etc.; the second threshold value may be greater than 80%, such as 75%, 70%, 60%, 55%, etc. It should be noted that, since the laser radar 1 may have a high anti-expansion phenomenon when working, that is, the point cloud formed by the target object with a high reflectivity value tends to partially expand outward on the basis of the theoretical point cloud, it is necessary to avoid the reflectivity of the reference area 4121 being too high to cause the above-mentioned high anti-expansion phenomenon.

[0042] As for the structural style and material composition of the reflective material layer 420, there are actually various types; for example, the reflective material layer may include a titanium reflective film, a silicon reflective film, or a reflective film based on titanium and silicon; that is, the material of the reflective material layer 420 may include titanium and / or silicon. Thus, when the detection light is emitted from the scanning module 300 to the reflective material layer 420, an echo light is also formed due to the reflection of the reflective material layer 420, and the echo light is further received by the transceiver module of the laser radar.

[0043] It should be noted that when the reflective material layer forms a reflective mirror surface, the reflection direction of the reflective material layer can be regarded as a single one, unlike diffuse reflection, which forms reflected echo light in all directions; at this time, the angle of the plane where the reflective material layer is located is very important. Specifically, the reflective material layer needs to be configured so that the optical path of the detection light emitted from the scanning module 300 to the reflective material layer is perpendicular to the reflective material layer; in this way, the echo light formed by the reflection of the reflective material layer can return along the original optical path and be received by the transceiver module 200, thereby forming a corresponding point cloud.

[0044] For example, see Figure 5In some applications, the reference area 4121 is provided with a boss 4122 on the side facing the scanning module 300, and a reflective material layer is provided on the top surface of the boss 4122. The top surface is configured such that the detection light emitted from the scanning module 300 to the boss 4122 is perpendicular to the top surface of the boss 4122; thus, the detection light will be incident vertically on the reflective material layer and return to the transceiver module 200 along the original optical path. For another example, in some other applications, the reference area 4121 is provided with a groove (not shown in the figure) on the side facing the scanning module 300, and a reflective material layer is provided on the bottom surface of the groove; wherein the bottom surface is configured such that the optical path of the detection light emitted from the scanning module 300 to the groove is perpendicular to the bottom surface; thus, the detection light will also be incident vertically on the reflective material layer and return to the transceiver module 200 along the original optical path. Preferably, in order to facilitate having a better reference surface when forming the top surface of the boss 4122 or the bottom surface of the groove, the reference area 4121 is provided with a slope inclined relative to the first preset direction X on the side facing the scanning module 300, and the slope is configured as follows: the optical path of the detection light emitted from the scanning module 300 to the boss or groove is perpendicular to the slope; then, when forming the top surface of the boss 4122 or the bottom surface of the groove, it is only necessary to control the top surface of the boss 4122 or the bottom surface of the groove to be parallel to the slope.

[0045] It is worth adding that, since the calibration module 400 is used to calibrate the direction angle scanned by the scanning element, it is necessary to ensure that the position and posture of the calibration module 400 do not change substantially during the service life of the laser radar 1. In the embodiment of the present application, if the above-mentioned fixing part 410 and the lens barrel 121 are formed separately, it should be ensured that the strength of the fixing part 410 itself is higher than the preset strength threshold, and the rigidity is higher than the preset rigidity threshold. The preset strength threshold and the preset rigidity threshold can be tested or simulated based on the use conditions of the laser radar 1. For example, the fixing part 410 can be formed by the same material as the lens barrel 121; in addition, when the fixing part 410 is fixed to the lens barrel 121, hard glue can be used to ensure the reliability of the connection, and of course, threaded fasteners can also be used for fixing. If the fixing part 410 and the lens barrel 121 are integrally formed, generally speaking, the strength of the fixing part 410 itself can be better guaranteed, and of course, the material of the lens barrel 121 can also be appropriately selected to improve the reliability of the structural form of the fixing part 410. As for the reflective material layer 420 , since it is a material layer formed on the surface of the fixing portion 410 , its position and posture relative to the fixing portion 410 is relatively stable, and it is only necessary to ensure that the position and posture of the fixing portion 410 has better durability.

[0046] It should be understood that even though the above-mentioned embodiment is described by taking the reflective material layer 420 forming a reflective mirror surface as an example, the present application is not limited to this. In other embodiments of the present application, the reflective material layer 420 may also be a diffuse reflective material layer. In this case, there is no need to specially configure the angle of the reflective material layer 420. This setting can make the design and manufacture of the shape and posture of the fixing portion 410 and the reflective material layer 420 more free and with a higher tolerance.

[0047] The above describes the structures of the shell module 100 , the transceiver module 200 , the scanning module 300 and the calibration module 400 in turn. Next, the working principle of the laser radar 1 that can be calibrated based on the calibration module 400 is briefly described.

[0048] When the laser radar is calibrated at the factory, the direction angle corresponding to the reflective material layer 420 can be obtained by scanning; for the sake of convenience, this direction angle is called the first preset direction angle. When the feedback sensitivity of the scanning element changes after the laser radar has been used for a long time, the direction angle corresponding to the reflective material layer 420 can be obtained by scanning; for the sake of convenience, this direction angle is called the second preset direction angle. In this way, based on the first preset direction angle and the second preset direction angle, the ratio of the change in the feedback sensitivity of the scanning element can be determined, and then the direction angle determined based on the feedback signal can be compensated based on the ratio to obtain the corrected direction angle.

[0049] Considering that the scanning direction angle of the scanning element is determined by the feedback signal output by the sensor (such as a piezoresistive sensor) integrated in the scanning element, and since the sensitivity of the sensor may vary in different parts, the feedback sensitivity changes of the scanning element on both sides of the central angle position of the second preset direction may not be consistent. To further improve this deficiency, in this embodiment, the laser radar 1 includes two calibration modules 400, which are arranged on both sides of the axis of the lens 120 along the second preset direction Y.

[0050] Based on this, in some applications, the change ratio of the feedback sensitivity on one side of the optical axis of the lens 120 can be determined by the calibration module 400 located on the side, and then the first compensation coefficient corresponding to the side can be determined. The change ratio of the feedback sensitivity on the side can be determined by the calibration module 400 located on the other side of the optical axis of the lens 120, and then the second compensation coefficient corresponding to the side can be determined; then, based on the first compensation coefficient and the second compensation coefficient, the direction angle compensation is performed on the point cloud points whose direction angles are on the same side in the point cloud data. This application method can use different compensation methods to compensate for the two specific azimuth sides when the scanning element scans in the second preset direction, which is conducive to improving the accuracy of the compensation process to a certain extent. In other applications, the first angle corresponding to the reflective material layer 420 of the two calibration modules 400 in the detection field of view of the laser radar 1 can be determined first when the laser radar leaves the factory. The first angle can be determined based on the direction angle corresponding to the reflective material layer 420 of one calibration module 400 and the direction angle corresponding to the reflective material layer 420 of the other calibration module 400 when the laser radar 1 leaves the factory; for example Figure 4 The direction angle corresponding to the reflective material layer 420 of the calibration module 400 on the right side (corresponding to the left side of the laser radar 1 field of view) is -55°, and the direction angle corresponding to the reflective material layer 420 of the calibration module 400 on the left side (corresponding to the right side of the laser radar 1 field of view) is 55°, so the first angle is 110°. Then determine the second angle corresponding to the current two calibration modules 400 in the detection field of view of the laser radar 1. The second angle can be determined based on the current direction angle corresponding to the reflective material layer 420 of one calibration module 400 and the direction angle corresponding to the reflective material layer 420 of the other calibration module 400; for example Figure 4 The direction angle corresponding to the reflective material layer of the calibration module on the right side (corresponding to the left side of the field of view of the laser radar 1) is -57°, and the direction angle corresponding to the reflective material layer of the calibration module on the left side (corresponding to the right side of the field of view of the laser radar 1) is 58°, so the second preset direction angle is 115°. Then the compensation coefficient is determined according to the second angle and the first angle; specifically, the ratio of the first angle to the second angle can be determined as the compensation coefficient; for example, based on the above example, the compensation coefficient α=110° / 115°=0.9565 can be determined. Afterwards, when the laser radar 1 detects and obtains point cloud data, the direction angle of the point cloud point in the point cloud data is multiplied by the above compensation coefficient. This application method uses the angle corresponding to the two calibration modules 400 to determine the compensation coefficient, which can balance the unilateral error introduced by the unilateral calibration module 400 when detecting its direction angle, which is conducive to improving the accuracy of the compensation process.

[0051] It is worth mentioning that the reflective material layers 420 of the two calibration modules 400 are staggered along the thickness direction Z, and the ratio of the distance of the two reflective material layers 420 staggered along the second preset direction Y and the distance of the two reflective material layers 420 staggered along the thickness direction Z is equal to the first ratio; wherein the first ratio is the ratio of the angular velocity of the scanning element deflecting along the second preset direction Y to the angular velocity of the scanning element deflecting along the thickness direction Z. Since the scanning element is a two-dimensional galvanometer, it rotates relative to the shell around the first rotation axis and the second rotation axis, that is, in the process of deflecting along the second preset direction Y to realize the horizontal scanning of the detection light, it will also deflect along the thickness direction Z, thereby making the detection light scan in the vertical direction; therefore, the above setting is conducive to: in the same horizontal scanning cycle of the scanning element, the detection light can pass through the reflective material layers 420 of the two calibration modules successively, thereby obtaining the corresponding point cloud data.

[0052] In summary, the laser radar 1 provided in the embodiment of the present application includes a housing module 100, a transceiver module 200, a scanning module 300 and a calibration module 400. The calibration module 400 includes a reflective material layer located in the detection field of the laser radar 1.

[0053] When the feedback sensitivity of the scanning element of the laser radar in the related art changes, it is necessary to place it in a preset calibration scene, and use a calibration element outside the laser radar and another laser radar (such as a true value laser radar with accurate directional angle) to perform a secondary calibration on the directional angle of the scanning element. In comparison, when the feedback sensitivity of the scanning element of the laser radar 1 provided in the embodiment of the present application changes, there is no need to use a calibration element outside the laser radar 1, nor is there a need to configure a corresponding calibration scene for the laser radar 1 separately. Instead, the change in the scanning angle caused by the change in the feedback sensitivity of the scanning element can be determined based on the built-in calibration module 400, so the calibration process is simpler. That is, the laser radar 1 provided in the embodiment of the present application can improve the current situation in which the laser radar in the related art needs to rely on the calibration components and calibration scenes outside the laser radar when recalibrating the scanning angle of the scanning element, which leads to a cumbersome calibration process.

[0054] In the description of the present application, it should be understood that the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances. In addition, in the description of the present application, unless otherwise specified, "multiple" refers to at least two, for example, two, three, four, etc. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the objects associated before and after are in an "or" relationship.

[0055] The above disclosure is only the preferred embodiment of the present application, which certainly cannot be used to limit the scope of rights of the present application. Therefore, equivalent changes made according to the claims of the present application are still within the scope covered by the present application.

Claims

1. A laser radar, characterized in that: include: Shell module; a transceiver module, housed in the housing module, for transmitting detection light to detect a target object, and receiving echo light, wherein the echo light is formed by the detection light being reflected by the target object; A scanning module, housed in the housing module, comprising a scanning element, the scanning element being rotatable relative to the housing module, the scanning element being used to receive the detection light and deflect it so that the detection light is emitted outside the laser radar; as well as A calibration module is installed on the shell module, including a fixing part and a reflective material layer. The fixing part is fixed to the shell module, and the reflective material layer is arranged on the surface of the fixing part and is located within the detection field of view of the laser radar. The reflective material layer is used to reflect the detection light emitted from the scanning element to form a corresponding echo light.

2. The laser radar according to claim 1, characterized in that: The fixing portion includes a reference area located within the detection field of view of the laser radar, and the reflective material layer is provided on the surface of the reference area; The reference area includes an area where the reflective material layer is not provided, and the reflective material layer has a different reflectivity from that of the reference area.

3. The laser radar according to claim 2, characterized in that: The reflectivity of the reflective material layer is higher than the reflectivity of the reference area; The reflectivity of the reflective material layer is a first reflectivity value, the reflectivity of the reference area is a second reflectivity value, and the difference between the first reflectivity value and the second reflectivity value is greater than 50%.

4. The laser radar according to claim 2, characterized in that: The reflectivity of the reflective material layer is lower than the reflectivity of the reference area.

5. The laser radar according to claim 2, characterized in that: The laser radar satisfies at least one of the following conditions: a) the reference area is provided with a groove on a side facing the scanning module, and the reflective material layer is provided on the bottom surface of the groove; b) The reference area is provided with a boss on a side facing the scanning module, and the reflective material layer is provided on a top surface of the boss.

6. The laser radar according to claim 1, characterized in that: The reflective material layer forms a reflective mirror surface, and the reflective material layer is configured such that an optical path of the detection light emitted from the scanning module to the reflective material layer is perpendicular to the reflective material layer.

7. The laser radar according to claim 6, characterized in that: The reflective material layer includes titanium and / or silicon.

8. The laser radar according to claim 2, characterized in that: The housing module comprises: A base shell defines a receiving cavity and is provided with a window connecting the receiving cavity with the external environment; and The lens comprises a lens barrel and a lens, wherein the lens barrel is mounted at the window and is provided with a mounting hole extending along a first preset direction, the lens is mounted in the mounting hole, the lens blocks the window, and the calibration module is mounted on the lens barrel; The mounting hole comprises a first cavity and a second cavity sequentially arranged along the first preset direction, the first cavity is closer to the scanning module than the second cavity, and when observed along the first preset direction, the edge contour of the first cavity is located within the edge contour of the second cavity, and the lens comprises two lenses, one of which is mounted in the first cavity, and the other is mounted in the second cavity; The fixing portion includes a first part and a second part. The first part is arranged on the bottom wall of the second cavity and is projected along the first preset direction. The second part extends into the first cavity. The second part includes the reference area.

9. The laser radar according to claim 8, characterized in that: One of the fixing part and the lens barrel is provided with a plurality of positioning posts, and the other is provided with a plurality of positioning holes, and each positioning post corresponds to one positioning hole; Each of the positioning posts extends into the corresponding positioning hole to position the fixing portion and the lens barrel.

10. The laser radar according to claim 8, characterized in that: The laser radar comprises two calibration modules, which are arranged on both sides of the axis of the lens along a second preset direction, and the second preset direction is respectively perpendicular to the first preset direction and the thickness direction of the laser radar; The scanning element includes a two-dimensional galvanometer, and the reflective material layers of the two calibration modules are staggered with each other along the thickness direction.

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