A method for arranging a plurality of detector units, a laser receiving device and a laser radar

Abstract

Embodiments of the present application provide a detector unit arrangement method, a laser receiving device and a laser radar, and relate to the field of optical ranging. The method comprises: determining a first image shift direction when a laser beam passes through a galvanometer and / or a second image shift direction when the laser beam passes through a prism, wherein the laser receiving device comprises the galvanometer and / or the prism, the prism is used for horizontal deflection of the laser beam, the galvanometer is used for vertical deflection of the horizontally deflected laser beam, and based on the first image shift direction and / or the second image shift direction, a plurality of detector units of a detector are arranged, wherein the detector units are gathered on the detector through a receiving lens after deflection of the laser beam through the galvanometer and / or the prism. The detector is composed of a plurality of detector units, and the arrangement mode of each detector unit is consistent with the image shift direction, which can reduce the field of view angle for obtaining the laser signal, thereby improving the signal-to-noise ratio and further improving the ranging of the laser radar.

Description

Technical Field

[0001] This invention relates to the field of optical ranging, and more specifically, to a method for arranging detector units, a laser receiving device, and a lidar. Background Technology

[0002] Currently, there are several methods for laser ranging, including triangulation, pulse-time-of-flight (PTF), continuous-wave PLF, and frequency-modulated continuous-wave (FM PLF). Due to its advantages such as simple ranging principle, high signal-to-noise ratio, low average power of the light source, and high ranging accuracy, the PLF is generally used for ranging in medium- and long-range 3D LiDAR systems.

[0003] The detection process of a pulse-time-of-flight (PTF) ranging lidar is as follows: a laser generates a pulse beam of light, which is collimated by an optical lens, deflected by a scanning device, and reaches the target. After being reflected, the light passes through the scanning device and the receiving lens into a photodetector, where it is converted into a photocurrent. After amplification, a pulse signal is generated. By calculating the time between the laser generating the pulse and the detector receiving the pulse, the distance at which the lidar reaches the target is obtained.

[0004] Because the scanning device of a lidar system rotates continuously, after the pulsed light is emitted from the radar and reflected back by the target, it travels for a flight time Δt before re-entering the radar. By this time, the scanning device has deflected by a certain angle θ due to its rotation. Therefore, in lidar design, the field of view of the detector unit needs to be considered at an angle of 2θ. This results in more ambient light noise entering the detector, generating greater ambient light noise, affecting the signal-to-noise ratio of the lidar, and ultimately reducing the lidar's range. Summary of the Invention

[0005] The purpose of this invention is to provide a method for arranging detector units, a laser receiving device, and a lidar, which can reduce the field of view for acquiring laser signals and improve the signal-to-noise ratio.

[0006] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows:

[0007] In a first aspect, embodiments of this application provide a method for arranging detector units, applied to a laser receiving device, the method comprising:

[0008] The laser receiving device includes a scanning device, which includes a galvanometer and / or a prism. The prism is used to deflect the laser beam in the horizontal direction, and the galvanometer is used to deflect the horizontally deflected laser beam in the vertical direction.

[0009] Based on the first image shift direction and / or the second image shift direction, multiple detector units of the detector are arranged, wherein the laser beam is deflected by a galvanometer and / or a prism and then focused onto the detector by a receiving lens.

[0010] In an optional implementation, the step of arranging the multiple detector elements of the detector based on the first image shift direction and / or the second image shift direction includes:

[0011] When the scanning device includes only a galvanometer, the detector units of the detector are arranged to form a detector unit array. The detector units in each row of the detector unit array are arranged according to the first image shift direction, wherein the number of rows of the detector unit array is the same as the number of channels.

[0012] In an optional implementation, the step of arranging the detector elements of the detector based on the first image shift direction and / or the second image shift direction includes:

[0013] When the scanning device includes only a prism, the detector units of the detector are arranged to form a detector unit array. The detector units in each row of the detector unit array are arranged according to the second image shift direction, wherein the number of rows of the detector unit array is the same as the number of channels.

[0014] In an optional implementation, the step of arranging the detector elements of the detector based on the first image shift direction and / or the second image shift direction includes:

[0015] When the scanning device includes a galvanometer and a prism, a first angular velocity of the galvanometer and a second angular velocity of the prism are determined;

[0016] When the first angular velocity is greater than the second angular velocity, the detector units of the detector are arranged to form a detector unit array. Each detector unit in the detector unit array is arranged according to the first image shift direction, wherein the number of rows of the detector unit array is the same as the number of channels.

[0017] When the first angular velocity is less than the second angular velocity, the detector units of the detector are arranged to form a detector unit array. Each detector unit in the detector unit array is arranged according to the second image shift direction, wherein the number of rows in the detector unit array is the same as the number of channels.

[0018] In an optional implementation, the method further includes:

[0019] When the first angular velocity is equal to the second angular velocity, the superimposed image displacement direction of the first image displacement direction and the second image displacement direction is determined;

[0020] The detector units of the detector constitute a detector unit array, and each detector unit in the detector unit array is arranged according to the superimposed image shift direction.

[0021] In an optional implementation, the method further includes:

[0022] Determine the first image displacement distance of the laser beam as it passes through the galvanometer and / or the second image displacement distance of the laser beam as it passes through the prism;

[0023] Determine the length of the laser beam spot on the detector;

[0024] The length of the detector is set based on the first image shift distance and / or the second image shift distance and the length of the light spot.

[0025] In an optional implementation, the step of setting the length of the detector based on the first image shift distance and / or the second image shift distance and the length of the light spot includes:

[0026] When the scanning device includes only a galvanometer, a first sum of the length of the light spot and the first image shift distance is determined;

[0027] The length of the detector is set to the first sum value;

[0028] When the scanning device comprises only a prism, a second sum of the length of the light spot and the second image shift distance is determined;

[0029] The length of the detector is set to the second sum value;

[0030] When the scanning device includes a galvanometer and a prism, the superimposed image displacement distance of the first image displacement distance and the second image displacement distance is determined;

[0031] Determine the third sum of the length of the light spot and the superimposed image shift distance;

[0032] The length of the detector is set to the third sum value.

[0033] Secondly, embodiments of this application provide a laser receiving device, the device comprising:

[0034] The device includes a scanning device, a detector unit array, and a receiving lens. The detector unit array is composed of multiple detector units, and the number of rows in the detector unit array is the same as the number of channels. The scanning device includes a prism and a galvanometer. The prism is used to deflect the emitted and received laser beams horizontally, and the galvanometer is used to deflect the horizontally deflected laser beams vertically. The galvanometer is disposed between the prism and the receiving lens.

[0035] The scanning device is used to deflect the emitted and received laser beams;

[0036] The detector unit array is disposed between the scanning device and the receiving lens;

[0037] The receiving lens is used to focus the laser beam onto the detector units of the detector unit array;

[0038] The arrangement direction of each detector unit in the detector unit array is parallel to the image shift direction of the laser beam, and the image shift direction is determined by the angular velocity of the prism and the rotating mirror in the scanning device.

[0039] In an optional embodiment, when the angular velocity of the prism is greater than the angular velocity of the galvanometer, each detector unit in the detector unit array is arranged in a horizontal direction, wherein the image shift direction of the laser beam is horizontal.

[0040] In an optional embodiment, when the angular velocity of the prism is less than the angular velocity of the galvanometer, each detector unit in the detector unit array is arranged in a vertical direction, wherein the image shift direction of the laser beam is vertical.

[0041] In an optional embodiment, when the angular velocity of the prism is equal to the angular velocity of the galvanometer, the arrangement direction of each detector unit in the detector unit array is arranged at a preset angle to the vertical direction, wherein the preset angle is obtained based on the horizontal image shift direction of the laser beam passing through the prism and the vertical image shift direction of the laser beam passing through the galvanometer.

[0042] In an optional implementation, the detector unit includes any one of the following: an avalanche photodiode, a silicon photomultiplier tube, or a single-photon avalanche diode.

[0043] In an optional implementation, the number of detector units in each row of the detector unit array is determined by the detector length, and the number of columns in the detector unit array is the same as the number of channels.

[0044] In an optional embodiment, when the angular velocity of the prism is greater than the angular velocity of the galvanometer, the length of the detector is set to a first length, wherein the first length is determined by the length of the laser beam spot and the horizontal image displacement distance of the laser beam through the galvanometer.

[0045] In an optional embodiment, when the angular velocity of the prism is less than the angular velocity of the galvanometer, the length of the detector is set to a second length, wherein the second length is determined by the sum of the length of the laser beam spot and the vertical image displacement distance of the laser beam through the prism.

[0046] In an optional embodiment, when the angular velocity of the prism is equal to the angular velocity of the galvanometer, the length of the detector is set to a third length, wherein the third length is determined by the superimposed image displacement distance determined by the horizontal image displacement distance of the laser beam and the vertical image displacement distance of the laser beam, and is determined by the sum of the superimposed image displacement distance and the length of the laser beam spot.

[0047] Thirdly, this application also provides a lidar, which includes the aforementioned laser receiving device.

[0048] This application has the following beneficial effects:

[0049] This application determines a first image shift direction when a laser beam passes through a galvanometer and / or a second image shift direction when the laser beam passes through a prism. The laser receiving device includes a galvanometer and / or a prism. The prism deflects the laser beam horizontally, and the galvanometer deflects the horizontally deflected laser beam vertically. Based on the first and / or second image shift directions, multiple detector units are arranged. The laser beam from each detector unit, after being deflected by the galvanometer and / or prism, is focused onto the detector by a receiving lens. By constructing a detector with multiple detector units and arranging them in accordance with the image shift directions, the field of view for acquiring the laser signal can be reduced, thereby improving the signal-to-noise ratio and ultimately increasing the range of the lidar. Attached Figure Description

[0050] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0051] Figure 1 A block diagram of an electronic device provided in an embodiment of the present invention;

[0052] Figure 2 This is one of the flowcharts illustrating a method for arranging detector units according to an embodiment of the present invention;

[0053] Figure 3 This is a second schematic flowchart illustrating a method for arranging detector units according to an embodiment of the present invention.

[0054] Figure 4 The third schematic flowchart illustrates a method for arranging detector units according to an embodiment of the present invention.

[0055] Figure 5 The fourth flowchart illustrates a method for arranging detector units according to an embodiment of the present invention.

[0056] Figure 6 A structural diagram of a laser receiving device provided in an embodiment of the present invention;

[0057] Figure 7 This is a schematic diagram of the detector structure provided in an embodiment of the present invention;

[0058] Figure 8 This is a schematic diagram showing the horizontal arrangement of each detector unit in the detector unit array provided in an embodiment of the present invention;

[0059] Figure 9 This is a schematic diagram showing the vertical arrangement of each detector unit in the detector unit array provided in an embodiment of the present invention;

[0060] Figure 10 This is an assembly diagram of the laser receiving device provided in an embodiment of the present invention;

[0061] Figure 11 This is a schematic diagram of the transmission direction of a laser beam in a laser receiving device provided in an embodiment of the present invention;

[0062] Figure 12 This is a schematic diagram showing the relationship between horizontal and vertical image shift. Detailed Implementation

[0063] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0064] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0065] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0066] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0067] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0068] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0069] Extensive research by the inventors revealed that because the scanning device of a lidar system rotates continuously, after the pulsed light is emitted from the radar and reflected back by the target, it travels for a flight time Δt before re-entering the radar. By this time, the scanning device has deflected by a certain angle θ due to its rotation. Therefore, lidar design must consider a 2θ angle for the detector unit's field of view, leading to more ambient light noise entering the detector, resulting in higher ambient light noise, affecting the lidar's signal-to-noise ratio, and ultimately reducing its range.

[0070] In view of the above-mentioned problems, this embodiment provides a detector unit arrangement method, a laser receiving device, and a lidar. It can form a detector by using multiple detector units and arrange each detector unit in the same way as the image shift direction, which can reduce the field of view of the laser signal acquisition, thereby improving the signal-to-noise ratio and thus increasing the lidar range. The solution provided in this embodiment will be described in detail below.

[0071] This embodiment provides an electronic device that can arrange detector units. In one possible implementation, the electronic device can be a user terminal, such as, but not limited to, a server, smartphone, personal computer (PC), tablet computer, personal digital assistant (PDA), mobile internet device (MID), etc.

[0072] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of the electronic device 100 provided in the embodiments of this application. The electronic device 100 may further include... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown. Figure 1 The components shown can be implemented using hardware, software, or a combination thereof.

[0073] The electronic device 100 includes a detector unit arrangement device 110, a memory 120, and a processor 130.

[0074] The components of the memory 120 and processor 130 are electrically connected directly or indirectly to achieve data transmission or interaction. For example, these components can be electrically connected to each other through one or more communication buses or signal lines. The detector unit arrangement device 110 includes at least one software function module that can be stored in the memory 120 in the form of software or firmware or embedded in the operating system (OS) of the electronic device 100. The processor 130 is used to execute executable modules stored in the memory 120, such as the software function modules and computer programs included in the detector unit arrangement device 110.

[0075] The memory 120 may be, but is not limited to, Random Access Memory (RAM), Read Only Memory (ROM), Programmable Read-Only Memory (PROM), Erasable Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), etc. The memory 120 is used to store programs, and the processor 130 executes the programs after receiving execution instructions.

[0076] Please refer to Figure 2 , Figure 2 For application Figure 1 The flowchart below shows a method for arranging detector units in an electronic device 100. The method includes detailed explanations of each step.

[0077] Step 201: Determine the first image shift direction when the laser beam passes through the galvanometer and / or the second image shift direction when the laser beam passes through the prism.

[0078] The laser receiving device includes a scanning device, which includes a galvanometer and / or a prism. The prism is used to deflect the laser beam in the horizontal direction, and the galvanometer is used to deflect the horizontally deflected laser beam in the vertical direction.

[0079] Step 202: Arrange multiple detector elements of the detector based on the first image shift direction and / or the second image shift direction.

[0080] In this process, the laser beam is deflected by a galvanometer and / or prism and then focused onto the detector by a receiving lens.

[0081] During laser ranging, due to the continuous rotation of the galvanometer and / or prism, the convergence point of the laser beam on the detector may shift towards either the first image shift direction when passing through the galvanometer or the second image shift direction when passing through the prism. To avoid this shift in the convergence point, multiple detector units are arranged based on the first and / or second image shift directions. This compensates for the shift in the convergence point caused by the optical axis deflection. Since the detector consists of multiple detector units, reducing the field of view during laser ranging reduces ambient light noise entering the detector, lowers the signal-to-noise ratio of the lidar, and ultimately increases its range.

[0082] Based on the first image shift direction and / or the second image shift direction, there are multiple ways to arrange the detector units of the detector. In one implementation, when the scanning device only includes a galvanometer, the detector units of the detector are arranged to form a detector unit array. The detector units in each row of the detector unit array are arranged according to the first image shift direction, wherein the number of rows of the detector unit array is the same as the number of channels.

[0083] The detector element array can be a multi-row, multi-column array or a single-row, multi-column array.

[0084] When the scanning device includes only a galvanometer, the laser receiving device also includes a receiving lens and a detector unit array composed of multiple detector units. The laser beam is deflected in the vertical direction by the galvanometer, the receiving lens receives the laser beam after it has been deflected by the galvanometer, and finally the laser beam is received by the detector unit array through the receiving lens. The laser beam is received by the detector units in the detector unit array. Each row of detector units in the detector unit array is arranged according to the first image shift direction when the laser beam passes through the galvanometer.

[0085] It should be noted that the first image shift direction is the vertical direction.

[0086] In another implementation, when the scanning device consists only of a prism, the detector units of the detector array form a detector unit array. The detector units in each row of the detector unit array are arranged according to the second image shift direction, wherein the number of rows of the detector unit array is the same as the number of channels.

[0087] When the scanning device includes only a prism, the laser receiving device also includes a receiving lens and a detector unit array composed of multiple detector units. The laser beam is deflected in the horizontal direction by the prism, the receiving lens receives the laser beam after it has been deflected by the prism, and finally the laser beam is received by the detector through the receiving lens. The laser beam is also received by the detector units in the detector unit array. The detector units in the detector unit array are arranged according to the second image shift direction when the laser beam passes through the prism.

[0088] It should be noted that the direction of the second image shift is horizontal.

[0089] For example, when the detector unit array is a single row with multiple columns, multiple detector units are arranged horizontally. The detector unit array includes a first detector unit, a second detector unit, a third detector unit, and a fourth detector unit, which are electrically connected sequentially from left to right. The emitted beam of the lidar is reflected by a prism and reaches the target being detected. Due to the time of flight of light Δt, when the reflected light passes through the prism again, the prism has rotated by a certain angle. The reflected light is then reflected by the prism and converged onto the detector unit array by the receiving lens. If the light spot falls completely onto the first detector unit, it indicates that the beam reflected from a nearby target is converged at the detector's position. If half of the light spot falls onto the second detector unit and the other half falls onto the third detector unit, it indicates that the beam reflected from a target at half the lidar's range is converged at the detector's position. The signals from the first, second, third, and fourth detector units together realize the optical signal detection of one detector channel, and the back-end data processing forms a range measurement data.

[0090] In another implementation of arranging the detector elements based on the first image shift direction and / or the second image shift direction, such as... Figure 3 As shown, the specific steps include:

[0091] Step 202-1: When the scanning device includes a galvanometer and a prism, determine the first angular velocity of the galvanometer and the second angular velocity of the prism.

[0092] Step 202-2: When the first angular velocity is greater than the second angular velocity, the detector units of the detector are arranged to form a detector unit array, and each detector unit in the detector unit array is arranged according to the first image shift direction.

[0093] In this array, the number of rows in the detector unit array is the same as the number of channels.

[0094] Step 202-3: When the first angular velocity is less than the second angular velocity, the detector units of the detector are arranged to form a detector unit array, and each detector unit in the detector unit array is arranged according to the second image shift direction.

[0095] In one example, when the scanning device includes both a galvanometer and a prism, the prism is used to deflect the emitted and received laser beams horizontally, and the galvanometer is used to deflect the horizontally deflected laser beams vertically. Both the galvanometer and prism are continuously rotating. A first angular velocity of the galvanometer and a second angular velocity of the prism are determined and compared. If the first angular velocity is greater than the second angular velocity, multiple detector units are arranged in a detector unit array, with each detector unit arranged according to a first image shift direction. If the first angular velocity is less than the second angular velocity, multiple detector units are arranged in a detector unit array, with each detector unit arranged according to a second image shift direction.

[0096] In another example, when the scanning device includes both a galvanometer and a prism, a first angular velocity of the galvanometer and a second angular velocity of the prism are determined. The absolute value of the difference between the first and second angular velocities is calculated. If the absolute value of the difference is greater than a first preset value, multiple detector units of the detector are arranged to form a detector unit array, with each detector unit in the array arranged according to a first image shift direction. If the absolute value of the difference is less than the first preset value, multiple detector units of the detector are arranged to form a detector unit array, with each detector unit in the array arranged according to a second image shift direction. Setting the arrangement direction of the multiple detector units based on the absolute value of the difference between the first and second angular velocities ensures that when the first angular velocity is much greater than the second angular velocity, the image shift direction with the faster scanning speed is preferentially matched when arranging the multiple detector units.

[0097] It should be noted that, in order to ensure that the first angular velocity is much greater than the second angular velocity, or the second angular velocity is much greater than the first angular velocity, the first preset value is set to a large value. The first preset value can be set to 90, 100, 110, etc., and this application embodiment does not impose specific restrictions on this.

[0098] For example, if the first angular velocity of the galvanometer is 10 revolutions per second and the angular velocity of the prism is 100 revolutions per second, then the arrangement direction of each detector unit in the detector unit array composed of multiple detector units is the same as the second image shift direction of the laser beam passing through the prism.

[0099] In another implementation of arranging the detector elements based on the first image shift direction and / or the second image shift direction, such as... Figure 4 As shown, the specific steps include:

[0100] Step 202-4: When the first angular velocity is equal to the second angular velocity, determine the superimposed image shift direction of the first image shift direction and the second image shift direction.

[0101] Step 202-5: Set the detector units of the detector to form a detector unit array, and arrange each detector unit in the detector unit array according to the superimposed image shift direction.

[0102] In one example, when the first angular velocity of the galvanometer and the second angular velocity of the prism are equal, the superimposed image shift direction of the first image shift direction and the second image shift direction is determined, and multiple detector units of the detector are set to form a detector unit array, in which each detector unit is arranged according to the superimposed image shift direction.

[0103] In another example, the absolute value of the difference between the first angular velocity of the galvanometer and the second angular velocity of the prism is calculated, and the absolute value of the difference is compared with a second preset value. When the absolute value of the difference between the first angular velocity and the second angular velocity is less than the second preset value, the superimposed image shift direction of the first image shift direction and the second image shift direction is determined, and each detector unit of the detector unit array is arranged according to the superimposed image shift direction, wherein the first preset value is greater than the second preset value.

[0104] The length of the detector is set, such as Figure 5 As shown, it includes the following steps:

[0105] Step 301: Determine the first image shift distance of the laser beam as it passes through the galvanometer and / or the second image shift distance of the laser beam as it passes through the prism.

[0106] Step 302: Determine the length of the laser beam spot on the detector.

[0107] Step 303: Set the length of the detector based on the first image shift distance and / or the second image shift distance and the length of the light spot.

[0108] In one example, the first image shift distance is calculated based on the following formula:

[0109] Where L1 is the first image shift distance, f is the focal length of the receiving lens, d is the range of the lidar, c is the speed of light, and γ1 is the first angular velocity of the galvanometer.

[0110] In another example, the second image shift distance is calculated based on the following formula:

[0111] Where L2 is the second image shift distance, f is the focal length of the receiving lens, d is the range of the lidar, c is the speed of light, and γ2 is the second angular velocity of the prism.

[0112] The length of the detector is set by the first image shift distance and / or the second image shift distance, as well as the length of the light spot.

[0113] In one example, when the scanning device consists only of a galvanometer and the detector is a single-row, multi-column array of detector units, the first sum of the first image shift distance of the laser beam as it passes through the galvanometer and the length of the light spot is calculated as the length of the detector, and the width of the detector is the width of the light spot.

[0114] It should be noted that, based on the first sum of the first image shift distance and the length of the light spot when the laser beam passes through the galvanometer, the length of the detector is set to be greater than or equal to the first sum in order to avoid the existence of errors, and the error between the set detector length and the first sum is within the error range.

[0115] In another example, when the scanning device consists only of a prism and the detector is a single-row, multi-column array of detector units, the second sum of the second image shift distance and the length of the light spot when the laser beam passes through the prism is calculated as the length of the detector, and the width of the detector is the width of the light spot.

[0116] It should be noted that, based on the second sum of the second image shift distance and the length of the light spot when the laser beam passes through the prism, the length of the detector is set to be greater than or equal to the second sum in order to avoid the existence of errors, and the error between the set detector length and the second sum is within the error range.

[0117] In another example, when the scanning device includes a galvanometer and a prism, and the detector is a single-row multi-column detector unit array, the superimposed image shift distance of the first image shift distance and the second image shift distance is determined, the third sum of the length of the light spot and the superimposed image shift distance is determined, and the length of the detector is set to the third sum.

[0118] It should be noted that, based on the third sum of the image shift distance and the length of the light spot, the length of the detector is set to be greater than or equal to the third sum in order to avoid errors, and the error between the set detector length and the third sum must meet the error range.

[0119] Reference Figure 6 This application also provides a laser receiving device, which includes: a scanning device 111, a detector 112, and a receiving lens 113. The detector 112 is composed of multiple detector units 1121, which form a detector unit array. The number of rows in the detector unit array is the same as the number of channels. The scanning device 111 includes a prism 1111 and a galvanometer 1112. The prism 1111 is used to deflect the emitted and received laser beams in the horizontal direction, and the galvanometer 1112 is used to deflect the horizontally deflected laser beams in the vertical direction. The galvanometer 1112 is disposed between the prism 1111 and the receiving lens.

[0120] The scanning device 111 is used to deflect the emitted and received laser beams;

[0121] The detector 112 is disposed between the scanning device and the receiving lens;

[0122] The receiving lens 113 is used to focus the laser beam onto the detector unit of the detector;

[0123] The arrangement direction of each detector unit in the detector unit array is parallel to the image shift direction of the laser beam, and the image shift direction is determined by the angular velocity of the prism 1111 and the galvanometer 1112 in the scanning device 111.

[0124] It should be noted that the detector unit includes any one of the following: avalanche photodiode, silicon photomultiplier tube, or single-photon avalanche diode.

[0125] In this embodiment, the detector unit includes multiple implementation structures, one of which is as follows: Figure 7 As shown, the detector 112 consists of a detector unit array composed of four detector units 1121, namely the first detector unit 11211, the second detector unit 11212, the third detector unit 11213, and the fourth detector unit 11214. The arrangement direction of each detector unit 1121 in the detector unit array is parallel to the translation direction of the laser beam. During the rotation of the scanning device 111, the time of flight of light changes with the change of the distance to the target. The detector 112 receives the laser beam through the receiving lens 113, and the light spot converges on different detector units. The closer the target is, the closer the light spot converges to the first detector unit 11211. The farther the target is, the closer the light spot converges to the fourth detector unit 11214.

[0126] The scanning device can include various implementation structures. In one implementation structure, the scanning device includes a prism for horizontally deflecting the emitted and received laser beams, and a detector unit array composed of multiple detector units, each detector unit in the detector unit array being arranged horizontally, such as... Figure 8 As shown, the detector unit array is a single row with multiple columns, and each detector unit in the detector unit array is arranged in a horizontal direction.

[0127] In another implementation, the scanning device of the laser receiver includes a galvanometer mirror. The galvanometer mirror deflects the emitted and received laser beams vertically. After being deflected by the galvanometer mirror, the laser beam is received by the receiving lens 113 and focused onto the vertically arranged detector element array of the detector. Figure 9 The diagram shows the arrangement of each detector unit in the detector unit array along the vertical direction.

[0128] In one implementation, the positions of the galvanometer 1112 and the prism 1111 can be set based on spatial position. That is, in spatial position, the galvanometer 1112 is set between the receiving lens 113 and the prism 1111. In other words, the laser beam is deflected in the following order: first by the prism, and then by the galvanometer.

[0129] In another implementation, the prism 1111 and prism 1112 can be configured based on the propagation direction of the laser beam.

[0130] like Figure 10 The diagram shows an assembly schematic of a laser receiver. The laser receiver includes a housing 114, a prism 1111 disposed on the bottom surface of the housing near the first housing sidewall 1141 and the second housing sidewall 1142 (which are perpendicular to each other), a galvanometer 1112 disposed on the third housing sidewall 1143 (which is parallel to the first housing sidewall 1141), and a receiving lens 113 disposed near the fourth housing sidewall 1144. Furthermore, the receiving lens 113 is spaced apart from the third housing sidewall 1143 by a first preset distance, and the receiving lens 113 is spaced apart from the third housing sidewall 1143 by a second preset distance, the second preset distance being greater than the first preset distance. The detector 112 is located near the fourth housing sidewall 1144 and is not attached to the fourth housing sidewall 1144. The detector 112 is located between the receiving lens 113 and the fourth housing sidewall 1144. The fourth housing sidewall 1144 and the receiving lens 113 are spaced apart by a third preset distance, the third preset distance being less than the second preset distance.

[0131] A drive motor is provided on the bottom surface of the housing at the location of prism 1111. The drive motor is electrically connected to prism 1111 and controls prism 1111 to rotate horizontally. A drive motor is provided on the third housing side wall 1143 at the location of galvanometer 1112. The drive motor is electrically connected to galvanometer 1112 and controls galvanometer 1112 to deflect vertically.

[0132] In this embodiment, the spatial relationship between the prism 1111, the galvanometer 1112, and the receiving lens 113 is such that the prism 1111 and the galvanometer 1112 are disposed on one side of the bottom surface of the housing, and the receiving lens 113 is disposed on the other side of the bottom surface of the housing. That is, the prism 1111, the galvanometer 1112, and the receiving lens are arranged based on the propagation direction of the laser beam, such as... Figure 11The diagram shows the transmission direction of a laser beam in a laser receiving device. The laser beam is horizontally deflected by a prism, then vertically deflected by a galvanometer, and finally converged by a receiving lens. The detector receives the spot of the converged laser beam.

[0133] When the laser receiving device includes both a prism and a galvanometer, the arrangement of each detector unit in the detector unit array composed of multiple detector units is at a preset angle to the vertical direction.

[0134] For example: the preset angle is obtained based on the horizontal image shift direction of the laser beam passing through the prism and the vertical image shift direction of the laser beam passing through the galvanometer, such as... Figure 12 The diagram shows the relationship between horizontal and vertical image shifts. The final image shift direction of the laser beam is determined based on the horizontal and vertical image shift directions.

[0135] There are several ways to determine the preset angle. In one method, the first image shift distance when the laser beam passes through the galvanometer is determined, and the second image shift distance when the laser beam passes through the prism is determined. The preset angle is then determined based on the first and second image shift distances. For example, when the first image shift distance is 'a' and the second image shift distance is 'b', and the first image shift distance is greater than the second image shift distance, the angle between the diagonal of the rectangle formed by length 'a' and width 'b' and the second image shift distance is the preset angle.

[0136] Wherein, the first image shift distance satisfies the following formula:

[0137] Where L1 is the first image shift distance, f is the focal length of the receiving lens, d is the range of the lidar, c is the speed of light, and γ1 is the first angular velocity of the galvanometer.

[0138] The second image shift distance satisfies the following formula:

[0139] Where L2 is the second image shift distance, f is the focal length of the receiving lens, d is the range of the lidar, c is the speed of light, and γ2 is the second angular velocity of the prism.

[0140] In another implementation, a preset angle is determined based on the angular velocities of the prism and the galvanometer. When the angular velocity of the galvanometer is greater than that of the prism, the preset angle between the arrangement direction of the multiple detector units and the vertical direction is 0 degrees. When the angular velocity of the prism is greater than that of the galvanometer, the preset angle between the arrangement direction of each detector unit in the detector unit array composed of multiple detector units and the vertical direction is 90 degrees.

[0141] To ensure that the laser beam can be received by the detector, the length of the detector needs to be set.

[0142] In one example, when the laser receiver contains only a galvanometer, the length of the detector is set to a first length.

[0143] There are several ways to determine the first length. In one method, the length of the laser beam spot is determined. When the spot is circular, the diameter of the spot is used as the length of the spot. The first image shift distance is calculated using the formula for the first image shift distance when the laser beam passes through the galvanometer. The sum of the first image shift distance and the spot length is set as the first length of the detector. That is, the length of each row of detector units in the detector unit array composed of multiple detector units is the first length. When the spot is circular, the diameter of the spot is used as the width of each row of detector units in the detector unit array.

[0144] In another example, when the laser receiver consists only of a prism, the length of the detector is set to a second length.

[0145] There are several ways to determine the second length. In one method, the length of the laser beam spot is determined, and the second image shift distance is calculated using the formula for the second image shift distance when the laser beam passes through the prism. The sum of the second image shift distance and the length of the spot is set as the second length of the detector. That is, the length of each row of detector units in the detector unit array composed of multiple detector units is the second length, and the width of each row of detector units in the detector unit array is the width of the spot.

[0146] In another example, when the laser receiver includes both a prism and a galvanometer, the length of the detector is set to a third length.

[0147] There are several ways to determine the third length. In one method, the first image shift distance in the vertical direction of the laser beam passing through the galvanometer and the second image shift distance in the horizontal direction passing through the prism are determined. The superimposed image shift distance is calculated based on the first and second image shift distances. The sum of the superimposed image shift distance and the length of the light spot is set as the third length of the detector. That is, the length of each row of detector units in the detector unit array composed of multiple detector units is the third length, and the width of each row of detector units in the detector unit array is the width of the light spot.

[0148] In another example, when the laser receiver includes both a galvanometer and a prism, the length of the detector is set to a fourth length.

[0149] There are several ways to determine the fourth length. In one method, the angular velocities of the prism and the galvanometer are determined. When the angular velocity of the galvanometer is greater than that of the prism, the length of the detector is set as the first length. When the angular velocity of the prism is greater than that of the galvanometer, the length of the detector is set as the second length. When the angular velocity of the prism is equal to that of the galvanometer, the length of the detector is set as the third length.

[0150] The number of detector elements in each row of the detector element array is determined by the detector length, and the number of columns in the detector element array is the same as the number of channels.

[0151] This application also provides an electronic device 100, which includes a processor 130 and a memory 120. The memory 120 stores computer-executable instructions, which, when executed by the processor 130, implement the arrangement method of the detector unit.

[0152] This application embodiment also provides a computer-readable storage medium storing a computer program, which, when executed by the processor 130, implements the arrangement method of the detector unit.

[0153] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can also be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0154] Furthermore, the functional modules in the various embodiments of this application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part. If the function is implemented as a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes: USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, optical disks, and other media capable of storing program code.

[0155] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0156] The above descriptions are merely various embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for arranging detector units, applied to a laser receiving device, characterized in that, The method includes: The laser beam is determined by first image shift direction when passing through a galvanometer and second image shift direction when passing through a prism. The laser receiving device includes a scanning device, which includes a galvanometer and a prism. The prism is used to deflect the laser beam in the horizontal direction, and the galvanometer is used to deflect the horizontally deflected laser beam in the vertical direction. Based on the first image shift direction and the second image shift direction, multiple detector units of the detector are arranged, wherein the laser beam is deflected by the galvanometer and prism and then focused onto the detector by the receiving lens; The step of arranging the detector elements of the detector based on the first image shift direction and the second image shift direction includes: Determine the first angular velocity of the galvanometer and the second angular velocity of the prism; When the first angular velocity is greater than the second angular velocity, the detector units of the detector are arranged to form a detector unit array. Each detector unit in the detector unit array is arranged according to the first image shift direction, wherein the number of rows of the detector unit array is the same as the number of channels. When the first angular velocity is less than the second angular velocity, the detector units of the detector are arranged to form a detector unit array, and each detector unit in the detector unit array is arranged according to the second image shift direction; When the first angular velocity is equal to the second angular velocity, the superimposed image displacement direction of the first image displacement direction and the second image displacement direction is determined; The detector units of the detector constitute a detector unit array, and each detector unit in the detector unit array is arranged according to the superimposed image shift direction.

2. The method according to claim 1, characterized in that, The method further includes: Determine the first image displacement distance of the laser beam when it passes through the galvanometer and the second image displacement distance of the laser beam when it passes through the prism; Determine the length of the laser beam spot on the detector; The length of the detector is set based on the first image shift distance, the second image shift distance, and the length of the light spot.

3. The method according to claim 2, characterized in that, The step of setting the length of the detector based on the first image shift distance, the second image shift distance, and the length of the light spot includes: Determine the superimposed image shift distance of the first image shift distance and the second image shift distance; determine the third sum of the length of the light spot and the superimposed image shift distance; set the length of the detector to the third sum.

4. A laser receiving device, characterized in that, The device includes: The device includes a scanning device, a detector, and a receiving lens. The detector is composed of multiple detector units, which form a detector unit array. The number of rows in the detector unit array is the same as the number of channels. The scanning device includes a prism and a galvanometer. The prism is used to deflect the emitted and received laser beams horizontally, and the galvanometer is used to deflect the horizontally deflected laser beams vertically. The galvanometer is disposed between the prism and the receiving lens. The scanning device is used to deflect the emitted and received laser beams; The detector is positioned after the scanning device and the receiving lens; The receiving lens is used to focus the laser beam onto the detector unit of the detector; The arrangement direction of each detector unit in the detector unit array is parallel to the image shift direction of the laser beam, and the image shift direction is determined by the angular velocity of the prism and galvanometer in the scanning device; When the angular velocity of the prism is greater than the angular velocity of the galvanometer, the detector units in each row of the detector unit array are arranged horizontally, wherein the image shift direction of the laser beam is horizontal; when the angular velocity of the prism is less than the angular velocity of the galvanometer, the detector units in each row of the detector unit array are arranged vertically, wherein the image shift direction of the laser beam is vertical; when the angular velocity of the prism is equal to the angular velocity of the galvanometer, the arrangement direction of each detector unit in the detector unit array is at a preset angle to the vertical direction, wherein the preset angle is obtained based on the horizontal image shift direction of the laser beam passing through the prism and the vertical image shift direction of the laser beam passing through the galvanometer.

5. The apparatus according to claim 4, characterized in that, The detector unit includes any one of the following: avalanche photodiode, silicon photomultiplier tube, or single-photon avalanche diode.

6. The apparatus according to claim 4, characterized in that, The number of detector units in each row of the detector unit array is determined by the detector length, and the number of rows in the detector unit array is the same as the number of channels.

7. The apparatus according to claim 4, characterized in that, When the angular velocity of the prism is greater than the angular velocity of the galvanometer, the length of the detector is set to a first length, wherein the first length is determined by the length of the laser beam spot and the horizontal image displacement distance of the laser beam through the galvanometer.

8. The apparatus according to claim 4, characterized in that, When the angular velocity of the prism is less than the angular velocity of the galvanometer, the length of the detector is set to a second length, wherein the second length is determined by the sum of the length of the laser beam spot and the vertical image displacement distance of the laser beam through the prism.

9. The apparatus according to claim 4, characterized in that, When the angular velocity of the prism is equal to the angular velocity of the galvanometer, the length of the detector is set to a third length, wherein the third length is determined by the superimposed image displacement distance determined by the horizontal image displacement distance of the laser beam and the vertical image displacement distance of the laser beam, and is determined by the sum of the superimposed image displacement distance and the length of the laser beam spot.

10. A lidar, characterized in that, The lidar includes the laser receiving device according to any one of claims 4-9.

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