Laser radar alignment method, device, storage medium and laser radar

Abstract

The present application provides a laser radar alignment method, device, storage medium and laser radar, which relates to the field of laser radar, wherein the laser radar includes a prism and a galvanometer. In the method, after the rotation speed of the prism is maintained at a preset rotation speed, the controller controls the galvanometer to rotate to the initial position of the galvanometer when the clock synchronization signal arrives, so that the laser emitted by the laser radar can be directed to the initial light-emitting point on the surface of the galvanometer; and obtain the rotation speed fine-tuning information of the current rotation speed of the prism; according to the rotation speed fine-tuning information, the current rotation speed of the prism is adjusted, so that the prism rotates to the initial position of the prism, so that the laser reflected by the galvanometer can be directed to the initial light-emitting point on the surface of the prism. In this way, the prism is first rotated to the preset rotation speed, and then the initial position of the galvanometer of the galvanometer is aligned with the clock synchronization signal, and then only a simple fine-tuning is required based on the preset rotation speed of the prism to align with the galvanometer in a short time.

Description

Technical Field

[0001] The present application relates to the field of laser radar, and more specifically, to a laser radar alignment method, device, storage medium and laser radar. Background Art

[0002] LiDAR is a remote sensing measurement technology that measures distance, direction and other information by emitting lasers at a target and analyzing the reflected light. Currently, LiDAR has been widely used in many fields, including geographic information systems, self-driving cars, drones, archeology, and forestry resource surveys.

[0003] In the LiDAR system, the galvanometer and prism are two crucial optical components, and each has its own function in the system. The prism is responsible for lateral rotation, while the galvanometer is responsible for longitudinal flipping, together realizing two-dimensional scanning of the laser in the horizontal and vertical directions. In order to ensure that the LiDAR can scan the space with predetermined performance parameters, the galvanometer and prism must work together in a specific rotation rhythm. Therefore, after the LiDAR is started, the prism and galvanometer need to be precisely aligned using a clock synchronization signal. However, how to achieve fast and accurate alignment has become a problem that needs to be solved urgently. Summary of the invention

[0004] In order to overcome at least one of the shortcomings of the prior art, the present application provides a laser radar alignment method, device, storage medium and laser radar, specifically including:

[0005] In a first aspect, the present application provides a laser radar alignment method, wherein the laser radar includes a prism and a galvanometer, and the method includes:

[0006] After the rotation speed of the prism is maintained at a preset rotation speed, the galvanometer is controlled to rotate to an initial position of the galvanometer when a clock synchronization signal arrives, so that the laser emitted by the laser radar can be directed to an initial light-emitting point on the surface of the galvanometer;

[0007] Obtaining speed fine-tuning information of the current speed of the prism;

[0008] The current rotation speed of the prism is adjusted according to the rotation speed fine-tuning information, so that the prism rotates to the initial position of the prism, so that the laser reflected by the galvanometer can be directed to the initial light-emitting point on the surface of the prism.

[0009] In combination with the optional implementation manner of the first aspect, the obtaining the speed fine-tuning information of the current speed of the prism includes:

[0010] Obtaining a current actual position of the prism and a current expected position of the prism;

[0011] The speed fine-tuning information is obtained according to a position error between the actual position and the expected position.

[0012] In combination with the optional implementation manner of the first aspect, obtaining the speed fine-tuning information according to the position error between the actual position and the expected position includes:

[0013] The position error is matched with a preset fine-tuning information table to obtain the speed fine-tuning information, wherein the fine-tuning information table records a mapping relationship between the position error and the speed fine-tuning information.

[0014] In combination with an optional implementation manner of the first aspect, the control system of the prism includes a speed loop, and adjusting the current speed of the prism according to the speed fine-tuning information includes:

[0015] Correcting the current speed control instruction of the prism according to the speed fine-tuning information to obtain a corrected speed control instruction;

[0016] The modified rotation speed control instruction is applied to the speed loop to adjust the current rotation speed of the prism.

[0017] In combination with the optional implementation manner of the first aspect, the step of controlling the galvanometer to rotate to an initial position of the galvanometer when a clock synchronization signal arrives includes:

[0018] Acquire target control information for rotating the galvanometer to an initial position of the galvanometer;

[0019] If the clock synchronization signal is received, the target control information is applied to the galvanometer, so that the galvanometer jumps from the current position to the initial position of the galvanometer.

[0020] In combination with the optional implementation manner of the first aspect, the obtaining of target control information for rotating the galvanometer to the initial position of the galvanometer includes:

[0021] During the period of controlling the galvanometer mirror to perform periodic rotation, recording the control information applied to the galvanometer mirror when the galvanometer mirror rotates to the initial position of the galvanometer mirror;

[0022] When the galvanometer is rotated to the initial position of the galvanometer, the control information applied to the galvanometer is used as the target control information.

[0023] In combination with the optional implementation manner of the first aspect, the step of controlling the galvanometer to rotate to an initial position of the galvanometer when a clock synchronization signal arrives includes:

[0024] Acquire target control information for rotating the galvanometer to an initial position of the galvanometer;

[0025] According to the target control information, the galvanometer is kept at the initial position of the galvanometer until a clock synchronization signal is received.

[0026] In combination with an optional implementation manner of the first aspect, the laser radar further includes a first processor and a second processor, the first processor is used to control the prism and the galvanometer, and after the prism rotates to the prism initial position, the method further includes:

[0027] A verification signal is sent to the second processor at a preset time point, wherein the verification signal is used to instruct the second processor to compare a reception time of the verification signal with the preset time point to verify whether the time between the first processor and the second processor is aligned.

[0028] In combination with an optional implementation manner of the first aspect, after the rotation speed of the prism is maintained at a preset rotation speed, controlling the galvanometer to rotate to an initial position of the galvanometer when a clock synchronization signal arrives, the method further includes:

[0029] Determine whether the error between the rotation speed of the prism and the preset rotation speed is less than an error threshold and is maintained for a preset time period;

[0030] If so, it is determined that the rotation speed of the prism is maintained at a preset rotation speed.

[0031] In a second aspect, the present application further provides a laser radar alignment device, wherein the laser radar includes a prism and a galvanometer, and the device includes:

[0032] A galvanometer control module controls the galvanometer to rotate to an initial position of the galvanometer when a clock synchronization signal arrives after the rotation speed of the prism is maintained at a preset rotation speed, so that the laser emitted by the laser radar can be directed to an initial light-emitting point on the surface of the galvanometer;

[0033] A prism control module, used to obtain speed fine-tuning information of the current speed of the prism;

[0034] The prism control module is also used to adjust the current rotation speed of the prism according to the rotation speed fine-tuning information, so that the prism rotates to the initial position of the prism, so that the laser reflected by the galvanometer can be directed to the initial light-emitting point on the surface of the prism.

[0035] In conjunction with the optional implementation manner of the second aspect, the prism control module is further specifically used for:

[0036] Obtaining a current actual position of the prism and a current expected position of the prism;

[0037] The speed fine-tuning information is obtained according to a position error between the actual position and the expected position.

[0038] In conjunction with the optional implementation manner of the second aspect, the prism control module is further specifically used for:

[0039] The position error is matched with a preset fine-tuning information table to obtain the speed fine-tuning information, wherein the fine-tuning information table records a mapping relationship between the position error and the speed fine-tuning information.

[0040] In conjunction with the optional implementation manner of the second aspect, the control system of the prism includes a speed loop, and the prism control module is further specifically used for:

[0041] Correcting the current speed control instruction of the prism according to the speed fine-tuning information to obtain a corrected speed control instruction;

[0042] The modified rotation speed control instruction is applied to the speed loop to adjust the current rotation speed of the prism.

[0043] In conjunction with the optional implementation manner of the second aspect, the galvanometer control module is further specifically used for:

[0044] Acquire target control information for rotating the galvanometer to an initial position of the galvanometer;

[0045] If the clock synchronization signal is received, the target control information is applied to the galvanometer, so that the galvanometer jumps from the current position to the initial position of the galvanometer.

[0046] In conjunction with the optional implementation manner of the second aspect, the galvanometer control module is further specifically used for:

[0047] During the period of controlling the galvanometer mirror to perform periodic rotation, recording the control information applied to the galvanometer mirror when the galvanometer mirror rotates to the initial position of the galvanometer mirror;

[0048] When the galvanometer is rotated to the initial position of the galvanometer, the control information applied to the galvanometer is used as the target control information.

[0049] In conjunction with the optional implementation manner of the second aspect, the galvanometer control module is further specifically used for:

[0050] Acquire target control information for rotating the galvanometer to an initial position of the galvanometer;

[0051] According to the target control information, the galvanometer is kept at the initial position of the galvanometer until a clock synchronization signal is received.

[0052] In combination with an optional implementation manner of the second aspect, the laser radar further includes a first processor and a second processor, the first processor is used to control the prism and the galvanometer, and after the prism rotates to the prism initial position, the prism control module is further used to:

[0053] A verification signal is sent to the second processor at a preset time point, wherein the verification signal is used to instruct the second processor to compare a reception time of the verification signal with the preset time point to verify whether the time between the first processor and the second processor is aligned.

[0054] In combination with the optional implementation manner of the second aspect, after the rotation speed of the prism is maintained at a preset rotation speed, the galvanometer is controlled to rotate to the initial position of the galvanometer when the clock synchronization signal arrives, and the prism control module is further used to:

[0055] Determine whether the error between the rotation speed of the prism and the preset rotation speed is less than an error threshold and is maintained for a preset time period;

[0056] If so, it is determined that the rotation speed of the prism is maintained at a preset rotation speed.

[0057] In a third aspect, the present application provides a storage medium storing a computer program, which, when executed by a processor, implements the laser radar alignment method.

[0058] In a fourth aspect, the present application also provides a laser radar, which includes a processor and a memory, wherein the memory stores a computer program, and when the computer program is executed by the processor, the laser radar alignment method is implemented.

[0059] Compared with the prior art, this application has the following beneficial effects:

[0060] The present application provides a laser radar alignment method, device, storage medium and laser radar, wherein the laser radar includes a prism and a galvanometer. In the method, after the rotation speed of the prism is maintained at a preset rotation speed, the controller controls the galvanometer to rotate to the initial position of the galvanometer when the clock synchronization signal arrives, so that the laser emitted by the laser radar can be directed to the initial light-emitting point on the surface of the galvanometer; and obtain the rotation speed fine-tuning information of the current rotation speed of the prism; according to the rotation speed fine-tuning information, the current rotation speed of the prism is adjusted, so that the prism rotates to the initial position of the prism, so that the laser reflected by the galvanometer can be directed to the initial light-emitting point on the surface of the prism. In this way, the prism is first rotated to the preset rotation speed, and then the initial position of the galvanometer of the galvanometer is aligned with the clock synchronization signal, and then it only needs to be simply fine-tuned based on the preset rotation speed of the prism to align with the galvanometer in a short time. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0062] Figure 1 A schematic diagram of the mechanical structure of a laser radar provided in an embodiment of the present application;

[0063] Figure 2 A schematic diagram of the misaligned scanning effect provided in an embodiment of the present application;

[0064] Figure 3 A schematic diagram of a flow chart of a laser radar alignment method provided in an embodiment of the present application;

[0065] Figure 4 A sawtooth waveform diagram of a position control signal provided in an embodiment of the present application;

[0066] Figure 5 A schematic diagram of the structure of a control system provided in an embodiment of the present application;

[0067] Figure 6 A schematic diagram of the structure of a laser radar alignment device provided in an embodiment of the present application;

[0068] Figure 7 Schematic diagram of the electrical structure of the laser radar provided in an embodiment of the present application.

[0069] Icons: 100 - laser light source; 101 - lens; 102 - galvanometer; 103 - prism; 104 - laser; 105 - initial light-emitting point on the surface of the galvanometer; 106 - initial light-emitting point on the surface of the prism; 107 - actual light-emitting point; 201 - galvanometer control module; 202 - prism control module; 301 - memory; 302 - processor; 303 - communication unit; 304 - system bus. DETAILED DESCRIPTION

[0070] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0071] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0072] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0073] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the invented product is usually placed when in use. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0074] In addition, the terms "comprises," "comprising," or any other variation thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0075] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0076] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0077] Based on the above statement, as introduced in the background technology, after the laser radar is started, the prism and the galvanometer need to be accurately aligned using a clock synchronization signal. However, how to achieve a fast and accurate alignment effect has become a problem that needs to be solved urgently. In order to have a clearer understanding of the technical problems to be solved in this embodiment, the structure of the laser radar is first described below.

[0078] like Figure 1 As shown, in addition to the laser light source 100 and the lens 101, the current laser radar mostly adopts a rotating mirror solution, that is, two rotating mirrors are integrated inside the radar, one is a prism 103 responsible for horizontal rotation, and the other is a galvanometer 102 responsible for vertical flipping, and the two cooperate with each other to realize two-dimensional scanning of the laser 104 emitted through the lens 101 in both horizontal and vertical directions. Among them, the larger the radius of rotation of the prism 103 or the fewer the number of faces of the prism 103, the larger the scanning range will be. Therefore, the structure of the prism 103 is very important, which is directly related to the laser imaging range and effect.

[0079] Continue to see Figure 1 When the laser radar is used as a vehicle-mounted device, it is not only necessary for the laser radar to be synchronized with the vehicle-mounted time, but also for the prism and the galvanometer to maintain a specific rotation rhythm. Therefore, ideally, when the laser light source 100 emits the first laser beam, the galvanometer and the prism must reach the set rotation speed, and the galvanometer must also be rotated to the initial position of the galvanometer so that the laser emitted by the laser radar is exactly directed to the initial light-emitting point 105 on the surface of the galvanometer; and the prism must also be rotated to the initial position of the prism so that the laser reflected by the galvanometer is exactly directed to the initial light-emitting point 106 on the surface of the prism. In this way, the laser radar can be operated according to Figure 1 The scanning direction shown in the figure is periodically scanned in two dimensions. However, the galvanometer and prism require not only a certain startup time to reach the set rotation speed; and, even if both reach the set rotation speed and the galvanometer rotates to the initial position of the galvanometer, it does not mean that the mirror rotates exactly to the initial position of the prism. Therefore, after the laser radar is powered on, the prism and the galvanometer need to be precisely aligned using a clock synchronization signal. If the prism and the galvanometer are not aligned using a clock synchronization signal, the following may occur: Figure 2 The scanning effect shown is similar to Figure 1 There are obvious differences in the expected scanning results.

[0080] Based on the discovery of the above technical problems, the inventors have proposed the following technical solutions to solve or improve the above problems through creative work. It should be noted that the defects in the solutions in the above prior art are the results obtained by the inventors after practice and careful research. Therefore, the discovery process of the above problems and the solutions proposed in the embodiments of the present application for the above problems below should all be the contributions made by the inventors to the present application in the process of invention and creation, and should not be understood as technical contents known to those skilled in the art.

[0081] In view of the above technical problems, this embodiment provides a laser radar alignment method, wherein the laser radar includes a prism and a galvanometer. In this method, after the rotation speed of the prism is maintained at a preset rotation speed, the controller controls the galvanometer to rotate to the initial position of the galvanometer when the clock synchronization signal arrives, so that the laser emitted by the laser radar can be directed to the initial light-emitting point on the surface of the galvanometer; and obtain the speed fine-tuning information of the current rotation speed of the prism; according to the speed fine-tuning information, the current rotation speed of the prism is adjusted, so that the prism rotates to the initial position of the prism, so that the laser reflected by the galvanometer can be directed to the initial light-emitting point on the surface of the prism. In this way, the prism is first rotated to the preset rotation speed, and then the initial position of the galvanometer of the galvanometer is aligned with the clock synchronization signal, and then only a simple fine-tuning is required based on the preset rotation speed of the prism to align with the galvanometer in a short time.

[0082] It should be noted that the controller may be a processor mounted in the laser radar. When the processor includes multiple processor cores, the controller may be one of the multiple processor cores. Figure 3 Each step of the method is described in detail. However, it should be understood that the operations of the flowchart may not be implemented in order, and steps without logical contextual relationships may be reversed in order or implemented simultaneously. In addition, those skilled in the art may add one or more other operations to the flowchart, or remove one or more operations from the flowchart under the guidance of the content of this application. Figure 3 As shown, the method includes:

[0083] S1, after the rotation speed of the prism is maintained at a preset rotation speed, the galvanometer is controlled to rotate to the initial position of the galvanometer when the clock synchronization signal arrives, so that the laser emitted by the laser radar can be directed to the initial light-emitting point on the surface of the galvanometer.

[0084] It should be understood that maintaining a stable rotation speed of the prism is of great significance to the subsequent fine-tuning effect. Therefore, this embodiment also provides corresponding means for determining whether the prism is in a stable rotation state. In a specific implementation, the controller determines whether the error between the rotation speed of the prism and the preset rotation speed is less than the error threshold and maintained for a preset time; if so, it determines that the rotation speed of the prism is maintained at the preset rotation speed.

[0085] Exemplarily, assume that the preset speed is 3000rpm. Control the prism to accelerate from a stationary state, and collect the actual speed of the prism at a high frequency during the rotation process and compare it with 3000rpm. If the difference between the two is ±0.5rpm and lasts for 16ms within the error range, the speed of the prism is deemed to remain at the preset speed. It should be noted that the parameters listed in the example are only for ease of understanding and cannot be regarded as a limitation of this embodiment. In other words, when implementing this solution, you can select a suitable preset speed, error threshold and preset duration as needed.

[0086] After the rotation speed of the prism is maintained at the preset rotation speed, this embodiment provides two control methods for the galvanometer, which are used to control the galvanometer to rotate to the initial position of the galvanometer when the clock synchronization signal arrives. The following describes these two control methods in detail. As one of the optional implementations, step S1 may include:

[0087] S1-1A, obtaining target control information for rotating the galvanometer to the initial position of the galvanometer.

[0088] It should be noted that, compared to the prism which rotates in a single direction at a constant speed during operation, the galvanometer performs periodic reciprocating motion. Figure 4 As shown, the position control information applied to the galvanometer presents a sawtooth wave pattern. It is not difficult to see from the position control information in the figure that the position control information applied is the smallest when the galvanometer is in the starting position. As the position control information increases, the angle of rotation of the galvanometer also increases. After the galvanometer rotates to the maximum rotation angle, the galvanometer returns to the starting position and repeats the above rotation process. Therefore, the galvanometer can be controlled to record the position control information when the galvanometer rotates to the initial position of the galvanometer during the rotation process as the target control information.

[0089] For example, assuming that the galvanometer needs to move periodically at a frequency of 10 Hz, and the main interrupt cycle of the motor is 40 us, then 100 ms includes a total of 100 ms / 40 us = 2500 interrupt cycles. Therefore, a counter can be set to increment from 0, that is, add 1 to the current accumulated count value every 40 us, and clear it after accumulating to 2499. Then, the position control information of the galvanometer from the initial position to the maximum rotation angle is planned according to the maximum count value, so as to ensure that each count value has corresponding position control information. In this way, the galvanometer can perform periodic rotation at a frequency of 1s / 100ms = 10 Hz. Then, the rotation of the galvanometer is controlled according to the above control method, and the count value when the galvanometer rotates to the initial position of the galvanometer is captured, and then the position control information corresponding to the count value is obtained as the target control information.

[0090] After obtaining the target control information of the galvanometer through the above embodiment, step S1 further includes:

[0091] S1-2A, if the clock synchronization signal is received, the target control information is applied to the galvanometer, so that the galvanometer jumps from the current position to the initial position of the galvanometer.

[0092] It can be understood that when any position control information is applied to the galvanometer in this embodiment, the rotation angle of the galvanometer can jump to the position corresponding to the position control information and continue to rotate. Therefore, when the clock synchronization signal is received, the previously recorded target control information is applied to the prism, and the galvanometer can jump to the initial position of the galvanometer, thereby synchronizing the galvanometer with the clock synchronization signal. The clock synchronization signal can be a clock signal obtained by the vehicle-mounted GPS from the GPS signal. For example, the controller detects the pin for collecting the clock signal in a query manner. When the signal value collected last time is 0, and the signal value collected this time is 1, it is considered that the clock synchronization signal is received. It should be noted that in this embodiment, the target control information applied to the prism is not applied to the non-prism itself, but the target control information is sent to the motor that drives the prism to rotate.

[0093] As another implementation method provided in this embodiment, step S1 may include:

[0094] S1-1B, obtaining target control information for rotating the galvanometer to the initial position of the galvanometer.

[0095] S1-2B, according to the target control information, the galvanometer is kept at the initial position of the galvanometer until a clock synchronization signal is received.

[0096] In this way, there is no need to perform jump adjustment on the rotation position of the galvanometer, and the galvanometer only needs to be kept at the initial position of the galvanometer and wait for the arrival of the clock synchronization signal.

[0097] After aligning the galvanometer with the clock synchronization signal based on the above embodiment, continue to refer to Figure 3 The laser radar alignment method provided in this embodiment also includes:

[0098] S2, obtaining the speed fine-tuning information of the current speed of the prism.

[0099] Continuing to refer to 2, it is assumed that when the galvanometer is controlled to rotate to the initial position of the galvanometer when the clock synchronization signal arrives, the prism has not rotated to the initial position of the prism at this time, resulting in the actual light-emitting point 107 reflected by the laser on the prism surface is not the initial light-emitting point 106 on the prism surface. Therefore, under ideal conditions, the prism and the galvanometer can be aligned by rotating the prism from the current position to the initial position of the prism in an instant. However, it is found in actual practice that when the above method is used to control the motor of the prism, the motor will produce violent oscillations. Therefore, this embodiment adopts the following optional implementation method for step S2:

[0100] S2-1, obtaining the current actual position of the prism and the current expected position of the prism.

[0101] S2-2, obtaining speed fine-tuning information according to the position error between the actual position and the expected position.

[0102] It can be understood that, in view of the many problems that may arise from directly adjusting the prism position, in this embodiment, the position error is mapped to the fine-tuning control information of the prism speed, and the purpose of indirect alignment with the galvanometer is achieved by adjusting the speed. As an optional implementation, the controller can match the position error with a preset fine-tuning information table to obtain the speed fine-tuning information, wherein the fine-tuning information table records the mapping relationship between the position error and the speed fine-tuning information.

[0103] Exemplarily, in this embodiment, the actual position of the prism can be obtained through an encoder. At this time, the actual position of the prism is the actual encoder value measured by the encoder, and the expected position of the prism is the expected encoder value of the encoder, and the position error is the encoding deviation between the actual encoder value and the expected encoding value. Then, the controller matches the encoding deviation with the encoding deviation to obtain the speed fine-tuning information, which can be the speed adjustment amount. The content in the fine-tuning information table can be shown in the following table:

[0104] Coding bias Speed ​​adjustment (rpm) (744,2976] -8 (44,744] -4 (24,44] -1 [6,24] -0.5 [-6,6] 0 (-24,-6) 0.5 (-44,-24] 1 (-744,-44] 4 (-2976,-744] 8

[0105] Therefore, the fine-tuning information table also records the correspondence between other encoding deviations and speed adjustment amounts. The fine-tuning information table can be used to map the position deviation to the speed fine-tuning information, which is used to rotate the prism relatively smoothly to the initial position of the prism. Figure 3 After obtaining the speed fine-tuning information, the laser radar alignment method further includes:

[0106] S3, adjusting the current rotation speed of the prism according to the rotation speed fine-tuning information, so that the prism rotates to the initial position of the prism, so that the laser reflected by the galvanometer can be directed to the initial light-emitting point on the surface of the prism.

[0107] In an optional embodiment, the control system of the prism includes a speed loop, and the controller corrects the current speed control instruction of the prism according to the speed fine-tuning information to obtain a corrected speed control instruction; the corrected speed control instruction is applied to the speed loop to adjust the current speed of the prism.

[0108] It can be understood that this embodiment adopts a closed-loop control system for the prism to keep the prism rotating at a preset speed. During the control process, it is necessary to continuously collect the actual speed of the prism and compare it with the preset speed, and adjust the speed control instruction applied to the prism according to the comparison result. For example, Figure 5As shown, the control system adopted for the prism in this embodiment can be a double closed-loop control system, in which the current loop is the inner loop and the speed loop is the outer loop. The speed loop is used to use the measured rotation speed of the prism as speed feedback, while the current loop uses the measured driving current of the prism as current feedback.

[0109] Continue to see Figure 5 , when the speed adjustment amount is used as the speed fine-tuning information, it is superimposed with the applied speed command to obtain the corrected speed control command. For example, if the speed of the prism needs to be maintained at 3000rpm, the speed control command of the prism is 3000rpm, and when the speed adjustment amount is -8rpm, the corrected speed control command obtained by superimposing the two is 2992rpm. Then, 2992rpm is input into the speed loop to adjust the current speed of the prism so that the laser reflected by the galvanometer can be directed to the initial light-emitting point on the surface of the prism, thereby aligning the galvanometer with the prism. In some cases, it may be necessary to adjust the speed of the prism multiple times to achieve the alignment effect. As the judgment standard for alignment, when the alignment accuracy is detected for 2 consecutive 100ms, it is determined that the clock synchronization signal, the galvanometer, and the prism are aligned.

[0110] Furthermore, this embodiment also verifies the clock synchronization signal of the alignment of the galvanometer and the prism. In a specific implementation, the laser radar also includes a first processor and a second processor, the first processor is used to control the prism and the galvanometer, and the second processor can be used to perform calculations on the collected laser reflection signal. After the prism rotates to the initial position of the prism, the first processor sends a verification signal to the second processor at a preset time point, and the verification signal is used to instruct the second processor to compare the reception time of the verification signal with the preset time point to verify whether the time between the first processor and the second processor is aligned.

[0111] It can be understood that the laser radar also uses a multi-core processor. For example, the first processor can be a slave processor in the multi-core processor, and the second processor is the master processor in the multi-core processor. The first processor and the second processor are aligned with the clock synchronization signal. If any one of them has an abnormality during the alignment process, the verification cannot be passed. Exemplarily, assuming that the preset time point is 12:00:00, the first processor sends a verification signal to the second processor. If the time point when the second processor receives the verification signal is not 12:00:00, it means that the time between the first processor and the second processor is not aligned.

[0112] Based on the same inventive concept as the laser radar alignment method provided in this embodiment, this embodiment also provides a laser radar alignment device, which includes at least one software function module that can be stored in a memory or fixed in the laser radar in the form of software. The processor in the laser radar is used to execute the executable module stored in the memory. For example, the software function module and computer program included in the laser radar alignment device. Please refer to Figure 6 , from the functional point of view, the laser radar alignment device can include:

[0113] The galvanometer control module 201 controls the galvanometer to rotate to the initial position of the galvanometer when the clock synchronization signal arrives after the rotation speed of the prism is maintained at a preset rotation speed, so that the laser emitted by the laser radar can be directed to the initial light-emitting point on the surface of the galvanometer;

[0114] The prism control module 202 is used to obtain the speed fine-tuning information of the current speed of the prism;

[0115] The prism control module 202 is also used to adjust the current rotation speed of the prism according to the rotation speed fine-tuning information, so that the prism rotates to the initial position of the prism, so that the laser reflected by the galvanometer can be directed to the initial light-emitting point on the surface of the prism.

[0116] In this embodiment, the galvanometer control module 201 is used to implement Figure 3 In step S1, the prism control module 202 is used to implement Figure 3 Therefore, for the detailed description of each of the above modules, please refer to the specific implementation of the corresponding step. In addition, it should be noted that due to the alignment device with the laser radar, the above modules can also be used to implement other steps or sub-steps of the method, which will not be described in detail in this embodiment.

[0117] In addition, the functional modules in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0118] It should also be understood that if the above implementation is implemented in the form of a software function 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 the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application.

[0119] Therefore, this embodiment further provides a storage medium, which is a computer-readable storage medium. The storage medium stores a computer program, and when the computer program is executed by the processor, the laser radar alignment method provided in this embodiment is implemented. Among them, the storage medium can be a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a disk or an optical disk, etc., which can store program codes.

[0120] This embodiment provides a laser radar that implements a laser radar alignment method. Figure 7 As shown, the laser radar may include a processor 302 and a memory 301. In addition, the memory 301 stores a computer program, and the processor implements the laser radar alignment method provided in this embodiment by reading and executing the computer program corresponding to the above implementation in the memory 301.

[0121] Continue to see Figure 7 The electronic device further includes a communication unit 303. The memory 301, the processor 302 and the communication unit 303 are directly or indirectly electrically connected to each other through a system bus 304 to achieve data transmission or interaction.

[0122] The memory 301 may be an information recording device based on any electronic, magnetic, optical or other physical principle, used to record execution instructions, data, etc. In some implementations, the memory 301 may be, but is not limited to, a volatile memory, a non-volatile memory, a storage drive, etc.

[0123] In some embodiments, the volatile memory may be a random access memory (RAM); in some embodiments, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable read-only memory (EEPROM), a flash memory, etc.; in some embodiments, the storage drive may be a disk drive, a solid-state drive, any type of storage disk (such as a CD, a DVD, etc.), or a similar storage medium, or a combination thereof, etc.

[0124] The communication unit 303 is used to send and receive data through a network. In some embodiments, the network may include a wired network, a wireless network, a fiber optic network, a telecommunication network, an intranet, the Internet, a local area network (LAN), a wide area network (WAN), a wireless local area network (WLAN), a metropolitan area network (MAN), a wide area network (WAN), a public switched telephone network (PSTN), a Bluetooth network, a ZigBee network, or a near field communication (NFC) network, or any combination thereof. In some embodiments, the network may include one or more network access points. For example, the network may include a wired or wireless network access point, such as a base station and / or a network switching node, through which one or more components of the service request processing system may be connected to the network to exchange data and / or information.

[0125] The processor 302 may be an integrated circuit chip having a signal processing capability, and the processor may include one or more processing cores (e.g., a single-core processor or a multi-core processor). By way of example only, the processor may include a central processing unit (CPU), an application specific integrated circuit (ASIC), an application specific instruction set processor (ASIP), a graphics processing unit (GPU), a physical processing unit (PPU), a digital signal processor (DSP), a field programmable gate array (FPGA), a programmable logic device (PLD), a controller, a microcontroller unit, a reduced instruction set computer (RISC), or a microprocessor, or any combination thereof.

[0126] Understandably, Figure 7The structure shown is for illustration only. Figure 7 More or fewer components than shown, or with Figure 7 Different configurations are shown. Figure 7 The components shown may be implemented in hardware, software or a combination thereof.

[0127] It should be understood that the apparatus and method disclosed in the above-mentioned embodiments can also be implemented in other ways. The apparatus embodiments described above are merely schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the apparatus, methods and computer program products according to the multiple embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the module, a program segment or a part of a code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or the flowchart, and the combination of boxes in the block diagram and / or the flowchart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0128] The above are only various implementations of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A laser radar alignment method, characterized in that: The laser radar includes a prism and a galvanometer, and the method includes: After the rotation speed of the prism is maintained at a preset rotation speed, the galvanometer is controlled to rotate to an initial position of the galvanometer when a clock synchronization signal arrives, so that the laser emitted by the laser radar can be directed to an initial light-emitting point on the surface of the galvanometer; Obtaining speed fine-tuning information of the current speed of the prism; The current rotation speed of the prism is adjusted according to the rotation speed fine-tuning information, so that the prism rotates to the initial position of the prism, so that the laser reflected by the galvanometer can be directed to the initial light-emitting point on the surface of the prism.

2. The laser radar alignment method according to claim 1, characterized in that: The obtaining of the speed fine-tuning information of the current speed of the prism includes: Obtaining a current actual position of the prism and a current expected position of the prism; The speed fine-tuning information is obtained according to a position error between the actual position and the expected position.

3. The laser radar alignment method according to claim 2, characterized in that: The obtaining the speed fine-tuning information according to the position error between the actual position and the expected position includes: The position error is matched with a preset fine-tuning information table to obtain the speed fine-tuning information, wherein the fine-tuning information table records a mapping relationship between the position error and the speed fine-tuning information.

4. The laser radar alignment method according to claim 1, characterized in that: The control system of the prism includes a speed loop, and the current speed of the prism is adjusted according to the speed fine-tuning information, including: Correcting the current speed control instruction of the prism according to the speed fine-tuning information to obtain a corrected speed control instruction; The modified rotation speed control instruction is applied to the speed loop to adjust the current rotation speed of the prism.

5. The laser radar alignment method according to claim 1, characterized in that: The controlling the galvanometer to rotate to an initial position of the galvanometer when a clock synchronization signal arrives comprises: Acquire target control information for rotating the galvanometer to an initial position of the galvanometer; If the clock synchronization signal is received, the target control information is applied to the galvanometer, so that the galvanometer jumps from the current position to the initial position of the galvanometer.

6. The laser radar alignment method according to claim 5, characterized in that: The step of obtaining target control information of rotating the galvanometer to the initial position of the galvanometer includes: During the period of controlling the galvanometer mirror to perform periodic rotation, recording the control information applied to the galvanometer mirror when the galvanometer mirror rotates to the initial position of the galvanometer mirror; When the galvanometer is rotated to the initial position of the galvanometer, the control information applied to the galvanometer is used as the target control information.

7. The laser radar alignment method according to claim 1, characterized in that: The step of controlling the galvanometer to rotate to an initial position of the galvanometer when a clock synchronization signal arrives comprises: Acquire target control information for rotating the galvanometer to an initial position of the galvanometer; According to the target control information, the galvanometer is kept at the initial position of the galvanometer until a clock synchronization signal is received.

8. The laser radar alignment method according to claim 1, characterized in that: The laser radar further includes a first processor and a second processor, wherein the first processor is used to control the prism and the galvanometer, and after the prism rotates to the initial position of the prism, the method further includes: A verification signal is sent to the second processor at a preset time point, wherein the verification signal is used to instruct the second processor to compare a reception time of the verification signal with the preset time point to verify whether the time between the first processor and the second processor is aligned.

9. The laser radar alignment method according to claim 1, characterized in that: After the rotation speed of the prism is maintained at a preset rotation speed, the galvanometer is controlled to rotate to an initial position of the galvanometer when a clock synchronization signal arrives, and the method further includes: Determine whether the error between the rotation speed of the prism and the preset rotation speed is less than an error threshold and is maintained for a preset time period; If so, it is determined that the rotation speed of the prism is maintained at a preset rotation speed.

10. A laser radar alignment device, characterized in that: The laser radar includes a prism and a galvanometer, and the device includes: A galvanometer control module controls the galvanometer to rotate to an initial position of the galvanometer when a clock synchronization signal arrives after the rotation speed of the prism is maintained at a preset rotation speed, so that the laser emitted by the laser radar can be directed to an initial light-emitting point on the surface of the galvanometer; A prism control module, used to obtain speed fine-tuning information of the current speed of the prism; The prism control module is also used to adjust the current rotation speed of the prism according to the rotation speed fine-tuning information, so that the prism rotates to the initial position of the prism, so that the laser reflected by the galvanometer can be directed to the initial light-emitting point on the surface of the prism.

11. A storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by a processor, the laser radar alignment method described in any one of claims 1 to 9 is implemented.

12. A laser radar, characterized in that: The laser radar includes a processor and a memory, the memory stores a computer program, and when the computer program is executed by the processor, the laser radar alignment method described in any one of claims 1 to 9 is implemented.

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