LiDAR error measurement methods, devices and systems

Abstract

This disclosure provides a method, apparatus, and system for measuring lidar errors. The method includes: acquiring first point cloud data generated after the lidar emits a laser beam at the movable target, and acquiring a true distance measured by a laser rangefinder after emitting a laser beam at the movable target, with the lidar at a preset temperature and a movable target moving to at least one preset distance; determining a first distance value between the lidar and the movable target based on the first point cloud data; compensating the true distance value based on the positional offset between the lidar and the laser rangefinder to obtain a compensated distance; and determining the ranging error of the lidar at the preset temperature, at at least one preset distance, and for an object with a preset reflectivity based on the first distance value corresponding to the at least one preset distance and the compensated distance. This disclosure helps improve the accuracy of error measurement.

Description

Technical Field

[0001] This disclosure relates to the field of lidar technology, and in particular to a lidar error measurement method, apparatus and system. Background Technology

[0002] Currently, lidar is commonly used as a depth acquisition module in 3D reconstruction to collect point cloud data. The ranging error of lidar (also known as ranging accuracy) has a significant impact on the accuracy of 3D reconstruction. Therefore, for high-precision 3D acquisition and reconstruction, it is necessary to measure the ranging error of lidar.

[0003] In the process of realizing this disclosure, the inventors discovered through research that lidar is usually used in a variety of environments, and the ranging error of lidar is affected by a variety of factors. For example, objects of different distances, temperatures, and reflectivities may all affect the ranging error of lidar.

[0004] Therefore, how to measure the ranging error of lidar under different conditions is an urgent problem to be solved. Summary of the Invention

[0005] This disclosure provides a lidar error measurement method, apparatus, and system to at least partially address problems in the related art.

[0006] One aspect of this disclosure provides a method for determining lidar error, comprising:

[0007] When the temperature of the lidar is at a preset temperature, the movable target is controlled to move sequentially to at least one preset distance from the lidar. When the movable target moves to at least one of the preset distances, the first point cloud data generated after the lidar emits a laser beam to the movable target is acquired, and the true distance value measured by the laser rangefinder after emitting a laser beam to the movable target is acquired. The movable target has a preset reflectivity.

[0008] A first distance value between the lidar and the movable target is determined based on the first point cloud data.

[0009] Based on the positional offset between the lidar and the laser rangefinder, the true distance value is compensated to obtain the compensated distance;

[0010] Based on the first distance value corresponding to at least one of the preset distances and the compensated distance, the ranging error of the lidar for an object with the preset reflectivity at the preset temperature and at the at least one preset distance is determined.

[0011] In one exemplary embodiment, the movable target includes a reflective target;

[0012] or,

[0013] The movable target includes multiple reflective targets with multiple preset reflectivities, and different reflective targets among the multiple reflective targets have different preset reflectivities;

[0014] The step of acquiring the first point cloud data generated after the lidar emits a laser beam at the movable target, and acquiring the true distance measured by the laser rangefinder after emitting a laser beam at the movable target, includes:

[0015] The system acquires multiple first point cloud data generated after the lidar emits laser beams at the multiple reflective targets, wherein each first point cloud data corresponds to one reflective target; and acquires multiple true distance values ​​measured by the laser rangefinder after emitting laser beams at the multiple reflective targets, wherein each true distance value corresponds to one reflective target.

[0016] The step of determining the ranging error of the lidar for an object with the preset reflectivity at the preset temperature, at the at least one preset distance, and based on a first distance value corresponding to at least one preset distance and a compensated distance includes:

[0017] Based on the multiple distance values ​​corresponding to the multiple reflective targets and the compensated distance corresponding to the preset distance, the ranging error of the lidar for the multiple preset reflectivities at the preset temperature and at the at least one preset distance is determined.

[0018] In one exemplary embodiment, the preset temperature includes at least one target temperature;

[0019] The step of controlling the movable target to move sequentially to at least one preset distance from the lidar when the lidar is at a preset temperature includes:

[0020] The lidar is sequentially adjusted to one of the at least one target temperatures, and while the lidar is at each target temperature, the movable target is sequentially moved to at least one preset distance from the lidar.

[0021] The determination of the ranging error of the lidar for an object with the preset reflectivity at the preset temperature, at the at least one preset distance, and based on a first distance value corresponding to at least one preset distance and a compensated true distance value includes:

[0022] Based on the first distance value corresponding to each preset distance and the compensated distance, the ranging error of the lidar for the object with the preset reflectivity at the target temperature and at the at least one preset distance is determined.

[0023] In one exemplary embodiment, the preset temperature includes at least one target temperature;

[0024] When the lidar is at a preset temperature, the movable target is controlled to move sequentially to at least one preset distance from the lidar. When the movable target moves to at least one of the preset distances, the first point cloud data generated after the lidar emits a laser beam at the movable target is acquired, and the true distance value measured by the laser rangefinder after emitting a laser beam at the movable target is acquired, including:

[0025] The movable target is controlled to move sequentially to at least one of the preset distances from the lidar. When the movable target moves to each preset distance, the lidar is sequentially adjusted to one of the at least one target temperatures. When the lidar is at each target temperature, the operation of acquiring the first point cloud data generated after the lidar emits a laser beam at the movable target and acquiring the true distance value measured by the laser rangefinder after emitting a laser beam at the movable target is performed.

[0026] The step of determining the ranging error of the lidar for an object with the preset reflectivity at the preset temperature, at the at least one preset distance, and based on a first distance value corresponding to at least one preset distance and a compensated distance includes:

[0027] Based on the first distance value corresponding to each preset distance and the compensated distance, the ranging error of the lidar for the object with the preset reflectivity at each preset distance under the preset temperature is determined.

[0028] In one exemplary embodiment, the method further includes:

[0029] The distance between the movable target and the lidar is detected to obtain a distance detection result, and the light emission direction of the lidar's laser beam is detected to obtain a light detection result;

[0030] If the distance detection result indicates that each position of the movable target is equidistant from the lidar, and the light detection result indicates that the light emission direction is perpendicular to the movable target, the movable target is controlled to move to the preset distance.

[0031] In one exemplary embodiment, at least one laser rangefinder is placed on each side of the lidar, and the distance between at least two laser rangefinders is positively correlated with the length of the movable target.

[0032] The process of detecting the distance between the movable target and the lidar to obtain a distance detection result includes:

[0033] Control the at least two laser rangefinders to emit laser beams toward the movable target, and obtain the distance values ​​measured by the at least two laser rangefinders;

[0034] Based on the positional offset between the lidar and each laser rangefinder, the distance value measured by each laser rangefinder is compensated to obtain the compensated distance corresponding to each laser rangefinder.

[0035] If the difference between the compensated distances of the at least two laser rangefinders is less than a preset threshold, the distance detection result is determined to be that each position of the movable target is equidistant from the laser radar.

[0036] In an exemplary embodiment, obtaining a light detection result by detecting the light emission direction of the laser beam of the lidar includes:

[0037] When the lidar emits the laser beam toward the movable target, the infrared camera is controlled to observe the laser beam and obtain a beam observation image;

[0038] When the beam observation image indicates that the laser beam is emitted to a preset height, the light detection result is determined to be that the light emission direction is perpendicular to the movable target.

[0039] In one exemplary embodiment, the method further includes:

[0040] Control the at least two laser rangefinders to emit laser beams toward the movable target;

[0041] When the distance between the laser target points on the movable target is the same as the distance between the emission points of the at least two laser rangefinders, and the height of the laser target points above the ground is the same as the height of the corresponding emission points above the ground, the step of detecting the distance between the movable target and the lidar to obtain the distance detection result is performed.

[0042] In one exemplary embodiment, a first laser rangefinder and a second laser rangefinder are respectively placed on both sides of the lidar.

[0043] The step of compensating the true distance value based on the offset between the lidar and the laser rangefinder to obtain the compensated distance includes:

[0044] The true distance value measured by the first laser rangefinder is compensated based on the offset between the lidar and the first laser rangefinder to obtain the first true distance value.

[0045] The true distance value measured by the second laser rangefinder is compensated based on the offset between the lidar and the second laser rangefinder to obtain the second true distance value.

[0046] The average of the first true distance value and the second true distance value is determined as the compensated distance.

[0047] Another aspect of this embodiment provides a lidar error measurement device, comprising:

[0048] The data acquisition module is used to control a movable target to move sequentially to at least one preset distance from the lidar when the lidar temperature is at a preset temperature, and to acquire the first point cloud data generated after the lidar emits a laser beam at the movable target when the movable target moves to at least one preset distance, and to acquire the true distance measured by the laser rangefinder after emitting a laser beam at the movable target, wherein the movable target has a preset reflectivity;

[0049] A distance determination module is used to determine a first distance value between the lidar and the movable target based on the first point cloud data;

[0050] The distance compensation module is used to compensate the true distance value based on the positional offset between the lidar and the laser rangefinder to obtain the compensated distance.

[0051] An error determination module is used to determine the ranging error of the lidar at the preset temperature, at the at least one preset distance, and for an object with the preset reflectivity, based on a first distance value corresponding to at least one preset distance and a compensated distance.

[0052] In another aspect of this embodiment, a lidar error measurement system is provided. The system includes a movable target device, a data acquisition device, and an electronic device. The movable target device includes a slide rail, a slide rail drive motor, and a movable target mounted on the slide rail drive motor. The movable target has a preset reflectivity. The data acquisition device includes a lidar, a laser rangefinder, and a temperature control module. The temperature control module is located at the bottom of the lidar.

[0053] The electronic device controls the temperature adjustment module to adjust the temperature of the lidar, and when the lidar is at a preset temperature, controls the slide rail drive motor to move the movable target sequentially to at least one preset distance from the lidar.

[0054] When the movable target moves to at least one of the preset distances, the electronic device acquires first point cloud data generated after the lidar emits a laser beam at the movable target, and acquires the true distance value measured by the laser rangefinder after emitting a laser beam at the movable target; determines a first distance value between the lidar and the movable target based on the first point cloud data; compensates the true distance value based on the positional offset between the lidar and the laser rangefinder to obtain a compensated distance; and determines the ranging error of the lidar for an object with a preset reflectivity at the preset temperature, at the at least one preset distance, and based on the first distance value corresponding to each preset distance and the compensated distance.

[0055] In one exemplary embodiment,

[0056] The movable target includes at least one reflective target having at least one preset reflectivity, wherein different reflective targets in the at least one reflective target have different preset reflectivity;

[0057] The electronic device acquires the first point cloud data generated after the lidar emits a laser beam at the movable target, and acquires the true distance value measured by the laser rangefinder after emitting a laser beam at the movable target, including:

[0058] The electronic device acquires at least one first point cloud data generated after the lidar emits laser beams at the at least one reflective target, wherein each first point cloud data corresponds to a reflective target; and acquires at least one true distance value measured by the laser rangefinder after emitting laser beams at the at least one reflective target, wherein each true distance value corresponds to a reflective target.

[0059] The electronic device determines the ranging error of the lidar at the preset temperature, at the at least one preset distance, and for an object with the preset reflectivity based on a first distance value corresponding to at least one preset distance and a compensated distance, including:

[0060] The electronic device determines the ranging error of the lidar at the preset temperature, at the at least one preset distance, and for the plurality of objects with preset reflectivity based on at least one distance value corresponding to the at least one reflective target and the compensated distance corresponding to the preset distance.

[0061] In one exemplary embodiment, the preset temperature includes at least one target temperature;

[0062] The electronic device controls the temperature regulation module to adjust the temperature of the lidar, and when the lidar is at a preset temperature, controls the slide rail drive motor to move the movable target sequentially to at least one preset distance from the lidar, including:

[0063] The electronic device controls the temperature adjustment module to adjust the temperature of the lidar, so that the lidar is sequentially at one of the at least one target temperature, and when the lidar is at each target temperature, the operation of controlling the movable target to sequentially move to at least one preset distance from the lidar is executed;

[0064] The electronic device determines the ranging error of the lidar at the preset temperature, at the at least one preset distance, and for an object with the preset reflectivity based on a first distance value corresponding to at least one preset distance and a compensated true distance value, including:

[0065] The electronic device determines the ranging error of the lidar at the target temperature, at the at least one preset distance, and for an object with the preset reflectivity based on the first distance value corresponding to each preset distance and the compensated distance.

[0066] In one exemplary embodiment, the preset temperature includes at least one target temperature;

[0067] When the lidar is at a preset temperature, the electronic device controls a movable target to move sequentially to at least one preset distance from the lidar. When the movable target moves to at least one of the preset distances, the electronic device acquires the first point cloud data generated after the lidar emits a laser beam at the movable target, and acquires the true distance value measured by the laser rangefinder after emitting a laser beam at the movable target, including:

[0068] The electronic device controls the slide rail drive motor to move the movable target sequentially to at least one preset distance from the lidar. When the movable target moves to each preset distance, the lidar is sequentially adjusted to one of the at least one target temperatures. When the lidar is at each target temperature, the operation of acquiring the first point cloud data generated after the lidar emits a laser beam at the movable target and acquiring the true distance value measured by the laser rangefinder after emitting a laser beam at the movable target is performed.

[0069] The electronic device determines the ranging error of the lidar at the preset temperature, at the at least one preset distance, and for an object with the preset reflectivity based on a first distance value corresponding to at least one preset distance and a compensated distance, including:

[0070] The electronic device determines the ranging error of the lidar at the preset temperature, at each preset distance, and for the object with the preset reflectivity based on the first distance value corresponding to each preset distance and the compensated distance.

[0071] In an exemplary embodiment, the electronic device further detects the distance between the movable target and the lidar to obtain a distance detection result, and detects the light emission direction of the lidar's laser beam to obtain a light detection result; if the distance detection result indicates that each position on the movable target is equidistant from the lidar, and the light detection result indicates that the light emission direction is perpendicular to the movable target, the electronic device controls the movable target to move to the preset distance.

[0072] In one exemplary embodiment, at least one laser rangefinder is placed on each side of the lidar, and the distance between at least two laser rangefinders is positively correlated with the length of the movable target.

[0073] The electronic device controls at least two laser rangefinders to emit laser beams toward the movable target and acquires the distance values ​​measured by the at least two laser rangefinders; based on the positional offset between the lidar and each laser rangefinder, the distance value measured by each laser rangefinder is compensated to obtain the compensated distance corresponding to each laser rangefinder.

[0074] If the difference between the compensated distances of the at least two laser rangefinders is less than a preset threshold, the distance detection result is determined to be that each position of the movable target is equidistant from the laser radar.

[0075] In one exemplary embodiment, the data acquisition device is further provided with an infrared camera;

[0076] When the lidar emits the laser beam toward the movable target, the electronic device controls an infrared camera to observe the laser beam and obtain a beam observation image; and when the beam observation image indicates that the laser beam has been emitted to a preset height, the electronic device determines that the light detection result is that the light emission direction is perpendicular to the movable target.

[0077] In an exemplary embodiment, the data acquisition device is further provided with a pitch angle adjustment slide, which is used to adjust the pitch angle of the lidar when the light detection result indicates that the light emission direction is not perpendicular to the movable target.

[0078] In another aspect of this embodiment, an electronic device is provided, comprising:

[0079] Memory, used to store computer programs;

[0080] A processor is configured to execute a computer program stored in the memory, and when the computer program is executed, to implement the lidar error measurement method described in any of the above embodiments.

[0081] In another aspect of this embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the lidar error measurement method described in any of the above embodiments.

[0082] In this embodiment, a lidar, a laser rangefinder, and a movable target are used to measure the ranging error of the lidar under different conditions. The movable target has a preset reflectivity. To fix the reflectivity, the lidar is controlled to operate at a preset temperature during the measurement process. The movable target is then moved sequentially to different distances from the lidar. Based on the point cloud data generated by the lidar at these different distances and the true distance measured by the laser rangefinder, the ranging error of the lidar at the preset temperature and at the multiple preset distances relative to the preset reflectivity is determined. This allows for automated measurement of the ranging error of the lidar at multiple preset distances under preset temperature and reflectivity conditions, improving the accuracy of lidar error measurement.

[0083] The technical solutions of this disclosure will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0084] The accompanying drawings, which form part of this specification, illustrate embodiments of this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0085] This disclosure will become clearer with reference to the accompanying drawings and the following detailed description, wherein:

[0086] Figure 1 A schematic diagram of the structure of a lidar error measurement system provided as an exemplary embodiment of this disclosure;

[0087] Figure 2 A flowchart of a lidar error measurement method provided as an exemplary embodiment of this disclosure;

[0088] Figure 3 A schematic diagram of the structure of a data acquisition module in a lidar error measurement system is provided as an exemplary embodiment of this disclosure;

[0089] Figure 4 A flowchart of a lidar error measurement method provided as another exemplary embodiment of this disclosure;

[0090] Figure 5A schematic diagram of the structure of a lidar error measuring device provided for an exemplary embodiment of the present disclosure;

[0091] Figure 6 This is a schematic diagram of the structure of an application embodiment of the electronic device disclosed herein. Detailed Implementation

[0092] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present disclosure.

[0093] Those skilled in the art will understand that the terms "first," "second," etc., in the embodiments of this disclosure are only used to distinguish different steps, devices, or modules, and do not represent any specific technical meaning, nor do they indicate a necessary logical order between them.

[0094] It should also be understood that in the embodiments disclosed herein, "a plurality of" may refer to two or more, and "at least one" may refer to one, two or more.

[0095] It should also be understood that any component, data or structure mentioned in the embodiments of this disclosure can generally be understood as one or more unless expressly defined or given to the contrary in the context.

[0096] Furthermore, the term "and / or" in this disclosure is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this disclosure generally indicates that the preceding and following related objects have an "or" relationship.

[0097] It should also be understood that the description of the various embodiments in this disclosure emphasizes the differences between the various embodiments, and the similarities or similarities can be referred to each other. For the sake of brevity, they will not be described in detail.

[0098] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0099] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this disclosure or its application or use.

[0100] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0101] 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 discussed further in subsequent figures.

[0102] The embodiments disclosed herein can be applied to electronic devices such as terminal devices, computer systems, and servers, and can operate together with a wide range of other general-purpose or special-purpose computing system environments or configurations. Examples of well-known terminal devices, computing systems, environments, and / or configurations suitable for use with electronic devices such as terminal devices, computer systems, and servers include, but are not limited to: personal computer systems, server computer systems, thin clients, thick clients, handheld or laptop devices, microprocessor-based systems, set-top boxes, programmable consumer electronics, network PCs, minicomputer systems, mainframe computer systems, and distributed cloud computing environments including any of the above systems, etc.

[0103] Electronic devices such as terminal devices, computer systems, and servers can be described in the general context of computer system executable instructions (such as program modules) executed by a computer system. Typically, program modules can include routines, programs, object programs, components, logic, data structures, etc., which perform specific tasks or implement specific abstract data types. Computer systems / servers can be implemented in distributed cloud computing environments, where tasks are executed by remote processing devices linked through communication networks. In distributed cloud computing environments, program modules can reside on local or remote computing system storage media, including storage devices.

[0104] Through research, the inventors discovered that the ranging accuracy of lidar is affected by a variety of factors. For example, lidar will produce different ranging errors at different distances; the temperature of the internal components of lidar will be different under different ambient temperatures, which will also lead to ranging errors; in addition, lidar will produce different ranging errors when detecting objects with different reflectivities. Therefore, it will have a significant impact on the 3D scanning and reconstruction results.

[0105] Therefore, before using LiDAR for 3D scanning, it is necessary to accurately measure the ranging error of LiDAR under different conditions in order to calibrate the ranging error in advance and to perform corresponding error compensation on the data in the production calibration process, data processing process and subsequent application process of 3D scanning equipment.

[0106] To address the problems in related technologies, this disclosure provides a method for measuring lidar errors, which is implemented using a lidar error measurement system. For example... Figure 1The diagram illustrates a system architecture of a lidar error measurement system provided in an exemplary embodiment of this disclosure. The system includes a movable target device 101, a data acquisition device 102, and an electronic device 103.

[0107] The movable target device 101 includes a slide rail, a slide rail drive motor, and a movable target mounted on the slide rail drive motor. The movable target has a preset reflectivity. The slide rail must be installed straight, and the movable target is installed perpendicular to the slide rail. The movable target is used to horizontally reflect the laser beam emitted by the lidar.

[0108] The data acquisition device 102 includes a lidar, a laser rangefinder, and a temperature control module. The lidar is fixed to a base via a quick-release mounting device, which connects to a slide rail. The quick-release mounting device includes a lidar housing to secure the lidar and prevent movement or angular sway during testing. Different lidar housings can be used for different types of lidar, and it should be noted that the centers of different lidars remain in the same position after being mounted on the quick-release mounting device. The laser rangefinder is mounted on the base and measures the actual distance from the center of the lidar to the movable target. The temperature control module is located at the bottom of the lidar and is used to regulate the temperature around it. Optionally, the temperature control module includes a temperature sensor.

[0109] Electronic device 103 is a device for data processing. Electronic device 103 establishes communication connections with the slide rail drive motor in movable target device 101, the lidar in data acquisition device 102, the laser rangefinder, and the temperature control module. In this embodiment, electronic device 103 controls the temperature control module to adjust the temperature of the lidar, and when the lidar is at a preset temperature, controls the slide rail drive motor to move the movable target sequentially to at least one preset distance from the lidar. Then, when the movable target moves to at least one preset distance, it acquires the first point cloud data generated after the lidar emits a laser beam at the movable target, and acquires the true distance value measured by the laser rangefinder after emitting a laser beam at the movable target. Based on the first point cloud data, it determines the first distance value between the lidar and the movable target; based on the positional offset between the lidar and the laser rangefinder, it compensates for the true distance value to obtain the compensated distance; based on the first distance value corresponding to at least one preset distance and the compensated distance, it determines the ranging error of the lidar at the preset temperature, at at least one preset distance, and for an object with a preset reflectivity.

[0110] After measuring the ranging error of the lidar, the lidar error can be calibrated. This calibration can then be used in the calibration process of 3D scanning equipment, data processing process, and subsequent application process to compensate for the corresponding errors in the lidar measurement data, which helps to improve the accuracy of 3D reconstruction.

[0111] Figure 2 This is a flowchart of a lidar error measurement method provided in an exemplary embodiment of this disclosure. The method is used in electronic device 103, and includes:

[0112] Step 201: When the lidar is at a preset temperature, control the movable target to move sequentially to at least one preset distance from the lidar. When the movable target moves to at least one preset distance, acquire the first point cloud data generated after the lidar emits a laser beam at the movable target, and acquire the true distance value measured by the laser rangefinder after emitting a laser beam at the movable target. The movable target has a preset reflectivity.

[0113] Since the ranging error of lidar is affected by temperature and reflectivity, in this embodiment of the present disclosure, the electronic device can control the temperature adjustment module to adjust the temperature so that the temperature of the lidar is at a preset temperature; in addition, according to the preset reflectivity, a movable target with preset reflectivity is used to measure the error, so as to measure the error of lidar under preset temperature conditions, preset reflectivity conditions, and at least one preset distance conditions.

[0114] In one possible implementation, the internal temperature of the lidar can be queried through its internal interface, and the temperature adjustment module can be adjusted to reach a preset temperature based on this internal temperature. In another possible implementation, when the lidar's internal interface cannot provide temperature information, the temperature can be adjusted based on the temperature sensor in the temperature adjustment module to reach the preset temperature, which is considered the current temperature of the lidar. When the lidar is at the preset temperature, the movable target can be controlled to move to at least a preset distance from the lidar.

[0115] Optionally, at least one preset distance includes a set of preset specified distances, i.e., multiple specified distances, to determine the ranging error of the lidar at different distances. Illustratively, the set of specified distances included in the multiple preset distances can be 0.2, 0.4, 0.6, 0.8, 1.0, 2.0, 3.0, ..., 10.0 (in meters), etc.

[0116] The electronic device can determine the distance between the movable target and the lidar based on the measurement value of the laser rangefinder. When each preset distance is reached, it can control the lidar and the laser rangefinder to emit a laser beam towards the movable target located at the preset distance, and then acquire the first point cloud data generated after the lidar emits the laser beam and the true distance value measured in real time by the laser rangefinder.

[0117] In one possible implementation, the electronic device can acquire multiple frames of point cloud data generated by a lidar, meaning the first point cloud data includes multiple frames of point cloud data generated by the lidar. The number of frames acquired can be set according to at least one of the following: lidar resolution, distance, measurement accuracy requirements, and point cloud quantity requirements. The number of frames is negatively correlated with lidar resolution, positively correlated with distance, and positively correlated with measurement accuracy.

[0118] Step 202: Determine the first distance value between the lidar and the movable target based on the first point cloud data.

[0119] In one possible implementation, multiple frames of point cloud data corresponding to a movable target with a preset reflectivity can be merged, and principal component analysis (PCA) can be performed on the merged point cloud data to obtain the corresponding normal vector. The minimum component of the PCA component obtained from the PCA analysis of the point cloud data is the normal vector of the point cloud data, representing the perpendicular direction of the laser radar incident on the preset reflective target. Then, the projection component of each point in the point cloud data along the normal vector direction is calculated to obtain the vertical distance of the laser radar to the movable target. Since a vertical distance can be calculated for each point in the point cloud, the average of the calculated vertical distances of multiple points can be determined as the first distance value of the laser radar to the movable target.

[0120] The first distance value is the distance between the laser radar and the movable target.

[0121] Step 203: Based on the positional offset between the lidar and the laser rangefinder, the true distance value is compensated to obtain the compensated distance.

[0122] The position offset is the distance difference between the lidar and the laser rangefinder in the direction perpendicular to the plane corresponding to the movable target.

[0123] Due to installation errors and other reasons, the lidar and the laser rangefinder may not be able to keep on the same horizontal line. That is, the distance between the laser rangefinder and the movable target is not equal to the distance between the lidar and the movable target. Therefore, it is necessary to compensate for the true distance between the laser rangefinder and the movable target based on the positional offset between the lidar and the laser rangefinder to obtain the compensated distance. The compensated distance can represent the true distance between the lidar and the movable target.

[0124] The positional offset between the lidar and the laser rangefinder is the distance difference between them in the perpendicular direction to the plane corresponding to the movable target. Specifically, it is the difference between the vertical distance from the lidar center to the movable target and the vertical distance from the laser rangefinder center to the movable target. This positional offset between the lidar and the laser rangefinder can be measured in advance.

[0125] When the distance between the lidar and the movable target is less than the distance between the laser rangefinder and the movable target, the difference between the true distance value measured by the laser rangefinder and the position offset can be determined as the compensated true distance value; when the distance between the lidar and the movable target is greater than the distance between the laser rangefinder and the movable target, the sum of the true distance value measured by the laser rangefinder and the position offset can be determined as the compensated true distance value.

[0126] Step 204: Based on the first distance value corresponding to at least one preset distance and the compensated distance, determine the ranging error of the lidar at a preset temperature, at at least one preset distance, and for an object with a preset reflectivity.

[0127] Among them, at least one preset distance corresponds to a first distance value and a compensated distance, including the first distance value and the compensated distance corresponding to each preset distance respectively.

[0128] Based on the difference between the first point cloud data collected at each preset distance and the corresponding compensated distance, the ranging error of the lidar at the preset temperature for an object with a preset reflectivity under each preset distance condition can be obtained.

[0129] In one possible implementation, multiple measurements can be performed at each preset distance, i.e., steps 201-203 above are repeated to obtain multiple sets of first distance values ​​and compensated distances. The difference between each set of first distance values ​​and compensated distances is calculated to obtain multiple ranging errors. The average of the multiple ranging errors is determined as the ranging error of the lidar at the preset distance and the preset temperature for an object with a preset reflectivity.

[0130] Furthermore, it can calculate the variance and standard deviation of multiple ranging errors to determine the data distribution of the errors, which can then be used to analyze the stability of an object with a preset reflectivity at a preset distance scanned by a lidar at a preset temperature.

[0131] In this embodiment, a lidar, a laser rangefinder, and a movable target are used to measure the ranging error of the lidar under different conditions. The movable target has a preset reflectivity. To fix the reflectivity, the lidar is controlled to operate at a preset temperature during the measurement process. The movable target is then moved sequentially to different distances from the lidar. Based on the point cloud data generated by the lidar at these different distances and the true distance measured by the laser rangefinder, the ranging error of the lidar at the preset temperature and at the multiple preset distances relative to the preset reflectivity is determined. This allows for automated measurement of the ranging error of the lidar at multiple preset distances under preset temperature and reflectivity conditions, improving the accuracy of lidar error measurement.

[0132] In one possible implementation, the movable target includes a reflective target having a preset reflectivity. In this way, the ranging error of an object with the preset reflectivity at multiple preset distances at a preset temperature can be measured.

[0133] Alternatively, in another possible implementation, the movable target includes multiple reflective targets with multiple preset reflectivities, and different reflective targets among the multiple reflective targets have different preset reflectivities, so as to measure the ranging error of the lidar for objects with different reflectivities.

[0134] In this case, step 201 above also includes step 2011:

[0135] Step 2011: Acquire multiple first point cloud data generated after the lidar emits laser beams at multiple reflective targets, wherein each first point cloud data corresponds to one reflective target; and acquire multiple true distance values ​​measured by the laser rangefinder after emitting laser beams at multiple reflective targets, wherein each true distance value corresponds to one reflective target.

[0136] Multiple preset reflectivities can be a pre-defined set of reflectivities, which can be combined with reflective targets having preset reflectivities to form a movable target for measuring lidar errors. Illustratively, the movable target includes three reflective targets with reflectivities of (10%), (50%), and (80%) respectively.

[0137] When the lidar temperature is at a preset temperature and the movable target moves to each preset distance, the lidar is controlled to emit laser beams towards the movable target, acquiring multiple first point cloud data generated by the lidar. Each of these first point cloud data sets includes point cloud data corresponding to a specific reflective target; that is, each first point cloud data set corresponds to one reflective target. Optionally, each first point cloud data set may include multiple frames of point cloud data corresponding to that reflective target.

[0138] In one possible implementation, after acquiring multiple generated first point cloud data, the first point cloud data corresponding to each reflective target can be filtered according to the different point cloud intensities, and PCA analysis can be performed on the first point cloud data corresponding to each reflective target to obtain the first distance value of the laser reaching each reflective target.

[0139] For each first point cloud data containing multiple frames of point cloud data, the electronic device can merge the multiple frames of point cloud data, and then perform data analysis on the merged point cloud data to obtain the first distance value of the laser reaching each reflective target.

[0140] After obtaining the first distance value of the laser radar reaching each reflective target, the ranging error can be determined by combining it with the compensated distance. Step 204 above further includes the following step 2041:

[0141] Step 2041: Based on the multiple distance values ​​corresponding to multiple reflective targets and the compensated distance corresponding to the preset distance, determine the ranging error of the lidar at a preset temperature, at at least one preset distance, and for multiple objects with preset reflectivity.

[0142] The compensated distance corresponding to the preset distance is the value obtained by compensating the true distance measured by the laser rangefinder after emitting a laser beam at a movable target at the preset distance using the position offset.

[0143] Based on the difference between the first distance value corresponding to each reflective target and the compensated distance corresponding to the preset distance, the ranging error of the lidar at the preset temperature for each reflective target at the preset distance can be obtained. That is, the ranging error of the lidar at the preset temperature, at at least one preset distance, for multiple objects with preset reflectivity can be obtained, thereby improving the accuracy of ranging error measurement.

[0144] In one possible implementation, multiple measurements can be performed at a preset temperature and a preset distance to obtain multiple sets of first distance values ​​corresponding to reflective targets and compensated distances. Each set of first distance values ​​includes multiple first distance values ​​corresponding to multiple reflective targets. The difference between each set of first distance values ​​and the compensated distance is calculated to obtain multiple ranging errors corresponding to each reflective target. The average of the multiple ranging errors is determined as the ranging error of the lidar at the preset temperature for an object with a preset reflectivity at a preset distance.

[0145] In this embodiment of the disclosure, by using movable targets with different reflectivities, the ranging error corresponding to different reflectivities under preset temperature and preset distance conditions can be measured, thereby improving the accuracy of the ranging error.

[0146] LiDAR systems exhibit varying ranging errors at different temperatures. In this embodiment, the ranging error of the LiDAR system at different temperatures can also be measured. Figure 3 As shown, in an exemplary embodiment, step 201 further includes the following steps:

[0147] Step 2013: Sequentially adjust the lidar to one of the target temperatures in at least one target temperature, and when the lidar is at each target temperature, perform the operation of controlling the movable target to move sequentially to at least one preset distance from the lidar.

[0148] The preset temperature includes at least one target temperature. Optionally, the at least one target temperature may include a set of specified temperatures to determine the ranging error of the lidar at different temperatures. Illustratively, the set of specified temperatures included in the preset temperature may be 0℃, 10℃, 20℃, 30℃, 40℃, etc.

[0149] The electronic device can control the temperature regulation module to adjust the temperature of the lidar, so that the lidar is sequentially at one of the target temperatures. Furthermore, while the lidar is at each target temperature, the control of the slide rail drive motor moves the movable target sequentially to at least one preset distance from the lidar, in order to measure the ranging error of an object with a preset reflectivity at the target temperature and at at least one preset distance.

[0150] After the movable target is moved sequentially to at least one preset distance from the lidar by the control slide rail drive motor, subsequent steps can be executed. Specifically, at each preset distance, the first point cloud data generated by the lidar and the true distance value measured by the laser rangefinder are acquired. Then, based on the first point cloud data, a first distance value between the movable target and the lidar is calculated. This first distance value is then compensated for using a position offset to obtain the compensated distance.

[0151] Step 204 above also includes step 2043:

[0152] Step 2043: Based on the first distance value corresponding to each preset distance and the compensated distance, determine the ranging error of the lidar at the target temperature, at at least one preset distance, and for an object with a preset reflectivity.

[0153] By using the above method, the first distance value corresponding to each preset distance and the compensated distance can be obtained at the target temperature, thereby determining the ranging error for an object with a preset reflectivity at at least one preset distance at each target temperature.

[0154] In this embodiment of the present disclosure, by controlling the movable target to move to different preset distances at each target temperature, the ranging error of an object with a preset reflectivity at at least one preset distance at each target temperature can be obtained based on the point cloud data generated by the lidar and the true distance measured by the laser rangefinder.

[0155] In conjunction with the above embodiments, the movable target includes multiple reflective targets with different preset reflectivities. By controlling the movable target with multiple reflective targets to move to different preset distances at each target temperature, the ranging error for objects with multiple preset reflectivities at at least one preset distance at each target temperature can be obtained based on the point cloud data generated by the lidar and the true distance measured by the laser rangefinder.

[0156] In the above embodiments, at each target temperature, the movable target is controlled to move to different preset distances. In another possible implementation, at each preset distance, the temperature of the lidar can be adjusted, and the ranging error for an object with a preset reflectivity at multiple target temperatures at the preset distance can be measured. Step 201 further includes the following step 2015:

[0157] Step 2015: Control the movable target to move sequentially to at least one preset distance from the lidar, and when the movable target moves to each preset distance, sequentially adjust the lidar to one of the target temperatures at at least one target temperature, and when the lidar is at each target temperature, perform the operation of acquiring the first point cloud data generated after the lidar emits a laser beam to the movable target, and acquiring the true distance value measured by the laser rangefinder after emitting a laser beam to the movable target.

[0158] The preset temperature includes at least one target temperature; optionally, the at least one target temperature may include a set of specified temperatures. The electronic device controls a slide rail drive motor to sequentially move the movable target to at least one preset distance from the lidar. As the movable target moves to each preset distance, the electronic device controls a temperature adjustment module to adjust the temperature of the lidar, ensuring the lidar is sequentially at one of the at least one target temperature. Upon reaching each target temperature, the device acquires the first point cloud data generated after the lidar emits a laser beam at the movable target, and acquires the true distance measured by a laser rangefinder after emitting a laser beam at the movable target. That is, the first point cloud data corresponding to the preset distance includes at least one first point cloud data corresponding to each of the at least one target temperature.

[0159] Subsequently, the first distance value between the movable target and the lidar can be calculated based on each of the multiple first point cloud data.

[0160] Step 204 also includes the following step 2045:

[0161] Step 2045: Based on the first distance value corresponding to each preset distance and the compensated distance, determine the ranging error of the lidar at each preset distance and at a preset temperature for an object with a preset reflectivity.

[0162] The compensated distance corresponding to the preset distance is the value obtained by compensating the true distance measured by the laser rangefinder after emitting a laser beam at a movable target at the preset distance using the offset.

[0163] The first distance value corresponding to each preset distance includes at least one first distance value corresponding to at least one target temperature. Based on the difference between at least one first distance value and the compensated distance, the ranging error of the lidar at each preset distance and at at least one target temperature for an object with a preset reflectivity can be determined, thereby realizing the measurement of the ranging error of the lidar at different preset temperatures under the same distance and reflectivity conditions.

[0164] In one possible implementation, multiple measurements can be performed at each target temperature to obtain multiple sets of first distance values ​​and compensated distances corresponding to each preset temperature. The difference between each set of first distance values ​​and the compensated distance is calculated to obtain multiple ranging errors. The average of the multiple ranging errors is determined as the ranging error of the lidar at the target temperature at the preset distance for an object with a preset reflectivity.

[0165] Furthermore, it can calculate the variance and standard deviation of multiple ranging errors to determine the data distribution of the errors, which can then be used to analyze the stability of the target reflectivity object at a preset distance scanned by the lidar under the target temperature.

[0166] In this embodiment of the present disclosure, when the movable target moves to each preset distance from the lidar, the lidar is adjusted to different target temperatures by the temperature adjustment module. The ranging error of the lidar is measured at different target temperatures. The ranging error of the lidar for objects with preset reflectivity at each preset distance can be obtained at different target temperatures, which helps to improve the accuracy of lidar error measurement.

[0167] Furthermore, in conjunction with the above embodiments, the movable target includes multiple reflective targets with different preset reflectivities. By adjusting the lidar to different target temperatures at each preset distance, the ranging error for objects with multiple preset reflectivities at each preset distance, under multiple target temperatures, and based on the point cloud data generated by the lidar and the true distance measured by the laser rangefinder, can be obtained respectively.

[0168] Before measuring with the lidar, it must be ensured that the laser beam emitted by the lidar is perpendicular to the movable target, and that the movable target has a relatively long length. It must also be ensured that all positions in the plane are equidistant from the lidar. When the movable target includes multiple reflective targets, it must be ensured that all reflective targets are equidistant from the lidar. In an exemplary embodiment, before step 201 above, the following steps are also included:

[0169] Step 11: Detect the distance between the movable target and the lidar to obtain the distance detection result, and detect the light emission direction of the lidar's laser beam to obtain the light detection result.

[0170] Because the movable target has a relatively long length, it may not be entirely on the same plane, meaning the entire movable target is uneven. In this case, the distance between the lidar and various positions on the movable target will not be equidistant, affecting the accuracy of error measurement. Therefore, before measurement, the distance between the movable target and the lidar needs to be detected to ensure that all positions on the movable target are equidistant from the center of the lidar. In one possible implementation, at least two laser rangefinders are used to detect the distance between the movable target and the lidar. At least one laser rangefinder is placed on each side of the lidar, i.e., at least two laser rangefinders are used. To ensure that all positions on the movable target are equidistant from the lidar, the spacing between the at least two laser rangefinders can be determined based on the length of the movable target, and the spacing between the at least two laser rangefinders is positively correlated with the length of the movable target. Optionally, the at least two laser rangefinders are evenly distributed on a horizontal line level with the length of the movable target. The detection process includes steps 11a-11c:

[0171] Step 11a: Control at least two laser rangefinders to emit laser beams toward the movable target and obtain the distance values ​​measured by at least two laser rangefinders.

[0172] It should be noted that at least two laser rangefinders must emit parallel light beams. With at least two laser rangefinders emitting parallel light beams, the electronic equipment controls at least two laser rangefinders to emit laser beams toward the movable target and acquires the distance values ​​measured by at least two laser rangefinders.

[0173] Step 11b: Based on the positional offset between the lidar and each laser rangefinder, compensate for the distance value measured by each laser rangefinder to obtain the compensated distance for each laser rangefinder.

[0174] For the distance value measured by each laser rangefinder, it is necessary to use the corresponding position offset to compensate for it, and obtain the compensated distance. The compensated distance is regarded as the distance between the laser radar and the movable target.

[0175] Step 11c: If the difference between the compensated distances of at least two laser rangefinders is less than a preset threshold, the distance detection result is determined to be that each position in the movable target is equidistant from the lidar.

[0176] After compensating the distance values ​​measured by each laser rangefinder, the compensated distance for each laser rangefinder is obtained. When all the compensated distances are the same, it can be determined that each reflective target in the movable target is equidistant from the lidar.

[0177] Due to measurement errors and other factors, in one possible implementation, when the difference between the compensated distances corresponding to at least two laser rangefinders is less than a preset threshold, the distance detection result is determined to be that each position on the movable target is equidistant from the lidar. Specifically, when the difference between the compensated distances corresponding to any two laser rangefinders is less than the preset threshold, the distance detection result is determined to be that each position on the movable target is equidistant from the lidar. However, when the difference between the compensated distances corresponding to two laser rangefinders is greater than the preset threshold, the distance detection result is determined to be that each position on the movable target is not equidistant from the lidar. In this case, the movable target or the slide rail on which the movable target is installed needs to be adjusted.

[0178] In one possible implementation, distance detection can be performed at multiple distances. When the distance detection results at multiple distances all indicate that the various positions of the movable target are not equidistant from the lidar, it indicates that the reflective targets within the movable target are uneven, and the movable target should be adjusted. Conversely, when the distance detection results at close range indicate that the various positions of the movable target are equidistant from the lidar, while the distance detection results at far range indicate that the various positions of the movable target are not equidistant from the lidar, it indicates that the sliding rail may be uneven, and the sliding rail can be adjusted.

[0179] Indicative, such as Figure 3As shown, the data acquisition device 102 includes two laser rangefinders, located on either side of the lidar. The lidar is fixed to the base via a quick-release mounting device. The distance between the two laser rangefinders can be set according to the length of the movable target. During distance detection, the distance values ​​measured by the two laser rangefinders are acquired, and the distance values ​​measured by the two rangefinders are compensated using the respective offsets of the two rangefinders, resulting in two compensated distances. When the difference between the two compensated distances is less than a preset threshold, it is determined that each reflective target in the movable target is equidistant from the lidar. The preset threshold can be 2mm.

[0180] Before measurement, it is necessary to ensure that the laser beam emitted by the lidar is perpendicular to the movable target, which requires light detection. The light detection process includes steps 11e-11f:

[0181] Step 11e: When the lidar emits a laser beam toward the movable target, the infrared camera is controlled to observe the laser beam and obtain an image of the beam.

[0182] In this embodiment of the disclosure, such as Figure 3 As shown, the data acquisition device 102 is also equipped with an infrared camera for observing the laser beam emitted by the lidar. The infrared camera must be in the same wavelength band as the lidar.

[0183] During the light detection process, when the lidar emits a laser beam towards the movable target, the electronic device controls the infrared camera to observe the laser beam. This can be achieved by sending an observation command to the infrared camera, which then captures an image of the laser beam.

[0184] Step 11f: When the beam observation image indicates that the laser beam has been emitted to a preset height, determine that the light detection result is that the light emission direction is perpendicular to the movable target.

[0185] When the incident point of the laser beam emitted onto the movable target in the beam observation image is located at a preset height, the electronic equipment determines the light detection result as the light detection direction being perpendicular to the movable target. The preset height can be the height of the lidar center above the ground.

[0186] If the laser beam is not emitted to the preset height, the light detection result indicates that the light emission direction is not perpendicular to the movable target. In this case, the lidar needs to be adjusted.

[0187] like Figure 3As shown, the data acquisition device 102 also includes a pitch angle adjustment slide, which is located at the bottom of the lidar. This slide adjusts the lidar's pitch angle when the light detection result indicates that the light emission direction is not perpendicular to the movable target. This allows for fine-tuning of the lidar's pitch angle, thus adjusting the horizontality of the emitted laser beam. In one possible implementation, the pitch angle can be manually adjusted, and the adjustment result observed based on the beam observation image acquired by the infrared camera. In another possible implementation, the pitch angle adjustment slide can also be connected to the electronic device 103. The electronic device 103 controls the pitch angle adjustment slide to automatically adjust based on the light direction in the beam observation image, ensuring that the laser beam emitted by the lidar is perpendicular to the movable target.

[0188] Step 12: If the distance detection result indicates that each position of the movable target is equidistant from the lidar, and the light detection result indicates that the light emission direction is perpendicular to the movable target, control the movable target to move to the preset distance.

[0189] When the distance detection result indicates that each position of the movable target is equidistant from the lidar, and the light detection result indicates that the light emission direction is perpendicular to the movable target, the error measurement of the lidar can begin, that is, the movable target is controlled to move to the preset distance, and steps 201-204 are executed.

[0190] Before using at least two laser rangefinders for distance measurement, it must be ensured that the light emitted by at least two laser rangefinders is horizontal. Prior to step 11, the following steps are also included:

[0191] Step 1a: Control at least two laser rangefinders to emit laser beams toward the movable target.

[0192] Electronic devices control each laser rangefinder to emit a laser beam toward the movable target.

[0193] Step 1b: When the distance between the laser target points on the movable target is the same as the distance between the emission points of at least two laser rangefinders, and the height of the laser target points above the ground is the same as the height of the corresponding emission points above the ground, perform the step of detecting the distance between the movable target and the lidar to obtain the distance detection result.

[0194] The horizontality of the laser beam emitted by the laser rangefinder can be determined by the distance between the laser target points on the movable target after the laser beam is emitted, the distance between the laser target points and the exit point of the laser rangefinder, and the height of the laser target points above the ground and the height of the exit point. When the distance between the laser target points on the movable target is the same as the distance between the corresponding exit points of the laser rangefinder, and the height of the laser target points above the ground is the same as the height of the corresponding exit points above the ground, the horizontality of the laser beam emitted by the laser rangefinder is determined, and the distance between the movable target and the lidar can be measured to obtain the distance detection result.

[0195] Indicative, such as Figure 3 As shown, when the distance between the two laser rangefinders on the horizontal line is the same as the distance between the laser target points incident on the movable target, and the height of the laser target points above the ground is the same as the height between the corresponding emission points, the horizontal light emitted by the two laser rangefinders is determined.

[0196] In this embodiment of the present disclosure, before measuring the error of the lidar, the distance between the lidar and multiple reflective targets in the movable target is detected, and the direction of the laser beam emitted by the lidar is detected, so as to ensure that the lidar and multiple reflective targets in the movable target are equidistant, and to ensure that the laser beam emitted by the lidar can be perpendicularly incident on the movable target, thereby ensuring the accuracy of the error measurement.

[0197] In one possible implementation, a first laser rangefinder and a second laser rangefinder are respectively placed on either side of the lidar. The process of compensating for the true distance value based on the offset between the lidar and the laser rangefinder to obtain the compensated true distance value further includes the following steps:

[0198] Step 2031: Compensate the true distance value measured by the first laser rangefinder based on the offset between the lidar and the first laser rangefinder to obtain the first true distance value.

[0199] To improve the accuracy of distance truth measurement, in this embodiment of the disclosure, a laser rangefinder is placed on each side of the lidar, including a first laser rangefinder and a second laser rangefinder. The offset between the first laser rangefinder and the lidar, and the offset between the second laser rangefinder and the lidar, are measured and recorded beforehand.

[0200] When the movable target moves to a preset distance, the distance is measured using the first laser rangefinder and the second laser rangefinder, and the true distance values ​​measured by the first laser rangefinder and the second laser rangefinder can be obtained respectively.

[0201] The true distance value measured by the first laser rangefinder is compensated by using the pre-measured offset between the lidar and the first laser rangefinder to obtain the first true distance value corresponding to the first laser rangefinder.

[0202] Step 2032: Compensate the true distance value measured by the second laser rangefinder based on the offset between the lidar and the second laser rangefinder to obtain the second true distance value.

[0203] The true distance value measured by the second laser rangefinder is compensated by using the pre-measured offset between the lidar and the second laser rangefinder to obtain the second true distance value corresponding to the second laser rangefinder.

[0204] Step 2033: The average of the first true distance value and the second true distance value is determined as the compensated distance.

[0205] The average of the first true distance value and the second true distance value can be determined as the compensated distance, which is the true distance between the lidar and the movable target.

[0206] In another possible implementation, to improve the accuracy of the distance true value measurement, the difference between the first distance true value and the second distance true value is first calculated. If the difference between the first distance true value and the second distance true value is less than a preset threshold, the mean between the first distance true value and the second distance true value is then calculated, and the mean is determined as the compensated distance true value.

[0207] like Figure 4 As shown, in an exemplary embodiment, the lidar error measurement method provided by this disclosure includes the following steps:

[0208] Step 401: Control the movable target to move to the farthest distance, detect the distance between the lidar and each reflective target in the movable target, and detect the direction of the lidar's light.

[0209] The distance between the detection lidar and each reflective target in the movable target is the distance between the detection lidar and each position in the movable target.

[0210] Step 402: If the distance detection and light detection pass, start the automated measurement.

[0211] Step 403: Control the temperature adjustment module to adjust the temperature of the lidar.

[0212] Step 404: Determine whether the preset temperature has been reached. If yes, proceed to step 405; otherwise, continue to step 403.

[0213] Step 405: Control the slide rail drive motor to move the movable target to a preset distance.

[0214] Step 406: Acquire data collected by the lidar and laser rangefinder, and calculate and store the ranging error based on the acquired data.

[0215] Step 407: Determine whether all preset distance corresponding tests have been completed. If yes, proceed to step 408; otherwise, proceed to step 405.

[0216] Step 408: Determine whether all preset temperature tests have been completed. If yes, end the test; otherwise, proceed to step 403.

[0217] The specific implementation methods for steps 401-408 can be found in the above embodiments, and will not be repeated in this embodiment.

[0218] Figure 5 This is a structural block diagram of a lidar error measurement device provided in an exemplary embodiment of this disclosure. Figure 5 As shown, the device includes:

[0219] The data acquisition module 501 is used to control a movable target to move sequentially to at least one preset distance from the lidar when the lidar temperature is at a preset temperature, and to acquire the first point cloud data generated after the lidar emits a laser beam to the movable target when the movable target moves to at least one preset distance, and to acquire the true distance measured by the laser rangefinder after emitting a laser beam to the movable target, wherein the movable target has a preset reflectivity;

[0220] The distance determination module 502 is used to determine a first distance value between the lidar and the movable target based on the first point cloud data;

[0221] The distance compensation module 503 is used to compensate the true distance value based on the positional offset between the lidar and the laser rangefinder to obtain the compensated distance.

[0222] The error determination module 504 is used to determine the ranging error of the lidar at the preset temperature, at the at least one preset distance, and for an object with the preset reflectivity, based on a first distance value corresponding to at least one preset distance and a compensated distance.

[0223] In one exemplary embodiment, the movable target includes a reflective target;

[0224] or,

[0225] The movable target includes multiple reflective targets with multiple preset reflectivities, and different reflective targets among the multiple reflective targets have different preset reflectivities;

[0226] The data acquisition module 501 is also used for:

[0227] The system acquires multiple first point cloud data generated after the lidar emits laser beams at the multiple reflective targets, wherein each first point cloud data corresponds to one reflective target; and acquires multiple true distance values ​​measured by the laser rangefinder after emitting laser beams at the multiple reflective targets, wherein each true distance value corresponds to one reflective target.

[0228] The error determination module 504 is further configured to:

[0229] Based on the multiple distance values ​​corresponding to the multiple reflective targets and the compensated distance corresponding to the preset distance, the ranging error of the lidar for the multiple preset reflectivities at the preset temperature and at the at least one preset distance is determined.

[0230] In one exemplary embodiment, the preset temperature includes at least one target temperature;

[0231] The data acquisition module 501 is also used for:

[0232] The lidar is sequentially adjusted to one of the at least one target temperatures, and while the lidar is at each target temperature, the movable target is sequentially moved to at least one preset distance from the lidar.

[0233] The error determination module 504 is further configured to:

[0234] Based on the first distance value corresponding to each preset distance and the compensated distance, the ranging error of the lidar for the object with the preset reflectivity at the target temperature and at the at least one preset distance is determined.

[0235] In one exemplary embodiment, the preset temperature includes at least one target temperature;

[0236] The data acquisition module 501 is also used for:

[0237] The movable target is controlled to move sequentially to at least one preset distance from the lidar. When the movable target moves to each preset distance, the lidar is sequentially adjusted to one of the at least one target temperatures. When the lidar is at each target temperature, the operation of acquiring the first point cloud data generated after the lidar emits a laser beam at the movable target and acquiring the true distance measured by the laser rangefinder after emitting a laser beam at the movable target is performed.

[0238] The error determination module 504 is further configured to:

[0239] Based on the first distance value corresponding to each preset distance and the compensated distance, the ranging error of the lidar for the object with the preset reflectivity at each preset distance under the preset temperature is determined.

[0240] In one exemplary embodiment, the apparatus further includes:

[0241] The detection module is used to detect the distance between the movable target and the lidar to obtain a distance detection result, and to detect the light emission direction of the lidar's laser beam to obtain a light detection result;

[0242] The control module is configured to control the movable target to move to the preset distance if the distance detection result indicates that each position of the movable target is equidistant from the lidar, and the light detection result indicates that the light emission direction is perpendicular to the movable target.

[0243] In one exemplary embodiment, at least one laser rangefinder is placed on each side of the lidar, and the distance between at least two laser rangefinders is positively correlated with the length of the movable target.

[0244] The detection module is also used for:

[0245] Control the at least two laser rangefinders to emit laser beams toward the movable target, and obtain the distance values ​​measured by the at least two laser rangefinders;

[0246] Based on the positional offset between the lidar and each laser rangefinder, the distance value measured by each laser rangefinder is compensated to obtain the compensated distance corresponding to each laser rangefinder.

[0247] If the difference between the compensated distances of the at least two laser rangefinders is less than a preset threshold, the distance detection result is determined to be that each position of the movable target is equidistant from the laser radar.

[0248] The detection module is also used for:

[0249] When the lidar emits the laser beam toward the movable target, the infrared camera is controlled to observe the laser beam and obtain a beam observation image;

[0250] When the beam observation image indicates that the laser beam is emitted to a preset height, the light detection result is determined to be that the light emission direction is perpendicular to the movable target.

[0251] The control module is further configured to control the at least two laser rangefinders to emit laser beams toward the movable target; when the distance between the laser target points on the movable target is the same as the distance between the emission points of the at least two laser rangefinders, and the height of the laser target points above the ground is the same as the height of the corresponding emission points above the ground, the module executes the step of detecting the distance between the movable target and the lidar to obtain a distance detection result.

[0252] In one exemplary embodiment, a first laser rangefinder and a second laser rangefinder are respectively placed on both sides of the lidar.

[0253] The distance compensation module 503 is also used for:

[0254] The true distance value measured by the first laser rangefinder is compensated based on the offset between the lidar and the first laser rangefinder to obtain the first true distance value.

[0255] The true distance value measured by the second laser rangefinder is compensated based on the offset between the lidar and the second laser rangefinder to obtain the second true distance value.

[0256] The average of the first true distance value and the second true distance value is determined as the compensated distance.

[0257] The lidar error measurement device and the lidar error measurement method disclosed herein correspond to each other, and related contents can be referred to each other, which will not be repeated here. The beneficial technical effects of the lidar error measurement device disclosed herein can be referred to the corresponding beneficial technical effects in the above-mentioned exemplary method section, which will not be repeated here.

[0258] In addition, this disclosure also provides an electronic device, including:

[0259] Memory, used to store computer programs;

[0260] A processor is configured to execute a computer program stored in the memory, and when the computer program is executed, to implement the lidar error measurement method described in any of the above embodiments of this disclosure.

[0261] Figure 6 This is a schematic diagram illustrating the structure of an application embodiment of the electronic device disclosed herein. Below, reference is made to… Figure 6 This describes an electronic device according to embodiments of the present disclosure. The electronic device may be either or both of a first device and a second device, or a standalone device independent of them, which may communicate with the first device and the second device to receive acquired input signals from them.

[0262] like Figure 6 As shown, the electronic device includes one or more processors and memory.

[0263] A processor can be a central processing unit (CPU) or other form of processing unit with data processing and / or instruction execution capabilities, and can control other components in an electronic device to perform desired functions.

[0264] The memory may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and a processor may execute the program instructions to implement the lidar error measurement methods of the various embodiments of this disclosure described above, and / or other desired functions.

[0265] In one example, the electronic device may also include input devices and output devices, which are interconnected via a bus system and / or other forms of connection mechanism (not shown).

[0266] In addition, the input device may include, for example, a keyboard, a mouse, etc.

[0267] This output device can output various information to the outside, including determined distance information, direction information, etc. The output device may include, for example, a display, a speaker, a printer, and a communication network and its connected remote output devices, etc.

[0268] Of course, for the sake of simplicity, Figure 6 Only some of the components of the electronic device relevant to this disclosure are shown, omitting components such as buses, input / output interfaces, etc. In addition, the electronic device may include any other suitable components depending on the specific application.

[0269] In addition to the methods and apparatus described above, embodiments of this disclosure may also be computer program products comprising computer program instructions that, when executed by a processor, cause the processor to perform the steps in the lidar error measurement methods according to various embodiments of this disclosure as described in the foregoing portion of this specification.

[0270] The computer program product can be written in any combination of one or more programming languages ​​to perform the operations of the embodiments of this disclosure. The programming languages ​​include object-oriented programming languages ​​such as Java and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on a user's computing device, partially on a user's computing device, as a standalone software package, partially on a user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0271] Furthermore, embodiments of this disclosure may also be computer-readable storage media storing computer program instructions thereon, which, when executed by a processor, cause the processor to perform the steps in the lidar error measurement methods according to various embodiments of this disclosure as described in the foregoing portion of this specification.

[0272] The computer-readable storage medium may be any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may, for example, include, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, or devices, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0273] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media that can store program code, such as ROM, RAM, magnetic disk, or optical disk.

[0274] The basic principles of this disclosure have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this disclosure are merely examples and not limitations, and should not be considered as essential features of each embodiment of this disclosure. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the scope of this disclosure to the necessity of employing the aforementioned specific details for implementation.

[0275] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For system embodiments, since they largely correspond to method embodiments, the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0276] The block diagrams of devices, apparatuses, devices, and systems disclosed herein are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0277] The methods and apparatus of this disclosure may be implemented in many ways. For example, they may be implemented by software, hardware, firmware, or any combination of software, hardware, and firmware. The above-described order of steps for the methods is for illustrative purposes only, and the steps of the methods of this disclosure are not limited to the order specifically described above unless otherwise specifically stated. Furthermore, in some embodiments, this disclosure may also be implemented as a program recorded on a recording medium, the program including machine-readable instructions for implementing the methods according to this disclosure. Thus, this disclosure also covers recording media storing programs for performing the methods according to this disclosure.

[0278] It should also be noted that in the apparatus, devices, and methods of this disclosure, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered as equivalent solutions to this disclosure.

[0279] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of this disclosure. Therefore, this disclosure is not intended to be limited to the aspects shown herein, but rather to be carried out within the widest scope consistent with the principles and novel features disclosed herein.

[0280] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this disclosure to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations therein.

Claims

1. A method for measuring lidar error, characterized in that, The method includes: When the lidar is at a preset temperature, the movable target is controlled to move sequentially to at least one preset distance from the lidar. When the movable target moves to at least one of the preset distances, the first point cloud data generated after the lidar emits a laser beam to the movable target is acquired, and the true distance value measured by the laser rangefinder after emitting a laser beam to the movable target is acquired. The movable target has a preset reflectivity. A first distance value between the lidar and the movable target is determined based on the first point cloud data. Based on the positional offset between the lidar and the laser rangefinder, the true distance value is compensated to obtain the compensated distance; Based on the first distance value corresponding to at least one of the preset distances and the compensated distance, the ranging error of the lidar for an object with the preset reflectivity at the preset temperature and at the at least one preset distance is determined. The movable target includes a reflective target; Alternatively, the movable target may include multiple reflective targets with multiple preset reflectivities, wherein different reflective targets among the multiple reflective targets have different preset reflectivities; The step of acquiring the first point cloud data generated after the lidar emits a laser beam at the movable target, and acquiring the true distance measured by the laser rangefinder after emitting a laser beam at the movable target, includes: The system acquires multiple first point cloud data generated after the lidar emits laser beams at the multiple reflective targets, wherein each first point cloud data corresponds to one reflective target; and acquires multiple true distance values ​​measured by the laser rangefinder after emitting laser beams at the multiple reflective targets, wherein each true distance value corresponds to one reflective target. The step of determining the ranging error of the lidar for an object with the preset reflectivity at the preset temperature, at the at least one preset distance, and based on a first distance value corresponding to at least one preset distance and a compensated distance includes: Based on the multiple distance values ​​corresponding to the multiple reflective targets and the compensated distance corresponding to the preset distance, the ranging error of the lidar for the multiple objects with preset reflectivity at the preset temperature and at the at least one preset distance is determined.

2. The method according to claim 1, characterized in that, The preset temperature includes at least one target temperature; The step of controlling the movable target to move sequentially to at least one preset distance from the lidar when the lidar is at a preset temperature includes: The lidar is sequentially adjusted to one of the at least one target temperatures, and while the lidar is at each target temperature, the movable target is sequentially moved to at least one preset distance from the lidar. The determination of the ranging error of the lidar for an object with the preset reflectivity at the preset temperature, at the at least one preset distance, and based on a first distance value corresponding to at least one preset distance and a compensated true distance value includes: Based on the first distance value corresponding to each preset distance and the compensated distance, the ranging error of the lidar for the object with the preset reflectivity at the target temperature and at the at least one preset distance is determined.

3. The method according to claim 1, characterized in that, The preset temperature includes at least one target temperature; When the lidar is at a preset temperature, the movable target is controlled to move sequentially to at least one preset distance from the lidar. When the movable target moves to at least one of the preset distances, the first point cloud data generated after the lidar emits a laser beam at the movable target is acquired, and the true distance value measured by the laser rangefinder after emitting a laser beam at the movable target is acquired, including: The movable target is controlled to move sequentially to at least one preset distance from the lidar. When the movable target moves to each preset distance, the lidar is sequentially adjusted to one of the at least one target temperatures. When the lidar is at each target temperature, the operation of acquiring the first point cloud data generated after the lidar emits a laser beam at the movable target and acquiring the true distance measured by the laser rangefinder after emitting a laser beam at the movable target is performed. The step of determining the ranging error of the lidar for an object with the preset reflectivity at the preset temperature, at the at least one preset distance, and based on a first distance value corresponding to at least one preset distance and a compensated distance includes: Based on the first distance value corresponding to each preset distance and the compensated distance, the ranging error of the lidar for the object with the preset reflectivity at each preset distance under the preset temperature is determined.

4. The method according to claim 1, characterized in that, The method further includes: The distance between the movable target and the lidar is detected to obtain a distance detection result, and the light emission direction of the lidar's laser beam is detected to obtain a light detection result; If the distance detection result indicates that each position of the movable target is equidistant from the lidar, and the light detection result indicates that the light emission direction is perpendicular to the movable target, the movable target is controlled to move to the preset distance.

5. The method according to claim 4, characterized in that, At least one laser rangefinder is placed on each side of the lidar, and the distance between at least two laser rangefinders is positively correlated with the length of the movable target. The process of detecting the distance between the movable target and the lidar to obtain a distance detection result includes: Control the at least two laser rangefinders to emit laser beams toward the movable target, and obtain the distance values ​​measured by the at least two laser rangefinders; Based on the positional offset between the lidar and each laser rangefinder, the distance value measured by each laser rangefinder is compensated to obtain the compensated distance corresponding to each laser rangefinder. If the difference between the compensated distances of the at least two laser rangefinders is less than a preset threshold, the distance detection result is determined to be that each position of the movable target is equidistant from the laser radar.

6. The method according to claim 4, characterized in that, The light detection result is obtained by detecting the light emission direction of the laser beam of the lidar, including: When the lidar emits the laser beam toward the movable target, the infrared camera is controlled to observe the laser beam and obtain a beam observation image; When the beam observation image indicates that the laser beam is emitted to a preset height, the light detection result is determined to be that the light emission direction is perpendicular to the movable target.

7. The method according to claim 5, characterized in that, The method further includes: Control the at least two laser rangefinders to emit laser beams toward the movable target; When the distance between the laser target points on the movable target is the same as the distance between the emission points of the at least two laser rangefinders, and the height of the laser target points above the ground is the same as the height of the corresponding emission points above the ground, the step of detecting the distance between the movable target and the lidar to obtain the distance detection result is performed.

8. The method according to claim 1, characterized in that, A first laser rangefinder and a second laser rangefinder are respectively placed on both sides of the lidar. The step of compensating the true distance value based on the offset between the lidar and the laser rangefinder to obtain the compensated distance includes: The true distance value measured by the first laser rangefinder is compensated based on the offset between the lidar and the first laser rangefinder to obtain the first true distance value. The true distance value measured by the second laser rangefinder is compensated based on the offset between the lidar and the second laser rangefinder to obtain the second true distance value. The average of the first true distance value and the second true distance value is determined as the compensated distance.

9. A lidar error measuring device, characterized in that, include: The data acquisition module is used to control a movable target to move sequentially to at least one preset distance from the lidar when the lidar temperature is at a preset temperature, and to acquire the first point cloud data generated after the lidar emits a laser beam at the movable target when the movable target moves to at least one preset distance, and to acquire the true distance measured by the laser rangefinder after emitting a laser beam at the movable target, wherein the movable target has a preset reflectivity; A distance determination module is used to determine a first distance value between the lidar and the movable target based on the first point cloud data; The distance compensation module is used to compensate the true distance value based on the positional offset between the lidar and the laser rangefinder to obtain the compensated distance. An error determination module is used to determine the ranging error of the lidar at the preset temperature, at the at least one preset distance, and for an object with the preset reflectivity, based on a first distance value corresponding to at least one preset distance and a compensated distance. The movable target includes a reflective target; Alternatively, the movable target may include multiple reflective targets with multiple preset reflectivities, wherein different reflective targets among the multiple reflective targets have different preset reflectivities; The data acquisition module is specifically used for: The system acquires multiple first point cloud data generated after the lidar emits laser beams at the multiple reflective targets, wherein each first point cloud data corresponds to one reflective target; and acquires multiple true distance values ​​measured by the laser rangefinder after emitting laser beams at the multiple reflective targets, wherein each true distance value corresponds to one reflective target. The error determination module is specifically used for: Based on the multiple distance values ​​corresponding to the multiple reflective targets and the compensated distance corresponding to the preset distance, the ranging error of the lidar for the multiple objects with preset reflectivity at the preset temperature and at the at least one preset distance is determined.

10. A lidar error measurement system, characterized in that, The system includes a movable target device, a data acquisition device, and electronic equipment. The movable target device includes a slide rail, a slide rail drive motor, and a movable target mounted on the slide rail drive motor. The movable target has a preset reflectivity. The data acquisition device includes a lidar, a laser rangefinder, and a temperature control module. The temperature control module is located at the bottom of the lidar. The electronic device controls the temperature adjustment module to adjust the temperature of the lidar, and when the lidar is at a preset temperature, controls the slide rail drive motor to move the movable target sequentially to at least one preset distance from the lidar. When the movable target moves to at least one of the preset distances, the electronic device acquires the first point cloud data generated after the lidar emits a laser beam at the movable target, and acquires the true distance value measured by the laser rangefinder after emitting a laser beam at the movable target; and determines the first distance value between the lidar and the movable target based on the first point cloud data. Based on the positional offset between the lidar and the laser rangefinder, the true distance value is compensated to obtain the compensated distance; based on the first distance value corresponding to each preset distance and the compensated distance, the ranging error of the lidar for the object with the preset reflectivity at the preset temperature and at the at least one preset distance is determined. The movable target includes a reflective target; Alternatively, the movable target may include multiple reflective targets with multiple preset reflectivities, wherein different reflective targets among the multiple reflective targets have different preset reflectivities; When the electronic device acquires the first point cloud data generated after the lidar emits a laser beam at the movable target, and acquires the true distance value measured by the laser rangefinder after emitting a laser beam at the movable target, it is specifically used for: acquiring multiple first point cloud data generated after the lidar emits laser beams at the multiple reflective targets, wherein each first point cloud data corresponds to one reflective target; and acquiring multiple true distance values ​​measured by the laser rangefinder after emitting laser beams at the multiple reflective targets, wherein each true distance value corresponds to one reflective target. When the electronic device determines the ranging error of the lidar at the preset temperature, at the at least one preset distance, and for an object with the preset reflectivity based on a first distance value corresponding to at least one preset distance and a compensated distance, it is specifically used to: determine the ranging error of the lidar at the preset temperature, at the at least one preset distance, and for an object with the preset reflectivity based on multiple distance values ​​corresponding to the multiple reflective targets and the compensated distance corresponding to the preset distance.

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