Calibration method for active target ball device of mobile robot and related equipment

Abstract

The invention belongs to the technical field of detection, and discloses a calibration method for an active target ball device of a mobile robot and related equipment, and the method comprises the steps: obtaining a rotation angle measurement value of the active target ball device of the mobile robot at a plurality of preset measurement points; the calculation module is used for calculating the measured value of the rotation angle increment of the reflection target ball at each preset measurement point relative to the reference measurement point, and calculating the reference value of the rotation angle increment of the reflection target ball at each preset measurement point relative to the reference measurement point according to the pre-calibrated center angle of each preset measurement point; the measurement value of the rotation angle increment is compared with the reference value, so that the measurement error of the rotation angle is calculated, and the measurement error of the rotation angle of the active target ball device of the mobile robot can be accurately calibrated.

Description

Technical Field

[0001] The present application relates to the field of detection technology, and in particular to a calibration method for an active target ball device of a mobile robot and related equipment. Background Art

[0002] The mobile robot active target ball device is a device installed on the mobile robot and used to cooperate with the laser tracker to measure the spatial coordinates and posture angle of the mobile robot in real time. The mobile robot active target ball device includes a rotating ball seat and a reflective target ball set on the rotating ball seat. During the movement of the mobile robot, the rotating ball seat will automatically adjust the angle of the reflective target ball so that the laser incident window of the reflective target ball is always aligned with the laser emission of the laser tracker, and the laser tracker uses the reflected laser to measure the distance.

[0003] Among them, during the operation of the mobile robot, the rotating ball seat will measure the rotation angle of the reflective target ball in real time (for example, using a rotary encoder for measurement), and the measurement result will be fed back to the controller of the rotating ball seat to achieve precise control of the rotation angle of the reflective target ball. The measurement result of the rotation angle of the reflective target ball will inevitably have errors. When the measurement error is unknown, it is not conducive to improving the control accuracy of the rotation angle of the reflective target ball. Summary of the invention

[0004] The purpose of the present application is to provide a method and related equipment for calibrating an active target ball device of a mobile robot, which can accurately calibrate the rotation angle measurement error of the active target ball device of the mobile robot.

[0005] In a first aspect, the present application provides a method for calibrating an active target ball device of a mobile robot, which is used to calibrate the measurement error of the rotation angle of the active target ball device of the mobile robot, comprising the steps of: A1. Place the active target ball device of the mobile robot at multiple preset measurement points at least once in sequence, and obtain the rotation angle measurement value of the reflective target ball of the active target ball device of the mobile robot when it is aligned with the laser tracker at each preset measurement point, which is recorded as the first angle value; the relative position between each preset measurement point and the laser tracker is fixed; A2. Taking one of the preset measurement points as a reference measurement point, calculating the deviation between the first angle value of each preset measurement point and the first angle value of the reference measurement point, and recording it as the measured rotation angle; A3. Calculate the deviation between the pre-calibrated center angle of each of the preset measurement points and the pre-calibrated center angle of the reference measurement point, and record it as the standard rotation angle; the pre-calibrated center angle is the circumferential angle of the preset measurement point relative to a reference position point with the laser tracker as the center; A4. Calculate the measurement error of the rotation angle of the active target ball device of the mobile robot based on the measured rotation angle and the standard rotation angle.

[0006] The mobile robot active target ball device calibration method obtains the rotation angle measurement value of the mobile robot active target ball device at multiple preset measurement points, which is used to calculate the measurement value of the rotation angle increment of the reflective target ball at each preset measurement point relative to the reference measurement point, and calculates the reference value of the rotation angle increment of the reflective target ball at each preset measurement point relative to the reference measurement point according to the pre-calibrated center angle of each preset measurement point, compares the measurement value of the rotation angle increment with the reference value, and thus calculates the measurement error of the rotation angle, which can accurately calibrate the rotation angle measurement error of the mobile robot active target ball device.

[0007] Preferably, the step of placing the mobile robot active target ball device at a plurality of preset measuring points at least once in sequence comprises: After the mobile robot active target ball device is installed on a mobile measuring vehicle, the mobile measuring vehicle carries the mobile robot active target ball device and moves to the plurality of preset measuring points in sequence at least once.

[0008] Using a mobile measuring vehicle to carry an active target sphere device for calibration can improve the calibration efficiency and the accuracy of the calibration results.

[0009] Optionally, the preset measurement points are evenly distributed on a circle centered on the laser tracker; In step A1, the active target ball device of the mobile robot is placed at each of the preset measuring points at least once in a clockwise direction along the circumference, and is placed at each of the preset measuring points at least once in a counterclockwise direction.

[0010] The accuracy and reliability of the calibration results can be effectively improved by presetting the circular layout of measurement points and bidirectional measurement.

[0011] Optionally, the preset measurement points are arranged at intervals along a straight line; In step A1, the active target ball device of the mobile robot is placed at each of the preset measuring points at least once in sequence along the positive direction of the straight line, and is placed at each of the preset measuring points at least once in sequence along the negative direction of the straight line.

[0012] Preferably, step A4 comprises: A401. Calculate the deviation between each measured rotation angle and the corresponding standard rotation angle, recorded as the first deviation; A402. Calculate the measurement error of the rotation angle of the active target ball device of the mobile robot based on the first deviation.

[0013] Preferably, step A402 includes: Preprocessing the first deviation; The average value of the first deviation after preprocessing is calculated as the measurement error of the rotation angle of the active target ball device of the mobile robot.

[0014] Preferably, after step A3 and before step A4, the method further comprises the following steps: A5. After the mobile robot active target ball device is rotated as a whole by a preset angle, return to step A1 and execute until the number of times the mobile robot active target ball device is rotated as a whole by the preset angle reaches a preset number threshold, then execute step A4.

[0015] In a second aspect, the present application provides an electronic device, including a processor and a memory, wherein the memory stores a computer program executable by the processor, and when the processor executes the computer program, it runs the steps in the mobile robot active target ball device calibration method as described above.

[0016] In a third aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps in the mobile robot active target ball device calibration method as described above are executed.

[0017] In a fourth aspect, the present application provides a mobile robot active target ball device calibration system, which is used to calibrate the measurement error of the rotation angle of the mobile robot active target ball device, including a laser tracker, a guide rail, a mobile measuring vehicle and a host computer, wherein the laser tracker and the mobile measuring vehicle are both communicatively connected to the host computer, and a plurality of preset measuring points are arranged at intervals on the guide rail, and the relative position between each of the preset measuring points and the laser tracker is fixed; The mobile measuring vehicle is movably arranged on the guide rail and used to install the mobile robot active target ball device, and is also used to carry the mobile robot active target ball device to move to the plurality of preset measuring points at least once in sequence, and obtain the rotation angle measurement value when the reflective target ball of the mobile robot active target ball device is aligned with the laser tracker at each preset measuring point, which is recorded as the first angle value, and the first angle value is sent to the host computer; The host computer is used to take one of the preset measurement points as a reference measurement point, calculate the deviation between the first angle value of each preset measurement point and the first angle value of the reference measurement point, and record it as the measured rotation angle; calculate the deviation between the pre-calibrated center angle of each preset measurement point and the pre-calibrated center angle of the reference measurement point, and record it as the standard rotation angle; the pre-calibrated center angle is the circumferential angle of the preset measurement point relative to a reference position point with the laser tracker as the center; and calculate the measurement error of the rotation angle of the active target ball device of the mobile robot based on the measured rotation angle and the standard rotation angle.

[0018] Beneficial effect: The mobile robot active target ball device calibration method and related equipment provided in the present application obtain the rotation angle measurement value of the mobile robot active target ball device at multiple preset measurement points, which are used to calculate the measurement value of the rotation angle increment of the reflective target ball at each preset measurement point relative to the reference measurement point, and calculate the reference value of the rotation angle increment of the reflective target ball at each preset measurement point relative to the reference measurement point according to the pre-calibrated center angle of each preset measurement point, compare the measurement value of the rotation angle increment with the reference value, and thus calculate the measurement error of the rotation angle, which can accurately calibrate the rotation angle measurement error of the mobile robot active target ball device. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a flow chart of a method for calibrating an active target ball device of a mobile robot provided in an embodiment of the present application.

[0020] Figure 2 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application.

[0021] Figure 3 A schematic diagram of a mobile robot active target ball device calibration system provided in an embodiment of the present application.

[0022] Figure 4 A schematic diagram of another mobile robot active target ball device calibration system provided in an embodiment of the present application.

[0023] Figure 5 This is a structural diagram of the mobile measuring vehicle.

[0024] Figure 6 This is the device module connection diagram for the mobile measuring vehicle.

[0025] Explanation of reference numerals: 1. Laser tracker; 2. Guide rail; 4. Host computer; 5. Mobile measuring vehicle; 501. Mobile base; 502. Rotating table; 503. Dual-axis micro-motion platform; 504. Central control device; 505. Battery; 506. Servo motor; 507. Rotating motor; 508. Communication module; 509. Laser sensor; 510. Identification device; 6. Laser reflector; 90. Active target ball device of mobile robot; 301. Processor; 302. Memory; 303. Communication bus. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0027] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0028] With the rapid development of industrial automation and intelligent manufacturing, mobile robots are increasingly used in factories, warehouses and other scenarios. In order to ensure that mobile robots can accurately locate and navigate, their spatial coordinates and posture angles need to be measured in real time. In this context, the use of active target ball devices for mobile robots in conjunction with laser trackers has become an important solution. However, the active target ball devices for mobile robots in the prior art still face some challenges in practical applications, especially the problem of rotation angle measurement errors.

[0029] In an actual working environment, a typical scenario may be like this: a mobile robot performs material handling tasks in a factory workshop. In order to ensure the accuracy of the handling, the position and posture of the robot need to be monitored in real time. At this time, the active target ball device installed on the robot will come into play. It can automatically adjust the angle of the reflective target ball so that it is always aligned with the laser tracker. However, if there is an error in the measurement of the rotation angle of the reflective target ball, it may lead to inaccurate measurement of the position and posture, thereby affecting the accuracy of the entire handling task. Therefore, before the active target ball device is installed on the robot, the measurement error of the rotation angle of the active target ball device needs to be calibrated.

[0030] In response to this problem, the present application proposes an innovative calibration method. The core idea of ​​this method is to obtain the rotation angle measurement value of the active target sphere device at multiple preset measurement points, which is used to calculate the measurement value of the rotation angle increment of the reflective target sphere at each preset measurement point relative to the reference measurement point, and calculate the reference value of the rotation angle increment of the reflective target sphere at each preset measurement point relative to the reference measurement point according to the pre-calibrated center angle of each preset measurement point, and compare the measurement value of the rotation angle increment with the reference value, so as to calculate the measurement error of the rotation angle. This method can not only effectively identify and quantify the measurement error, but also provide a basis for subsequent error compensation.

[0031] Before delving into the specific implementation methods of this application, it is necessary to explain several key concepts. "Mobile robot active target ball device" refers to a device used on a mobile robot and used to cooperate with a laser tracker to spatially position the robot. It is mainly composed of a rotating ball seat and a reflective target ball. "Laser tracker" is a high-precision three-dimensional measuring device that measures the spatial position of a target object by emitting lasers and receiving reflected signals. "Preset measurement point" refers to a predetermined spatial position point used for calibration measurement.

[0032] Please refer to Figure 1 , Figure 1 A mobile robot active target ball device calibration method in some embodiments of the present application is used to calibrate the measurement error of the rotation angle of the mobile robot active target ball device, comprising the steps of: A1. Place the active target ball device of the mobile robot at multiple preset measurement points at least once in sequence, and obtain the rotation angle measurement value of the reflective target ball of the active target ball device of the mobile robot when it is aligned with the laser tracker at each preset measurement point (referring to when the laser incident window of the reflective target ball is aligned with the emitted laser of the laser tracker), which is recorded as the first angle value; the relative position between each preset measurement point and the laser tracker is fixed; A2. Taking one of the preset measurement points as the reference measurement point, calculate the deviation between the first angle value of each preset measurement point and the first angle value of the reference measurement point, and record it as the measured rotation angle; A3. Calculate the deviation between the pre-calibrated center angle of each preset measurement point and the pre-calibrated center angle of the reference measurement point, and record it as the standard rotation angle; the pre-calibrated center angle is the circumferential angle of the preset measurement point relative to a reference position point with the laser tracker as the center; A4. Calculate the measurement error of the rotation angle of the active target ball device of the mobile robot based on the measured rotation angle and the standard rotation angle.

[0033] The mobile robot active target ball device calibration method obtains the rotation angle measurement value of the mobile robot active target ball device at multiple preset measurement points, which is used to calculate the measurement value of the rotation angle increment of the reflective target ball at each preset measurement point relative to the reference measurement point (i.e. the measured rotation angle), and calculates the reference value of the rotation angle increment of the reflective target ball at each preset measurement point relative to the reference measurement point (i.e. the standard rotation angle) according to the pre-calibrated center angle of each preset measurement point, compares the measurement value of the rotation angle increment with the reference value (i.e. compares the measured rotation angle with the standard rotation angle), thereby calculating the measurement error of the rotation angle, and can accurately calibrate the rotation angle measurement error of the mobile robot active target ball device.

[0034] In some embodiments, the step of placing the mobile robot active target ball device at a plurality of preset measurement points at least once in sequence includes: After the mobile robot active target ball device is installed on a mobile measuring vehicle, the mobile measuring vehicle carries the mobile robot active target ball device and moves to a plurality of preset measuring points at least once in sequence.

[0035] In practical applications, in order to improve the accuracy and efficiency of the calibration process, this application introduces an important element, a mobile measuring vehicle. The use of the mobile measuring vehicle solves the problems of inaccurate positioning and cumbersome operation that may be caused by manually moving the active target ball device.

[0036] Specifically, a mobile measuring vehicle is a device specially designed for precise positioning and movement. It is usually equipped with a high-precision positioning system and drive mechanism, and can move smoothly and accurately on a preset track or path. Installing the mobile robot active target ball device on the mobile measuring vehicle can ensure that the active target ball device can be accurately positioned at the position of each preset measurement point, thereby improving the accuracy of the entire calibration process.

[0037] The use of mobile measuring vehicles is mainly reflected in the following aspects: First of all, the mobile measuring vehicle can achieve precise position control. Through pre-programming, remote control or sensor positioning, the mobile measuring vehicle can move accurately to each measuring point along the preset path. This not only improves the accuracy of positioning, but also greatly improves the efficiency of measurement.

[0038] Secondly, the mobile measurement vehicle can provide additional functional support. For example, it can integrate a power supply system to provide continuous and stable power for the active target device; it can also integrate a data acquisition and transmission system to transmit measurement data to the host computer in real time.

[0039] In actual operation, the mobile measuring vehicle can be used in a variety of ways. For example, in one embodiment, the mobile measuring vehicle can move along a preset straight track, and a plurality of preset measuring points are evenly distributed on the track. The mobile measuring vehicle carrying the active target ball device stops at each measuring point in turn, and moves to the next point after completing the measurement.

[0040] In another embodiment, the mobile measuring vehicle can move on a circular track, the center of which is the location of the laser tracker. This layout can conveniently test the performance of the active target ball device at different angles.

[0041] In addition, the mobile measuring vehicle can also adopt a trackless design and move freely in open space through a high-precision navigation system. This method is more flexible and can adapt to more complex measurement environments.

[0042] Using a mobile measuring vehicle to carry the active target sphere device for calibration has significant advantages over the traditional manual movement method. First, it greatly improves the efficiency of measurement. The mobile measuring vehicle can move quickly and accurately between various measuring points, reducing the time and error of manual operation. Second, it improves the accuracy of measurement. The mobile measuring vehicle can ensure that the position of the active target sphere device is accurate and consistent at each measuring point, reducing the position error caused by manual operation. Third, it enhances the repeatability of measurement. Through the preset movement path and precise positioning system, it can ensure that each measurement is carried out under the same conditions, improving the reliability of the measurement results.

[0043] Optionally, the preset measurement points are evenly distributed on a circle centered on the laser tracker; In step A1, the active target ball device of the mobile robot is placed at each preset measuring point at least once in a clockwise direction along the circumference, and is placed at each preset measuring point at least once in a counterclockwise direction.

[0044] In the process of implementing the mobile robot active target ball device calibration method, in order to more comprehensively evaluate and calibrate the performance of the device, this application proposes an innovative measurement point layout and measurement method. This method can not only improve the accuracy and reliability of calibration, but also better reflect the performance of the active target ball device at different positions and angles.

[0045] Specifically, the present application evenly distributes the preset measurement points on a circle centered on the laser tracker. This layout has several significant advantages: first, it can ensure the uniform distribution of the measurement points in space, avoiding the deviation of the measurement data; second, the circular layout can simulate the various angles and positions that the active target ball device may encounter in actual applications, thereby providing a more comprehensive performance evaluation; finally, this layout facilitates the implementation of bidirectional measurement, that is, measurement in both clockwise and counterclockwise directions.

[0046] In the measurement process, the present application adopts a bidirectional measurement method. Specifically, the mobile robot active target ball device is first placed at each preset measurement point at least once in a clockwise direction along the circumference, and then placed at each preset measurement point at least once in a counterclockwise direction. This bidirectional measurement method has several important technical advantages: Eliminate systematic errors: By measuring in both clockwise and counterclockwise directions, the systematic errors caused by the measurement system itself can be effectively eliminated, thus improving the accuracy of the measurement results.

[0047] Evaluating repeatability: Bidirectional measurement allows multiple measurements at the same location, which helps evaluate the measurement repeatability of the active target device, which is one of the important indicators of device performance.

[0048] Detecting direction-dependent errors: Certain errors may be dependent on the measurement direction. Bidirectional measurements can be used to identify and quantify these direction-dependent errors.

[0049] Improve data reliability: Increasing the number and direction of measurements provides more data points, thus improving the reliability and accuracy of statistical analysis.

[0050] In practice, there are many ways to achieve this circular layout and bidirectional measurement. For example, a circular rail can be used, preset measurement points can be evenly set on the rail, and then a mobile measurement vehicle can be used to move along the rail, carrying the active target device for measurement. Another method is to use a robotic arm, and by precisely controlling the movement of the robotic arm, the active target device can be moved along a predetermined circular trajectory and measured.

[0051] To further illustrate the application of this method, we can consider a specific implementation example. Assume that 12 preset measurement points are evenly set on a circle with a radius of 5 meters, and the angular interval between each point is 30 degrees. First, the active target ball device of the mobile robot starts from the 0-degree position and measures at 0 degrees, 30 degrees, 60 degrees... until 330 degrees in a clockwise direction. Then, starting from the 330-degree position, it measures at 330 degrees, 300 degrees, 270 degrees... until 0 degrees in a counterclockwise direction. At each measurement point, the rotation angle measurement value when the reflective target ball of the active target ball device is aligned with the laser tracker is recorded.

[0052] This circular layout and bidirectional measurement method play an important role in solving the problem of rotation angle measurement error of the active target device of the mobile robot. First, the circular layout ensures the uniform distribution of measurement points in space, which helps to comprehensively evaluate the performance of the active target device at different positions and angles. Second, the bidirectional measurement method can not only eliminate systematic errors, but also detect and quantify direction-related errors, which is crucial to improve the accuracy and reliability of calibration.

[0053] By implementing this method, the present application is able to more accurately quantify the rotation angle measurement error of the active target ball device of the mobile robot. Compared with traditional single-point or unidirectional measurement, this method provides a more comprehensive and reliable performance evaluation. It can not only identify and quantify different types of errors (such as systematic errors, random errors, direction-related errors, etc.), but also provide a more reliable data basis for subsequent error compensation.

[0054] Optionally, the preset measuring points are arranged at intervals along a straight line; In step A1, the active target ball device of the mobile robot is placed at each preset measurement point at least once in sequence along the positive direction of the straight line, and is placed at each preset measurement point at least once in sequence along the negative direction of the straight line.

[0055] When implementing the aforementioned calibration method, some new challenges may be encountered. For example, when the preset measurement points are distributed on a circle, it may not be possible to completely cover all the motion trajectories of the mobile robot in actual work. In order to solve this problem, the present application proposes a solution of arranging the preset measurement points at intervals along a straight line.

[0056] This linear arrangement has several advantages. First, it can better simulate the linear motion trajectory of the mobile robot in actual work. Second, by measuring in both the forward and reverse directions, the system error that may be caused by unidirectional measurement can be effectively eliminated. In addition, the linear arrangement is also convenient for calibration in a larger spatial range, which is suitable for scenarios that require long-distance precise positioning.

[0057] The following methods can be used for specific implementation: Fixed rail method: Install a linear rail on the ground or workbench, and set preset measurement points at equal intervals along the rail. The mobile robot active target ball device can be moved on the rail by the mobile measuring vehicle to ensure the accuracy of the measurement position.

[0058] Laser guidance method: Use a laser projector to project a straight line on the ground and mark the preset measurement points along this line. This method is highly flexible and suitable for temporary calibration needs.

[0059] Visual positioning method: Straight tape with special marks is pasted on the ground. The robot's own visual system recognizes these marks and accurately locates each preset measurement point.

[0060] To further illustrate the application of this method, we can consider a specific embodiment. A straight calibration path of up to 50 meters can be set. On this path, a preset measurement point is set every 5 meters, for a total of 11 points. The mobile robot active target ball device first passes through these 11 points from the starting point to the end point for measurement, and then returns from the end point to the starting point and passes through these 11 points again for measurement. In this way, not only can the main working area in the warehouse be covered, but the accuracy of the calibration can also be improved through round-trip measurement.

[0061] This linear arrangement scheme of the present application plays an important role in solving technical problems. First, by setting preset measurement points along the straight line, the performance of the mobile robot active target ball device at different distances and angles can be more comprehensively evaluated. Secondly, the measurement in both the forward and reverse directions can effectively eliminate the possible systematic errors in unidirectional measurement and improve the reliability of the calibration results. In addition, this method can also flexibly adjust the spacing and number of measurement points to adapt to working environments of different scales.

[0062] During the calibration process, the mobile robot's active target ball device first moves in a straight line to each preset measurement point in turn, and obtains the rotation angle measurement value when the reflective target ball is aligned with the laser tracker at each point. Then, the process is repeated in the opposite direction. This two-way measurement not only increases the data samples, but also offsets the possible unidirectional cumulative error. The host computer then processes this data, calculates the measured rotation angle and the standard rotation angle, and finally obtains the measurement error of the rotation angle.

[0063] Compared with the circular arrangement, the linear arrangement is easier to expand the measurement range. It only requires extending the guide rail or marking line without redesigning the entire measurement layout.

[0064] Among them, one or both of the above two schemes (circular arrangement scheme and linear arrangement scheme) can be selected according to actual needs to measure the first angle value. When two schemes are selected, steps A2 to A3 are respectively performed for the first angle value obtained by each scheme (mainly because the two schemes need to select reference measurement points respectively, and the reference measurement points cannot be mixed with each other).

[0065] In step A2, a preset measurement point may be randomly selected as a reference measurement point, or a pre-specified preset measurement point may be used as a reference measurement point.

[0066] In step A3, the reference position point may be one of the preset measurement points or a position point other than the preset measurement points. The pre-calibrated center angles corresponding to the preset measurement points are pre-calibrated, and the positions of the calibrated laser tracker and the preset measurement points are fixed. Figure 3 and Figure 4 , the angle a1 in the figure is the pre-calibrated center angle of the preset measuring point O1, and the angle a2 is the pre-calibrated center angle of the preset measuring point O2.

[0067] In some embodiments, step A4 comprises: A401. Calculate the deviation between each measured rotation angle and the corresponding standard rotation angle, recorded as the first deviation; A402. Calculate the measurement error of the rotation angle of the active target ball device of the mobile robot based on the first deviation.

[0068] The technical solution proposed in this application provides an intermediate step for calculating the measurement error by introducing the concept of the first deviation. This method not only simplifies the calculation process, but also improves the reliability of the results. Specifically, first calculate the deviation between the measured rotation angle and the corresponding standard rotation angle, and record it as the first deviation. This step can effectively capture the error situation of each measurement point. Then, based on these first deviations, calculate the final rotation angle measurement error.

[0069] This step-by-step calculation method has several distinct advantages. First, it allows the error of each measurement point to be analyzed individually, which helps to identify possible systematic errors or outliers. Second, by introducing intermediate steps, necessary preprocessing of the data can be performed before the final calculation, such as removing outliers or smoothing the data, thereby improving the accuracy of the final result.

[0070] In practical applications, the first deviation is obtained by subtracting the corresponding standard rotation angle from the measured rotation angle.

[0071] Further, step A402 includes: Preprocessing the first deviation; The average value of the preprocessed first deviation is calculated as the measurement error of the rotation angle of the active target ball device of the mobile robot.

[0072] In the process of calibrating the active target ball device of the mobile robot, after obtaining the measured rotation angle and the standard rotation angle, these data need to be further processed to obtain accurate rotation angle measurement errors. However, directly using the raw data may be affected by various factors, such as environmental noise, random errors of the measuring equipment, etc., thus affecting the accuracy and reliability of the final results.

[0073] In order to solve this problem, the present application proposes an innovative data processing method. First, the calculated first deviation is preprocessed. Preprocessing is an important step that can effectively remove outliers, reduce the impact of random errors, and improve the quality and reliability of data. Preprocessing can include a variety of methods, such as outlier detection and removal, data smoothing, normalization, etc.

[0074] For example, statistical methods such as box plots or Z-score methods can be used to detect and remove outliers. These outliers may be caused by unexpected interference in the measurement process or temporary equipment failure. Removing them can significantly improve the representativeness of the data. Another preprocessing method is data smoothing, which can use techniques such as moving average or weighted average to reduce random fluctuations in the data and highlight the overall trend.

[0075] After preprocessing, the average value of these processed first deviations is calculated and used as the rotation angle measurement error of the active target ball device of the mobile robot. Using the average value can further reduce the influence of random errors and provide a more stable and reliable error estimate.

[0076] An important advantage of this approach is its flexibility. Depending on the specific application scenario and data characteristics, the most suitable preprocessing method can be selected. For example, in a noisy environment, stronger smoothing may be required; while in applications with extremely high accuracy requirements, stricter outlier detection criteria may be required.

[0077] The method of the present application adopts a systematic data processing method when solving the problem of rotation angle measurement error of the active target ball device of the mobile robot. First, by preprocessing the first deviation, the outliers and noise in the original data are effectively removed, and the data quality is improved. This step is crucial to improving the reliability of the final result because it can reduce the influence of environmental factors and random errors. Next, by calculating the average value of the preprocessed first deviation, the method of the present application further improves the stability of the measurement error estimation. The use of the average value can not only provide a comprehensive error estimate, but also smooth out the remaining random fluctuations, so that the final rotation angle measurement error is more accurate and reliable.

[0078] Preferably, after step A3 and before step A4, the method further comprises the following steps: A5. After the active target ball device of the mobile robot is rotated as a whole by a preset angle, return to step A1 and execute until the number of times the active target ball device of the mobile robot is rotated as a whole by the preset angle reaches a preset number threshold, then execute step A4.

[0079] In the process of executing the mobile robot active target ball device calibration method, a problem may be encountered: a single measurement may not fully reflect the performance of the active target ball device at different angles. In order to solve this problem, the present application introduces the concept of multiple overall rotations.

[0080] The core idea of ​​this method is to rotate the active target sphere device as a whole by a preset angle after completing a round of measurement, and then repeat the entire measurement process. In this way, multiple measurements can be performed at different angles, thereby more comprehensively evaluating and calibrating the performance of the active target sphere device.

[0081] Specifically, after completing step A3 (calculating the standard rotation angle), instead of directly entering step A4 (calculating the measurement error), the newly added step A5 is first executed. In step A5, the mobile robot active target ball device is first rotated as a whole by a preset angle. This preset angle can be set according to actual needs, for example, 30 degrees, 45 degrees or 60 degrees.

[0082] After the rotation is completed, the system will return to step A1, that is, the active target ball device is placed at multiple preset measurement points in sequence again, and new rotation angle measurement values ​​are obtained. This process will be repeated until the number of rotations of the active target ball device as a whole reaches a preset threshold. This threshold can also be determined according to actual needs, for example, it can be 3 times, 5 times or more.

[0083] When the preset number of times is reached, the system will execute step A4 to calculate the final rotation angle measurement error. At this time, the calculation will be based on the data of multiple measurements, not just the result of a single measurement.

[0084] There are many ways to implement this method. For example, a motor control system can be used to achieve precise rotation of the active target ball device (for example, a rotating table is set on the mobile measurement vehicle, and the mobile robot active target ball device is installed on the rotating table, and the rotating table is used to achieve the overall rotation of the mobile robot active target ball device). Another way is to use a manual adjustment mechanism, and the operator adjusts it according to the scale. It is also possible to consider using a servo system to ensure the accuracy of the rotation angle through feedback control.

[0085] In the specific implementation, the following aspects can be considered: First, the selection of preset angles should take into account the working characteristics of the active target device and the possible error distribution. For example, if the error is suspected to be large within certain specific angle ranges, more intensive measurements can be selected within these ranges. Second, the determination of the preset number threshold should balance measurement accuracy and efficiency. The more measurements are made, the more reliable the results are, but at the same time, the calibration time will increase. Finally, multiple rotation measurements under different environmental conditions can be considered to evaluate the impact of environmental factors on the measurement results.

[0086] By introducing this additional step, the calibration method of the present application can more comprehensively evaluate the performance of the active target ball device of the mobile robot. It can not only detect the systematic errors that may exist at a specific angle position, but also reduce the influence of random errors through multiple measurements.

[0087] As can be seen from the above, the mobile robot active target ball device calibration method places the mobile robot active target ball device at multiple preset measurement points at least once in sequence, and obtains the rotation angle measurement value when the reflective target ball of the mobile robot active target ball device is aligned with the laser tracker at each preset measurement point, which is recorded as the first angle value; the relative position between each preset measurement point and the laser tracker is fixed; taking one of the preset measurement points as the reference measurement point, calculating the deviation between the first angle value of each preset measurement point and the first angle value of the reference measurement point, which is recorded as the measured rotation angle; calculating the deviation between the pre-calibrated center angle of each preset measurement point and the pre-calibrated center angle of the reference measurement point, which is recorded as the standard rotation angle; the pre-calibrated center angle is the circumferential angle of the preset measurement point relative to a reference position point with the laser tracker as the center; according to the measured rotation angle and the standard rotation angle, the measurement error of the rotation angle of the mobile robot active target ball device is calculated; thereby the rotation angle measurement error of the mobile robot active target ball device can be accurately calibrated.

[0088] Please refer to Figure 2 , Figure 2 The present application provides a structural diagram of an electronic device provided in an embodiment of the present application. The present application provides an electronic device, including: a processor 301 and a memory 302. The processor 301 and the memory 302 are interconnected and communicate with each other through a communication bus 303 and / or other forms of connection mechanisms (not shown). The memory 302 stores a computer program executable by the processor 301. When the electronic device is running, the processor 301 executes the computer program to execute the mobile robot active target ball device calibration method in any optional implementation of the above embodiment to achieve the following functions: placing the mobile robot active target ball device at multiple preset measurement points at least once in sequence, and obtaining feedback from the mobile robot active target ball device. The rotation angle measurement value of the target ball when it is aligned with the laser tracker at each preset measurement point is recorded as the first angle value; the relative position between each preset measurement point and the laser tracker is fixed; taking one of the preset measurement points as the reference measurement point, the deviation between the first angle value of each preset measurement point and the first angle value of the reference measurement point is calculated, which is recorded as the measured rotation angle; the deviation between the pre-calibrated center angle of each preset measurement point and the pre-calibrated center angle of the reference measurement point is calculated, which is recorded as the standard rotation angle; the pre-calibrated center angle is the circumferential angle of the preset measurement point relative to a reference position point with the laser tracker as the center; based on the measured rotation angle and the standard rotation angle, the measurement error of the rotation angle of the active target ball device of the mobile robot is calculated.

[0089] The embodiment of the present application provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the mobile robot active target ball device calibration method in any optional implementation of the above embodiment is executed to achieve the following functions: the mobile robot active target ball device is placed at a plurality of preset measurement points at least once in sequence, and the rotation angle measurement value when the reflective target ball of the mobile robot active target ball device is aligned with a laser tracker at each preset measurement point is obtained, which is recorded as a first angle value; the relative position between each preset measurement point and the laser tracker is fixed; one of the preset measurement points is used as a reference measurement point, and the deviation between the first angle value of each preset measurement point and the first angle value of the reference measurement point is calculated, which is recorded as the measured rotation angle; the deviation between the pre-calibrated center angle of each preset measurement point and the pre-calibrated center angle of the reference measurement point is calculated, which is recorded as the standard rotation angle; the pre-calibrated center angle is the circumferential angle of the preset measurement point relative to a reference position point with the laser tracker as the center; the measurement error of the rotation angle of the mobile robot active target ball device is calculated according to the measured rotation angle and the standard rotation angle. Among them, the computer-readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable red-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk or optical disk.

[0090] refer to Figure 3-Figure 6 The present application provides a mobile robot active target ball device calibration system, which is used to calibrate the measurement error of the rotation angle of the mobile robot active target ball device 90, including a laser tracker 1, a guide rail 2, a mobile measuring vehicle 5 and a host computer 4, the laser tracker 1 and the mobile measuring vehicle 5 are both connected to the host computer 4 for communication, and a plurality of preset measuring points are arranged at intervals on the guide rail 2, and the relative position between each preset measuring point and the laser tracker 1 is fixed (for example, the position of the preset measuring point and the position of the laser tracker 1 are fixed); The mobile measuring vehicle 5 is movably arranged on the guide rail 2 and used to install the mobile robot active target ball device 90, and is also used to carry the mobile robot active target ball device 90 to move to multiple preset measuring points at least once in sequence, and obtain the rotation angle measurement value of the reflective target ball of the mobile robot active target ball device when it is aligned with the laser tracker at each preset measuring point, which is recorded as the first angle value (refer to the above step A1 for details), and the first angle value is sent to the host computer 4; The upper computer 4 is used to use one of the preset measurement points as the reference measurement point, calculate the deviation between the first angle value of each preset measurement point and the first angle value of the reference measurement point, and record it as the measured rotation angle (specifically refer to step A2 of the previous text), calculate the deviation between the pre-calibrated center angle of each preset measurement point and the pre-calibrated center angle of the reference measurement point, and record it as the standard rotation angle (specifically refer to step A3 of the previous text), the pre-calibrated center angle is the circumferential angle of the preset measurement point relative to a reference position point with the laser tracker as the center, and calculate the measurement error of the rotation angle of the active target ball device of the mobile robot according to the measured rotation angle and the standard rotation angle (specifically refer to step A4 of the previous text).

[0091] The guide rail 2 may be a circular guide rail centered on the position of the laser tracker 1 (eg Figure 3 As shown), it can also be a linear guide (such as Figure 4 as shown).

[0092] Preferably, the preset measuring points are arranged at equal intervals on the guide rail 2, but this is not limited thereto.

[0093] In some preferred embodiments, the mobile measuring vehicle 5 includes a mobile base 501 and a rotating platform 502 disposed on the mobile base 501, and the rotating platform 502 is used to install the mobile robot active target ball device 90. Thus, the mobile robot active target ball device 90 can be driven to rotate as a whole by the rotating platform 502.

[0094] On this basis, in some embodiments, after calculating the deviation between the pre-calibrated center angle of each preset measurement point and the pre-calibrated center angle of the reference measurement point and recording it as the standard rotation angle, and before calculating the measurement error of the rotation angle of the active target ball device of the mobile robot according to the measured rotation angle and the standard rotation angle, the host computer 4 further executes: After sending a rotation instruction to the mobile measuring vehicle 5 to rotate the rotating table 502 of the mobile measuring vehicle 5 by a preset angle, sending a measurement instruction to the mobile measuring vehicle 5 to make the mobile measuring vehicle 5 collect the first angle value again (refer to step A1 in the previous text for the specific process), and calculating the measured rotation angle and the standard rotation angle based on the first angle value collected again by the mobile measuring vehicle 5 (refer to steps A2 and A3 in the previous text respectively), until the number of times the rotating table 502 rotates by the preset angle reaches a preset number threshold, and then calculating the measurement error of the rotation angle of the active target ball device of the mobile robot (refer to step A4 in the previous text for details).

[0095] Furthermore, a dual-axis fine motion platform 503 may be provided on the rotating table 502, and the dual-axis fine motion platform 503 is used to connect with the mobile robot active target ball device 90, and adjust the horizontal position of the mobile robot active target ball device 90, so that the rotation center axis of the reflective target ball of the mobile robot active target ball device 90 coincides with the rotation center axis of the rotating table 502, so as to avoid the misalignment of the rotation center axis of the reflective target ball with the rotation center axis of the rotating table 502, resulting in additional errors introduced by the rotation of the rotating table 502. The dual-axis fine motion platform 503 is a prior art, and will not be described in detail here.

[0096] In some embodiments, see Figure 6 The mobile measuring vehicle 5 also includes a central control device 504 (for example, an MCU module, a single-chip microcomputer, etc.), a battery 505, a servo motor 506, a rotating motor 507 and a communication module 508. The battery 505, the servo motor 506, the rotating motor 507 and the communication module 508 are all electrically connected to the central control device 504, and the mobile robot active target ball device 90 is electrically connected to the central control device 504 through a pluggable electrical connector; wherein the servo motor 506 is used to drive the mobile base 501 to move, the rotating motor 507 is used to drive the rotating table 502 to rotate, the communication module 508 is used to communicate with the host computer, and the battery 505 is used to supply power to the mobile measuring vehicle 5 and the mobile robot active target ball device 90.

[0097] Furthermore, in order to improve the positioning accuracy of the mobile measuring vehicle 5 at each preset measuring point, a laser sensor 509 can be provided on the mobile measuring vehicle 5, the laser sensor 509 is electrically connected to the central control device 504, and a laser reflector 6 for triggering the laser sensor 509 is provided at each preset measuring point. When the mobile measuring vehicle 5 moves to the point where the laser sensor 509 is aligned with the laser reflector 6, the laser sensor 509 receives the emission light emitted by the laser reflector 6, thereby stopping the movement of the mobile measuring vehicle 5. By positioning the mobile measuring vehicle 5 using the laser sensor 509 and the laser reflector 6, the mobile measuring vehicle 5 can accurately reach each preset measuring point.

[0098] Preferably, a measuring point identifier may be set at each preset measuring point, and an identification device 510 electrically connected to the central control device 504 may be set on the mobile measuring vehicle 5. The measuring point identifier is used to record the identity information of the corresponding preset measuring point, and the identification device 510 is used to identify the identity information in the measuring point identifier. Thus, the mobile measuring vehicle 5 collects the identity information of the corresponding preset measuring point while collecting the first angle value. After the identity information is sent to the host computer 4 together with the first angle value, it can help the host computer 4 to quickly associate the first angle value with the corresponding preset measuring point.

[0099] The measuring point identifier may be, but is not limited to, a QR code, an RFID tag, etc. Correspondingly, the identification device 510 may be, but is not limited to, a camera, an RFID tag reader / writer.

[0100] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of the devices or units can be electrical, mechanical or other forms.

[0101] In addition, the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, and may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0102] Furthermore, the functional modules in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0103] In this document, relational terms such as first and second, etc. are used merely to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0104] The above description is only an embodiment of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for calibrating an active target ball device of a mobile robot, used to calibrate the measurement error of the rotation angle of the active target ball device of the mobile robot, characterized in that: Includes steps: A1. Place the active target ball device of the mobile robot at multiple preset measurement points at least once in sequence, and obtain the rotation angle measurement value of the reflective target ball of the active target ball device of the mobile robot when it is aligned with the laser tracker at each preset measurement point, which is recorded as the first angle value; the relative position between each preset measurement point and the laser tracker is fixed; A2. Taking one of the preset measurement points as a reference measurement point, calculating the deviation between the first angle value of each preset measurement point and the first angle value of the reference measurement point, and recording it as the measured rotation angle; A3. Calculate the deviation between the pre-calibrated center angle of each of the preset measurement points and the pre-calibrated center angle of the reference measurement point, and record it as the standard rotation angle; the pre-calibrated center angle is the circumferential angle of the preset measurement point relative to a reference position point with the laser tracker as the center; A4. Calculate the measurement error of the rotation angle of the active target ball device of the mobile robot based on the measured rotation angle and the standard rotation angle.

2. The mobile robot active target ball device calibration method according to claim 1, characterized in that: The step of placing the mobile robot active target ball device at a plurality of preset measuring points at least once in sequence comprises: After the mobile robot active target ball device is installed on a mobile measuring vehicle, the mobile measuring vehicle carries the mobile robot active target ball device and moves to the plurality of preset measuring points in sequence at least once.

3. The mobile robot active target ball device calibration method according to claim 1, characterized in that: The preset measurement points are evenly distributed on a circle centered on the laser tracker; In step A1, the active target ball device of the mobile robot is placed at each of the preset measuring points at least once in a clockwise direction along the circumference, and is placed at each of the preset measuring points at least once in a counterclockwise direction.

4. The mobile robot active target ball device calibration method according to claim 1, characterized in that: The preset measuring points are arranged at intervals along a straight line; In step A1, the active target ball device of the mobile robot is placed at each of the preset measuring points at least once in sequence along the positive direction of the straight line, and is placed at each of the preset measuring points at least once in sequence along the negative direction of the straight line.

5. The mobile robot active target ball device calibration method according to claim 1, characterized in that: Step A4 includes: A401. Calculate the deviation between each measured rotation angle and the corresponding standard rotation angle, recorded as the first deviation; A402. Calculate the measurement error of the rotation angle of the active target ball device of the mobile robot based on the first deviation.

6. The mobile robot active target ball device calibration method according to claim 5, characterized in that: Step A402 includes: Preprocessing the first deviation; The average value of the first deviation after preprocessing is calculated as the measurement error of the rotation angle of the active target ball device of the mobile robot.

7. The mobile robot active target ball device calibration method according to claim 1, characterized in that: After step A3 and before step A4, the method further includes the following steps: A5. After the mobile robot active target ball device is rotated as a whole by a preset angle, return to step A1 and execute until the number of times the mobile robot active target ball device is rotated as a whole by the preset angle reaches a preset number threshold, then execute step A4.

8. An electronic device, characterized in that: It comprises a processor and a memory, wherein the memory stores a computer program executable by the processor, and when the processor executes the computer program, it runs the steps in the mobile robot active target ball device calibration method as described in any one of claims 1-7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the processor, the steps in the method for calibrating the active target ball device of a mobile robot as described in any one of claims 1-7 are executed.

10. A mobile robot active target ball device calibration system, used to calibrate the measurement error of the rotation angle of the mobile robot active target ball device, characterized in that: It includes a laser tracker, a guide rail, a mobile measuring vehicle and a host computer. The laser tracker and the mobile measuring vehicle are both connected to the host computer for communication. A plurality of preset measuring points are arranged at intervals on the guide rail. The relative position between each preset measuring point and the laser tracker is fixed. The mobile measuring vehicle is movably arranged on the guide rail and used to install the mobile robot active target ball device, and is also used to carry the mobile robot active target ball device to move to the plurality of preset measuring points at least once in sequence, and obtain the rotation angle measurement value when the reflective target ball of the mobile robot active target ball device is aligned with the laser tracker at each preset measuring point, which is recorded as the first angle value, and the first angle value is sent to the host computer; The host computer is used to take one of the preset measurement points as a reference measurement point, calculate the deviation between the first angle value of each preset measurement point and the first angle value of the reference measurement point, and record it as the measured rotation angle; calculate the deviation between the pre-calibrated center angle of each preset measurement point and the pre-calibrated center angle of the reference measurement point, and record it as the standard rotation angle; the pre-calibrated center angle is the circumferential angle of the preset measurement point relative to a reference position point with the laser tracker as the center; and calculate the measurement error of the rotation angle of the active target ball device of the mobile robot based on the measured rotation angle and the standard rotation angle.

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