Wheel spacing and wheel diameter calibration method and device for double-wheel differential mobile robot

Abstract

The application discloses a wheel spacing and wheel diameter calibration method and device for a double-wheel differential mobile robot. The method obtains a first parameter collected by a laser radar and a second parameter collected by an odometer during movement of the mobile robot, determines a relative pose of the mobile robot and calculates a pose, sets the calculated pose to be equal to the relative pose, establishes an over-determined equation set, and determines an optimal solution of the over-determined equation set, so as to obtain radii of two wheels of the mobile robot and wheel spacing. The relative pose of the pose at the end of the calibration process relative to the pose at the beginning, combined with the calculated pose of the odometer, simultaneously calibrates the radii of the two wheels of the mobile robot and the wheel spacing, eliminates an initial error, and improves the final calibration accuracy.

Description

Technical Field

[0001] This application relates to the field of robotics technology, and in particular to a method and apparatus for calibrating the wheel spacing and wheel diameter of a two-wheeled differential mobile robot. Background Technology

[0002] Currently, with rapid economic growth, rising labor costs, and increasing complexity in the labor field, robots replacing human workers has become a trend. Within the entire field of robotics, mobile robots are intelligent robots that operate in complex environments and possess self-organization, autonomous operation, and autonomous planning capabilities. Due to their inherent characteristics, determining their own position is a prerequisite for mobile robots to complete their various tasks.

[0003] However, traditional testing methods require the radii of the two wheels of the mobile robot to be known, and the distance between the two wheels is determined based on this. But in reality, since the two wheels of the mobile robot are made of rubber, the load radius and the unload radius are not the same. The load radius cannot be measured manually. If the calculation is performed directly based on the unload diameter, the final calibration accuracy will be greatly reduced. Summary of the Invention

[0004] In view of this, this application provides a method and apparatus for calibrating the wheel spacing and wheel diameter of a two-wheeled differential speed mobile robot to solve at least one of the technical problems in the prior art, namely, the mobile robot calibration results being affected by initial values ​​and the calibration accuracy being low.

[0005] The technical solution of this application is implemented as follows:

[0006] The first aspect of this application provides a method for calibrating the wheel spacing and wheel diameter of a two-wheeled differential speed mobile robot. The method is applied to the mobile robot, which is equipped with a lidar and an odometer. The method includes:

[0007] During the movement of the mobile robot, the first parameter collected by the lidar and the second parameter collected by the odometer are acquired respectively; the first parameter characterizes the relative pose of the mobile robot between the observation start time and the observation end time, and the second parameter includes the angular velocity parameters of the two wheels of the mobile robot and the observation duration.

[0008] Determine the calculated pose; the calculated pose is related to the second parameter, the respective radii of the two wheels of the mobile robot, and the wheel spacing.

[0009] By setting the calculated pose to be equal to the relative pose, an overdetermined set of equations related to multiple sets of relative poses and the second parameter is established, and the optimal solution of the overdetermined set of equations is determined.

[0010] Based on the optimal solution, the radius and wheel spacing of the two wheels of the mobile robot are determined.

[0011] Optionally, the relative pose includes an angle-relative pose; the calculated pose includes an angle-calculated pose.

[0012] The step of determining the calculated pose includes: determining the angle calculated pose based on the second parameter and the rotation parameter; the rotation parameter is related to the radius of each of the two wheels of the mobile robot and the wheel spacing;

[0013] The step of establishing an overdetermined system of equations related to multiple sets of relative poses and the second parameter by setting the calculated pose to be equal to the relative pose, and determining the optimal solution of the overdetermined system of equations, includes:

[0014] By setting the relative pose of the angle to be equal to the calculated pose of the angle, a first overdetermined set of equations related to the rotation parameter, multiple sets of the relative pose, and the second parameter is established, and the optimal solution of the rotation parameter is determined based on the first overdetermined set of equations.

[0015] Optionally, the relative pose further includes a distance-relative pose; the calculated pose further includes a distance-calculated pose; and determining the radius and wheel spacing of the two wheels of the mobile robot based on the optimal solution includes:

[0016] By setting the relative pose of the distance to be equal to the calculated pose of the distance, a second overdetermined equation set related to the wheel spacing, the optimal solution of the rotation parameter, multiple sets of the relative pose and the second parameter is established, and the wheel spacing is determined based on the second overdetermined equation set.

[0017] The radii of the two wheels of the mobile robot are determined based on the optimal solution of the wheel spacing and the rotation parameters.

[0018] Optionally, before acquiring the first parameter collected by the lidar and the second parameter collected by the odometer, the method further includes:

[0019] Multiple frames of detection data are acquired within a preset area; the detection data includes a first type of feature within the preset area and a second type of feature located on the mobile robot.

[0020] Based on the first type of features and the second type of features in any two adjacent frames of detection data in the multi-frame detection data, feature matching is performed, and the feature similarity of the two adjacent frames of detection data is determined based on the matching result.

[0021] When the feature similarity is greater than a first preset threshold, it is determined that the detection data of the two adjacent frames are successfully matched;

[0022] Determine the number of successfully matched adjacent two frames of detection data in the multi-frame detection data;

[0023] When the number of successful matches exceeds a second preset threshold, the preset site is determined to be the calibration site.

[0024] Within the calibrated area, the radius and wheel spacing of each of the two wheels of the mobile robot are determined.

[0025] Optionally, after determining the radius and wheel spacing of the robot's two wheels, the method includes:

[0026] Based on the radius and wheel spacing of the robot's two wheels, a reference calculated pose is determined;

[0027] Determine the error between the reference calculated pose and the standard pose acquired by the lidar, and obtain a first error value;

[0028] If the first error value does not exceed the third preset threshold, it is determined that the radius and wheel spacing of the robot's two wheels meet the calibration requirements.

[0029] Optionally, the method further includes:

[0030] The calculated pose of the mobile robot after moving a preset distance and the relative pose obtained by the lidar are periodically acquired; the calculated pose is determined based on the radius of each of the robot's two wheels and the wheel spacing.

[0031] Based on the calculated pose and the relative pose, the movement distance error and movement angle error of the mobile robot are determined.

[0032] If the distance error is greater than a fourth preset threshold and the angle error is greater than a fifth preset threshold, the radius and wheel spacing of the two wheels of the mobile robot are redefined.

[0033] A second aspect of this application provides a device for calibrating the wheel spacing and wheel diameter of a two-wheel differential speed mobile robot. The device is applied to the mobile robot, which is equipped with a lidar and an odometer. The device includes:

[0034] The acquisition module is used to acquire a first parameter collected by the lidar and a second parameter collected by the odometer during the movement of the mobile robot; the first parameter represents the relative pose of the mobile robot between the start and end times of the observation, and the second parameter includes the angular velocity parameters of the two wheels of the mobile robot and the observation duration.

[0035] The first determining module is used to determine the calculated pose; the calculated pose is related to the second parameter, the radius of each of the two wheels of the mobile robot, and the wheel spacing.

[0036] The second determining module is used to establish an overdetermined set of equations related to multiple sets of relative poses and the second parameter by setting the calculated pose to be equal to the relative pose, and to determine the optimal solution of the overdetermined set of equations.

[0037] The third determining module is used to determine the radius and wheel spacing of the two wheels of the mobile robot based on the optimal solution.

[0038] Optionally, the relative pose includes an angle-relative pose; the calculated pose includes an angle-calculated pose.

[0039] The first determining module is specifically used to: determine the angle and calculate the pose based on the second parameter and the rotation parameter; the rotation parameter is related to the radius and wheel spacing of the two wheels of the mobile robot;

[0040] The second determining module is specifically used to: establish a first overdetermined equation set related to the rotation parameter, multiple sets of the relative pose, and the second parameter by setting the angle relative pose to be equal to the angle calculated pose, and determine the optimal solution of the rotation parameter based on the first overdetermined equation set.

[0041] Optionally, the relative pose further includes a distance relative pose; the calculated pose further includes a distance calculated pose; the third determining module is specifically used for:

[0042] By setting the relative pose of the distance to be equal to the calculated pose of the distance, a second overdetermined equation set related to the wheel spacing, the optimal solution of the rotation parameter, multiple sets of the relative pose and the second parameter is established, and the wheel spacing is determined based on the second overdetermined equation set.

[0043] The radii of the two wheels of the mobile robot are determined based on the optimal solution of the wheel spacing and the rotation parameters.

[0044] Optionally, the device includes a field calibration module, the field calibration module being used for:

[0045] Multiple frames of detection data are acquired within a preset area; the detection data includes a first type of feature within the preset area and a second type of feature located on the mobile robot.

[0046] Based on the first type of features and the second type of features in any two adjacent frames of detection data in the multi-frame detection data, feature matching is performed, and the feature similarity of the two adjacent frames of detection data is determined based on the matching result.

[0047] When the feature similarity is greater than a first preset threshold, it is determined that the detection data of the two adjacent frames are successfully matched;

[0048] Determine the number of successfully matched adjacent two frames of detection data in the multi-frame detection data;

[0049] When the number of successful matches exceeds a second preset threshold, the preset site is determined to be the calibration site.

[0050] Within the calibrated area, the radius and wheel spacing of each of the two wheels of the mobile robot are determined.

[0051] Optionally, the device includes a verification module, the verification module being used for:

[0052] Based on the radius and wheel spacing of the robot's two wheels, a reference calculated pose is determined;

[0053] Determine the error between the reference calculated pose and the standard pose acquired by the lidar, and obtain a first error value;

[0054] If the first error value does not exceed the third preset threshold, it is determined that the radius and wheel spacing of the robot's two wheels meet the calibration requirements.

[0055] Optionally, the device includes a verification module, the verification module being used for:

[0056] The calculated pose of the mobile robot after moving a preset distance and the relative pose obtained by the lidar are periodically acquired; the calculated pose is determined based on the radius of each of the robot's two wheels and the wheel spacing.

[0057] Based on the calculated pose and the relative pose, the movement distance error and movement angle error of the mobile robot are determined.

[0058] If the distance error is greater than a fourth preset threshold and the angle error is greater than a fifth preset threshold, the radius and wheel spacing of the two wheels of the mobile robot are redefined.

[0059] A third aspect of this application provides an electronic device, the electronic device including a memory and a processor, wherein the memory stores instructions;

[0060] The processor is used to execute instructions stored in the memory, which, when executed by the processor, implement the steps of any of the methods described in the first aspect above.

[0061] A fourth aspect of this application provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, it implements the steps of the method described in any of the first aspects above.

[0062] This application provides a method and apparatus for calibrating the wheel spacing and wheel diameter of a two-wheeled differential mobile robot. The method acquires first parameters from a lidar sensor and second parameters from an odometer during the robot's movement to determine its relative and calculated poses. By setting the calculated pose equal to the relative pose, an overdetermined system of equations is established, and the optimal solution is determined, thereby obtaining the radius and wheel spacing of each wheel. This application establishes and solves the overdetermined system of equations by combining the relative pose at the end of the calibration process with the calculated pose from the odometer. Using accurate measurement parameters as the calculation basis, the radius and wheel spacing of the two wheels of the mobile robot are calibrated simultaneously, eliminating initial errors and improving the final calibration accuracy. Attached Figure Description

[0063] Figure 1 This is a flowchart illustrating the method for calibrating the wheel spacing and wheel diameter of a two-wheeled differential mobile robot provided in an embodiment of this application.

[0064] Figure 2 This is a schematic diagram of the pose of the mobile robot at the start of the observation.

[0065] Figure 3 This is a schematic diagram of the pose of the mobile robot at the end of the observation period;

[0066] Figure 4 This is a schematic diagram of the relative pose of the mobile robot between the start and end times of the observation.

[0067] Figure 5 This is a schematic diagram of the wheel spacing and wheel diameter calibration device for a two-wheeled differential mobile robot provided in an embodiment of this application.

[0068] Figure 6 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0069] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0070] Currently, determining the position of a mobile robot requires knowing the radii of its two wheels to determine the distance between them. However, in reality, because the robot's wheels are made of rubber, the load radius and the unloaded radius are not the same. The load radius cannot be measured manually, and directly calculating using the unloaded diameter would significantly reduce the final calibration accuracy. Based on this, the following embodiments of this application are proposed.

[0071] Please see Figure 1 , Figure 1 This is a flowchart illustrating the wheel spacing and wheel diameter calibration method for a two-wheeled differential speed mobile robot provided in this application embodiment. The method is applied to a mobile robot equipped with a lidar and an odometer. The method provided in this application includes...

[0072] S101, during the movement of the mobile robot, the first parameter collected by the lidar and the second parameter collected by the odometer are acquired respectively; the first parameter represents the relative pose of the mobile robot between the start and end of the observation, and the second parameter includes the angular velocity parameters of the two wheels of the mobile robot and the observation duration.

[0073] In one embodiment, see Figure 2 , Figure 3 and Figure 4 ,in, Figure 2 This is a schematic diagram of the mobile robot's pose at the start of the observation. Figure 3 This is a schematic diagram of the mobile robot's pose at the end of the observation. Figure 4 This diagram illustrates the relative pose of the mobile robot between the start and end of the observation. In the diagram, 20 represents the mobile robot at the start of the observation, 21 represents the obstacle, and 22 represents the mobile robot at the end of the observation.

[0074] Specifically, a spatial coordinate system is established. Based on the lidar, the pose of the mobile robot at the start of the observation is acquired, and this pose is used as the origin of the spatial coordinate system (0, 0, 0). The pose of the mobile robot at the end of the observation is acquired, and the spatial coordinates (s) of this pose relative to the origin are determined. x s y s θ Since the pose of the mobile robot at the start of observation is taken as the origin of the spatial coordinate system, the relative pose of the mobile robot between the start and end of observation is (s). x s y s θ ).

[0075] The angular velocity ω of the left wheel during the movement of the mobile robot can be measured by the odometer installed on it. L and the angular velocity ω of the right wheel R The observation duration ΔT is recorded, which is the difference between the end time and the start time of the observation.

[0076] S102, determine the calculated pose; the calculated pose is related to the second parameter, the radius of each of the two wheels of the mobile robot, and the wheel spacing.

[0077] The calculated pose of the mobile robot can be obtained by integrating the second parameter measured by the odometry.

[0078] Specifically, the calculated pose of the mobile robot can be represented as (r x r y r θ ),in,

[0079]

[0080]

[0081]

[0082] ω represents the angular velocity of the observation point on the mobile robot, J 21 and J 22 is a rotational parameter, which is related to the radius of each of the two wheels of the mobile robot and the wheel spacing; v(t) represents the linear velocity of the observation point on the mobile robot at time t, and b represents the wheel spacing between the left and right wheels of the mobile robot.

[0083] S103, by setting the calculated pose to be equal to the relative pose, establish an overdetermined set of equations related to multiple sets of relative poses and second parameters, and determine the optimal solution of the overdetermined set of equations.

[0084] The relative pose (s) of the mobile robot between the start and end times of observation, obtained based on lidar. x s y s θ ), and the calculated pose of the mobile robot based on odometry (r x r y r θ To establish an overdetermined system of equations, which is a system of equations where the number of equations is greater than the number of unknowns, let r be an example. θ =s θ r x =s x r y =s y The optimal solution is obtained based on multiple equations.

[0085] S104, based on the optimal solution, determine the radius and wheel spacing of the two wheels of the mobile robot.

[0086] For example, based on r θ =s θ Establish the first set of overdetermined equations, obtain the optimal solution to the overdetermined equations, and substitute the obtained optimal solution as known quantities into the equations based on r. x =s x r y =s y The second set of overdetermined equations was established, thereby determining the radii and wheel spacing of the two wheels of the mobile robot.

[0087] This application embodiment establishes and solves an overdetermined system of equations by combining the relative pose at the end of the calibration process with the initial pose, and using accurate measurement parameters as the basis for calculation. This simultaneously calibrates the two wheel radii and wheel spacing of the mobile robot, eliminating initial errors and improving the final calibration accuracy.

[0088] In one embodiment, relative pose includes angular relative pose; calculated pose includes angular calculated pose.

[0089] The pose is calculated based on the angle determined by the second parameter and the rotation parameter; the rotation parameter is related to the radius of each of the two wheels of the mobile robot and the wheel spacing.

[0090] By setting the relative pose of the angle to be equal to the calculated pose of the angle, a first set of overdetermined equations related to the rotation parameter, multiple sets of relative poses, and the second parameter is established, and the optimal solution of the rotation parameter is determined based on the first set of overdetermined equations.

[0091] In this embodiment, the angle relative to the pose is s. θ The pose is calculated by angle r. θ Based on r θ =s θ Establish the first overdetermined system of equations:

[0092]

[0093] Where, ω Ln For the nth set of measured left wheel angular velocity parameters, ω Rn For the nth set of measured right wheel angular velocity parameters, s θn The nth set of relative pose angles was measured.

[0094] make

[0095] Therefore, the optimal solution can be obtained by using the least squares method for the overdetermined system of equations. The rotational parameter J can then be obtained. 21 and rotational parameter J 22 .

[0096] In one embodiment, the relative pose further includes a distance relative pose; the calculated pose further includes a distance calculated pose.

[0097] By setting the distance relative pose to be equal to the distance calculation pose, a second overdetermined equation set related to the optimal solution of wheel spacing and rotation parameters, multiple sets of relative poses and second parameters is established, and the wheel spacing is determined based on the second overdetermined equation set.

[0098] The radii of the two wheels of the mobile robot are determined based on the optimal solution of the wheel spacing and rotation parameters.

[0099] In this embodiment, the distance relative to the pose is s. x s y The pose is calculated by angle r. x r y , let r x =s x =c x b, r y =s y =c y b. Establish the second set of overdetermined equations:

[0100]

[0101] in, n represents the (n+1)th set of parameters.

[0102] make

[0103] Therefore, by using the least squares method for the overdetermined system of equations, the optimal solution b = (B) is obtained. T B) -1 B T h, where b is the wheel spacing between the left and right wheels.

[0104] Given J 21 J 22 Based on b, the radii of the robot's left and right wheels can be obtained as follows:

[0105]

[0106]

[0107] In one embodiment, before acquiring the first parameter acquired by the lidar and the second parameter acquired by the odometer, the method further includes:

[0108] Acquire multiple frames of detection data within a preset area; the detection data includes first-type features within the preset area and second-type features located on the mobile robot.

[0109] Feature matching is performed based on the first and second type features in any two adjacent frames of detection data in multi-frame detection data, and the feature similarity between the two adjacent frames of detection data is determined based on the matching results.

[0110] When the feature similarity is greater than the first preset threshold, it is determined that the detection data of two adjacent frames are successfully matched;

[0111] Determine the number of successful matches between two adjacent frames of detection data in a multi-frame detection dataset;

[0112] When the number of successful matches exceeds the second preset threshold, the preset site is determined as the calibration site;

[0113] Within the calibrated area, determine the radius and wheel spacing of each of the two wheels of the mobile robot.

[0114] Before determining the radii and wheel spacing of the left and right wheels of the mobile robot, a suitable pre-defined site needs to be established. This pre-defined site must contain first-type features. Based on these first-type features, the positions of second-type features on the mobile robot are determined. The positions of these second-type features can be represented by establishing a spatial coordinate system.

[0115] For example, the robot is slowly pushed along a preset area for one revolution, obtaining 100 frames of image data through LiDAR detection. First and second type features of adjacent frames are matched, and the feature similarity between adjacent frames is determined based on the matching results. A successful match is considered to occur when the feature similarity is greater than a first preset threshold, where the first threshold can be an Euclidean distance value, the specific value of which can be determined based on experience or accuracy requirements. After all 100 frames of image data have been matched, if more than 90 matches are successful, the preset area is considered to meet the requirements. This preset area is used as a calibration area, and within the calibration area, the first and second parameters of the mobile robot are obtained, thereby determining the radius and wheel spacing of the robot's two wheels.

[0116] In this embodiment, feature matching of the detection data is completed through simple site conditions. It is only necessary to ensure that the first type of feature exists in the preset site, which reduces the requirements for the calibration site and frees the calibration algorithm from the mandatory requirements of the site and the lidar.

[0117] In one embodiment, after determining the radius and wheel spacing of the robot's two wheels, the process includes:

[0118] The reference calculated pose is determined based on the radius and wheel spacing of the robot's two wheels;

[0119] Determine the error between the reference calculated pose and the standard pose acquired by the lidar, and obtain the first error value;

[0120] If the first error value does not exceed the third preset threshold, it is determined that the radius and wheel spacing of the robot's two wheels meet the calibration requirements.

[0121] Based on the photoelectric encoder on the odometer, the arc traveled by the robot's wheels within a certain time period can be measured. This arc, combined with the calculated radii and wheel spacing of the robot's two wheels, is then used to determine a reference calculated pose. The reference calculated pose is compared with the standard pose acquired by the lidar. If the error between the two does not exceed a third preset threshold, the robot's wheel radii and wheel spacing meet the calibration requirements. Conversely, if the error exceeds the third preset threshold, the robot's wheel radii and wheel spacing do not meet the calibration requirements. The third preset threshold can be determined based on experience or calibration accuracy requirements.

[0122] In one embodiment, the calculated pose of the mobile robot after moving a preset distance and the relative pose obtained by the lidar are periodically acquired; the calculated pose is determined based on the radius of each of the robot's two wheels and the wheel spacing.

[0123] Based on the calculated pose and the relative pose, the movement distance error and movement angle error of the mobile robot are determined.

[0124] If the distance error exceeds the fourth preset threshold and the angle error exceeds the fifth preset threshold, the radius and wheel spacing of the two wheels of the mobile robot are redefined.

[0125] As robots are used and age, the original calibration parameters change. Therefore, it is necessary to verify the current calibration parameters regularly. When the verification fails, the invalid parameters can be promptly alerted to prevent the robot's positioning accuracy from decreasing and losing positioning after the calibration parameters become invalid.

[0126] For example, stop using the standard pose (s) of the lidar x s y s θ ) Reference calculated pose (r) for calibrating the odometer x r y r θ The mobile robot was instructed to move 100 meters to record the standard pose of the lidar. 100x s 100y s 100θ ) and the reference calculated pose of the odometer (r 100x ,r 100y ,r 100θBased on the standard pose and the reference calculated pose, the translation distance error ΔL and translation angle error Δθ are calculated, where,

[0127] ΔL=(s 100x -r 100x ) 2 +(s 100y -r 100y ) 2 ;

[0128] Δθ=|s 100θ -r 100θ |;

[0129] If the distance error ΔL is greater than the fourth preset threshold and the angle error Δθ is greater than the fifth preset threshold, it indicates that the previous calibration parameters have significant errors and need to be recalibrated to determine the radius and wheel spacing of the two wheels of the mobile robot.

[0130] Based on the foregoing embodiments, please refer to Figure 5 , Figure 5 This is a schematic diagram of the wheel spacing and wheel diameter calibration device for a two-wheeled differential mobile robot provided in an embodiment of this application. The wheel spacing and wheel diameter calibration device for this two-wheeled differential mobile robot is applied to a mobile robot equipped with a lidar and an odometer; the device includes:

[0131] The acquisition module 501 is used to acquire the first parameter collected by the lidar and the second parameter collected by the odometer during the movement of the mobile robot. The first parameter represents the relative pose of the mobile robot between the start and end of the observation. The second parameter includes the angular velocity parameters of the two wheels of the mobile robot and the observation duration.

[0132] Specifically, a spatial coordinate system is established. Based on the lidar, the pose of the mobile robot at the start of the observation is acquired, and this pose is used as the origin of the spatial coordinate system (0, 0, 0). The pose of the mobile robot at the end of the observation is acquired, and the spatial coordinates (s) of this pose relative to the origin are determined. x s y s θ Since the pose of the mobile robot at the start of observation is taken as the origin of the spatial coordinate system, the relative pose of the mobile robot between the start and end of observation is (s). x s y s θ ).

[0133] The odometer installed on the mobile robot can measure the angular velocity ω of the left wheel during the robot's movement. L and the angular velocity ω of the right wheel RThe observation duration ΔT is recorded, which is the difference between the end time and the start time of the observation.

[0134] The first determining module 502 is used to determine the calculated pose; the calculated pose is related to the second parameter, the radius of each of the two wheels of the mobile robot, and the wheel spacing.

[0135] The calculated pose of the mobile robot can be obtained by integrating the second parameter measured by the odometry. Specific examples are as described in the method examples above, and will not be repeated here.

[0136] The second determining module 503 is used to establish an overdetermined set of equations related to multiple sets of relative poses and second parameters by setting the calculated pose to be equal to the relative pose, and to determine the optimal solution of the overdetermined set of equations.

[0137] The relative pose (s) of the mobile robot between the start and end times of observation, obtained based on lidar. x s y s θ ), and the calculated pose of the mobile robot based on odometry (r x r y r θ To establish an overdetermined system of equations, which is a system of equations where the number of equations is greater than the number of unknowns, let r be an example. θ =s θ r x =s x r y =s y The optimal solution is obtained based on multiple equations.

[0138] The third determining module 504 is used to determine the radius and wheel spacing of the two wheels of the mobile robot based on the optimal solution.

[0139] For example, based on r θ =s θ Establish the first set of overdetermined equations, obtain the optimal solution to the overdetermined equations, and substitute the obtained optimal solution as known quantities into the equations based on r. x =s x r y =s y The second set of overdetermined equations was established, thereby determining the radii and wheel spacing of the two wheels of the mobile robot.

[0140] This application embodiment establishes and solves an overdetermined system of equations by combining the relative pose at the end of the calibration process with the initial pose, and using accurate measurement parameters as the basis for calculation. This simultaneously calibrates the two wheel radii and wheel spacing of the mobile robot, eliminating initial errors and improving the final calibration accuracy.

[0141] In one embodiment, relative pose includes angular relative pose; calculated pose includes angular calculated pose.

[0142] The first determining module 502 is specifically used to determine the pose based on the second parameter and the rotation parameter; the rotation parameter is related to the radius of each of the two wheels of the mobile robot and the wheel spacing;

[0143] The second determining module 503 is specifically used to establish a first overdetermined equation set related to the rotation parameter, multiple sets of relative poses and the second parameter by setting the relative pose of the angle to be equal to the calculated pose of the angle, and to determine the optimal solution of the rotation parameter based on the first overdetermined equation set.

[0144] In one embodiment, the relative pose further includes a distance relative pose; the calculated pose further includes a distance calculated pose.

[0145] The third determination module is specifically used to establish a second overdetermined equation set related to the wheel spacing, rotation parameters, multiple sets of relative poses, and second parameters by setting the relative pose to be equal to the calculated pose. The wheel spacing is then determined based on this second overdetermined equation set. Finally, the radii of the two wheels of the mobile robot are determined based on the optimal solution of the wheel spacing and rotation parameters.

[0146] In one embodiment, the wheel spacing and wheel diameter calibration device for a two-wheeled differential mobile robot includes a field calibration module, which is used for:

[0147] Acquire multiple frames of detection data within a preset area; the detection data includes first-class features within the preset area and second-class features located on the mobile robot.

[0148] Feature matching is performed based on the first and second type features in any two adjacent frames of detection data in multi-frame detection data, and the feature similarity between the two adjacent frames of detection data is determined based on the matching results.

[0149] When the feature similarity is greater than the first preset threshold, it is determined that the detection data of two adjacent frames are successfully matched;

[0150] Determine the number of successful matches between two adjacent frames of detection data in a multi-frame detection dataset;

[0151] When the number of successful matches exceeds the second preset threshold, the preset site is determined as the calibration site;

[0152] Within the calibrated area, determine the radius and wheel spacing of each of the two wheels of the mobile robot.

[0153] In one embodiment, the wheel spacing and wheel diameter calibration device for a two-wheeled differential mobile robot includes a verification module, which is used for:

[0154] The reference calculated pose is determined based on the radius and wheel spacing of the robot's two wheels;

[0155] Determine the error between the reference calculated pose and the standard pose acquired by the lidar, and obtain the first error value;

[0156] If the first error value does not exceed the third preset threshold, it is determined that the radius and wheel spacing of the robot's two wheels meet the calibration requirements.

[0157] In one embodiment, the wheel spacing and wheel diameter calibration device for a two-wheel differential mobile robot includes a calibration module, which is used for:

[0158] The calculated pose of the mobile robot after moving a preset distance and the relative pose obtained by the lidar are periodically acquired; the calculated pose is determined based on the radius of each of the robot's two wheels and the wheel spacing.

[0159] Based on the calculated pose and relative pose, the movement distance error and movement angle error of the mobile robot are determined.

[0160] If the distance error exceeds the fourth preset threshold and the angle error exceeds the fifth preset threshold, the radius and wheel spacing of the two wheels of the mobile robot are redefined.

[0161] It should be noted that the above method embodiments are also applicable to the wheel spacing and wheel diameter calibration device of the two-wheel differential mobile robot, and will not be described in detail here.

[0162] This application embodiment establishes and solves an overdetermined system of equations by combining the relative pose at the end of the calibration process with the initial pose, along with the calculated pose from the odometry. Using accurate measurement parameters as the basis for calculation, it simultaneously calibrates the wheel radii and wheel spacing of the mobile robot, eliminating initial errors and improving the final calibration accuracy. Furthermore, after calibrating the wheel radii and wheel spacing, this application verifies the accuracy of these calibration parameters to ensure the reliability of the calibration. Additionally, by periodically or irregularly inspecting the robot after prolonged use and aging, timely warnings are provided for invalid parameters, preventing a series of unexpected situations such as reduced robot positioning accuracy, easy loss of positioning, or even complete loss of positioning after calibration parameter failure.

[0163] This application also provides an electronic device, such as Figure 6 As shown, the electronic device includes a memory and a processor. The memory stores instructions, and the processor runs the instructions stored in the memory. When the instructions are run by the processor, the steps of the above-mentioned method for calibrating the wheel spacing and wheel diameter applied to a two-wheeled differential mobile robot can be implemented.

[0164] Optionally, the various components in an electronic device can be coupled together via a bus system. It is understood that the bus system is used to enable communication and connection between these components. In addition to a data bus, the bus system also includes a power bus, a control bus, and a status signal bus.

[0165] Alternatively, the memory can be implemented using any type of volatile or non-volatile storage device, or a combination thereof.

[0166] Optionally, the processor can be an integrated circuit chip with signal processing capabilities. In implementation, the steps of the above method can be completed through software instructions or through integrated hardware logic circuits. The processor can be a general-purpose processor, a digital signal processor (DSP), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0167] This application also provides a computer-readable storage medium storing a computer program thereon. When the computer program is executed by a processor, it can complete any step in the above-described method for calibrating the wheel spacing and wheel diameter of a two-wheeled differential mobile robot.

[0168] The methods disclosed in the several method embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments.

[0169] The features disclosed in the several product embodiments provided in this application can be arbitrarily combined without conflict to obtain new product embodiments.

[0170] The features disclosed in the several method or device embodiments provided in this application can be arbitrarily combined without conflict to obtain new method or device embodiments.

[0171] In the several embodiments provided in this application, it should be understood that the disclosed methods, apparatus, and storage media can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple modules or components can be combined, or integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or modules can be electrical, mechanical, or other forms.

[0172] The modules described above as separate components may or may not be physically separate. The components shown as modules may or may not be physical units, that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules may be selected to achieve the purpose of this embodiment according to actual needs.

[0173] In addition, each functional module in the various embodiments of this application can be integrated into one processing module, or each module can be a separate module, or two or more modules can be integrated into one module; the integrated module can be implemented in hardware or in the form of hardware plus software functional modules.

[0174] 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 capable of storing program code, such as mobile storage devices, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0175] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for calibrating the wheel spacing and wheel diameter of a two-wheeled differential speed mobile robot, characterized in that, The method is applied to a mobile robot, which is equipped with a lidar and an odometer; the method includes: Multiple frames of detection data are acquired within a preset area; the detection data includes a first type of feature within the preset area and a second type of feature located on the mobile robot. Based on the first type of features and the second type of features in any two adjacent frames of detection data in the multi-frame detection data, feature matching is performed, and the feature similarity of the two adjacent frames of detection data is determined based on the matching result. When the feature similarity is greater than a first preset threshold, it is determined that the detection data of the two adjacent frames are successfully matched; Determine the number of successfully matched adjacent two frames of detection data in the multi-frame detection data; When the number of successful matches exceeds a second preset threshold, the preset site is determined to be the calibration site. Within the calibration area, determine the radius and wheel spacing of each of the two wheels of the mobile robot; During the movement of the mobile robot, the first parameter collected by the lidar and the second parameter collected by the odometer are acquired respectively; the first parameter characterizes the relative pose of the mobile robot between the observation start time and the observation end time, and the second parameter includes the angular velocity parameters of the two wheels of the mobile robot and the observation duration. Determine the calculated pose; the calculated pose is related to the second parameter, the respective radii of the two wheels of the mobile robot, and the wheel spacing. By setting the calculated pose to be equal to the relative pose, an overdetermined set of equations related to multiple sets of relative poses and the second parameter is established, and the optimal solution of the overdetermined set of equations is determined. Based on the optimal solution, the radius and wheel spacing of the two wheels of the mobile robot are determined.

2. The method according to claim 1, characterized in that, The relative pose includes the angular relative pose; the calculated pose includes the angular calculated pose; The step of determining the calculated pose includes: determining the angle calculated pose based on the second parameter and the rotation parameter; the rotation parameter is related to the radius of each of the two wheels of the mobile robot and the wheel spacing; The step of establishing an overdetermined system of equations related to multiple sets of relative poses and the second parameter by setting the calculated pose to be equal to the relative pose, and determining the optimal solution of the overdetermined system of equations, includes: By setting the relative pose of the angle to be equal to the calculated pose of the angle, a first overdetermined set of equations related to the rotation parameter, multiple sets of the relative pose, and the second parameter is established, and the optimal solution of the rotation parameter is determined based on the first overdetermined set of equations.

3. The method according to claim 2, characterized in that, The relative pose further includes a distance relative pose; the calculated pose further includes a distance calculated pose; determining the radius and wheel spacing of the two wheels of the mobile robot based on the optimal solution includes: By setting the relative pose of the distance to be equal to the calculated pose of the distance, a second overdetermined equation set related to the wheel spacing, the optimal solution of the rotation parameter, multiple sets of the relative pose and the second parameter is established, and the wheel spacing is determined based on the second overdetermined equation set. The radii of the two wheels of the mobile robot are determined based on the optimal solution of the wheel spacing and the rotation parameters.

4. The method according to claim 1, characterized in that, After determining the radius and wheel spacing of the robot's two wheels, the method includes: Based on the radius and wheel spacing of the robot's two wheels, a reference calculated pose is determined; Determine the error between the reference calculated pose and the standard pose acquired by the lidar, and obtain a first error value; If the first error value does not exceed the third preset threshold, it is determined that the radius and wheel spacing of the robot's two wheels meet the calibration requirements.

5. The method according to claim 1, characterized in that, The method further includes: The calculated pose of the mobile robot after moving a preset distance and the relative pose obtained by the lidar are periodically acquired; the calculated pose is determined based on the radius of each of the robot's two wheels and the wheel spacing. Based on the calculated pose and the relative pose, the movement distance error and movement angle error of the mobile robot are determined. If the distance error is greater than a fourth preset threshold and the angle error is greater than a fifth preset threshold, the radius and wheel spacing of the two wheels of the mobile robot are redefined.

6. A device for calibrating the wheel spacing and wheel diameter of a two-wheeled differential speed mobile robot, characterized in that, The device is applied to a mobile robot, which is equipped with a lidar and an odometer; the device includes: A calibration module is used to acquire multiple frames of detection data within a preset area. The detection data includes a first type of feature within the preset area and a second type of feature located on the mobile robot. Feature matching is performed based on the first and second types of features in any two adjacent frames of detection data. The feature similarity between the two adjacent frames is determined based on the matching result. When the feature similarity is greater than a first preset threshold, the two adjacent frames are determined to be successfully matched. The number of successfully matched adjacent frames is determined. When the number of successfully matched frames is greater than a second preset threshold, the preset area is determined to be a calibration area. Within the calibration area, the radius and wheel spacing of each of the two wheels of the mobile robot are determined. The acquisition module is used to acquire a first parameter collected by the lidar and a second parameter collected by the odometer during the movement of the mobile robot; the first parameter represents the relative pose of the mobile robot between the start and end times of the observation, and the second parameter includes the angular velocity parameters of the two wheels of the mobile robot and the observation duration. The first determining module is used to determine the calculated pose; the calculated pose is related to the second parameter, the radius of each of the two wheels of the mobile robot, and the wheel spacing. The second determining module is used to establish an overdetermined set of equations related to multiple sets of relative poses and the second parameter by setting the calculated pose to be equal to the relative pose, and to determine the optimal solution of the overdetermined set of equations. The third determining module is used to determine the radius and wheel spacing of the two wheels of the mobile robot based on the optimal solution.

7. The apparatus according to claim 6, characterized in that, The relative pose includes the angular relative pose; the calculated pose includes the angular calculated pose; The first determining module is specifically used to: determine the angle and calculate the pose based on the second parameter and the rotation parameter; the rotation parameter is related to the radius and wheel spacing of the two wheels of the mobile robot; The second determining module is specifically used to: establish a first overdetermined equation set related to the rotation parameter, multiple sets of the relative pose, and the second parameter by setting the angle relative pose to be equal to the angle calculated pose, and determine the optimal solution of the rotation parameter based on the first overdetermined equation set.

8. The apparatus according to claim 7, characterized in that, The relative pose further includes a distance relative pose; the calculated pose further includes a distance calculated pose; the third determining module is specifically used for: By setting the relative pose of the distance to be equal to the calculated pose of the distance, a second overdetermined equation set related to the wheel spacing, the optimal solution of the rotation parameter, multiple sets of the relative pose and the second parameter is established, and the wheel spacing is determined based on the second overdetermined equation set. The radii of the two wheels of the mobile robot are determined based on the optimal solution of the wheel spacing and the rotation parameters.

9. The apparatus according to claim 6, characterized in that, The device includes a verification module, the verification module being used for: Based on the radius and wheel spacing of the robot's two wheels, a reference calculated pose is determined; Determine the error between the reference calculated pose and the standard pose acquired by the lidar, and obtain a first error value; If the first error value does not exceed the third preset threshold, it is determined that the radius and wheel spacing of the robot's two wheels meet the calibration requirements.

10. The apparatus according to claim 6, characterized in that, The device includes a verification module, the verification module being used for: The calculated pose of the mobile robot after moving a preset distance and the relative pose obtained by the lidar are periodically acquired; the calculated pose is determined based on the radius of each of the robot's two wheels and the wheel spacing. Based on the calculated pose and the relative pose, the movement distance error and movement angle error of the mobile robot are determined. If the distance error is greater than a fourth preset threshold and the angle error is greater than a fifth preset threshold, the radius and wheel spacing of the two wheels of the mobile robot are redefined.

11. An electronic device, characterized in that, The electronic device includes a memory and a processor, wherein the memory stores instructions; The processor is used to execute instructions stored in the memory, which, when executed by the processor, implement the steps of the method according to any one of claims 1 to 5.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 5.

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