Calibration method, program product and calibration device for positioning device and odometer

Abstract

The present invention provides a positioning device calibration method for calibrating a positioning device of an autonomous mobile device. The positioning device is fixedly mounted on the autonomous mobile device and is capable of outputting position and posture information. The positioning device calibration method comprises: causing the autonomous mobile device to move at a uniform speed along at least two arc-shaped motion paths with unequal radii on a plane, wherein during movement along each motion path, a set of position and posture information output by the positioning device is recorded at at least two different measurement moments; and determining calibration parameters of the positioning device based on the at least two sets of position and posture information output by the positioning device, wherein the calibration parameters of the positioning device represent the position and orientation of the positioning device in the autonomous mobile device. The present invention also relates to an odometer calibration method, a computer program product, and a calibration device for calibrating an odometer of the autonomous mobile device. With the aid of the present invention, the positioning device and odometer can be calibrated efficiently and accurately.

Description

Technical Field

[0001] The present invention relates to the field of positioning of autonomous mobile devices, and in particular to a positioning device calibration method for calibrating a positioning device of an autonomous mobile device, an odometer calibration method for calibrating an odometer of an autonomous mobile device, and corresponding computer program products and calibration devices. Background Art

[0002] With rapid economic growth, rising labor costs, and increasingly complex labor markets, autonomous mobile devices, such as mobile robots, are becoming increasingly widespread. Determining the position of autonomous mobile devices is a prerequisite for completing their various tasks and has long been a hot topic of research in academia and industry. This often requires the involvement of an odometry system, which provides the displacement of the autonomous mobile device and serves as the input for its position or position calculation. Clearly, a more accurate odometry system facilitates the positioning of autonomous mobile devices. One method for improving odometry accuracy is accurate calibration.

[0003] Typically, to calibrate the odometry of an autonomous mobile device, either offline calibration or online calibration can be used.

[0004] Offline calibration requires manual measurement to obtain the pose of the autonomous mobile device (such as measuring with a ruler or obtaining it from scale paper). This may introduce measurement errors manually, is not automated, and is inefficient.

[0005] Online calibration uses an external sensing positioning device (e.g., a laser positioning sensor) mounted on the autonomous mobile device to estimate its position and pose in real time, enabling automated labeling. However, due to installation errors in external sensing positioning devices, new systematic errors are introduced into the measurement information. Therefore, calibration of these external sensing positioning devices is also necessary.

[0006] Currently, an online calibration method has been published. It uses two error calibration filters (EKFs) to iteratively calibrate the odometry system error and the external sensing positioning device installation error, ignoring the error of one when calibrating the other. This method has strong nonlinearity and is complex to operate. Furthermore, the six parameters that cause the error are divided into linear and nonlinear according to the robot's motion model. The nonlinear parameter estimation requires a large number of nonlinear calculations, and the coupling relationship between the parameters is not easy to intuitively understand.

[0007] The existing technology still has many deficiencies in the calibration of odometers and positioning devices for autonomous mobile devices. Summary of the Invention

[0008] The object of the present invention is to provide an improved method for calibrating a positioning device and an odometer of an autonomous mobile device, so as to overcome the above-mentioned deficiencies of the prior art in at least one aspect.

[0009] According to a first aspect of the present invention, a positioning device calibration method for calibrating a positioning device of an autonomous mobile device is provided, wherein the positioning device is fixedly mounted on the autonomous mobile device and configured to output position and posture information of the positioning device, wherein the positioning device calibration method comprises the following steps:

[0010] The autonomous mobile device is caused to move at a uniform speed on a plane along at least two arc-shaped motion paths having unequal radii, wherein during the movement along each motion path, a set of position and posture information output by the positioning device is recorded at a set of at least two different measurement moments; and

[0011] The calibration parameters of the positioning device are determined according to at least two sets of position and posture information output by the positioning device, wherein the calibration parameters of the positioning device represent the position and orientation of the positioning device in the autonomous mobile device.

[0012] Optionally, the calibration parameters of the positioning device include the horizontal coordinate of the origin of the coordinate system of the positioning device in the coordinate system of the autonomous mobile device. R x S and the vertical axis R y S and the angle θ between the coordinate system of the positioning device and the coordinate system of the autonomous mobile device S .

[0013] Optionally, the calibration parameters of the positioning device are determined by the property that the position and posture of the positioning device on the autonomous mobile device remain unchanged during movement.

[0014] Optionally, the number of each group of measurement moments is greater than 2.

[0015] Optionally, the motion path is a complete circle.

[0016] Optionally, the posture information represents the posture of the positioning device in the world coordinate system.

[0017] Optionally, the coordinate origin of the positioning device is in the coordinate system of the autonomous mobile device. R x S and the vertical axis R y S The following formula is used to obtain the at least two sets of posture information:

[0018]

[0019] in, and They represent the horizontal and vertical coordinates and attitude angle of the positioning device in the world coordinate system at the k+1th measurement moment, k>0, θ0 represents the attitude angle of the autonomous mobile device in the world coordinate system at the first measurement moment, θ k_0 represents the rotation angle of the autonomous mobile device from the 1st measurement moment to the k+1th measurement moment, and ρ represents the radius of the motion path of the autonomous mobile device.

[0020] Optionally, the angle θ of the coordinate system of the positioning device relative to the coordinate system of the autonomous mobile device is S It is derived from the following formula:

[0021]

[0022] θ k =θ0+θ k_0

[0023] Among them, θ k represents the attitude angle of the autonomous mobile device in the world coordinate system at the k+1th measurement moment.

[0024] Optionally, the position and posture information represents the position and posture of the positioning device in the coordinate system of the positioning device at the first measurement moment in each group of measurement moments.

[0025] Optionally, the calibration parameters of the positioning device R x S 、 R y S and θ S The following formula is used to obtain the at least two sets of posture information:

[0026]

[0027]

[0028] in, and Respectively represent the horizontal and vertical coordinates and attitude angle of the positioning device at the k+1th measurement time in the coordinate system of the positioning device at the corresponding 1st measurement time, k>0, θ (k-1)_0 represents the rotation angle of the autonomous mobile device from the first measurement moment to the kth measurement moment, θ k_(k-1) represents the rotation angle of the autonomous mobile device from the kth measurement moment to the k+1th measurement moment, and ρ represents the radius of the motion path of the autonomous mobile device.

[0029] Optionally, the position and posture information represents the position and posture of the positioning device in the coordinate system of the positioning device at a previous measurement moment in each group of measurement moments.

[0030] Optionally, the calibration parameters of the positioning device R xS 、 R y S and θ S The following formula is used to obtain the at least two sets of posture information:

[0031]

[0032] in, and They represent the horizontal and vertical coordinates and attitude angle of the positioning device at the k+1th measurement time in the coordinate system of the positioning device at the kth measurement time, respectively. and They represent the horizontal and vertical coordinates and attitude angle of the positioning device in the coordinate system of the positioning device at the kth measurement moment, respectively, k>0, θ k_(k-1) represents the rotation angle of the autonomous mobile device from the kth measurement moment to the k+1th measurement moment, and ρ represents the radius of the motion path of the autonomous mobile device.

[0033] Optionally, the number of each group of measurement moments is greater than 2, and the intervals between each group of measurement moments are equal.

[0034] Optionally, the calibration parameters of the positioning device R x S 、 R y S and θ S The following formula is used to obtain the at least two sets of posture information:

[0035]

[0036] in, and They represent the horizontal and vertical coordinates and attitude angle of the positioning device at the k+1th measurement time in the coordinate system of the positioning device at the kth measurement time, respectively. and They represent the horizontal and vertical coordinates and attitude angle of the positioning device in the coordinate system of the positioning device at the kth measurement moment, respectively, k>0, and the left side of the equation represents the average value of the posture change between the two measurement moments, θ k_(k-1) represents the rotation angle of the autonomous mobile device from the kth measurement moment to the k+1th measurement moment, and ρ represents the radius of the motion path of the autonomous mobile device.

[0037] Optionally, the at least two motion paths include at least three motion paths.

[0038] Optionally, the calibration parameters of the positioning device are determined by optimizing an objective function, wherein the objective function minimizes the total error of the calculation results under all motion paths with different radii.

[0039] Optionally, the at least three motion paths are divided into a plurality of groups of motion paths each including two motion paths, and the posture information corresponding to each group of motion paths is processed and a standard deviation and a mean of the processing results are determined.

[0040] Optionally, if the standard deviation is large, recalibrate.

[0041] According to a second aspect of the present invention, there is provided an odometer calibration method for calibrating an odometer of an autonomous mobile device, wherein the autonomous mobile device has a differential wheel motion system, and the odometer calibration method comprises: performing automatic calibration using a positioning device installed on the autonomous mobile device, wherein the positioning device is calibrated by the positioning device calibration method according to the present invention.

[0042] Optionally, the calibration parameters of the odometer include the left wheel radius r of the autonomous mobile device L , right wheel radius r R and wheelbase b, left wheel radius r L , the right wheel radius rR and wheelbase b are obtained using the following formula:

[0043]

[0044]

[0045] Where ω represents the angular velocity of the coordinate system of the autonomous mobile device, ω R and ω L represent the angular velocity of the left wheel and the angular velocity of the right wheel respectively.

[0046] Optionally, the calibration parameters of the odometer are determined together with the calibration parameters of the positioning device in step S2 of the positioning device calibration method.

[0047] Optionally, in the case where a group of measurement moments with a total number greater than 2 are separated by equal time intervals T, the calibration parameters of the odometer and / or the calibration parameters of the positioning device are calculated using the following formula.

[0048] θ k_(k-1) =T·ω

[0049] Among them, θ k(k-1) represents the rotation angle of the autonomous mobile device from the kth measurement moment to the k+1th measurement moment.

[0050] According to a third aspect of the present invention, a computer program product is provided, comprising computer program instructions, wherein, when the computer program instructions are executed by one or more processors, the processors are capable of executing the positioning device calibration method according to the present invention or the odometer calibration method according to the present invention.

[0051] According to a fourth aspect of the present invention, a calibration device is provided, which includes a processor and a computer-readable storage device communicatively connected to the processor, wherein a computer program is stored in the computer-readable storage device. When the computer program is executed by the processor, it is used to implement the positioning device calibration method according to the present invention or the odometer calibration method according to the present invention.

[0052] The present invention determines the position and posture of a positioning device on an autonomous mobile device through at least two circular motions of the device. Simultaneously, it can also determine the calibration parameters of the odometer. This calibration method is simple to operate, produces accurate results, and is fast. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The present invention will be described in more detail below with reference to the accompanying drawings, so that the principles, features and advantages of the present invention can be better understood. The accompanying drawings include:

[0054] Figure 1 A positioning device calibration method for calibrating a positioning device of an autonomous mobile device according to an exemplary embodiment of the present invention is schematically illustrated;

[0055] Figure 2 Schematically illustrates an autonomous mobile device moving along an arc-shaped motion path according to an exemplary embodiment of the present invention; and

[0056] Figure 3 A calibration device according to an exemplary embodiment of the present invention is schematically shown. DETAILED DESCRIPTION

[0057] In order to make the technical problems, technical solutions and beneficial technical effects to be solved by the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and multiple exemplary embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the scope of protection of the present invention.

[0058] The present invention is applicable to autonomous mobile devices, which can be any mechanical device capable of autonomous spatial movement, such as unmanned vehicles, drones, robots, etc. For example, autonomous mobile devices can be warehouse robots, cleaning robots, home care robots, welcoming robots, etc.

[0059] Autonomous mobile devices are usually equipped with an odometer (proprioception sensor). During the movement of the autonomous mobile device, the odometer can output data such as the moving distance and angle of the autonomous mobile device. The odometer mainly calculates the change in the distance and direction angle of the autonomous mobile device relative to the ground based on the change in the pulse of the photoelectric encoder within the sampling period, thereby calculating the initial position of the autonomous mobile device in the semantic map. Autonomous mobile devices are also usually equipped with external perception positioning devices, such as lidar, depth cameras, etc. The positioning device can be any positioning device based on the TOF positioning principle. The positioning device can determine the posture of the positioning device, and can be used to determine the posture of the autonomous mobile device after calibration.

[0060] The following describes in detail the positioning device calibration process and the odometer calibration process of the present invention in conjunction with the accompanying drawings.

[0061] Figure 1 A method for calibrating a positioning device of an autonomous mobile device according to an exemplary embodiment of the present invention is schematically shown. The positioning device is fixedly mounted on the autonomous mobile device and configured to output position information of the positioning device. The positioning device calibration method comprises the following steps:

[0062] Step S1: moving the autonomous mobile device at a constant speed along at least two circular arc-shaped motion paths with unequal radii on a plane, such as a flat ground, wherein, during the movement along each motion path, a set of position and posture information output by a positioning device is recorded at a set of at least two different measurement times; and

[0063] Step S2: determining calibration parameters of the positioning device based on at least two sets of position information output by the positioning device, wherein the calibration parameters of the positioning device represent the position and orientation of the positioning device in the autonomous mobile device.

[0064] Thus, the position and attitude of the positioning device on the autonomous mobile device can be determined by the circular motion of the autonomous mobile device. This positioning device calibration method is simple to operate, has accurate calibration results, and is fast. It should be understood that the posture information includes position information and attitude angle information.

[0065] Step S1 may specifically include the following steps:

[0066] Step S11: the autonomous mobile device is caused to move at a uniform speed along a circular arc-shaped motion path having a first radius on a plane, wherein a first set of position and posture information output by a positioning device is recorded at a first set of at least two different measurement moments during the motion process;

[0067] Step S12: the autonomous mobile device is caused to move at a uniform speed on a plane along an arc-shaped motion path having a second radius different from the first radius, wherein a second set of position and posture information output by the positioning device is recorded at a second set of at least two different measurement moments during the motion process;

[0068] In step S1 , the number of each group of measurement moments is at least 2. Optionally, the number of each group of measurement moments is greater than 2.

[0069] Optionally, the motion path is a complete circle. The motion path can also be an arc smaller or larger than 360°.

[0070] Figure 2 The figure schematically shows an autonomous mobile device moving along an arc-shaped motion path according to an exemplary embodiment of the present invention. Figure 2 The world coordinate system XO is shown in W Y, coordinate system XO of autonomous mobile device R Y and the coordinate system XO of the positioning device S Y. The autonomous mobile device has a differential wheel motion system. The differential wheel motion system includes two driving wheels: a left wheel and a right wheel, wherein the radius of the left wheel is r L , the right wheel radius is r R , wheelbase is b. Coordinate system XO of autonomous mobile device R Origin of Y R Located at the center of the two drive wheel axes, the X direction can point to the forward direction of the autonomous mobile device, and the Y direction can point to the left wheel of the autonomous mobile device. The calibration parameters of the odometer may include the radius r of the left wheel of the autonomous mobile device. L , right wheel radius r R and wheelbase b.

[0071] According to the present invention, an odometer calibration method for calibrating an odometer of an autonomous mobile device may include: performing automatic calibration using a positioning device installed on the autonomous mobile device, wherein the positioning device is calibrated by the positioning device calibration method according to the present invention.

[0072] According to the motion model of the two-wheel differential motion system, the angular velocity ω of the autonomous mobile device satisfies the following formula (1):

[0073]

[0074] Among them, ω R and ω L Represent the angular velocity of the right wheel and the left wheel respectively. By setting the appropriate ω R and ω L The autonomous mobile device can be moved along a circular motion path. R and ω LIt can be further used to determine the calibration parameters of the odometer and the calibration parameters of the positioning device.

[0075] When an autonomous mobile device moves along a circular path at a uniform speed on a plane, the radius of the path can be expressed by formula (2):

[0076]

[0077] Where ρ represents the radius of the motion path.

[0078] Left wheel radius r of autonomous mobile device L , right wheel radius r R and wheelbase b can be obtained using the above formulas (1) and (2).

[0079] As mentioned above, the positioning device is fixedly mounted on the autonomous mobile device, and the mounting plane of the positioning device can be parallel to the movement plane of the autonomous mobile device, that is, the ground. The calibration parameters of the positioning device may include the horizontal coordinate of the origin of the coordinate system of the positioning device in the coordinate system of the autonomous mobile device. R x S and the vertical axis R y S and the angle θ between the coordinate system of the positioning device and the coordinate system of the autonomous mobile device S θ S It can be expressed as the angle between the X-axis of the coordinate system of the positioning device and the X-axis of the coordinate system of the autonomous mobile device. Since the positioning device is fixedly installed on the autonomous mobile device, the position and posture of the positioning device on the autonomous mobile device at any time ( R x S , R y S ,θ S ) remain unchanged, and the calibration parameters of the positioning device can be determined by this rigid body position invariance.

[0080] Figure 2 The figure schematically shows the position of the autonomous mobile device moving along an arc-shaped motion path at the first measurement moment in a set of measurement moments using a solid line, and the figure schematically shows the position of the autonomous mobile device moving along the same motion path at the second measurement moment in the same set of measurement moments using a dotted line.

[0081] In an exemplary embodiment, the pose information represents the pose of the positioning device in a world coordinate system.

[0082] The horizontal coordinate of the origin of the coordinate system of the positioning device in the coordinate system of the autonomous mobile device R x S and the vertical axis R y SThe following formula (3) can be used to obtain the at least two sets of posture information:

[0083]

[0084] in, and They represent the horizontal and vertical coordinates and attitude angle of the positioning device in the world coordinate system at the first measurement moment, and They represent the horizontal and vertical coordinates and attitude angle of the positioning device in the world coordinate system at the k+1th measurement moment, k>0, θ0 represents the attitude angle of the autonomous mobile device in the world coordinate system at the first measurement moment, θ k_0 represents the rotation angle of the autonomous mobile device from the 1st measurement moment to the k+1th measurement moment, and ρ represents the radius of the motion path of the autonomous mobile device.

[0085] According to formula (3), when the autonomous mobile device moves along an arc-shaped trajectory, the change in the position of the positioning device at the kth measurement moment relative to the first measurement moment in the world coordinate system can be determined by the following parameters: the attitude angle θ0 of the autonomous mobile device in the world coordinate system at the first measurement moment, the rotation angle θ of the autonomous mobile device from the first measurement moment to the k+1th measurement moment k_0 , the horizontal coordinate of the origin of the positioning device's coordinate system in the coordinate system of the autonomous mobile device R x S and the vertical axis R y S and the radius ρ of the motion path of the autonomous mobile device. Measurements by the positioning device can reveal the position of the positioning device relative to the world coordinate system at different measurement times. By moving the autonomous mobile device along at least two circular arc-shaped trajectories with different radii, sufficient equations can be generated to solve for the unknown parameters.

[0086] In step S2, formula (3) can be combined with formula (1) and formula (2) so that the calibration parameters of the odometer and the calibration parameters of the positioning device are determined together.

[0087] The angle θ between the coordinate system of the positioning device and the coordinate system of the autonomous mobile device S It can be obtained by the following formula:

[0088]

[0089] θ k =θ0+θ k_0

[0090] Among them, θ k represents the attitude angle of the autonomous mobile device in the world coordinate system at the k+1th measurement moment.

[0091] In an exemplary embodiment, the position information represents the position of the positioning device in the coordinate system of the positioning device at the first measurement moment in each group of measurement moments. This is particularly applicable when a global map is not available.

[0092] Calibration parameters of positioning device R x S 、 R y S and θ S The following formula (4) can be used to obtain the at least two sets of posture information:

[0093]

[0094] in, and Respectively represent the horizontal and vertical coordinates and attitude angle of the positioning device at the k+1th measurement time in the coordinate system of the positioning device at the corresponding 1st measurement time, k>0, θ (k-1)_0 represents the rotation angle of the autonomous mobile device from the first measurement moment to the kth measurement moment, θ k_(k-1) represents the rotation angle of the autonomous mobile device from the kth measurement moment to the k+1th measurement moment, and ρ represents the radius of the motion path of the autonomous mobile device. In step S2, formula (4) can be combined with formula (1) and formula (2) to determine the calibration parameters of the odometer and the calibration parameters of the positioning device together.

[0095] To simplify the solution, in an exemplary embodiment, the position information represents the position of the positioning device in the coordinate system of the positioning device at the previous measurement time in each set of measurement time. This is also particularly applicable when a global map is not available.

[0096] Calibration parameters of positioning device R x S 、 R y S and θ S The following formula (5) is used to obtain the at least two sets of posture information:

[0097]

[0098] in, and They represent the horizontal and vertical coordinates and attitude angle of the positioning device at the k+1th measurement time in the coordinate system of the positioning device at the kth measurement time, respectively. and They represent the horizontal and vertical coordinates and attitude angle of the positioning device in the coordinate system of the positioning device at the kth measurement moment, respectively, k>0, θk_(k-1) represents the rotation angle of the autonomous mobile device from the kth measurement moment to the k+1th measurement moment, and ρ represents the radius of the motion path of the autonomous mobile device.

[0099] Optionally, the interval between a set of measurement moments with a total number greater than 2 is fixed to T. Then, the rotation angle of the positioning device from any measurement moment to the next measurement moment will be constant. As shown in the following formula (6):

[0100] θ k_(k-1) =T·ω

[0101] Among them, θ k_(k-1) represents the rotation angle of the autonomous mobile device from the kth measurement moment to the k+1th measurement moment. This formula can be used to calculate the calibration parameters of the odometer and / or the calibration parameters of the positioning device.

[0102] When the interval between measurement moments is fixed, the position change of the positioning device from any measurement moment to the next measurement moment will also be constant. Making the interval between each set of measurement moments equal can advantageously simplify measurement and calculation.

[0103] Therefore, the calibration parameters of the positioning device R x S 、 R y S and θ S According to the posture information, the following formula (7) is used to obtain:

[0104]

[0105] in, and They represent the horizontal and vertical coordinates and attitude angle of the positioning device at the k+1th measurement time in the coordinate system of the positioning device at the kth measurement time, respectively. and They represent the horizontal and vertical coordinates and attitude angle of the positioning device in the coordinate system of the positioning device at the kth measurement moment, respectively, k>0, and the left side of the equation represents the average value of the posture change between the two measurement moments, θ k_(k-1) represents the rotation angle of the autonomous mobile device from the kth measurement moment to the k+1th measurement moment, and ρ represents the radius of the autonomous mobile device's motion path. When the positioning device error follows a Gaussian white noise distribution and there are a sufficient number of measurement moments, this can effectively reduce the error and significantly reduce the computational effort. Because the pose changes are constant, the accuracy of the measurement data can be verified by calculating the standard deviation. Excessively large standard deviations or excessive deviations from a normal distribution indicate data anomalies.

[0106] Formula (1), formula (2), formula (6) and formula (7) can be combined to determine the calibration parameters of the odometer and the calibration parameters of the positioning device. Here, the time interval T, the angular velocity ω of the right wheel R , the angular velocity of the left wheel ω L The average value of the position change of the positioning device between the two measurement moments is known. Through the equation group, the calibration parameters of the odometer and the positioning device to be solved and the process variable θ can be output k_(k-1) , ω and ρ.

[0107] In an exemplary embodiment, the at least two motion paths include at least three motion paths. Thus, the positioning device can determine at least three sets of pose information. In step S2, calibration parameters of the positioning device can be determined based on the at least three sets of pose information output by the positioning device. Having more motion paths helps reduce errors.

[0108] Optionally, the calibration parameters of the positioning device are determined by optimizing an objective function, wherein the objective function minimizes the total error of the calculation results under all motion paths with different radii.

[0109] For example, the at least three motion paths are divided into multiple groups of motion paths, each including two motion paths. The posture information corresponding to each group of motion paths is processed, and the standard deviation and mean of the processing results are determined. The standard deviation and mean can be, for example, the standard deviation and mean of the posture change between two adjacent measurement moments. Alternatively, the standard deviation and mean can also be the standard deviation and mean of the calibration parameters of the positioning device.

[0110] The standard deviation can be used to measure the accuracy of the calibration. Optionally, if the standard deviation is large, recalibration is performed.

[0111] Figure 3 The present invention schematically illustrates a calibration device according to an exemplary embodiment of the present invention. The calibration device may include a processor 10 and a computer-readable storage device 20 communicatively coupled to the processor 10. The computer-readable storage device 20 stores computer program instructions for calibration. The processor 10 may invoke the computer program instructions stored in the computer-readable storage device 20 and execute the calibration method according to the present invention.

[0112] In the present invention, the computer-readable storage medium 20 may include, for example, a high-speed random access memory, and may also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, at least one disk storage device, a flash memory device, or other volatile solid-state storage device. The processor 10 may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc.

[0113] The calibration device also includes, for example: a user interface 30 for interacting with a user, which includes, for example, a display screen and / or an input unit such as a keyboard; a network interface 40 for communicating data with a network server, which includes, for example, a standard wired interface and / or a wireless interface; and a communication bus 50 for connecting the various components of the calibration device.

[0114] In addition, the present invention also relates to a computer program product comprising computer program instructions. When the computer program instructions are executed by one or more processors 10, the processor 10 is capable of executing the positioning device calibration method according to the present invention or the odometer calibration method according to the present invention.

[0115] Although specific embodiments of the present invention are described in detail herein, they are provided for illustrative purposes only and should not be considered to limit the scope of the present invention. Various substitutions, changes, and modifications may be conceived without departing from the spirit and scope of the present invention.

Claims

1. A positioning device calibration method for calibrating a positioning device of an autonomous mobile device, wherein: The positioning device is fixedly mounted on an autonomous mobile device and configured to output position information of the positioning device, wherein the positioning device calibration method comprises the following steps: Step S1, causing the autonomous mobile device to move at a uniform speed along at least two arc-shaped motion paths with unequal radii on a plane, wherein during the movement along each motion path, a set of position and posture information output by a positioning device is recorded at a set of at least two different measurement moments; and Step S2: determining calibration parameters of the positioning device based on at least two sets of posture information output by the positioning device, wherein the calibration parameters of the positioning device represent the position and orientation of the positioning device in the autonomous mobile device, wherein the calibration parameters of the positioning device include the horizontal coordinate of the origin of the coordinate system of the positioning device in the coordinate system of the autonomous mobile device. R x S and the vertical axis R y S and the angle θ between the coordinate system of the positioning device and the coordinate system of the autonomous mobile device S , The pose information represents the pose of the positioning device in the world coordinate system, and the coordinate origin of the positioning device is the horizontal coordinate of the coordinate system of the autonomous mobile device. R x S and the vertical axis R y S The following formula is used to obtain the at least two sets of posture information: in, and They represent the horizontal and vertical coordinates and attitude angle of the positioning device in the world coordinate system at the first measurement moment, and They represent the horizontal and vertical coordinates and attitude angle of the positioning device in the world coordinate system at the k+1th measurement moment, k>0, θ0 represents the attitude angle of the autonomous mobile device in the world coordinate system at the first measurement moment, θ k_0 represents the rotation angle of the autonomous mobile device from the 1st measurement moment to the k+1th measurement moment, and ρ represents the radius of the motion path of the autonomous mobile device.

2. The positioning device calibration method according to claim 1, wherein: The angle θ between the coordinate system of the positioning device and the coordinate system of the autonomous mobile device S It is derived from the following formula: i k =θ0+θ k_0 Among them, θ k represents the attitude angle of the autonomous mobile device in the world coordinate system at the k+1th measurement moment.

3. A positioning device calibration method for calibrating a positioning device of an autonomous mobile device, wherein: The positioning device is fixedly mounted on an autonomous mobile device and configured to output position information of the positioning device, wherein the positioning device calibration method comprises the following steps: Step S1, causing the autonomous mobile device to move at a uniform speed along at least two arc-shaped motion paths with unequal radii on a plane, wherein during the movement along each motion path, a set of position and posture information output by a positioning device is recorded at a set of at least two different measurement moments; and Step S2: determining calibration parameters of the positioning device based on at least two sets of posture information output by the positioning device, wherein the calibration parameters of the positioning device represent the position and orientation of the positioning device in the autonomous mobile device, wherein the calibration parameters of the positioning device include the horizontal coordinate of the origin of the coordinate system of the positioning device in the coordinate system of the autonomous mobile device. R x S and the vertical axis R y S and the angle θ between the coordinate system of the positioning device and the coordinate system of the autonomous mobile device S , Among them, the posture information represents the posture of the positioning device in the coordinate system of the positioning device at the first measurement time in each group of measurement time, and the calibration parameters of the positioning device are R x S 、 R y S and θ S The following formula is used to obtain the at least two sets of posture information: in, and Respectively represent the horizontal and vertical coordinates and attitude angle of the positioning device at the k+1th measurement time in the coordinate system of the positioning device at the corresponding 1st measurement time, k>0, θ (k-1)_0 represents the rotation angle of the autonomous mobile device from the first measurement moment to the kth measurement moment, θ k_(k-1) represents the rotation angle of the autonomous mobile device from the kth measurement moment to the k+1th measurement moment, and ρ represents the radius of the motion path of the autonomous mobile device.

4. A positioning device calibration method for calibrating a positioning device of an autonomous mobile device, wherein: The positioning device is fixedly mounted on an autonomous mobile device and configured to output position information of the positioning device, wherein the positioning device calibration method comprises the following steps: Step S1, causing the autonomous mobile device to move at a uniform speed along at least two arc-shaped motion paths with unequal radii on a plane, wherein during the movement along each motion path, a set of position and posture information output by a positioning device is recorded at a set of at least two different measurement moments; and Step S2: determining calibration parameters of the positioning device based on at least two sets of posture information output by the positioning device, wherein the calibration parameters of the positioning device represent the position and orientation of the positioning device in the autonomous mobile device, wherein the calibration parameters of the positioning device include the horizontal coordinate of the origin of the coordinate system of the positioning device in the coordinate system of the autonomous mobile device. R x S and the vertical axis R y S and the angle θ between the coordinate system of the positioning device and the coordinate system of the autonomous mobile device S , Among them, the posture information represents the posture of the positioning device in the coordinate system of the positioning device at the previous measurement time in each group of measurement time, and the calibration parameters of the positioning device are R x S 、 R y S and θ S The following formula is used to obtain the at least two sets of posture information: in, and They represent the horizontal and vertical coordinates and attitude angle of the positioning device at the k+1th measurement time in the coordinate system of the positioning device at the kth measurement time, respectively. and They represent the horizontal and vertical coordinates and attitude angle of the positioning device in the coordinate system of the positioning device at the kth measurement moment, k>0, θ k_(k-1) represents the rotation angle of the autonomous mobile device from the kth measurement moment to the k+1th measurement moment, and ρ represents the radius of the motion path of the autonomous mobile device.

5. A positioning device calibration method for calibrating a positioning device of an autonomous mobile device, wherein: The positioning device is fixedly mounted on an autonomous mobile device and configured to output position information of the positioning device, wherein the positioning device calibration method comprises the following steps: Step S1, causing the autonomous mobile device to move at a uniform speed along at least two arc-shaped motion paths with unequal radii on a plane, wherein during the movement along each motion path, a set of position and posture information output by a positioning device is recorded at a set of at least two different measurement moments; and Step S2: determining calibration parameters of the positioning device based on at least two sets of posture information output by the positioning device, wherein the calibration parameters of the positioning device represent the position and orientation of the positioning device in the autonomous mobile device, wherein the calibration parameters of the positioning device include the horizontal coordinate of the origin of the coordinate system of the positioning device in the coordinate system of the autonomous mobile device. R x S and the vertical axis R y S and the angle θ between the coordinate system of the positioning device and the coordinate system of the autonomous mobile device S , The pose information represents the pose of the positioning device in the coordinate system of the positioning device at the previous measurement moment in each group of measurement moments. The number of each group of measurement moments is greater than 2, the interval time of each group of measurement moments is equal, and the calibration parameters of the positioning device are R x S 、 R y S and θ S The following formula is used to obtain the at least two sets of posture information: in, and They represent the horizontal and vertical coordinates and attitude angle of the positioning device at the k+1th measurement time in the coordinate system of the positioning device at the kth measurement time, respectively. and They represent the horizontal and vertical coordinates and attitude angle of the positioning device in the coordinate system of the positioning device at the kth measurement moment, respectively, k>0, and the left side of the equation represents the average value of the posture change between the two measurement moments, θ k_(k-1) represents the rotation angle of the autonomous mobile device from the kth measurement moment to the k+1th measurement moment, and ρ represents the radius of the motion path of the autonomous mobile device.

6. The positioning device calibration method according to any one of claims 1 to 5, wherein: The calibration parameters of the positioning device are determined by utilizing the property that the position and posture of the positioning device on the autonomous mobile device remain unchanged during movement.

7. The positioning device calibration method according to any one of claims 1 to 5, wherein: The number of measurement moments in each group is greater than 2; and / or The motion path is a complete circle.

8. The positioning device calibration method according to any one of claims 1 to 5, wherein: The at least two motion paths include at least three motion paths.

9. The positioning device calibration method according to claim 8, wherein: The calibration parameters of the positioning device are determined by optimizing an objective function, which minimizes the total error of the calculation results under all motion paths with different radii.

10. The positioning device calibration method according to claim 8, wherein: The at least three motion paths are divided into a plurality of groups of motion paths each including two motion paths, and the posture information corresponding to each group of motion paths is processed to determine a standard deviation and a mean of the processing results.

11. The positioning device calibration method according to claim 10, wherein: If the standard deviation is large, recalibrate.

12. A method for calibrating an odometer of an autonomous mobile device, wherein: The autonomous mobile device has a differential wheel motion system, and the odometer calibration method includes: Automatic calibration is performed using a positioning device installed on an autonomous mobile device, wherein the positioning device is calibrated by the positioning device calibration method according to any one of claims 1 to 11.

13. The odometer calibration method according to claim 12, wherein: The calibration parameters of the odometer include the left wheel radius r of the autonomous mobile device L , right wheel radius r R and wheelbase b, left wheel radius r L , right wheel radius r R and wheelbase b are obtained using the following formula: Where ω represents the angular velocity of the coordinate system of the autonomous mobile device, ω R and ω L represent the angular velocity of the left wheel and the angular velocity of the right wheel respectively; and / or The calibration parameters of the odometer are determined together with the calibration parameters of the positioning device in step S2 of the positioning device calibration method.

14. The odometer calibration method according to claim 12, wherein: In the case of a group of measurement moments with a total number greater than 2 and with equal intervals T between them, the calibration parameters of the odometer and / or the positioning device are calculated using the following formula: i k_(k-1) =T·ω Among them, θ k_(k-1) represents the rotation angle of the autonomous mobile device from the kth measurement moment to the k+1th measurement moment.

15. A computer program product comprising computer program instructions, wherein: When the computer program instructions are executed by one or more processors, the processor (10) is capable of executing the positioning device calibration method according to any one of claims 1-11 or the odometer calibration method according to any one of claims 12-14.

16. A calibration device, comprising a processor (10) and a computer-readable storage device (20) in communication with the processor (10), wherein the computer-readable storage device (20) stores a computer program, and when the computer program is executed by the processor (10), the computer program is used to implement the positioning device calibration method according to any one of claims 1 to 11 or the odometer calibration method according to any one of claims 12 to 14.

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