Calibration method, device, system and electronic equipment for joint arm

Abstract

This application discloses a calibration method, apparatus, system, and electronic device for an articulated arm, belonging to the field of measurement calibration technology. The method includes: displaying a suggested position diagram of a calibration piece; the suggested position diagram indicates the recommended placement position of the calibration piece; displaying a sampling operation guidance diagram; wherein, in ball calibration mode, the sampling operation guidance diagram displays a target area on the calibration piece that is suggested to be touched; and / or, in posture-guided calibration mode, the sampling operation guidance diagram displays a sequence of motion postures of the measuring piece, the motion posture sequence indicating the suggested motion posture of the measuring piece at the same touch point on the calibration piece; sampling to obtain multiple sampling point data; displaying the calibration error; the calibration error is determined based on the multiple sampling point data. This application can improve the calibration accuracy of articulated arm measuring machines.

Description

Technical Field

[0001] This application belongs to the field of measurement and calibration technology, and in particular relates to a calibration method, device, system and electronic equipment for an articulated arm. Background Technology

[0002] Articulated arm measuring machines are high-precision portable measuring devices widely used in machinery manufacturing, aerospace, mold processing, and other fields. To ensure the motion accuracy of the articulated arm meets the requirements of practical applications, it needs to be calibrated regularly before and during use.

[0003] In related technologies, the calibration of articulated arm measuring machines typically employs a guided motion calibration method. This method involves driving the articulated arm to move along a preset direction to a specific spatial position. Based on the consistent motion relationship between the joints of the articulated arm, the operator observes the real-time image of the articulated arm's end effector on a monitor and compares it with a preset desired image. Visual feedback is used to determine the degree of deviation between the current position and the desired position, thereby determining and correcting the calibration parameters. However, this calibration process relies on precise motion guidance of a "specified direction + specified position," requiring high precision in the motion control of the articulated arm, making it prone to errors and resulting in relatively low calibration accuracy. Summary of the Invention

[0004] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a calibration method, apparatus, system, and electronic device for articulated arms to improve the calibration accuracy of articulated arm measuring machines.

[0005] In a first aspect, this application provides a calibration method for an articulated arm, wherein a measuring element is mounted on the end effector of the articulated arm; the method includes: A suggested location diagram for the calibration component is provided; the suggested location diagram indicates the recommended placement position of the calibration component. The sampling operation guidance diagram is displayed; wherein, in ball calibration mode, the sampling operation guidance diagram shows the target area to be touched on the calibration piece; and / or, in attitude guidance calibration mode, the sampling operation guidance diagram shows the motion attitude sequence of the measuring piece, the motion attitude sequence being used to indicate the suggested motion attitude of the measuring piece at the same touch point on the calibration piece; Multiple sampling point data are obtained by sampling, including sensor data representing the position of each joint in the articulated arm collected when the measuring component touches the calibration component; The calibration error is displayed; the calibration error is determined based on data from multiple sampling points.

[0006] According to the articulated arm calibration method of this application, the calibration process is guided by illustrations, and multiple sampling point data are acquired when the measuring part touches the calibration part. Each sampling point data includes sensor data characterizing the position of each joint. Based on the multiple sampling point data, the calibration error is determined and displayed. This allows sampling point data to be acquired within the range where the measuring part touches the target area during the calibration process, or the motion posture sequence when the measuring part touches the calibration part to be sampled. It does not require driving the articulated arm to move precisely to the precise coordinate point or motion posture, which reduces the control requirements on the touch position and touch direction of the measuring part, reduces the introduction of errors, and thus improves the calibration accuracy of the articulated arm measuring machine.

[0007] According to one embodiment of this application, the illustration showing the suggested location of the calibration piece includes: In response to a trigger command for a target calibration mode, the target calibration mode is activated, and a suggested position diagram of the calibration component corresponding to the target calibration mode is displayed; wherein, the target calibration mode includes a ball calibration mode or an attitude guidance calibration mode.

[0008] In this embodiment, by displaying a diagram showing the suggested location of the calibrator for the target calibration mode, the spatial arrangement of the calibrator is made to match the selected calibration mode, thereby improving the accuracy of the calibration operation.

[0009] According to one embodiment of this application, in the ball calibration mode, the calibration element is a sphere, and / or, in the attitude guidance calibration mode, the calibration element is a cone.

[0010] In this embodiment, when the measuring probe touches the surface of the sphere, the spatial coordinates of the touch point can be fitted based on the nominal diameter of the sphere, and the effective radius of the measuring probe and the tip coordinates of the measuring component can be calculated. When the tip of the measuring component contacts the conical cavity, the converging geometry of the conical cavity can guide the probe to adjust the touch angle at the same touch point, thereby improving the accuracy of the tip coordinate calculation.

[0011] According to one embodiment of this application, in the ball calibration mode, different sampling point data correspond to different touch points, and / or, in the posture guidance calibration mode, different sampling point data correspond to different motion postures of the measuring element at the same touch point.

[0012] In this embodiment, by having the measuring component touch different touch points on the calibration component and sampling them respectively, multiple sampling point data corresponding to different touch points are obtained, thereby covering multiple spatial position points of the calibration component and improving calibration accuracy. By sampling the measuring component multiple times at the same touch point, and with different sampling point data corresponding to different motion postures, since the poses of each joint of the articulated arm are different under different motion postures at the same touch point, by obtaining sampling point data under multiple different motion postures at the same touch point, it is possible to use the different poses of the articulated arm for constraint under the same spatial position, which can reduce the influence of random errors on geometric parameter estimation and thus improve calibration accuracy.

[0013] According to one embodiment of this application, the sampling obtains multiple sampling point data, including: In the ball calibration mode, when the measuring element touches any position in the target area, sampling is performed in response to the sampling command to obtain sampling point data; In response to the completion of sampling, an updated sampling operation guidance diagram is displayed; wherein the updated sampling operation guidance diagram updates the position of the target area; When the measuring element touches any position in the updated target area, sampling is performed in response to the sampling command to obtain sampling point data; Multiple sampling point data are obtained based on sampling point data corresponding to multiple different target areas.

[0014] In this embodiment, sampling can be performed in response to commands by touching any position of the measuring element in each target area to obtain sampling point data. It is not necessary to drive the articulated arm to move precisely to the accurate coordinate point, which reduces the control requirements on the contact position of the measuring element and further reduces the introduction of errors, thereby improving the calibration accuracy of the articulated arm measuring machine.

[0015] According to one embodiment of this application, the sampled data includes multiple sampling points, including: In the attitude-guided calibration mode, when the measuring element touches the target position on the calibration element, in response to the sampling command, the sampling point data corresponding to multiple consecutive motion postures of the measuring element in the motion posture sequence are collected; In response to the completion of sampling, an updated sampling operation guidance diagram is displayed; wherein the updated sampling operation guidance diagram updates the motion posture sequence; When the measuring element touches the target position on the calibration element, in response to the sampling command, the sampling point data corresponding to multiple consecutive motion postures of the measuring element in the updated motion posture sequence are collected; Multiple sampling point data are obtained based on sampling point data corresponding to multiple different motion posture sequences.

[0016] In this embodiment, by continuously sampling any motion posture sequence, the sampling point data is continuously distributed, which can cover the continuous posture changes under the motion posture sequence. Compared with the single-point scattered sampling method, the continuity of sampling is improved. Furthermore, by setting multiple motion posture sequences, the sampling point data can form redundant constraints from multiple motion posture sequences, reducing local errors and further improving the calibration accuracy.

[0017] According to one embodiment of this application, the calibration error is determined as follows: The geometric parameters of the measuring component are determined based on the data from multiple sampling points and the kinematic model of the articulated arm. The calibration error is calculated based on the geometric parameters of the measuring component.

[0018] In this embodiment, the geometric parameters of the measuring component are determined based on multiple sampling point data and the kinematic model of the articulated arm, and then the calibration error is calculated based on the geometric parameters. This allows the calibration error to reflect the degree of fitting deviation between the kinematic model and the measured data, further improving the calibration accuracy of the articulated arm measuring machine.

[0019] According to one embodiment of this application, in the ball calibration mode, the geometric parameters of the measuring element include the effective radius of the measuring element probe and the tip coordinates of the measuring element; The determination of the geometric parameters of the measuring component based on multiple sampling point data and the kinematic model of the articulated arm includes: Obtain the nominal diameter of the calibration piece and the nominal diameter of the probe of the measuring piece; The sensor data in each sampling point is converted into angle data of each joint, and the angle data is substituted into the kinematic model of the joint arm to obtain the initial pose trajectory of the measuring probe. Using the tip coordinates and the effective radius of the measuring probe as optimization variables, a first nonlinear error equation is constructed based on the initial pose trajectory, multiple sampling point data, the structural model of the articulated arm, the nominal diameter of the calibration component, and the nominal diameter of the measuring probe. The effective radius of the probe and the coordinates of the needle tip are obtained by iteratively solving the first nonlinear error equation.

[0020] In this embodiment, by converting the sensing data into angle data and substituting it into the kinematic model to obtain the initial pose trajectory, it is possible to optimize and provide an initial solution based on the physical motion constraints of the articulated arm. This allows the optimization variables to be searched within the solution space that conforms to the structural characteristics of the articulated arm, reducing the difficulty of iterative convergence and improving the accuracy of the calculation of the geometric parameters of the measuring component.

[0021] According to one embodiment of this application, the calibration element is a sphere; the calculation of the calibration error based on the geometric parameters of the measuring element includes: Based on the effective radius of the probe and the coordinates of the needle tip, calculate the first position data of the needle tip of the measuring component in the base coordinate system corresponding to each sampling point data; The center of the sphere is obtained by fitting the data at each of the first positions; Calculate the distance from each of the first position data points to the center of the sphere, and the difference between the sum of the nominal radius of the sphere and the effective radius of the probe, to obtain the error corresponding to each sampling point data point; The calibration error is obtained based on the error corresponding to the data at each sampling point.

[0022] In this embodiment, the sampling point data is converted into the spatial position of the needle tip in the base coordinate system based on the effective radius of the probe and the needle tip coordinates. By fitting the center of the sphere and comparing the distance from each needle tip position to the center of the sphere with the theoretical value, the error corresponding to each sampling point data can reflect the degree of deviation between the estimated geometric parameters and the geometry of the standard sphere, thereby improving the accuracy of calibration error calculation.

[0023] According to one embodiment of this application, in attitude-guided calibration mode, the geometric parameters of the measuring element include the tip coordinates of the measuring element; The determination of the geometric parameters of the measuring component based on multiple sampling point data and the kinematic model of the articulated arm includes: The sensor data in each sampling point is converted into angle data of each joint, and the angle data is substituted into the kinematic model of the joint arm to obtain the initial position data of the measuring probe under each touch angle. Using the needle tip coordinates of the measuring component as the optimization variable, a second nonlinear error equation is constructed based on the initial position data, multiple sampling point data, and the structural model of the articulated arm. The nonlinear error equation is solved iteratively to obtain the needle tip coordinates.

[0024] In this embodiment, an error equation is constructed using the initial position data of the measuring probe at each touch angle. This fully utilizes the sampling information under different postures, which can compensate for the effects of kinematic model fitting deviation, joint sensing data error, posture position disturbance, etc., thereby improving the accuracy of needle tip coordinate solution.

[0025] According to one embodiment of this application, the calibration element is a conical socket; the calculation of the calibration error based on the geometric parameters of the measuring element includes: Based on the needle tip coordinates, calculate the second position data of the measuring component needle tip in the base coordinate system corresponding to each of the sampling point data; Calculate the distance from each of the second position data points to the vertex of the cone to obtain the error corresponding to each of the sampling point data points; The calibration error is obtained based on the error corresponding to the data at each sampling point.

[0026] In this embodiment, the sampling point data is converted into the spatial position of the needle tip in the base coordinate system based on the needle tip coordinates. The distance from each needle tip position to the apex of the cone is calculated by using the apex of the cone as the spatial reference point. This allows the point calibration error corresponding to each sampling point data to reflect the degree of deviation between the estimated needle tip coordinate value and the geometric center of the cone, thereby improving the accuracy of the calibration error calculation.

[0027] According to one embodiment of this application, the calibration element is located within a target range of the working radius of the articulated arm.

[0028] In this embodiment, by placing the calibration piece within the target range of the working radius of the articulated arm, the articulated arm can control the measuring piece to touch the calibration piece and adjust its posture in various postures, without having to drive the articulated arm to extend beyond its range or into extreme postures, thus further improving the accuracy of the calibration.

[0029] According to one embodiment of this application, the sampling point data includes temperature data collected when the measuring element touches the calibration element.

[0030] In this embodiment, since the joints and links of the articulated arm will experience thermal expansion and contraction when the temperature changes, there will be a temperature-related deviation between the joint angle sensing data and the actual spatial position. By collecting temperature data, temperature compensation can be introduced during the calibration process to correct the structural deformation error caused by uneven temperature field distribution or temperature drift, thereby further improving the calibration accuracy.

[0031] Secondly, this application provides a calibration method for an articulated arm, wherein a measuring element is mounted on the end effector of the articulated arm; the method includes: The data obtained from multiple sampling points when the measuring component touches the calibration component is acquired; the sampling point data includes sensor data characterizing the position of each joint in the articulated arm; The calibration error is determined based on data from multiple sampling points.

[0032] According to the articulated arm calibration method of this application, multiple sampling point data are acquired when the measuring component touches the calibration component. Each sampling point data includes sensor data characterizing the position of each joint. The calibration error is determined based on the multiple sampling point data. Compared with the guided motion calibration method that relies on visual feedback and pre-set expected image overlay comparison, it does not require visual feedback to drive the articulated arm to move precisely to a specific spatial position in a specified direction. This reduces the requirements for the motion control accuracy of the articulated arm, reduces the introduction of errors, and thus improves the calibration accuracy of the articulated arm measuring machine.

[0033] Thirdly, this application provides a calibration device for an articulated arm, wherein a measuring element is mounted on the end effector of the articulated arm; the device includes: The first display module is used to display a suggested location diagram of the calibration component; the suggested location diagram is used to indicate the recommended placement position of the calibration component. The second display module is used to display a sampling operation guidance diagram; wherein, in ball calibration mode, the sampling operation guidance diagram displays the target area to be touched on the calibration piece; and / or, in attitude guidance calibration mode, the sampling operation guidance diagram displays the motion attitude sequence of the measuring piece, the motion attitude sequence being used to indicate the suggested motion attitude of the measuring piece at the same touch point on the calibration piece; The sampling module is used to sample and obtain multiple sampling point data, including sensor data representing the position of each joint in the articulated arm collected when the measuring component touches the calibration component. The third display module is used to display the calibration error; the calibration error is determined based on data from multiple sampling points.

[0034] According to the articulated arm calibration device of this application, the calibration process is guided by illustrations, and multiple sampling point data are acquired when the measuring part touches the calibration part. Each sampling point data includes sensor data characterizing the position of each joint. Based on the multiple sampling point data, the calibration error is determined and displayed. This allows sampling point data to be acquired within the range where the measuring part touches the target area during the calibration process, or the motion posture sequence when the measuring part touches the calibration part to be sampled. It does not require driving the articulated arm to move precisely to the accurate coordinate point or motion posture, which reduces the control requirements on the touch position and touch direction of the measuring part, reduces the introduction of errors, and thus improves the calibration accuracy of the articulated arm measuring machine.

[0035] Fourthly, this application provides a calibration system for an articulated arm, comprising: An articulated arm, wherein a measuring element is mounted at the actuating end of the articulated arm; The articulated arm is used to perform the articulated arm calibration method as described in the first aspect above.

[0036] Fifthly, this application provides an electronic device including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the articulated arm calibration method as described in the first aspect above.

[0037] In a sixth aspect, this application provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the articulated arm calibration method as described in the first aspect above.

[0038] In a seventh aspect, this application provides a chip including a processor and a communication interface, the communication interface being coupled to the processor, the processor being used to run programs or instructions to implement the articulated arm calibration method as described in the first aspect above.

[0039] The above-described one or more technical solutions in the embodiments of this application have at least the following technical effects: According to the articulated arm calibration method of this application, the calibration process is guided by illustrations, and multiple sampling point data are acquired when the measuring part touches the calibration part. Each sampling point data includes sensor data characterizing the position of each joint. Based on the multiple sampling point data, the calibration error is determined and displayed. This allows sampling point data to be acquired within the range where the measuring part touches the target area during the calibration process, or the motion posture sequence when the measuring part touches the calibration part to be sampled. It does not require driving the articulated arm to move precisely to the precise coordinate point or motion posture, which reduces the control requirements on the touch position and touch direction of the measuring part, reduces the introduction of errors, and thus improves the calibration accuracy of the articulated arm measuring machine.

[0040] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0041] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is one of the flowcharts illustrating the calibration method for the articulated arm provided in this application embodiment; Figure 2 This is a schematic diagram illustrating the suggested location provided in the embodiments of this application; Figure 3This is one of the sampling operation guidance diagrams provided in the ball calibration mode according to the embodiments of this application; Figure 4 This is the second of the sampling operation guidance diagrams provided in the ball calibration mode of this application embodiment; Figure 5 This is the third illustration of the sampling operation guidance in the ball calibration mode provided in the embodiments of this application; Figure 6 This is the fourth illustration of the sampling operation guidance in the ball calibration mode provided in the embodiments of this application; Figure 7 This is one of the sampling operation guidance diagrams provided in the attitude guidance calibration mode according to the embodiments of this application; Figure 8 This is the second illustration of the sampling operation guidance in the attitude guidance calibration mode provided in the embodiments of this application; Figure 9 This is the third illustration of the sampling operation guidance in the attitude guidance calibration mode provided in the embodiments of this application; Figure 10 This is the fourth illustration of the sampling operation guidance in the attitude guidance calibration mode provided in the embodiments of this application; Figure 11 This is the second schematic flowchart of the articulated arm calibration method provided in the embodiments of this application; Figure 12 This is a schematic diagram of the structure of the calibration device for the articulated arm provided in the embodiments of this application; Figure 13 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0043] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0044] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0045] The calibration method, apparatus, system, and electronic equipment for articulated arms provided in this application will be described in detail below with reference to the accompanying drawings and through specific embodiments and application scenarios.

[0046] The calibration method for the articulated arm can be applied to the terminal, and can be executed by the hardware or software in the terminal.

[0047] The terminal includes, but is not limited to, portable communication devices such as mobile phones or tablets with touch-sensitive surfaces (e.g., touchscreen displays and / or touchpads). It should also be understood that, in some embodiments, the terminal may not be a portable communication device, but rather a desktop computer with touch-sensitive surfaces (e.g., touchscreen displays and / or touchpads).

[0048] The following embodiments describe a terminal including a display and a touch-sensitive surface. However, it should be understood that the terminal may include one or more other physical user interface devices such as a physical keyboard, mouse, and joystick.

[0049] The articulated arm calibration method provided in this application embodiment can be executed by an electronic device or a functional module or entity in an electronic device that can implement the articulated arm calibration method. The electronic devices mentioned in this application embodiment include, but are not limited to, servers, personal computers, articulated arms, etc. The following uses an electronic device as the execution subject to illustrate the articulated arm calibration method provided in this application embodiment.

[0050] In this embodiment, the articulated arm, or articulated arm measuring machine, is a multi-degree-of-freedom portable coordinate measuring device, including a base and multiple rotary joints. The joint rotation angle is fed back in real time through the angle encoder built into each joint, and the three-dimensional pose of the end effector in space is calculated by combining the forward kinematics algorithm to adapt to the spatial position requirements of different measurement scenarios.

[0051] The end effector of the articulated arm is the motion output end of the articulated arm. It can be used to carry measurement and scanning actuators, such as measuring devices, scanning devices, or other functional measurement accessories. The end effector is fixedly connected to the articulated arm body through a mechanical interface. The spatial pose of the end effector can be controlled by the movement of each joint of the articulated arm. The articulated arm can also collect and record the absolute position coordinates and attitude parameters of the end effector in its own base coordinate system.

[0052] In this embodiment, a measuring element is installed at the end of the articulated arm. The measuring element can be a trigger-type probe, a scanning probe, etc., used to acquire the three-dimensional coordinate information of the surface of the workpiece being measured. One end of the measuring element is a probe tip, which can be a spherical structure, such as a ruby ​​sphere made of ruby ​​material. The other end of the measuring element is fixedly connected to the end of the articulated arm via a standard mechanical interface, such as a threaded connection or a magnetic chuck connection. After assembly, the relative position and orientation of the probe and the end of the articulated arm remain fixed. During measurement, the probe contacts the surface of the workpiece, triggering a sampling signal. The articulated arm acquires and records the three-dimensional spatial coordinates of the probe's center (i.e., the tip of the measuring element) in the articulated arm's base coordinate system. Combined with a probe radius compensation algorithm, the actual three-dimensional coordinates of the measured point are calculated.

[0053] Since the probe radius and tip coordinates of the measuring component are parameters used by the articulated arm for measurement compensation and coordinate calculation, these parameters may change or deviate during actual use due to factors such as component replacement, wear, collision deformation, or thermal expansion. Therefore, calibration of the measuring component is necessary to ensure measurement accuracy. For example, in some scenarios, such as when a new measuring component is installed, the effective radius and tip coordinates of the probe are unknown, and the user needs to obtain these coordinates to establish a measurement compensation model. In other scenarios, such as when the probe radius is known or only the probe position needs to be verified, the user only needs to obtain the tip coordinates to confirm the spatial positioning accuracy of the current measuring component.

[0054] like Figure 1 As shown, the calibration method for the articulated arm includes steps 110, 120, 130, and 140.

[0055] Step 110: Display a suggested location diagram for the calibration piece; the suggested location diagram is used to indicate the recommended placement of the calibration piece.

[0056] Measuring components can be, for example, ruby ​​probes, trigger probes, or scanning probes. Calibration components can be standard objects with known geometric characteristics, such as standard spheres, standard holes, standard planes, standard gauge blocks, standard conical sockets, etc.

[0057] Different calibration components can be used depending on the specific calibration requirements. For example, in some scenarios, such as when a new measuring component is used, the effective radius and tip coordinates of the probe are unknown. Users need to obtain these coordinates to establish a measurement compensation model, and a standard sphere can be used as the calibration component. The standard sphere has geometric properties such as a definite center position, a known radius, and isotropy. When the measuring component touches the surface of the standard sphere from different directions, the distance from the contact point to the center is always equal to the sum of the sphere's radius and the probe's effective radius. This allows the establishment of constraint equations regarding the probe's effective radius and tip coordinates, which can then be solved through multi-directional sampling. In other scenarios, such as when the probe radius is known or only the probe position needs to be verified, users only need to obtain the tip coordinates to confirm the spatial positioning accuracy of the current measuring component. In these cases, a standard cone-shaped cavity can be used as the calibration component. The standard cone-shaped cavity has geometric features such as precise cone angles and a definite vertex position. Combining the known cone angle and depth parameters of the cavity, constraint equations regarding the tip coordinates can be established, thereby solving for the tip coordinates.

[0058] In this embodiment, when the measuring probe touches the surface of the sphere, the spatial coordinates of the touch point can be fitted based on the nominal diameter of the sphere, and the effective radius of the measuring probe and the tip coordinates of the measuring probe can be calculated. When the tip of the measuring probe touches the conical cavity, the convergent geometry of the conical cavity can guide the probe to adjust the touch angle at the same touch point, thereby improving the accuracy of the tip coordinate calculation.

[0059] Before sampling, the relative position between the calibration piece and the articulated arm needs to be determined. Specifically, the calibration piece can be placed within the workspace of the articulated arm, allowing the measuring element to be touched from multiple different directions.

[0060] In this embodiment, the suggested location diagram is a graphical representation of the information presented to the operator to guide the spatial placement of the calibration components. The suggested location diagram may include a top view, side view, or three-dimensional view of the articulated arm's workspace, and the recommended placement of the calibration components can be indicated by highlighting, shading, or coordinate markings.

[0061] In some embodiments, the calibration element can be placed within a target range of the articulated arm's working radius. The working radius of the articulated arm refers to the maximum distance the measuring element can reach when the articulated arm is fully extended, and the target range refers to a preset percentage range of the working radius, for example, 30% to 70% of the working radius. Placing the calibration element within the target range allows the articulated arm to control the measuring element to contact the calibration element in more different postures, improving the coverage and uniformity of sampling point data in the joint space.

[0062] In one example, an operator can enter calibration mode, and in response to the operator's action, a suggested location diagram can be displayed, such as... Figure 2 As shown, it is recommended to place the calibration piece at half the length of the articulated arm.

[0063] In this embodiment, by placing the calibration piece within the target range of the working radius of the articulated arm, the articulated arm can control the measuring piece to touch the calibration piece and adjust its posture in various postures, without having to drive the articulated arm to extend beyond its range or into extreme postures, thus further improving the accuracy of the calibration.

[0064] In some embodiments, the calibrator can be fixed by an auxiliary positioning device, such as a magnetic base, a V-block, or a special clamp, to prevent displacement of the calibrator due to contact force during sampling.

[0065] Step 120: Display a sampling operation guidance diagram; wherein, in ball calibration mode, the sampling operation guidance diagram displays the target area to be touched on the calibrator; and / or, in attitude-guided calibration mode, the sampling operation guidance diagram displays a motion attitude sequence of the measuring device, the motion attitude sequence being used to indicate the recommended motion attitude of the measuring device at the same touch point on the calibrator.

[0066] In some embodiments, a sampling operation guidance diagram may be displayed after a first instruction is triggered. The first instruction is a confirmation instruction triggered by the operator after placing the calibrator, such as clicking a confirmation button on the interface or issuing a voice confirmation instruction. In response to the first instruction, after confirming that the calibrator has been placed, the sampling operation guidance stage begins, and the sampling operation guidance diagram is displayed.

[0067] The sampling operation guide diagram is an interactive graphical interface used to guide operators step by step in completing the operation of touching the calibration piece with the measuring piece.

[0068] The sampling operation guidance diagram may include an identifier of the target area or location to be touched, a suggested touch angle range, arrows indicating the direction of the articulated arm's posture adjustment, a progress bar showing the number of completed sampling points and the total number of sampling points, the number of the current sampling point, and the corresponding angle range prompt. Depending on the calibration mode, the sampling operation guidance diagram may include different content.

[0069] In some embodiments, multiple calibration modes may be provided, such as ball calibration mode, attitude guidance calibration mode, etc.

[0070] In ball calibration mode, the calibration piece can be a standard sphere. Utilizing the known geometric features of the standard sphere, such as a fixed center and a fixed radius, the articulated arm is guided to touch and sample different areas of the sphere. This not only allows the coordinate position of the probe tip relative to the end of the articulated arm to be calculated, but also allows the effective radius of the probe to be calculated by fitting the spherical data.

[0071] The sampling operation guidance diagram includes the suggested target area to be touched on the calibration piece and the suggested pose of the articulated arm. For example, the sampling operation guidance diagram can indicate the target area to be touched by highlighting it on a standard sphere diagram, and use arrows to indicate the approach direction of the measurement piece. In one example, in sphere calibration mode, the sampling operation guidance diagram looks like this: Figure 3-6 As shown, sampling can be performed by responding to sampling commands at any position where the measuring piece touches each target area to obtain sampling point data. This eliminates the need to drive the articulated arm to move precisely to the accurate coordinate point, reducing the control requirements on the contact position of the measuring piece and further reducing the introduction of errors, thereby improving the calibration accuracy of the articulated arm measuring machine.

[0072] In attitude-guided calibration mode, the sampling operation guidance diagram displays a sequence of motion postures of the measuring component. This sequence indicates the recommended motion posture of the measuring component at the same contact point on the calibrator. The motion posture sequence can include a series of continuous combinations of joint angles or paths of contact angle changes. This guides the operator to continuously adjust the joint arm posture while keeping the contact point between the measuring component and the calibrator constant, thereby adjusting the motion posture of the measuring component and allowing it to contact the same position at different contact angles.

[0073] Taking a cone-shaped fossa as the calibration component as an example, the sampling operation guidance diagram can display a cross-sectional view of the cone-shaped fossa, and use animation or arrow sequences to indicate the adjustment direction of the measuring component from the current posture to the next posture. It can also indicate suggested touch angle values ​​or angle ranges, and display the number of completed postures and the total number of postures in real time. The posture-guided calibration mode is suitable for scenarios where the probe tip coordinates are calibrated and the probe radius is known. Utilizing multi-posture constraints at the same touch point, it can reduce posture-related errors and accurately calculate the probe tip coordinates. In one example, the sampling operation guidance diagram in posture-guided calibration mode is as follows: Figure 7-10 As shown. In this embodiment, by sampling the motion posture sequence when the measuring component touches the calibration component, continuous posture changes under this motion posture sequence can be covered. Compared with the single-point scattered sampling method, the continuity of sampling is improved, and the accuracy of the geometric parameter calculation of the measuring component is further improved.

[0074] It should be noted that the ball calibration mode and the attitude-guided calibration mode can be selected according to the actual calibration needs. When the measuring part is a newly replaced part and the effective radius is unknown, the ball calibration mode should be used first; when only the tip coordinates need to be verified or updated, the attitude-guided calibration mode can be used. When the operator's actual operation deviates from the guidance requirements, error correction reminders can be given through color, text prompts, or vibration.

[0075] Step 130: Sample multiple sampling point data, including sensor data representing the position of each joint in the articulated arm collected when the measuring component touches the calibration component.

[0076] In this embodiment, the sampling point data refers to data collected by sensors when the measuring and calibrating components installed at the end effector of the articulated arm come into physical contact, reflecting the current state of the articulated arm. Each sampling point data includes sensor data characterizing the position of each joint in the articulated arm.

[0077] Sensing data can be acquired by sensing elements such as encoders, rotary transformers, or optical sensors installed at each joint. For example, the sensing data can be joint pulse data acquired by the encoder. Based on the joint pulse data and the kinematic model of the joint arm, position parameters such as rotation angle, angular displacement, absolute angle value, and relative angle change of each joint can be calculated.

[0078] In some embodiments, the data at each sampling point may also include temperature data collected when the measuring element touches the calibration element. The temperature data reflects the thermal state of each joint and link of the articulated arm during operation, while the sensing data characterizes the angular position or angular displacement information of each joint.

[0079] During operation, articulated arms experience varying degrees of thermal deformation in their joints and connecting rods due to factors such as motor heating, frictional heat, and changes in ambient temperature. This deformation causes the actual geometric parameters of the articulated arm to deviate from their nominal values, affecting measurement accuracy. Therefore, calibration using temperature data is necessary. Temperature data can include, but is not limited to, the temperatures of the motors in each joint, the bearing temperatures in the joints, the surface temperatures of the connecting rods, and the ambient temperature. By using temperature data, errors caused by thermal deformation can be compensated for during calibration, thereby improving calibration accuracy.

[0080] In this embodiment, since the joints and links of the articulated arm will experience thermal expansion and contraction when the temperature changes, there will be a temperature-related deviation between the joint angle sensing data and the actual spatial position. By collecting temperature data, temperature compensation can be introduced during the calibration process to correct the structural deformation error caused by uneven temperature field distribution or temperature drift, thereby further improving the calibration accuracy.

[0081] In some embodiments, multiple sampling point data can be obtained after a sampling command is triggered. The sampling command is a sampling trigger command that is triggered when the measuring element and the calibration element come into physical contact. When the operator follows the guidance of the sampling operation diagram and controls the measuring element to touch the corresponding position on the calibration element, the operator can generate a sampling command by clicking a button on the interface. In response to the sampling command, sampling is performed, and a set of articulated arm temperature data and sensor data at the current moment are collected to form a sampling point data. Multiple sampling point data can be obtained through multiple samplings.

[0082] In some embodiments, the movement of the measuring element can be controlled by adjusting the pose of each joint of the articulated arm. When the measuring element touches the calibration element, a sampling signal can be triggered to record the current temperature data and sensing data, forming a sampling point data. By adjusting the touch position or touch angle of the measuring element and triggering sampling, multiple sampling point data can be obtained.

[0083] In some embodiments, to improve the coverage of sampling point data, the articulated arm can be controlled to contact the calibration element with the measuring element in different postures and positions, thereby acquiring multiple sampling point data distributed within the workspace of the articulated arm. The number of sampling point data can be set as needed; for example, 50, 100, 200, or more sampling point data can be collected.

[0084] For example, in ball calibration mode, the operator can follow the sampling operation guide diagram to touch the target area to sample and obtain data from multiple sampling points. In attitude-guided calibration mode, the operator can follow the sampling operation guide diagram to adjust the motion attitude of the measuring device to sample and obtain data from multiple sampling points.

[0085] Step 140: Display the calibration error; the calibration error is determined based on data from multiple sampling points.

[0086] In this embodiment of the application, calibration error is an indicator that measures the degree to which the current articulated arm deviates from the ideal state.

[0087] In some embodiments, the calibration error can be displayed after a second instruction is triggered. The second instruction is a calculation start instruction triggered by the operator after obtaining data from multiple sampling points, such as clicking the "Confirm Calibration" button on the interface or issuing a voice calibration command. In response to the second instruction, the calibration error is calculated based on the collected data from multiple sampling points, and the calibration error is displayed after the calculation is completed.

[0088] In some embodiments, the calculation process can also be performed by other terminal devices. For example, after collecting data from multiple sampling points, the data can be sent to other terminals to calculate the geometric parameters of the measured component. The geometric parameters of the measured component calculated by other terminals can be obtained and displayed.

[0089] According to the articulated arm calibration method of this application, the calibration process is guided by illustrations, and multiple sampling point data are acquired when the measuring part touches the calibration part. Each sampling point data includes sensor data characterizing the position of each joint. Based on the multiple sampling point data, the calibration error is determined and displayed. This allows sampling point data to be acquired within the range where the measuring part touches the target area during the calibration process, or the motion posture sequence when the measuring part touches the calibration part to be sampled. It does not require driving the articulated arm to move precisely to the precise coordinate point or motion posture, which reduces the control requirements on the touch position and touch direction of the measuring part, reduces the introduction of errors, and thus improves the calibration accuracy of the articulated arm measuring machine.

[0090] In some embodiments, a suggested location diagram of the calibration element is shown, including: In response to the trigger command of the target calibration mode, the target calibration mode is started and the suggested position diagram of the calibration component corresponding to the target calibration mode is displayed; wherein, the target calibration mode includes ball calibration mode or attitude guidance calibration mode.

[0091] During the initial interface or calibration preparation phase, operators can be provided with an entry point to select the calibration mode. Operators can trigger the corresponding target calibration mode command based on the current calibration requirements. For example, when replacing a new measuring component and needing to calibrate the effective radius of the probe and the tip coordinates, the operator can trigger the ball calibration mode command; when the probe radius is known and only verification or updating of the tip coordinates is required, the operator can trigger the attitude-guided calibration mode command.

[0092] The system can display suggested location diagrams based on the selected calibration mode. For example, in sphere calibration mode, if the calibrator is a standard sphere, the suggested location diagram will show a standard sphere; in attitude guidance calibration mode, if the calibrator is a cone-shaped depression, the suggested location diagram will show a cone-shaped depression. Of course, depending on the actual needs, the positions of the calibrators in the suggested location diagrams for different calibration modes can be the same or different.

[0093] In this embodiment, by displaying a diagram showing the suggested location of the calibrator for the target calibration mode, the spatial arrangement of the calibrator is made to match the selected calibration mode, thereby improving the accuracy of the calibration operation.

[0094] In some embodiments, the calibrator is a sphere in ball calibration mode, and / or a cone in attitude-guided calibration mode.

[0095] In this embodiment, when the measuring probe touches the surface of the sphere, the spatial coordinates of the touch point can be fitted based on the nominal diameter of the sphere, and the effective radius of the measuring probe and the tip coordinates of the measuring probe can be calculated. When the tip of the measuring probe touches the conical cavity, the convergent geometry of the conical cavity can guide the probe to adjust the touch angle at the same touch point, thereby improving the accuracy of the tip coordinate calculation.

[0096] In some embodiments, in ball calibration mode, different sampling point data correspond to different touch points, and / or, in attitude-guided calibration mode, different sampling point data correspond to different motion postures of the measuring element at the same touch point.

[0097] In this embodiment, the movement of the articulated arm can be controlled so that the measuring component touches the calibration component in different postures and incident directions. Each time the measuring component touches the calibration component, the contact point between the measuring component and the calibration component is located at a different position on the surface of the calibration component. After touching the calibration component, sampling can be triggered to collect temperature data and sensing data, thereby obtaining sampling point data corresponding to different contact points.

[0098] In this embodiment, the contact angle is the angle between the axis of the measuring component or the contact direction and the normal to the surface of the calibrator when the measuring component contacts the calibrator. After the measuring component contacts the calibrator, the motion posture of the measuring component can be changed by adjusting the posture of each joint of the articulated arm, so that the contact point between the measuring component and the calibrator remains unchanged, while the contact angle is changed.

[0099] By changing the touch angle, sampling can be performed to obtain sensor data and temperature data corresponding to multiple touch angles.

[0100] In this embodiment, by having the measuring component touch different touch points on the calibration component and sampling them respectively, multiple sampling point data corresponding to different touch points are obtained, thereby covering multiple spatial position points of the calibration component and improving calibration accuracy. By sampling the measuring component multiple times at the same touch point, and with different sampling point data corresponding to different motion postures, since the poses of each joint of the articulated arm are different under different motion postures at the same touch point, by obtaining sampling point data under multiple different motion postures at the same touch point, it is possible to use the different poses of the articulated arm for constraint under the same spatial position, which can reduce the influence of random errors on geometric parameter estimation and thus improve calibration accuracy.

[0101] In some embodiments, sampling yields multiple sampling point data, including: In ball calibration mode, when the measuring piece touches any position in the target area, sampling is performed in response to the sampling command to obtain sampling point data; In response to the completion of sampling, an updated sampling operation guide icon is displayed; the updated sampling operation guide icon updates the location of the target area; When the measuring piece touches any position in the updated target area, it responds to the sampling command to perform sampling and obtain sampling point data. Multiple sampling point data are obtained based on sampling point data corresponding to multiple different target areas.

[0102] In this embodiment, for the ball calibration mode, the target area position in the sampling operation guidance diagram can be updated to guide the operator to perform touch sampling at different spatial positions.

[0103] Specifically, an initial sampling operation guide can be displayed, allowing the operator to control the articulated arm movement, moving the measuring component toward the target area currently indicated on the calibration piece. When the measuring component touches any point within the target area, an internal trigger mechanism, an external sensor detecting the touch event, or a user clicking a button on the interface generates a sampling command. In response to the sampling command, the current articulated arm temperature data and sensor data are collected to form the sampling point data corresponding to the first target area. Because sampling can be triggered at any point within the target area, the operator does not need to precisely control the measuring component to reach a preset specific touch point, reducing the requirements for the precision of the articulated arm movement control.

[0104] Upon completion of sampling, the sampling operation guidance icon can be updated. The updated sampling operation guidance icon reflects the location of the target area. Different sampling operation guidance icons are shown below. Figure 3-6 As shown.

[0105] The operator, following the updated sampling operation guidance diagram, controls the measuring device to touch the new target area. When the measuring device touches any position within the updated target area, it initiates sampling in response to the sampling command, obtaining sampling point data corresponding to the second target area. This process is repeated until the target number of sampling point data points are collected. It should be noted that a target area can correspond to multiple sampling point data points, or it can correspond to only one sampling point data point; this embodiment does not limit this. Multiple sampling point data sets can be obtained based on the sampling point data corresponding to multiple different target areas.

[0106] In this embodiment, sampling can be performed in response to commands by touching any position of the measuring element in each target area to obtain sampling point data. It is not necessary to drive the articulated arm to move precisely to the accurate coordinate point, which reduces the control requirements on the contact position of the measuring element, further reduces the introduction of errors, and thus improves the calibration accuracy.

[0107] In some embodiments, sampling yields multiple sampling point data, including: In attitude-guided calibration mode, when the measuring component touches the target position on the calibration component, in response to the sampling command, the sampling point data corresponding to multiple consecutive motion postures of the measuring component in the motion posture sequence are collected. In response to the completion of sampling, an updated sampling operation guidance diagram is displayed; the updated sampling operation guidance diagram updates the motion posture sequence. When the measuring component touches the target position on the calibration component, in response to the sampling command, the sampling point data corresponding to multiple consecutive motion postures of the measuring component in the updated motion posture sequence are collected. Multiple sampling point data are obtained based on the sampling point data corresponding to multiple different motion posture sequences.

[0108] In this embodiment, for the posture guidance calibration mode, the motion posture sequence in the sampling operation guidance diagram can be updated to guide the operator to perform touch sampling within the touch angle range.

[0109] Among them, different motion posture sequences correspond to different touch angle ranges under the same touch point. Each angle range can cover various postures of joint arm movement, and different angle ranges can partially overlap or not overlap.

[0110] For example, the angle range can be divided into multiple continuous angle ranges such as [0°, 15°], [15°, 30°], and [30°, 45°], or it can be divided into low angle ranges (such as [0°, 20°]), medium angle ranges (such as [20°, 50°]), and high angle ranges (such as [50°, 80°]). This application does not limit this.

[0111] The movement of the articulated arm can be controlled to bring the measuring piece to the target position on the calibration piece. The target position is a pre-determined contact point on the surface of the calibration piece. Taking the calibration piece as a conical recess as an example, the target position can be the apex of the conical recess, which can play a limiting role and reduce the displacement of the probe during the adjustment of the contact angle.

[0112] Specifically, an initial sampling operation guide diagram can be displayed. The operator controls the movement of the articulated arm to move the measuring component to the target position, such as the apex of the cone. When the measuring component touches the target position, the button can be pressed continuously to trigger the sampling command and continuously adjust the movement posture of the measuring component to sample. The temperature data and sensing data corresponding to different movement postures are recorded to form the first set of sampling point data.

[0113] After continuously sampling a motion posture sequence, the sampling operation guide icon can be updated. The updated sampling operation guide icon updates the motion posture sequence, and the new motion posture sequence can correspond to different touch angle ranges. Different sampling operation guide icons are shown below. Figure 7-10 As shown.

[0114] Following the updated sampling operation guide, the operator controls the articulated arm to move the measuring element to the target position. When the measuring element touches the target position, the operator can continuously press the button to trigger the sampling command and continuously adjust the measuring element's posture for sampling. Temperature and sensor data corresponding to different postures are recorded, forming a second set of sampling point data. This process is repeated until the target number of sampling point data sets are collected.

[0115] In this embodiment, by continuously sampling any motion posture sequence, the sampling point data is continuously distributed, which can cover the continuous posture changes under the motion posture sequence. Compared with the single-point scattered sampling method, the continuity of sampling is improved. Furthermore, by setting multiple motion posture sequences, the sampling point data can form redundant constraints from multiple motion posture sequences, reducing local errors and further improving the calibration accuracy.

[0116] In some embodiments, the calibration error is determined as follows: The geometric parameters of the measuring component are determined based on data from multiple sampling points and the kinematic model of the articulated arm. The calibration error is calculated based on the geometric parameters of the measured part.

[0117] In this embodiment, the geometric parameters of the measuring element refer to the measuring element parameters related to the calibration accuracy. For example, the geometric parameters of the measuring element may include the coordinates of the probe ball center of the measuring element in the articulated arm base coordinate system, that is, the needle tip coordinates of the measuring element. The geometric parameters of the measuring element may also include the length of the measuring element, the effective radius of the probe, the connection eccentricity between the measuring element and the end effector of the articulated arm, etc. This application embodiment does not limit this.

[0118] In this embodiment, the kinematic model of the articulated arm is a mathematical model describing the mapping relationship between the motion of each joint of the articulated arm and the pose of the end effector. The kinematic model of the articulated arm can be established using the Denavit-Hartenberg (DH) parametric model or a modified DH parametric model. The geometric parameters in the kinematic model may include the link length of each joint, joint torsion angle, joint offset, and the mounting parameters of the measuring element relative to the end effector.

[0119] Since the measuring component comes into contact with the calibration component when it touches it, theoretically the contact point should be located on the geometric surface of the calibration component. Therefore, an equation can be established using contact constraints to match the pose of the articulated arm end effector corresponding to each sampling point with the known geometric features of the calibration component. An optimization algorithm can then be used to solve for the geometric parameters of the measuring component that minimize the matching error.

[0120] In one example, for each sampling point, the pose of the end effector can be calculated based on the sensor data and kinematic model. Since the end effector is fixed to the measuring device, the pose of the measuring device can be further determined. Because the measuring device touches the calibrator, the contact point should satisfy the geometric constraint equations of the calibrator. For example, when the calibrator is a standard sphere, the distance from the contact point to the center of the sphere is equal to the radius of the sphere. Therefore, nonlinear equations or error functions regarding the geometric parameters of the measuring device can be established.

[0121] After establishing the error functions for each sampling point, the error functions of the data from each sampling point are integrated to construct a global optimization objective function. This global optimization objective function can be in the form of the sum of squared errors of the data from each sampling point, with the independent variables being the geometric parameters of the measured part. By minimizing this objective function, the optimal geometric parameter estimates can be obtained.

[0122] In some embodiments, considering the influence of temperature data on the joint arm, a temperature compensation model can be introduced into the kinematic model. This temperature compensation model describes thermal errors such as changes in link length and joint angle drift caused by temperature variations. The temperature compensation model can be a linear model, a polynomial model, or a neural network model, etc. During the solution of geometric parameters, temperature data can be used as input to the temperature compensation model to correct the kinematic model, thereby obtaining the temperature-compensated geometric parameters. In some embodiments, optimization methods such as least squares, genetic algorithms, or particle swarm optimization can be used to solve the global optimization objective function; this application does not limit this approach.

[0123] After obtaining the geometric parameters of the measuring component, the theoretical constraint values ​​corresponding to the data of each sampling point can be recalculated based on the geometric parameters, and compared with the actual measured values ​​to obtain the error of each sampling point data. Then, the calibration error can be obtained through comprehensive evaluation.

[0124] In this embodiment, the geometric parameters of the measuring component are determined based on multiple sampling point data and the kinematic model of the articulated arm, and then the calibration error is calculated based on the geometric parameters. This allows the calibration error to reflect the degree of fitting deviation between the kinematic model and the measured data, further improving the calibration accuracy of the articulated arm measuring machine.

[0125] In some embodiments, in ball calibration mode, the geometric parameters of the measuring element include the effective radius of the measuring element probe and the tip coordinates of the measuring element; The geometric parameters of the measuring component are determined based on data from multiple sampling points and the kinematic model of the articulated arm, including: Obtain the nominal diameter of the calibration piece and the nominal diameter of the probe of the measuring piece; The sensor data from each sampling point is converted into angle data for each joint, and the angle data is substituted into the kinematic model of the joint arm to obtain the initial pose trajectory of the measuring probe. Using the tip coordinates and the effective radius of the measuring probe as optimization variables, and based on the initial pose trajectory, multiple sampling point data, the structural model of the articulated arm, the nominal diameter of the calibration component, and the nominal diameter of the measuring probe, a first nonlinear error equation is constructed. The effective radius of the probe and the coordinates of the needle tip are obtained by iteratively solving the first nonlinear error equation.

[0126] In this embodiment, the calibration component can be a standard sphere, thereby enabling the establishment of a nonlinear optimization model based on spherical constraints, and the geometric parameters of the measurement component can be solved iteratively.

[0127] The nominal diameter of the calibration piece is the standard geometric dimension calibrated at the factory, which is a standard value that has been precisely measured and has traceability. The nominal diameter of the probe of the measuring piece is the theoretical design dimension, and half of the nominal diameter can be used as the initial estimate for iterative optimization of the effective radius.

[0128] In some embodiments, the sensing data can be the number of pulses or voltage signals output by the encoder. Based on the sensor's resolution, transmission ratio, and zero-point calibration parameters, the sensing data can be converted into angle data such as absolute angle values ​​or relative angle changes for each joint. The converted angle data is then substituted into the kinematic model of the articulated arm. Through forward kinematics derivation, the pose of the end effector corresponding to the sampling point data is calculated. Then, based on the relative positional relationship between the end effector and the measuring element, the initial pose coordinates of the measuring element's probe, i.e., the probe's center coordinates, are obtained. The sequence of initial pose coordinates corresponding to multiple sampling point data constitutes the initial pose trajectory of the measuring element's probe. It should be noted that since the tip coordinates and the effective radius of the probe are not yet accurately determined, the probe's center coordinates in the initial pose trajectory are approximate values.

[0129] In this embodiment, the tip coordinates and the effective radius of the measuring probe can be used as optimization variables. Based on the initial pose trajectory, multiple sampling point data, the structural model of the articulated arm, the nominal diameter of the calibration component, and the nominal diameter of the measuring probe, a first nonlinear error equation is constructed. The tip coordinates are the coordinates of the probe's center of gravity in the articulated arm's base coordinate system, representing the spatial position of the measuring component relative to the articulated arm's base coordinate system. The structural model of the articulated arm includes structural parameters such as the length, torsion angle, and offset of each link, which are known constants.

[0130] In one example, taking the calibration piece as a standard sphere, let the nominal diameter of the standard sphere be... The nominal diameter of the measuring probe is The initial pose trajectory of the measuring probe is as follows: in, Indicates the first The initial pose coordinates of the probe corresponding to each sampling point data point. .

[0131] The optimization variables are:

[0132] in, Indicates the coordinates of the needle tip. This indicates the effective radius of the measuring probe.

[0133] The ideal geometric constraint relationship is: when the probe of the measuring piece touches the surface of the standard sphere, the first... The initial pose coordinates of the measuring probe corresponding to each sampling point data point To the coordinates of the center of the standard sphere European-style spatial distance It should be equal to the sum of the radius of the standard sphere and the effective radius of the probe, that is:

[0134] Due to factors such as joint sensing error, connecting rod manufacturing error, temperature deformation, tip installation eccentricity, and probe wear, the actual calculated position deviates from the ideal spherical constraint. Therefore, a single-point residual equation is defined as follows:

[0135] Among them, residual For optimization variables Nonlinear functions.

[0136] By combining the residuals from the data at each of the n sampling points, we obtain the first nonlinear error equation:

[0137] Written in matrix-vector form:

[0138] in, This is the residual vector.

[0139] In some embodiments, nonlinear iterative algorithms, such as the Gauss-Newton method or the Levenberg-Marquardt method, can be used to solve the first nonlinear error equation.

[0140] For example, the design coordinates of the probe tip and the nominal radius of the probe can be used as initial values ​​for iteration. At each iteration point, a first-order Taylor expansion is performed on the first nonlinear error equation to linearize it, and the Jacobian matrix is ​​constructed. The variable correction is then solved by least squares. And update and optimize the variables:

[0141] in, Let represent the optimization variables in the k-th iteration.

[0142] Will Substitute into the first nonlinear error equation and recalculate. Repeat the above process until the residual norm is... If the value is less than the preset precision threshold, or if the change in the optimized variable during iteration is less than the preset change threshold, stop the iteration and output the optimized variable at this point.

[0143] In some embodiments, the first nonlinear error equation may also be in other forms, such as the sum of squared residuals corresponding to the data at each sampling point, which is not limited in this application.

[0144] In some embodiments, considering that temperature changes can cause thermal deformation of the articulated arm structure, thereby affecting the calculation accuracy of the kinematic model, the initial pose trajectory of the measuring probe can be corrected based on the temperature data in the data from each sampling point during the construction of the first nonlinear error equation. Specifically, based on the temperature data corresponding to each sampling point, the structural parameters in the articulated arm's structural model, such as link length and joint offset, are corrected using a preset temperature compensation model to obtain temperature-compensated structural parameters. These temperature-compensated structural parameters are then substituted into the kinematic model for forward kinematics calculation to obtain the corrected initial pose trajectory. The first nonlinear error equation is then constructed based on the corrected initial pose trajectory.

[0145] In this embodiment, by converting the sensing data into angle data and substituting it into the kinematic model to obtain the initial pose trajectory, it is possible to optimize and provide an initial solution based on the physical motion constraints of the articulated arm. This allows the optimization variables to be searched within the solution space that conforms to the structural characteristics of the articulated arm, reducing the difficulty of iterative convergence and improving the accuracy of the calculation of the geometric parameters of the measuring component.

[0146] In some embodiments, the calibration element is a sphere; the calibration error is calculated based on the geometric parameters of the measuring element, including: Based on the effective radius of the probe and the coordinates of the needle tip, calculate the first position data of the needle tip of the measuring component in the base coordinate system corresponding to the data of each sampling point; The center of the sphere is obtained by fitting data from each first position. Calculate the distance from each first position data point to the center of the sphere, and the difference between the nominal radius of the sphere and the sum of the effective radius of the probe, to obtain the error corresponding to each sampling point data point; The calibration error is obtained based on the error corresponding to the data at each sampling point.

[0147] In this embodiment, the probe tip coordinates are the coordinates of the probe ball center in the coordinate system of the articulated arm base. For each sampling point data, the sensor data in the sampling point data can be converted into angle data of each joint, and then the converted angle data can be substituted into the kinematic model of the articulated arm. Through forward kinematics derivation, the pose of the execution end corresponding to the sampling point data can be calculated. Then, based on the relative positional relationship between the execution end and the measuring device, the initial pose coordinates of the measuring device probe are obtained, that is, the probe ball center coordinates, which are also the first position data of the measuring device tip in the base coordinate system.

[0148] The coordinates of the sphere's center can be obtained by fitting the first position data corresponding to each sampling point. The distance from each first position data point to the sphere's center is calculated. Theoretically, the distance from each first position data point to the sphere's center is equal to the sum of the sphere's nominal radius and the probe's effective radius.

[0149] The error corresponding to each sampling point can be obtained by calculating the difference between the distance from each first position data point to the center of the sphere and the sum of the nominal radius of the sphere and the effective radius of the probe. Specifically, first calculate the distance from each first position data point to the center of the sphere, and then calculate the sum of the nominal radius of the sphere and the effective radius of the probe; finally, calculate the difference between the two. This difference is the error corresponding to the sampling point data.

[0150] Statistical analysis can be performed on the errors corresponding to each sampling point. The average, median, and maximum values ​​of the errors corresponding to each sampling point can be used to obtain other statistical quantities as calibration errors.

[0151] In this embodiment, the sampling point data is converted into the spatial position of the needle tip in the base coordinate system based on the effective radius of the probe and the needle tip coordinates. By fitting the center of the sphere and comparing the distance from each needle tip position to the center of the sphere with the theoretical value, the error corresponding to each sampling point data can reflect the degree of deviation between the estimated geometric parameters and the geometry of the standard sphere, thereby improving the accuracy of calibration error calculation.

[0152] In some embodiments, in attitude-guided calibration mode, the geometric parameters of the measuring element include the tip coordinates of the measuring element; The geometric parameters of the measuring component are determined based on data from multiple sampling points and the kinematic model of the articulated arm, including: The sensor data from each sampling point is converted into angle data for each joint, and the angle data is substituted into the kinematic model of the joint arm to obtain the initial position data of the measuring probe at each touch angle. Using the needle tip coordinates of the measuring component as the optimization variable, a second nonlinear error equation is constructed based on the initial position data, multiple sampling point data, and the structural model of the articulated arm. The nonlinear error equation is solved iteratively to obtain the needle tip coordinates.

[0153] In this embodiment, the calibration component can be a conical socket. A nonlinear optimization model based on conical surface constraints is established, and the tip coordinates of the measuring component are calculated iteratively. This method is suitable for scenarios where the effective radius of the probe is known or where only the spatial positioning accuracy of the probe needs to be verified.

[0154] In some embodiments, the sensing data can be the number of pulses or voltage signals output by the encoder. Based on the sensor's resolution, transmission ratio, and zero-point calibration parameters, the sensing data can be converted into angle data such as absolute angle values ​​or relative angle changes for each joint. The converted angle data is then substituted into the kinematic model of the articulated arm. Through forward kinematics derivation, the pose of the actuator corresponding to each contact angle is calculated. Finally, based on the relative positional relationship between the actuator and the measuring element, the initial position data of the measuring element's probe, i.e., the probe's center coordinates, is obtained. It should be noted that since the probe tip coordinates and the effective radius of the probe are not yet accurately determined, the probe's center coordinates in the initial position data are approximate values.

[0155] In one example, taking the calibration piece as a conical socket, the same contact point is the apex of the conical socket, and the effective radius of the measuring piece probe is... The initial position data of the measuring probe is , Indicates the first Initial position data of the probe of the measuring component at each touch angle .

[0156] The optimization variables are:

[0157] in, This represents the coordinates of the needle tip.

[0158] The ideal geometric constraint relationship is: the Euclidean spatial distance from the center of the sphere to the vertex N of the cone. Equal to probe radius ,Right now:

[0159] Due to factors such as joint sensing error, connecting rod manufacturing error, temperature deformation, needle tip installation eccentricity, and probe wear, the actual calculated position deviates from the ideal cone-shaped recess vertex constraint. Therefore, a single-point residual equation is defined as follows:

[0160] Among them, residual For optimization variables Nonlinear functions.

[0161] By combining the residuals from the data at each of the n sampling points, we obtain the second nonlinear error equation:

[0162] Written in matrix-vector form:

[0163] in, This is the residual vector.

[0164] In some embodiments, nonlinear iterative algorithms, such as the Gauss-Newton method or the Levenberg-Marquardt method, can be used to solve the second nonlinear error equation.

[0165] For example, the design coordinates of the needle tip can be used as the initial value for iteration. At each iteration point, the second nonlinear error equation is linearized using a first-order Taylor expansion to construct the Jacobian matrix, and the variable correction is solved using least squares. And update and optimize the variables:

[0166] in, Let represent the optimization variables in the k-th iteration.

[0167] Will Substitute into the second nonlinear error equation and recalculate. Repeat the above process until the residual norm is... If the value is less than the preset precision threshold, or if the change in the optimized variable during iteration is less than the preset change threshold, stop the iteration and output the optimized variable at this point.

[0168] In some embodiments, a second nonlinear error equation can be constructed and solved based on the sampling point data corresponding to each touch angle within each angle range to obtain the initial needle tip coordinates. The needle tip coordinates are then determined based on the initial needle tip coordinates corresponding to different angle ranges. For example, the average value of the initial needle tip coordinates corresponding to different angle ranges can be taken as the needle tip coordinates.

[0169] In some embodiments, the second nonlinear error equation may also be in other forms, such as the sum of squared residuals corresponding to the data at each sampling point, which is not limited in this application.

[0170] In some embodiments, considering that temperature changes can cause thermal deformation of the articulated arm structure, thereby affecting the calculation accuracy of the kinematic model, the initial position data of the measuring probe can be corrected based on the temperature data in the data from each sampling point during the construction of the second nonlinear error equation. Specifically, based on the temperature data corresponding to each sampling point, the structural parameters in the articulated arm's structural model, such as link length and joint offset, are corrected using a preset temperature compensation model to obtain temperature-compensated structural parameters. These temperature-compensated structural parameters are then substituted into the kinematic model for forward kinematics calculation to obtain the corrected initial position data. The second nonlinear error equation is then constructed based on the corrected initial position data.

[0171] In this embodiment, an error equation is constructed using the initial position data of the probe at each touch angle. This fully utilizes the sampling information under different postures, which can compensate for the effects of kinematic model fitting deviation, joint sensing data error, posture position disturbance, etc., thereby improving the accuracy of needle tip coordinate solution.

[0172] In some embodiments, the calibration element is a conical socket; the calibration error is calculated based on the geometric parameters of the measuring element, including: Based on the needle tip coordinates, calculate the second position data of the needle tip of the measuring piece in the base coordinate system corresponding to the data of each sampling point; Calculate the distance from each second position data point to the vertex of the cone to obtain the error corresponding to each sampling point data point; The calibration error is obtained based on the error corresponding to the data at each sampling point.

[0173] In this embodiment, for each sampling point data, the sensor data in the sampling point data can be converted into angle data of each joint, and then the converted angle data can be substituted into the kinematic model of the joint arm. Through forward kinematics derivation, the pose of the execution end corresponding to the sampling point data can be calculated. Then, based on the relative positional relationship between the execution end and the measuring device, the initial pose coordinates of the measuring device probe are obtained, that is, the probe ball center coordinates, which are also the second position data of the measuring device tip in the base coordinate system.

[0174] Since the measuring probe touches the same position of the cone cavity, namely the apex of the cone cavity, the theoretical distance between the probe's center and the apex of the cone cavity is always equal to the probe's radius. Therefore, the distance from each second position data point to the apex of the cone cavity can be calculated to obtain the error corresponding to each sampling point data point.

[0175] Statistical analysis can be performed on the errors corresponding to each sampling point. The average, median, and maximum values ​​of the errors corresponding to each sampling point can be used to obtain other statistical quantities as calibration errors.

[0176] In this embodiment, the sampling point data is converted into the spatial position of the needle tip in the base coordinate system based on the needle tip coordinates. The distance from each needle tip position to the apex of the cone is calculated by using the apex of the cone as the spatial reference point. This allows the point calibration error corresponding to each sampling point data to reflect the degree of deviation between the estimated needle tip coordinate value and the geometric center of the cone, thereby improving the accuracy of the calibration error calculation.

[0177] The following scenario example illustrates the calibration process of this application under different calibration modes.

[0178] In this example, the operator can select either ball calibration mode or attitude guidance calibration mode in the system interface.

[0179] If you select the ball calibration mode, the following steps are included: Step 1: First, the "Suggested Position Diagram" will be displayed. The operator should place the standard ball at half the length of the joint arm according to the diagram, and then press and hold the "green button" to proceed to Step 2.

[0180] Step 2: Display the sampling operation guide diagram. The operator should manually move the articulated arm to any position within the suggested "target range" according to the diagram, contact the standard ball, and briefly press the "green button" to perform sampling.

[0181] Step 3: Guide the operator to operate the articulated arm to control the measuring element to contact the standard ball in different "target ranges" through the sampling operation guide diagram until 56 steps are completed, thus obtaining 56 sampling point data.

[0182] Step 4: After obtaining data from 56 sampling points, calculate the probe tip coordinates and the effective radius of the probe to complete the sphere calibration.

[0183] If you select the attitude-guided calibration mode, the following steps are included: Step 1: First, the "Suggested Position Diagram" will be displayed. The operator should place the cone socket at half the length of the joint arm according to the diagram, and then press and hold the "green button" to proceed to Step 2.

[0184] Step 2: Display the sampling operation guide diagram. The operator adjusts the articulated arm to the recommended angle range according to the diagram, and presses and holds the "green button" to continuously collect multiple points within the angle range (up to 200 points can be collected in each angle range) to obtain a set of sampling point data.

[0185] Step 3: After completing the sampling data of the first group, release the green button to jump to the second group, that is, to sample within another angle range. Repeat step 2 until four groups are completed.

[0186] Step 4: Based on the four sets of sampling point data, calculate the needle tip coordinates and complete the attitude guidance calibration.

[0187] This application also provides a calibration method for an articulated arm, such as... Figure 11 As shown, the calibration method for the articulated arm includes steps 1110 and 1120.

[0188] Step 1110: Obtain multiple sampling point data obtained when the measuring component touches the calibration component; each sampling point data includes a set of temperature data of the articulated arm and sensor data characterizing the position of each joint in the articulated arm; Step 1120 determines the geometric parameters of the measuring component based on multiple sampling point data and the kinematic model of the articulated arm.

[0189] According to the articulated arm calibration method of this application, multiple sampling point data are acquired when the measuring component touches the calibration component. Each sampling point data includes the temperature data of the articulated arm and the sensor data characterizing the position of each joint. The geometric parameters of the measuring component are determined based on the multiple sampling point data and the kinematic model of the articulated arm. Then, the geometric parameters of the measuring component are determined by solving the kinematic model of the articulated arm. Compared with the guided motion calibration method that relies on visual feedback and pre-set expected image overlay comparison, it does not require visual feedback to drive the articulated arm to move precisely to a specific spatial position in a specified direction. This reduces the requirements for the motion control accuracy of the articulated arm, reduces the introduction of errors, and thus improves the calibration accuracy of the articulated arm measuring machine.

[0190] The articulated arm calibration method provided in this application can be executed by an articulated arm calibration device. This application uses an articulated arm calibration device executing the articulated arm calibration method as an example to illustrate the articulated arm calibration device provided in this application.

[0191] This application embodiment also provides a calibration device for an articulated arm, wherein a binocular scanner is installed at the end of the articulated arm, and multiple marker points are arranged on the object being measured or the target area surrounding the object being measured.

[0192] like Figure 12 As shown, the calibration device for the articulated arm includes: The first display module 1210 is used to display a suggested location diagram of the calibration piece; the suggested location diagram is used to indicate the suggested placement position of the calibration piece. The second display module 1220 is used to display a sampling operation guidance diagram in response to the first instruction; wherein, in ball calibration mode, the sampling operation guidance diagram displays the target area to be touched on the calibration piece; and / or, in attitude guidance calibration mode, the sampling operation guidance diagram displays a motion attitude sequence of the measuring piece, the motion attitude sequence being used to indicate the suggested motion attitude of the measuring piece at the same touch point on the calibration piece. The sampling module 1230 is used to sample multiple sampling point data in response to the sampling command. Each sampling point data includes a set of temperature data of the articulated arm collected when the measuring component touches the calibration component and sensor data characterizing the position of each joint in the articulated arm. The third display module 1240 is used to display the geometric parameters of the measuring component in response to a third instruction. The geometric parameters are determined based on multiple sampling point data and the kinematic model of the articulated arm.

[0193] According to the articulated arm calibration device of this application, the calibration process is guided by illustrations. Multiple sampling point data are acquired when the measuring component touches the calibration component. Each sampling point data includes the temperature data of the articulated arm and the sensor data characterizing the position of each joint. The geometric parameters of the measuring component are determined based on the multiple sampling point data and the kinematic model of the articulated arm. The geometric parameters of the measuring component are then determined by solving the kinematic model of the articulated arm. Sampling point data can be acquired within the range where the measuring component touches the target area, or the motion posture sequence when the measuring component touches the calibration component can be sampled. It is not necessary to drive the articulated arm to move precisely to the precise coordinate point or motion posture, which reduces the control requirements for the touch position and touch direction of the measuring component, reduces the introduction of errors, and thus improves the calibration accuracy of the articulated arm measuring machine.

[0194] The calibration device for the articulated arm in this embodiment can be an electronic device or a component within an electronic device, such as an integrated circuit or a chip. The electronic device can be a terminal or other devices besides a terminal. For example, the electronic device can be an articulated arm, a mobile phone, tablet computer, laptop computer, PDA, mobile internet device (MID), ultra-mobile personal computer (UMPC), netbook, or personal digital assistant (PDA), etc., and can also be a server, network attached storage (NAS), personal computer (PC), etc. This embodiment does not specifically limit the specific device.

[0195] The articulated arm calibration device in this embodiment can be a device with an operating system. This operating system can be a Microsoft (Windows) operating system, an Android operating system, an iOS operating system, or other possible operating systems, such as embedded operating systems. This embodiment does not specifically limit the specific operating system.

[0196] In some embodiments, such as Figure 13As shown, this application embodiment also provides an electronic device 1300, including a processor 1301, a memory 1302, and a computer program stored in the memory 1302 and executable on the processor 1301. When the program is executed by the processor 1301, it implements the various processes of the above-described articulated arm calibration method embodiment and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0197] This application also provides a calibration system for an articulated arm, including: Articulated arm, with a measuring element mounted at the end of the articulated arm; The articulated arm is used to perform the calibration method described above.

[0198] This application also provides a non-transitory computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it implements the various processes of the above-described articulated arm calibration method embodiments and achieves the same technical effect. To avoid repetition, it will not be described again here.

[0199] The processor is the processor in the electronic device described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.

[0200] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described articulated arm calibration method.

[0201] The processor is the processor in the electronic device described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.

[0202] This application also provides a chip, which includes a processor and a communication interface. The communication interface and the processor are coupled. The processor is used to run programs or instructions to implement the various processes of the above-described articulated arm calibration method embodiments and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0203] It should be understood that the chip mentioned in the embodiments of this application may also be referred to as a system-on-a-chip, system chip, chip system, or system-on-a-chip, etc.

[0204] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0205] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a computer software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0206] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

[0207] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0208] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A calibration method for an articulated arm, characterized in that, The end effector of the articulated arm is equipped with a measuring element; the method includes: A suggested location diagram for the calibration component is provided; the suggested location diagram indicates the recommended placement position of the calibration component. The sampling operation guidance diagram is displayed; wherein, in ball calibration mode, the sampling operation guidance diagram shows the target area to be touched on the calibration piece; and / or, in attitude guidance calibration mode, the sampling operation guidance diagram shows the motion attitude sequence of the measuring piece, the motion attitude sequence being used to indicate the suggested motion attitude of the measuring piece at the same touch point on the calibration piece; Multiple sampling point data are obtained by sampling, including sensor data representing the position of each joint in the articulated arm collected when the measuring component touches the calibration component; The calibration error is displayed; the calibration error is determined based on data from multiple sampling points.

2. The method according to claim 1, characterized in that, The diagram showing the suggested location of the calibration piece includes: In response to a trigger command for a target calibration mode, the target calibration mode is activated, and a suggested position diagram of the calibration component corresponding to the target calibration mode is displayed; wherein, the target calibration mode includes a ball calibration mode or an attitude guidance calibration mode.

3. The method according to claim 1, characterized in that, In the ball calibration mode, the calibration element is a sphere, and / or, in the attitude guidance calibration mode, the calibration element is a cone-shaped depression.

4. The method according to claim 1, characterized in that, In the ball calibration mode, different sampling point data correspond to different touch points, and / or, in the attitude guidance calibration mode, different sampling point data correspond to different motion postures of the measuring device at the same touch point.

5. The method according to claim 1, characterized in that, The sampling yields data from multiple sampling points, including: In the ball calibration mode, when the measuring element touches any position in the target area, sampling is performed in response to the sampling command to obtain sampling point data; In response to the completion of sampling, an updated sampling operation guidance diagram is displayed; wherein the updated sampling operation guidance diagram updates the position of the target area; When the measuring element touches any position in the updated target area, sampling is performed in response to the sampling command to obtain sampling point data; Multiple sampling point data are obtained based on sampling point data corresponding to multiple different target areas.

6. The method according to claim 1, characterized in that, The sampling yields data from multiple sampling points, including: In the attitude-guided calibration mode, when the measuring element touches the target position on the calibration element, in response to the sampling command, the sampling point data corresponding to multiple consecutive motion postures of the measuring element in the motion posture sequence are collected; In response to the completion of sampling, an updated sampling operation guidance diagram is displayed; wherein the updated sampling operation guidance diagram updates the motion posture sequence; When the measuring element touches the target position on the calibration element, in response to the sampling command, the sampling point data corresponding to multiple consecutive motion postures of the measuring element in the updated motion posture sequence are collected; Multiple sampling point data are obtained based on sampling point data corresponding to multiple different motion posture sequences.

7. The method according to claim 1, characterized in that, The calibration error is determined according to the following method: The geometric parameters of the measuring component are determined based on the data from multiple sampling points and the kinematic model of the articulated arm. The calibration error is calculated based on the geometric parameters of the measuring component.

8. The method according to claim 7, characterized in that, In the ball calibration mode, the geometric parameters of the measuring element include the effective radius of the measuring element probe and the tip coordinates of the measuring element; The determination of the geometric parameters of the measuring component based on multiple sampling point data and the kinematic model of the articulated arm includes: Obtain the nominal diameter of the calibration piece and the nominal diameter of the probe of the measuring piece; The sensor data in each sampling point is converted into angle data of each joint, and the angle data is substituted into the kinematic model of the joint arm to obtain the initial pose trajectory of the measuring probe. Using the tip coordinates and the effective radius of the measuring probe as optimization variables, a first nonlinear error equation is constructed based on the initial pose trajectory, multiple sampling point data, the structural model of the articulated arm, the nominal diameter of the calibration component, and the nominal diameter of the measuring probe. The effective radius of the probe and the coordinates of the needle tip are obtained by iteratively solving the first nonlinear error equation.

9. The method according to claim 8, characterized in that, The calibration element is a sphere; the calibration error calculated based on the geometric parameters of the measuring element includes: Based on the effective radius of the probe and the coordinates of the needle tip, calculate the first position data of the needle tip of the measuring component in the base coordinate system corresponding to each sampling point data; The center of the sphere is obtained by fitting the data at each of the first positions; Calculate the distance from each of the first position data points to the center of the sphere, and the difference between the sum of the nominal radius of the sphere and the effective radius of the probe, to obtain the error corresponding to each sampling point data point; The calibration error is obtained based on the error corresponding to the data at each sampling point.

10. The method according to claim 7, characterized in that, In attitude-guided calibration mode, the geometric parameters of the measuring element include the tip coordinates of the measuring element; The determination of the geometric parameters of the measuring component based on multiple sampling point data and the kinematic model of the articulated arm includes: The sensor data in each sampling point is converted into angle data of each joint, and the angle data is substituted into the kinematic model of the joint arm to obtain the initial position data of the measuring probe under each touch angle. Using the needle tip coordinates of the measuring component as the optimization variable, a second nonlinear error equation is constructed based on the initial position data, multiple sampling point data, and the structural model of the articulated arm. The nonlinear error equation is solved iteratively to obtain the needle tip coordinates.

11. The method according to claim 10, characterized in that, The calibration element is a conical socket; the calibration error calculated based on the geometric parameters of the measuring element includes: Based on the needle tip coordinates, calculate the second position data of the measuring component needle tip in the base coordinate system corresponding to each of the sampling point data; Calculate the distance from each of the second position data points to the vertex of the cone to obtain the error corresponding to each of the sampling point data points; The calibration error is obtained based on the error corresponding to the data at each sampling point.

12. The method according to claim 1, characterized in that, The calibration component is located within the target range of the working radius of the articulated arm.

13. The method according to claim 1, characterized in that, The sampling point data includes temperature data collected when the measuring device touches the calibration device.

14. A calibration method for an articulated arm, characterized in that, The end effector of the articulated arm is equipped with a measuring element; the method includes: The data obtained from multiple sampling points when the measuring component touches the calibration component is acquired; the sampling point data includes sensor data characterizing the position of each joint in the articulated arm; The calibration error is determined based on data from multiple sampling points.

15. A calibration device for an articulated arm, characterized in that, The end effector of the articulated arm is equipped with a measuring element; the device includes: The first display module is used to display a suggested location diagram of the calibration component; the suggested location diagram is used to indicate the recommended placement position of the calibration component. The second display module is used to display a sampling operation guidance diagram; wherein, in ball calibration mode, the sampling operation guidance diagram displays the target area to be touched on the calibration piece; and / or, in attitude guidance calibration mode, the sampling operation guidance diagram displays the motion attitude sequence of the measuring piece, the motion attitude sequence being used to indicate the suggested motion attitude of the measuring piece at the same touch point on the calibration piece; The sampling module is used to sample and obtain multiple sampling point data, including sensor data representing the position of each joint in the articulated arm collected when the measuring component touches the calibration component. The third display module is used to display the calibration error; the calibration error is determined based on data from multiple sampling points.

16. A calibration system for an articulated arm, characterized in that, include: An articulated arm, wherein a measuring element is mounted at the actuating end of the articulated arm; The articulated arm is used to perform the method as described in any one of claims 1-13.

17. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the method as described in any one of claims 1-13.

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