A mechanical arm dual-shaft comprehensive motion position precision verification method and system

Abstract

This invention relates to the field of precision testing technology and discloses a method for verifying the positional accuracy of a robotic arm's dual-axis integrated motion. The method includes: establishing an initial coordinate system by measuring the trajectory of a mirror fixed to the end of the end-effector when the robotic arm is in its initial pose; rotating the base axis by a first theoretical angle and the end-effector by a second theoretical angle to reach the target pose; virtually rotating the initial coordinate system around its own Y1 axis by a second theoretical angle to construct an intermediate coordinate system; determining the actual spatial axis of the end-effector in the target pose; defining the angle between the actual spatial axis and the X2 axis in the intermediate coordinate system as the first measured angle, and defining the angle between the projection line of the actual spatial axis on the Y2-O2-Z2 plane and the Y2 axis as the second measured angle; calculating a third and fourth theoretical angle using a first and second transformation formula, and using these angles to determine whether the positional accuracy is acceptable. This method can directly and effectively verify the positional accuracy of a six-axis robotic arm's dual-axis integrated motion.

Description

Technical Field

[0001] This invention relates to the field of precision testing technology, and in particular to a method and system for verifying the integrated motion position accuracy of a robotic arm with two axes. Background Technology

[0002] Microwave anechoic chamber testing systems are key devices for evaluating the performance of guidance equipment, simulating the attitude of the guidance equipment in space using a turntable. To improve flexibility and reduce costs, some systems use a six-axis robotic arm to replace the traditional turntable.

[0003] like Figure 1 The diagram shows a three-dimensional representation of the six-axis robotic arm, consisting of six axes: J1 through J6. In actual testing, the guidance device is installed at the end of the six-axis robotic arm. Often, some joints need to be locked, and only the base axis (e.g., J1 axis) and the end axis (e.g., J6 axis) perform combined rotational motion to simulate orientation and rolling posture. That is, the rotational motion of the J1 axis replaces the movement of the turntable around the orientation axis, and the rotational motion of the J6 axis replaces the movement of the turntable around the rolling axis. Therefore, the overall positional accuracy when these two axes are linked directly determines the reliability of the testing results.

[0004] Currently, the verification of the accuracy of the aforementioned six-axis robotic arm mainly relies on the "single-axis testing method." This method separately tests the single-axis positioning accuracy and repeatability of the J1 and J6 axes, and individually measures the perpendicularity and intersection between the two axes. If these sub-indicators are all qualified, it is indirectly inferred that the positional accuracy of the combined dual-axis motion meets the requirements. However, this method has obvious limitations: when the six-axis robotic arm is in dual-axis linkage, its accuracy is affected by the complex coupling of multiple factors such as single-axis error, inter-axis geometric error, load changes, and the coupling characteristics of the control system; only isolated testing and superimposed judgment of each factor cannot truly and intuitively reflect the comprehensive error under linkage conditions, leading to a disconnect between accuracy evaluation and actual situation, and making it difficult to verify the rationality of the sub-indicator design.

[0005] Therefore, there is an urgent need to provide a method and system for verifying the integrated motion position accuracy of a robotic arm with two axes, which can directly and effectively verify the integrated motion position accuracy of a six-axis robotic arm with two axes. Summary of the Invention

[0006] Based on this, it is necessary to provide a method and system for verifying the integrated motion position accuracy of a robotic arm on two axes, in order to directly and effectively verify the integrated motion position accuracy of a six-axis robotic arm on two axes.

[0007] The first aspect of this application provides a method for verifying the positional accuracy of a robotic arm with dual-axis integrated motion. The robotic arm includes a base axis and an end axis. The rotational motion of the base axis replaces the motion of a turntable around an orientation axis, and the rotational motion of the end axis replaces the motion of the turntable around a rolling axis. The method includes:

[0008] Step S1: When the robotic arm is in the initial pose, control the base axis and the end axis to rotate independently and sequentially, and establish an initial coordinate system by measuring the trajectory of the reflector using a laser tracker, wherein the reflector is fixed to the end of the end axis;

[0009] Step S2: Rotate the base axis by a first theoretical angle and simultaneously rotate the end axis by a second theoretical angle to reach the target pose through dual-axis integrated motion; virtually rotate the initial coordinate system around its own Y1 axis by the second theoretical angle to virtually construct an intermediate coordinate system;

[0010] Step S3: Control the rotation of the end axis under the target pose, and use a laser tracker to measure the reflector to determine the actual spatial axis of the end axis;

[0011] Step S4: In the intermediate coordinate system, define the angle between the actual spatial axis and the X2 axis as the first measured angle, project the actual spatial axis onto the Y2-O2-Z2 plane to form a projection line, and define the angle between the projection line and the Y2 axis as the second measured angle.

[0012] Step S5: Based on the first theoretical angle and the second theoretical angle, calculate the third theoretical angle and the fourth theoretical angle using the first conversion formula and the second conversion formula respectively;

[0013] Step S6: Compare the error between the first measured angle and the third theoretical angle, and compare the error between the second measured angle and the fourth theoretical angle. Based on the result of the error comparison, determine whether the position accuracy of the dual-axis integrated motion of the robotic arm is qualified.

[0014] In some embodiments, step S1, when the robotic arm is in its initial pose, involves controlling the base axis and the end effector axis to rotate independently and sequentially, and establishing an initial coordinate system by measuring the trajectory of the reflector using a laser tracker. The reflector is fixed to the end of the end effector axis.

[0015] Step S11: When the robotic arm is in the initial pose, control the base axis to rotate independently, and use a laser tracker to measure the trajectory of the reflector fixed on the end of the end axis and fit it to obtain the first circumference, with the normal direction of the first circumference as the first reference axis.

[0016] Step S12: Control the end shaft to rotate independently, and measure the trajectory of the reflector with a laser tracker and fit it to obtain the second circumference, with the normal direction of the second circumference as the second reference axis;

[0017] Step S13: Based on the first reference axis and the second reference axis, establish an initial coordinate system, wherein the intersection of the first reference axis and the second reference axis is the center of the circle.

[0018] In some embodiments, measuring the trajectory of the reflector fixed to the end of the end shaft using a laser tracker and fitting it to obtain a first circumference includes controlling the base shaft to rotate at least one revolution, and using the laser tracker to collect the coordinates of at least 6 points on the trajectory of the reflector for spatial circle fitting to obtain the first circumference; measuring the trajectory of the reflector using a laser tracker and fitting it to obtain a second circumference includes controlling the end shaft to rotate at least one revolution, and using the laser tracker to collect the coordinates of at least 6 points on the trajectory of the reflector for spatial circle fitting to obtain the second circumference.

[0019] In some embodiments, step S3, controlling the rotation of the end effector axis under the target pose and measuring the reflector using a laser tracker to determine the actual spatial axis of the end effector axis, includes:

[0020] Under the target pose, the end axis is controlled to rotate independently, the trajectory of the reflector is measured by a laser tracker, and a third circle is obtained by fitting. The axis of the third circle is defined as the actual spatial axis of the end axis under the target pose.

[0021] In some embodiments, controlling the end-effector to rotate independently under the target pose, measuring the trajectory of the reflector using a laser tracker, and fitting a third circle includes:

[0022] Under the target pose, the end axis is controlled to rotate independently according to a preset step angle, and the coordinates of no less than 6 points on the trajectory of the reflector are collected by the laser tracker to perform spatial circle fitting to obtain the third circle.

[0023] In some embodiments, step S5, calculating the third and fourth theoretical angles based on the first and second theoretical angles using the first and second conversion formulas respectively, includes:

[0024] Obtain the first theoretical perspective and the second theoretical perspective;

[0025] The third theoretical angle is obtained by calculating the first conversion formula, which is expressed as θ = arccos(sinα*cosβ).

[0026] The fourth theoretical angle is obtained by calculating using the second conversion formula, which is expressed as follows:

[0027] Among them, the first theoretical angle is α, the second theoretical angle is β, the third theoretical angle is θ, and the fourth theoretical angle is φ.

[0028] In some embodiments, step S6, comparing the error between the first measured angle and the third theoretical angle, comparing the error between the second measured angle and the fourth theoretical angle, and determining whether the position accuracy of the robotic arm's dual-axis integrated motion is qualified based on the error comparison results, includes:

[0029] The absolute value of the difference between the first measured angle and the third theoretical angle is taken as the first deviation value;

[0030] The absolute value of the difference between the second measured angle and the fourth theoretical angle is taken as the second deviation value;

[0031] If at least one of the first deviation value and the second deviation value is greater than a preset threshold, the position accuracy is unqualified.

[0032] In some embodiments, the robotic arm is a six-axis robotic arm for a microwave anechoic chamber inspection system. The robotic arm also includes other mechanical axes located between the base axis and the end axis, wherein when the base axis or the end axis is rotated individually or when the robotic arm performs the dual-axis combined motion, the other mechanical axes are in a locked state.

[0033] In some embodiments, the theoretical positional relationship between the base axis and the end axis is that they are spatially perpendicular and intersecting.

[0034] The second aspect of this application provides a dual-axis integrated motion position accuracy verification system for a robotic arm, comprising:

[0035] A robotic arm includes a base axis and an end axis, wherein the rotational motion of the base axis replaces the motion of the turntable about an orientation axis, and the rotational motion of the end axis replaces the motion of the turntable about a rolling axis;

[0036] A reflector is fixed to the end of the end shaft;

[0037] A laser tracker is used to track and measure the trajectory of a reflector.

[0038] A controller and processor are connected to the robotic arm and the laser tracker. The controller and processor are configured to execute the robotic arm dual-axis integrated motion position accuracy verification method described in any of the above embodiments.

[0039] The beneficial effects of this invention are:

[0040] This invention achieves a target pose through dual-axis integrated motion by rotating the base axis by a first theoretical angle and simultaneously rotating the end-effector axis by a second theoretical angle. An intermediate coordinate system is virtually constructed by virtually rotating the initial coordinate system around its Y1 axis by the second theoretical angle. Then, under the target pose, the end-effector axis is rotated, and a laser tracker is used to measure the reflector to determine the actual spatial axis of the end-effector axis. Next, in the intermediate coordinate system, the angle between the actual spatial axis and the X2 axis is defined as the first measured angle. The actual spatial axis is projected onto the Y2-O2-Z2 plane to form a projection line, and the angle between the projection line and the Y2 axis is defined as the second measured angle. Then, based on the first and second theoretical angles, a third and fourth theoretical angle are calculated using a first and a second conversion formula, respectively. Finally, the errors of the first and third measured angles are compared, and the errors of the second and fourth measured angles are compared, allowing for the determination of the acceptable positional accuracy of the dual-axis integrated motion of the robotic arm based on the error comparison results. Therefore, by transforming the problem of dual-axis linkage accuracy into the problem of measuring the deviation of the third and fourth theoretical angles in a specially constructed intermediate coordinate system, it achieves a direct, intuitive and effective evaluation of the combined effect of all error sources under dual-axis linkage conditions. This solves the problem that the position accuracy of the robotic arm's dual-axis integrated motion cannot be verified, and it can better match the actual detection situation of the guidance equipment in field use. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only one embodiment of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0042] Figure 1 A three-dimensional structural schematic diagram of a six-axis robotic arm provided for some embodiments of the present invention;

[0043] Figure 2 A flowchart illustrating a method for verifying the integrated motion position accuracy of a robotic arm along two axes, provided for some embodiments of the present invention;

[0044] Figure 3 A schematic diagram of the initial coordinate system constructed for the robotic arm dual-axis integrated motion position accuracy verification method provided for some embodiments of the present invention;

[0045] Figure 4 A schematic diagram illustrating the construction of an intermediate coordinate system based on an initial coordinate system in the construction of a method for verifying the dual-axis integrated motion position accuracy of a robotic arm provided for some embodiments of the present invention;

[0046] Figure 5 This is an auxiliary diagram illustrating the derivation of the first and second conversion formulas in the method for verifying the dual-axis integrated motion position accuracy of a robotic arm provided for some embodiments of the present invention. Detailed Implementation

[0047] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0048] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0049] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0050] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0051] In this invention, unless otherwise explicitly specified and limited, a feature "above" or "below" the second feature may mean that the feature is in direct contact with the second feature or indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature may mean that the feature is directly above or diagonally above the second feature, or simply indicates that the feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "beneath" of the second feature may mean that the feature is directly below or diagonally below the second feature, or simply indicates that the feature is at a lower horizontal level than the second feature.

[0052] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0053] First, let me introduce the embodiments of this invention. Figures 1 to 5 The content. Figure 1 A three-dimensional structural diagram of a six-axis robotic arm provided for some embodiments of the present invention, which has six axes from J1 to J6; Figure 2 A flowchart illustrating a method for verifying the integrated motion position accuracy of a robotic arm along two axes, provided for some embodiments of the present invention; Figure 3 A schematic diagram of the initial coordinate system constructed for the robotic arm dual-axis integrated motion position accuracy verification method provided for some embodiments of the present invention; Figure 4 A schematic diagram illustrating the construction of an intermediate coordinate system based on an initial coordinate system in the construction of a method for verifying the dual-axis integrated motion position accuracy of a robotic arm provided for some embodiments of the present invention; Figure 5 This is an auxiliary diagram illustrating the derivation of the first and second conversion formulas in the method for verifying the dual-axis integrated motion position accuracy of a robotic arm provided for some embodiments of the present invention.

[0054] refer to Figures 1-5 The embodiments of this application provide a method for verifying the dual-axis integrated motion position accuracy of a robotic arm. The robotic arm includes a base axis and an end axis. The rotational motion of the base axis replaces the motion of the turntable around the orientation axis, and the rotational motion of the end axis replaces the motion of the turntable around the rolling axis. The method includes:

[0055] Step S1: When the robotic arm is in the initial pose, control the base axis and the end axis to rotate independently and sequentially, and establish an initial coordinate system by measuring the trajectory of the reflector using a laser tracker, wherein the reflector is fixed to the end of the end axis;

[0056] Step S2: Rotate the base axis by a first theoretical angle and simultaneously rotate the end axis by a second theoretical angle to reach the target pose through dual-axis integrated motion; virtually rotate the initial coordinate system around its own Y1 axis by the second theoretical angle to virtually construct an intermediate coordinate system;

[0057] Step S3: Control the rotation of the end axis under the target pose, and use a laser tracker to measure the reflector to determine the actual spatial axis of the end axis;

[0058] Step S4: In the intermediate coordinate system, define the angle between the actual spatial axis and the X2 axis as the first measured angle, project the actual spatial axis onto the Y2-O2-Z2 plane to form a projection line, and define the angle between the projection line and the Y2 axis as the second measured angle.

[0059] Step S5: Based on the first theoretical angle and the second theoretical angle, calculate the third theoretical angle and the fourth theoretical angle using the first conversion formula and the second conversion formula respectively;

[0060] Step S6: Compare the error between the first measured angle and the third theoretical angle, and compare the error between the second measured angle and the fourth theoretical angle. Based on the result of the error comparison, determine whether the position accuracy of the dual-axis integrated motion of the robotic arm is qualified.

[0061] Explanatoryly, the theoretical positional relationship between the base axis and the end axis is that they are spatially perpendicular and intersecting, which is a prerequisite upon which the subsequent methods of the embodiments of this application depend. Furthermore, the base axis corresponds to... Figure 1 and Figure 3 The J1 axis of the robotic arm corresponds to the J6 axis at its end effector. Furthermore, for ease of understanding of the technical solution of this application, see references. Figure 3 The initial coordinate system is denoted by O1, and it has Y1, X1, and Z1 axes. (Reference) Figure 4 The center of the intermediate coordinate system is denoted as O2, and it has Y2, X2, and Z2 axes. (Reference) Figure 4 The first theoretical angle is α, the second theoretical angle is β, the third theoretical angle is θ, and the fourth theoretical angle is... Furthermore, the first measured angle can be represented by θ1, and the second measured angle can be represented by... The steps will be described in detail later and will not be repeated here. Step S4 provides the first measured angle obtained by the laser tracker and the measured value of the first measured angle. The first measured angle and the measured value of the first measured angle can be found by the laser tracker or the corresponding software system for subsequent error comparison.

[0062] As described above, the method for verifying the position accuracy of a robotic arm's dual-axis integrated motion in this application transforms the problem of dual-axis linkage accuracy into the problem of measuring the deviation between the third and fourth theoretical angles in a specially constructed intermediate coordinate system. This achieves a direct, intuitive, and effective evaluation of the combined effect of all error sources under dual-axis linkage conditions, solving the problem that the position accuracy of the robotic arm's dual-axis integrated motion cannot be verified, and better reflects the actual testing conditions of guidance equipment in field use. Furthermore, traditional evaluation schemes generally do not perform coordinate system rotation. In the implementation method of this application, the initial coordinate system is rotated in step S2, virtually constructing an intermediate coordinate system, which facilitates subsequent angle derivation calculations. Moreover, the position accuracy evaluation method that compares the error between the first measured angle and the third theoretical angle, and the error between the second measured angle and the fourth theoretical angle, includes the influence of multiple factors such as the single-axis positioning accuracy of the robotic arm, the perpendicularity and intersection of the base axis and the end axis, and the load changes of the robotic arm during movement, as well as the influence of other existing but unconfirmed or undefined factors. This allows for a more reasonable evaluation of the position accuracy of the robotic arm's dual-axis integrated motion.

[0063] In some implementations, reference Figures 1-5 The robotic arm is a six-axis robotic arm used in a microwave anechoic chamber inspection system. The robotic arm also includes other mechanical axes located between the base axis and the end axis. When controlling the base axis or the end axis to rotate individually, or when the robotic arm performs the combined dual-axis movement, the other mechanical axes are all in a locked state. Having all other mechanical axes locked reduces errors introduced by unintended movements of the mechanical axes.

[0064] refer to Figures 1-5 In some embodiments, step S1, when the robotic arm is in its initial pose, involves controlling the base axis and the end effector axis to rotate independently and sequentially, and establishing an initial coordinate system by measuring the trajectory of the reflector using a laser tracker. The reflector is fixed to the end of the end effector axis.

[0065] Step S11: When the robotic arm is in the initial pose, control the base axis to rotate independently, and use a laser tracker to measure the trajectory of the reflector fixed on the end of the end axis and fit it to obtain the first circumference, with the normal direction of the first circumference as the first reference axis.

[0066] Step S12: Control the end shaft to rotate independently, and measure the trajectory of the reflector with a laser tracker and fit it to obtain the second circumference, with the normal direction of the second circumference as the second reference axis;

[0067] Step S13: Based on the first reference axis and the second reference axis, establish an initial coordinate system, wherein the intersection of the first reference axis and the second reference axis is the center of the circle.

[0068] The split-axis motion described above effectively decouples the motion of the base axis and the end axis, and completes the construction of the initial coordinate system, laying the foundation for subsequent analysis.

[0069] In some implementations, reference Figures 1-5 The process of measuring and fitting the trajectory of the reflector fixed to the end of the end shaft using a laser tracker to obtain a first circumference includes controlling the base shaft to rotate at least one revolution, and using the laser tracker to collect the coordinates of at least six points on the trajectory of the reflector for spatial circle fitting to obtain the first circumference. Similarly, the process of measuring and fitting the trajectory of the reflector to obtain a second circumference using a laser tracker includes controlling the end shaft to rotate at least one revolution, and using the laser tracker to collect the coordinates of at least six points on the trajectory of the reflector for spatial circle fitting to obtain the second circumference. Using the coordinates of at least six points for spatial circle fitting effectively ensures the fitting accuracy.

[0070] refer to Figures 1-5 In some embodiments, step S3, controlling the rotation of the end effector axis under the target pose and measuring the reflector using a laser tracker to determine the actual spatial axis of the end effector axis, includes:

[0071] Under the target pose, the end axis is controlled to rotate independently, the trajectory of the reflector is measured by a laser tracker, and a third circle is obtained by fitting. The axis of the third circle is defined as the actual spatial axis of the end axis under the target pose.

[0072] In some implementations, reference Figures 1-5 The step of controlling the end axis to rotate independently under the target pose, measuring the trajectory of the reflector using a laser tracker, and fitting a third circle includes:

[0073] Under the target pose, the end axis is controlled to rotate independently according to a preset step angle, and the coordinates of no less than 6 points on the trajectory of the reflector are collected by the laser tracker to perform spatial circle fitting to obtain the third circle.

[0074] The above method uses the coordinates of no less than 6 points to perform spatial circle fitting, which can effectively ensure the fitting accuracy.

[0075] Further, refer to Figures 1-5 In some embodiments, step S5, calculating the third and fourth theoretical angles based on the first and second theoretical angles using the first and second conversion formulas respectively, includes:

[0076] Step S51: Obtain the first theoretical angle and the second theoretical angle;

[0077] Step S52: Calculate the third theoretical angle using the first conversion formula, which is expressed as θ = arccos(sinα*cosβ);

[0078] Step S53: Calculate the fourth theoretical angle using the second conversion formula, which is expressed as follows:

[0079] Among them, the first theoretical angle is α, the second theoretical angle is β, the third theoretical angle is θ, and the fourth theoretical angle is φ.

[0080] The specific derivation process of the first and second transformation formulas is as follows:

[0081] according to Figure 3 and Figure 4 From the geometric relationships shown, we can obtain:

[0082]

[0083] O2D=O2A*cosθ=O2A*sinα*cosβ

[0084] Eliminating O2A from both sides of the equals sign yields:

[0085]

[0086] cosθ=sinα*cosβ

[0087] Simplifying, we get:

[0088] θ = arccos(sinα*cosβ)

[0089]

[0090] As described above, the third and fourth theoretical angles can be calculated directly using the first and second conversion formulas respectively. By simplifying and eliminating O2A, the third and fourth theoretical angles can be obtained directly from the first and second conversion formulas.

[0091] refer to Figures 1-5 In some embodiments, step S6, comparing the error between the first measured angle and the third theoretical angle, comparing the error between the second measured angle and the fourth theoretical angle, and determining whether the position accuracy of the robotic arm's dual-axis integrated motion is qualified based on the error comparison results, includes:

[0092] The absolute value of the difference between the first measured angle and the third theoretical angle is taken as the first deviation value;

[0093] The absolute value of the difference between the second measured angle and the fourth theoretical angle is taken as the second deviation value;

[0094] If at least one of the first deviation value and the second deviation value is greater than a preset threshold, the positional accuracy is unqualified. The preset threshold can be set according to accuracy requirements or user definition, such as 0.01°, 0.5°, etc., details of which will not be elaborated further.

[0095] Of course, if neither the first deviation value nor the second deviation value is greater than the preset threshold, then the position accuracy is qualified.

[0096] Some embodiments of this application also provide a dual-axis integrated motion position accuracy verification system for a robotic arm, including a robotic arm, a reflector, a laser tracker, and a controller and processor. The controller and processor can be integrated into the software system of the laser tracker or set up separately. The robotic arm includes a base axis and an end axis. The rotational motion of the base axis replaces the motion of the turntable around the orientation axis, and the rotational motion of the end axis replaces the motion of the turntable around the rolling axis. The reflector is fixed to the end of the end axis. The laser tracker is used to track and measure the trajectory of the reflector. The controller and processor are connected to the robotic arm and the laser tracker, and the controller and processor are configured to execute the dual-axis integrated motion position accuracy verification method for a robotic arm described in any of the above embodiments. The controller and processor can be a virtual device or a physical unit structure, and there is no specific limitation.

[0097] Finally, it should be noted that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments have been described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0098] The above-described embodiments are merely one implementation of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A method for verifying the position accuracy of a comprehensive motion of a dual-axis robot arm, the robot arm comprising a base axis and an end axis, the rotational motion of the base axis being used to replace the motion of a turntable about an azimuth axis, and the rotational motion of the end axis replacing the motion of a turntable about a roll axis, characterized in that, The method includes: Step S1: When the robotic arm is in the initial pose, control the base axis and the end axis to rotate independently and sequentially, and establish an initial coordinate system by measuring the trajectory of the reflector using a laser tracker, wherein the reflector is fixed to the end of the end axis; Step S2: Rotate the base axis by a first theoretical angle and simultaneously rotate the end axis by a second theoretical angle to reach the target pose through dual-axis integrated motion; virtually rotate the initial coordinate system around its own Y1 axis by the second theoretical angle to virtually construct an intermediate coordinate system; Step S3: Control the rotation of the end axis under the target pose, and use a laser tracker to measure the reflector to determine the actual spatial axis of the end axis; Step S4: In the intermediate coordinate system, define the angle between the actual spatial axis and the X2 axis as the first measured angle, project the actual spatial axis onto the Y2-O2-Z2 plane to form a projection line, and define the angle between the projection line and the Y2 axis as the second measured angle. Step S5: Based on the first theoretical angle and the second theoretical angle, calculate the third theoretical angle and the fourth theoretical angle using the first conversion formula and the second conversion formula respectively; Step S6: Compare the error between the first measured angle and the third theoretical angle, and compare the error between the second measured angle and the fourth theoretical angle. Based on the result of the error comparison, determine whether the position accuracy of the dual-axis integrated motion of the robotic arm is qualified.

2. The method of claim 1, wherein, Step S1 involves controlling the base axis and the end effector axis to rotate independently and sequentially when the robotic arm is in its initial pose, and establishing an initial coordinate system by measuring the trajectory of the reflector using a laser tracker. The reflector is fixed to the end of the end effector axis. Step S11: When the robotic arm is in the initial pose, control the base axis to rotate independently, and use a laser tracker to measure the trajectory of the reflector fixed on the end of the end axis and fit it to obtain the first circumference, with the normal direction of the first circumference as the first reference axis. Step S12: Control the end shaft to rotate independently, and measure the trajectory of the reflector with a laser tracker and fit it to obtain the second circumference, with the normal direction of the second circumference as the second reference axis; Step S13: Based on the first reference axis and the second reference axis, establish an initial coordinate system, wherein the intersection of the first reference axis and the second reference axis is the center of the circle.

3. The method for verifying the dual-axis integrated motion position accuracy of a robotic arm according to claim 2, characterized in that, The step of measuring the trajectory of the reflector fixed on the end of the end shaft by a laser tracker and fitting it to obtain the first circumference includes controlling the base shaft to rotate at least one revolution, and using the laser tracker to collect the coordinates of no less than 6 points on the trajectory of the reflector to perform spatial circle fitting to obtain the first circumference. The step of measuring the trajectory of the reflector and fitting the second circle using a laser tracker includes controlling the end shaft to rotate at least one revolution, and using the laser tracker to collect the coordinates of at least 6 points on the trajectory of the reflector to perform spatial circle fitting to obtain the second circle.

4. The method of claim 1, wherein, Step S3, controlling the rotation of the end effector axis under the target pose and measuring the reflector using a laser tracker to determine the actual spatial axis of the end effector axis, includes: Under the target pose, the end axis is controlled to rotate independently, the trajectory of the reflector is measured by a laser tracker, and a third circle is obtained by fitting. The axis of the third circle is defined as the actual spatial axis of the end axis under the target pose.

5. The method of claim 4, wherein, Under the target pose, controlling the end axis to rotate independently, measuring the trajectory of the reflector using a laser tracker, and fitting the third circle includes: Under the target pose, the end axis is controlled to rotate independently according to a preset step angle, and the coordinates of no less than 6 points on the trajectory of the reflector are collected by the laser tracker to perform spatial circle fitting to obtain the third circle.

6. The method of claim 1, wherein, Step S5, calculating the third and fourth theoretical angles based on the first and second theoretical angles using the first and second conversion formulas respectively, includes: Obtain the first theoretical perspective and the second theoretical perspective; The third theoretical angle is obtained by calculating the first conversion formula, which is expressed as θ = arccos(sinα*cosβ). A fourth theoretical angle is calculated by a second conversion formula, which is expressed as Among them, the first theoretical angle is α, the second theoretical angle is β, the third theoretical angle is θ, and the fourth theoretical angle is φ.

7. The method of claim 1, wherein, Step S6, comparing the error between the first measured angle and the third theoretical angle, and comparing the error between the second measured angle and the fourth theoretical angle, and determining whether the position accuracy of the robotic arm's dual-axis integrated motion is qualified based on the error comparison results, includes: The absolute value of the difference between the first measured angle and the third theoretical angle is taken as the first deviation value; The absolute value of the difference between the second measured angle and the fourth theoretical angle is taken as the second deviation value; If at least one of the first deviation value and the second deviation value is greater than a preset threshold, the position accuracy is unqualified.

8. The method of claim 1, wherein, The robotic arm is a six-axis robotic arm used in a microwave anechoic chamber inspection system. The robotic arm also includes other mechanical axes located between the base axis and the end axis. When the base axis or the end axis is rotated individually or when the robotic arm performs the dual-axis combined motion, the other mechanical axes are in a locked state.

9. The method of claim 1, wherein, The theoretical positional relationship between the base axis and the end axis is that they are spatially perpendicular and intersecting.

10. A dual-axis integrated motion position accuracy verification system for a robotic arm, characterized in that, include: A robotic arm includes a base axis and an end axis, wherein the rotational motion of the base axis replaces the motion of the turntable about an orientation axis, and the rotational motion of the end axis replaces the motion of the turntable about a rolling axis; A reflector is fixed to the end of the end shaft; A laser tracker is used to track and measure the trajectory of a reflector. A control and processor, connected to the robotic arm and the laser tracker, is configured to execute the robotic arm dual-axis integrated motion position accuracy verification method according to any one of claims 1-8.

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