DH parameter calibration method and device for rope-driven agile space manipulator

Abstract

The application relates to the technical field of robots, in particular to a DH parameter calibration method and device for a rope-driven agile space manipulator, wherein the method comprises the following steps: determining the spatial position of a shoulder joint axis by means of a scanning circumferential mode; determining the spatial position of a linkage elbow joint by means of translation elimination of small linkage offset; determining the spatial position of a virtual base on the basis of first preset theoretical DH parameters; determining the spatial position of a linkage wrist pitch joint by means of translation elimination of small linkage offset; determining the spatial position of a linkage wrist rotation joint by means of a terminal installation target ball mode; and determining the conversion relationship of a terminal tool coordinate system relative to a calibration terminal coordinate system by using second preset theoretical DH parameters. Therefore, the problems in the prior art that the joints of the rope-driven agile space manipulator are linkage joints, DH parameter calibration is difficult, the positions and postures of the joints are difficult to accurately determine, the control difficulty is increased, the reliability and adaptability are reduced and the like are solved.

Description

Technical Field

[0001] This application relates to the field of robotics technology, and in particular to a method and apparatus for calibrating the DH parameters of a rope-driven agile spatial robotic arm. Background Technology

[0002] In related technologies, for robot systems, DH parameters can be easily obtained through models. However, due to minor errors in assembly and processing, the DH parameters of actual products often have certain errors. Therefore, DH parameters can be calibrated through methods such as direct measurement and indirect fitting.

[0003] However, in related technologies, since the joints of the rope-driven agile space robot are linked joints, each joint degree of freedom corresponds to two or more rotation axes, and the wrist is a virtual joint with many rotation axes, it is impossible to use related technologies for DH parameter calibration. This may lead to the inability to accurately determine the position and attitude of the joints, increase the difficulty of control, and cause a decrease in reliability and limited adaptability, which urgently needs to be improved. Summary of the Invention

[0004] This application provides a method and apparatus for calibrating the DH parameters of a rope-driven agile spatial manipulator, in order to solve the problems in related technologies, such as the difficulty in calibrating DH parameters because the joints of the rope-driven agile spatial manipulator are linkage joints, which may make it difficult to accurately determine the position and attitude of the joints, increase the difficulty of control, and reduce reliability and adaptability.

[0005] The first aspect of this application provides a method for calibrating the DH parameters of a rope-driven agile spatial manipulator, comprising the following steps: determining the spatial position of the shoulder joint axis by scanning a circle; determining the spatial position of the linked elbow joint by eliminating small link offset using a first translation method; determining the spatial position of the virtual base based on a first preset theoretical DH parameter and under the condition of no actual base; determining the spatial position of the linked wrist pitch joint by eliminating small link offset using a second translation method; determining the spatial position of the linked wrist rotation joint by installing a target ball at the end effector; and determining the transformation relationship between the end effector coordinate system and the calibrated end effector coordinate system using the second preset theoretical DH parameter.

[0006] Optionally, in one embodiment of this application, the method further includes: identifying the joint type of the joint; if the joint type is a non-heterogeneous joint, installing a laser tracker target ball at the distal end of the linkage joint, and using a single-joint motion to fit a circular axis to determine the joint axis; if the joint type is a planar heterogeneous linkage joint, using a linkage joint motion to fit a circular axis through a translation method to determine the joint axis.

[0007] Optionally, in one embodiment of this application, the method further includes: when the joint type is a quaternion joint, fitting the rotation joint axis and the pitch joint axis by changing the quaternion orientation.

[0008] Optionally, in one embodiment of this application, the method of using linked joint motion to fit the circular axis by translation to determine the joint axis includes: acquiring the position of the target ball at multiple angles, translating the target ball according to the rotation angle, fitting the circumference of the translated set of points using the least squares method, and taking the axis as the joint axis.

[0009] Optionally, in one embodiment of this application, the translated set of points is:

[0010]

[0011] Where i is the index of a set of points being measured, X i ″″ Let X be the coordinates of the translated point. i ′ represents the coordinates of the end node of the linkage joint being measured, X oi The coordinates of the measured joint base end node are given. For X oi The average value.

[0012] A second aspect of this application provides a DH parameter calibration device for a rope-driven agile spatial robotic arm, comprising: a first determining module for determining the spatial position of the shoulder joint axis by scanning a circle; a second determining module for determining the spatial position of the linked elbow joint by eliminating small link offset by a first translation; a third determining module for determining the spatial position of a virtual base based on a first preset theoretical DH parameter and under conditions without an actual base; a fourth determining module for determining the spatial position of the linked wrist pitch joint by eliminating small link offset by a second translation; a fifth determining module for determining the spatial position of the linked wrist rotation joint by installing a target ball at the end effector; and a sixth determining module for determining the transformation relationship between the end effector coordinate system and the calibration end effector coordinate system using the second preset theoretical DH parameter.

[0013] Optionally, in one embodiment of this application, it further includes: an identification module for identifying the joint type of the joint; a seventh determination module for, when the joint type is a non-heterogeneous joint, installing a laser tracker target ball at the distal end of the linkage joint and using a single-joint motion to fit a circular axis to determine the joint axis; and an eighth determination module for, when the joint type is a planar heterogeneous linkage joint, using a linkage joint motion to fit a circular axis through a translation method to determine the joint axis.

[0014] Optionally, in one embodiment of this application, it further includes: a fitting module, used to fit the rotation joint axis and the pitch joint axis by changing the quaternion orientation when the joint type is a quaternion joint.

[0015] Optionally, in one embodiment of this application, the eighth determining module includes: a fitting unit, used to acquire the position of the target ball at multiple angles, translate the target ball according to the rotation angle, fit the circumference of a set of translated points using the least squares method, and take the axis as the joint axis.

[0016] Optionally, in one embodiment of this application, the translated set of points is:

[0017]

[0018] Where i is the index of a set of points being measured, X i ″″ Let X be the coordinates of the translated point. i ′ represents the coordinates of the end node of the linkage joint being measured, X oi The coordinates of the measured joint base end node are given. For X oi The average value.

[0019] A third aspect of 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 program to implement the DH parameter calibration method for a rope-driven agile space robot as described in the above embodiments.

[0020] A fourth aspect of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for calibrating the DH parameters of a rope-driven agile space robot.

[0021] A fifth aspect of this application provides a computer program product, which, when executed, is used to implement the above-described method for calibrating the DH parameters of a rope-driven agile space robot.

[0022] This application embodiment can determine the spatial position of the shoulder joint axis by scanning a circle, determine the spatial positions of the linked elbow joint and wrist pitch joint by translating to eliminate small link offset, and determine the spatial position of the linked wrist rotation joint by using a first preset theoretical DH parameter combined with the determination of the spatial position of the virtual base under the condition of no actual base, and determine the spatial position of the linked wrist rotation joint by using a target ball installed at the end effector. Then, using a second preset theoretical DH parameter combined with the determination of the transformation relationship between the end effector coordinate system and the calibration end effector coordinate system, the DH parameter calibration of the rope-driven agile spatial manipulator is achieved, improving the accuracy and efficiency of the calibration. Therefore, it solves the problems in related technologies where the joints of the rope-driven agile spatial manipulator are linked joints, making DH parameter calibration difficult, potentially making it difficult to accurately determine the position and attitude of the joints, increasing control difficulty, and reducing reliability and adaptability.

[0023] 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

[0024] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0025] Figure 1 This is a flowchart of a DH parameter calibration method for a rope-driven agile space robot provided according to an embodiment of this application;

[0026] Figure 2 This is a schematic diagram showing the location of the shoulder marker mounting point according to one embodiment of this application;

[0027] Figure 3 This is a schematic diagram showing the location of the elbow and wrist marker mounting points according to an embodiment of this application;

[0028] Figure 4 This is a schematic diagram of a DH parameter calibration device for a rope-driven agile space robot provided in an embodiment of this application;

[0029] Figure 5 This is a schematic diagram of the structure of an electronic device provided according to an embodiment of this application. Detailed Implementation

[0030] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0031] The following describes a method and apparatus for calibrating the DH parameters of a rope-driven agile spatial manipulator according to embodiments of this application, with reference to the accompanying drawings. Addressing the issues raised in the background section regarding the related technologies where the joints of the rope-driven agile spatial manipulator are linked joints, making DH parameter calibration difficult and potentially hindering accurate determination of joint positions and orientations, thus increasing control complexity and reducing reliability and adaptability, this application provides a method for calibrating the DH parameters of a rope-driven agile spatial manipulator. This method utilizes a circumferential scanning method to determine the spatial position of the shoulder joint axis, a translation method to eliminate small link offsets to determine the spatial positions of the linked elbow joint and wrist pitch joint, and, based on a first preset theoretical DH parameter, combines the determination of the spatial position of a virtual base under conditions without an actual base, and uses a target ball mounted at the end effector to determine the spatial position of the linked wrist rotation joint. Finally, a second preset theoretical DH parameter is used to determine the transformation relationship between the end effector coordinate system and the calibration end effector coordinate system, thereby achieving DH parameter calibration of the rope-driven agile spatial manipulator and improving the accuracy and efficiency of the calibration. This solves the problems in related technologies, such as the difficulty in calibrating DH parameters due to the linkage joints of the rope-driven agile space robot, which may make it difficult to accurately determine the position and attitude of the joints, increasing the difficulty of control, and reducing reliability and adaptability.

[0032] Specifically, Figure 1 This is a flowchart illustrating a method for calibrating the DH parameters of a rope-driven agile space robot provided in an embodiment of this application.

[0033] like Figure 1 As shown, the DH parameter calibration method for this rope-driven agile space robot includes the following steps:

[0034] In step S101, the spatial position of the shoulder joint axis is determined by scanning a circle.

[0035] It is understandable that spatial position refers to the specific location and orientation of an object in three-dimensional space, usually represented by (X,Y,Z) coordinates in a three-dimensional coordinate system.

[0036] Specifically, in this embodiment, a sensor can be used to rotate or move around the shoulder joint, record data at each position, and then analyze and process the data to obtain the spatial position of the shoulder joint axis, such as (10, 20, 30).

[0037] This application embodiment uses a circumferential scanning method to determine the spatial position of the shoulder joint axis, which can acquire a large number of data points, thereby more accurately determining the position of the shoulder joint axis. Furthermore, it can acquire the position information of the shoulder joint axis in real time, which helps to monitor and analyze the movement of the shoulder joint in real time.

[0038] Optionally, in one embodiment of this application, the method further includes: identifying the joint type of the joint; and in the case that the joint type is a non-heterogeneous joint, installing a laser tracker target ball at the distal end of the linkage joint, and using a single-joint motion method to fit the circular axis to determine the joint axis.

[0039] It is understandable that the joint type can be either a non-heterogeneous joint or a heterogeneous joint.

[0040] Specifically, in combination Figure 2 As shown, in this embodiment, the joint can extend radially along the rotation axis of shoulder joint 1, with a marker point installed at the end. The red circle indicates the approximate location of the marker installation, which can be marked as target ball 1. When the joint is identified as a single-axis joint, a laser tracker target ball can be installed at the distal end, with the other end fixed. The connecting rod can then rotate around the fixed end at multiple angles, acquiring the target ball position at different angles. The least squares method is used to fit the circumference, and the axis is taken as the joint axis.

[0041] In this embodiment of the application, when the joint type is a non-heterogeneous joint, a laser tracker target ball is installed at the distal end of the link joint. By using a single joint motion method to fit the circular axis, the accuracy of joint axis determination is improved. Furthermore, using a laser tracker target ball can reduce the influence of measurement errors and data noise, thereby improving the accuracy of the fitting results.

[0042] In step S102, the spatial position of the linked elbow joint is determined by using the first translation to eliminate the offset of the small connecting rod.

[0043] In actual implementation, the embodiments of this application can eliminate or correct the offset of the small connecting rod to a certain extent by performing translation operations on the small connecting rod, thereby determining the specific coordinates or position information of the elbow joint in three-dimensional space.

[0044] It is worth noting that the specific implementation method may vary depending on the application scenario and specific needs. In practical applications, it can be combined with other technologies and measurement methods, such as sensor measurement and kinematic analysis.

[0045] This application embodiment, by eliminating the offset of the small connecting rod, can reduce the errors and uncertainties caused by the offset of the small connecting rod, more accurately determine the spatial position of the linked elbow joint, improve the accuracy and reliability of the position determination, and enhance the reliability of the system.

[0046] In step S103, based on the first preset theoretical DH parameters, the spatial location of the virtual base is determined under the condition of no actual base.

[0047] Understandably, theoretical DH parameters refer to a mathematical model used to describe a robot linkage mechanism, which includes four parameters: link length, link torsion angle, joint offset, and joint rotation angle.

[0048] Specifically, this embodiment uses a classic DH coordinate system, where each coordinate system axis is the z-axis, a common perpendicular is established as the x-axis, and the intersection of the z-axis and x-axis is chosen as the origin. Note that the x-axis of coordinate system 0 is the same as that of coordinate system 1, and is translated along the z-axis to make its d-parameter the same as the theoretical value. In the DH parameters, a i Let θ be the negative of the rotational attitude angle along the X-axis in coordinate system i-1 in RPY representation. i Let a be the rotation angle of coordinate system i along the Z-axis in coordinate system i-1 in RPY representation. i Let d be the negative of the distance translated along the X-axis in coordinate system i-1. i Given the distance the coordinate system i is translated along the Z-axis in coordinate system i-1, the embodiments of this application can calculate the position of the virtual base in space without an actual base by using preset theoretical DH parameters.

[0049] Based on the first preset theoretical DH parameters, this application embodiment can quickly determine the position of the virtual base under the condition of no actual base, which improves the working efficiency of the system, increases the flexibility and adaptability of the system, and reduces hardware costs and space requirements.

[0050] In step S104, the spatial position of the linkage wrist pitch joint is determined by using the second translation to eliminate the offset of the small connecting rod.

[0051] In actual implementation, the embodiments of this application can eliminate or correct the offset of the small link by performing a translation operation, thereby determining the specific coordinates or position information of the wrist pitch joint in three-dimensional space, which helps to further correct the joint position and improve the accuracy and reliability of determining the spatial position of the wrist pitch joint.

[0052] Optionally, in one embodiment of this application, the method further includes: when the joint type is a planar heterogeneous linkage joint, using the linkage joint movement method, fitting the circular axis by translation method to determine the joint axis.

[0053] It is understandable that a planar heterogeneous linkage joint is a joint with a special structure and motion mode. By controlling the movement of the joint, it can perform complex motion trajectories within a plane. The motion mode of a linkage joint refers to the overall action achieved through the coordinated movement between multiple joints, including but not limited to: joint coordination, motion trajectory planning, and force and torque transmission.

[0054] This application embodiment determines the axial position of the joint by allowing the planar heterogeneous linkage joint to perform specific movements and by using a translation method to fit a circular axis.

[0055] Optionally, in one embodiment of this application, the joint axis is determined by fitting the circular axis through a translation method using a linkage joint motion method, including: acquiring the position of the target ball at multiple angles, translating the target ball according to the rotation angle, fitting the circumference of the translated set of points using the least squares method, and taking the axis as the joint axis.

[0056] Specifically, in this embodiment of the application, for a planar linkage joint, a laser tracker target ball can be installed at the far end, and the other end can be fixed. The connecting rod can be rotated around the fixed end, rotating at multiple angles. The position of the target ball can be collected at different angles. The target ball can be translated according to the rotation angle. The least squares method is used to fit a circle to a set of translated points, and the axis is taken as the joint axis.

[0057] Among them, such as Figure 3 As shown, in this embodiment of the application, there are two mounting points around the first and second rotation axes at the elbow (two each at elbow 1 and elbow 2), where the red circles indicate the approximate positions of the marker installation. These are marked as target balls 2, 3, 4, and 5. At the front and rear ends of the wrist, one marker is located after the second rotation axis of the elbow 2 joint, on the axis of the three rotation axes of the wrist, close to the wrist joint; the other marker is located at the rear end of the wrist, on the axis of the three rotation axes of the wrist, away from the wrist joint, with its relative position to the groove of the gripper fixing handle known, and located on the central axis of the wrist. The red circles indicate the approximate positions of the marker installation, marked as target balls 6 and 7.

[0058] Furthermore, the translation point can be calculated as follows:

[0059] First, calculate the offset from the front axis of elbow 1 to the rear axis of elbow 2. The front axis of elbow 1 can be established in the following way:

[0060]

[0061] Where i represents the sequence number of a set of points being measured, ΔX i θ represents the offset of the two endpoints on the rear link (equivalent to the link between elbow 1 and elbow 2 when calculating elbow 1), a3 represents the length of the rear link, and θ represents the offset of the two endpoints on the rear link. i This indicates the deflection angle of the connecting rod.

[0062] The target ball acquisition point at the rear end of elbow 1 is shifted according to the offset as follows:

[0063] X i ′=X i -ΔX i

[0064] Where i represents the sequence number of a set of points being measured, X i ′ represents the coordinate of the end node of the linkage joint (equivalent to the rear end node of elbow 1 when calculating elbow 1), X i The coordinate ΔX represents the coordinate of the end node of the rear link of the linkage joint (equivalent to the front node of elbow 2 when calculating elbow 1). i This indicates the offset of the two endpoints on the rear link (equivalent to the link between elbow 1 and elbow 2 when calculating elbow 1).

[0065] Calculate the offset of the target ball at the rear end of elbow 1 relative to the target ball at the front end after translation, and translate the center position of the target ball at the front end to obtain a set of points.

[0066] Optionally, in one embodiment of this application, the translated set of points is:

[0067]

[0068] Where i is the index of a set of points being measured, and X i " represents the coordinates of the translated point, X i ′ represents the coordinates of the end node of the linkage joint being measured, X oi The coordinates of the measured joint base end node are given. For X oi The average value.

[0069] Furthermore, by fitting this set of points to a circle, the axis of the front end of elbow 1 can be obtained. The calculation methods for elbow 2 and the yaw joint of the wrist are the same as those for elbow 1.

[0070] This application embodiment, by acquiring the position of the target ball from multiple angles and performing translation and circumference fitting, can more comprehensively consider the range of motion of the joint, thereby more accurately determining the joint axis. Furthermore, using the least squares method to fit the circumference can reduce the influence of measurement errors and data noise, improve the accuracy of the fitting results, and provide a better foundation for subsequent motion analysis and control.

[0071] In step S105, the spatial position of the linkage wrist rotation joint is determined by installing a target ball at the end.

[0072] Specifically, in this embodiment of the application, a target ball can be installed at the end of the linkage wrist rotation joint, and then the coordinates of the target ball at different positions can be obtained by measuring equipment (such as a laser tracker, photogrammetry system, etc.), wherein the coordinates can be coordinate values ​​in three-dimensional space.

[0073] This application embodiment determines the spatial position of the rotary joint by measuring and analyzing the target ball coordinates at multiple locations, avoiding errors caused by indirect measurement. At the same time, the accuracy and reliability of position determination are improved by measuring multiple locations.

[0074] Optionally, in one embodiment of this application, the method further includes: when the joint type is a quaternion joint, fitting the rotation joint axis and the pitch joint axis by changing the quaternion orientation.

[0075] Understandably, a quaternion joint is a type of joint used to describe the rotation of an object in three-dimensional space. It consists of four real numbers that can represent the direction and angle of rotation.

[0076] Specifically, in this embodiment of the application, for the wrist quaternion joint rotation joint, a target ball can be installed on the extension line of the distal axis. By rotating the quaternion joint pointing, the least squares method is used to fit the rotation joint axis and the pitch joint axis. In addition, two additional target balls are placed on the gripper, orthogonal to target ball 7, to determine the distal position and attitude, and are labeled as target balls 8 and 9.

[0077] This application's embodiment, for the wrist quaternion rotation joint, utilizes a target ball mounted on the extended line of the distal axis and rotation of the quaternion joint's orientation to more comprehensively consider the joint's range of motion, thereby more accurately determining the joint axis. Furthermore, the method of fitting the rotation and pitch joint axes using the least squares method improves the accuracy of the fitting results, contributing to enhanced joint motion performance and stability. In addition, it effectively determines the distal end position and orientation, improving operational accuracy and efficiency.

[0078] In step S106, the transformation relationship between the end tool coordinate system and the calibration end tool coordinate system is determined using the second preset theoretical DH parameters.

[0079] This application embodiment uses pre-set theoretical DH parameters, combined with other measurement or calculation methods, to determine the transformation relationship between the end-effector coordinate system and the calibrated end-effector coordinate system, which can effectively improve positioning accuracy and can adapt to different working scenarios and task requirements.

[0080] The DH parameter calibration method for the rope-driven agile spatial manipulator proposed in this application can determine the spatial position of the shoulder joint axis by scanning a circle, determine the spatial positions of the linked elbow joint and wrist pitch joint by translating to eliminate small link offsets, and determine the spatial position of the linked wrist rotation joint by using a first preset theoretical DH parameter combined with determining the spatial position of the virtual base under conditions without an actual base, and determining the spatial position of the linked wrist rotation joint by installing a target ball at the end effector. Then, a second preset theoretical DH parameter is used to determine the transformation relationship between the end effector coordinate system and the calibration end effector coordinate system, thereby achieving DH parameter calibration of the rope-driven agile spatial manipulator and improving the accuracy and efficiency of calibration. This solves the problems in related technologies where the joints of the rope-driven agile spatial manipulator are linked joints, making DH parameter calibration difficult, potentially leading to inaccurate determination of joint position and attitude, increased control difficulty, and reduced reliability and adaptability.

[0081] Next, referring to the accompanying drawings, a DH parameter calibration device for a rope-driven agile space robot arm according to an embodiment of this application is described.

[0082] Figure 4 This is a block diagram of the DH parameter calibration device for a rope-driven agile space robot according to an embodiment of this application.

[0083] like Figure 4 As shown, the DH parameter calibration device 10 of the rope-driven agile space robot arm includes: a first determining module 100, a second determining module 200, a third determining module 300, a fourth determining module 400, a fifth determining module 500, and a sixth determining module 600.

[0084] Specifically, the first determining module 100 is used to determine the spatial position of the shoulder joint axis by scanning a circle;

[0085] The second determining module 200 is used to determine the spatial position of the linked elbow joint by using the first translation to eliminate the offset of the small connecting rod.

[0086] The third determining module 300 is used to determine the spatial location of the virtual base based on the first preset theoretical DH parameters and under the condition of no actual base.

[0087] The fourth determining module 400 is used to determine the spatial position of the linkage wrist pitch joint by using the second translation to eliminate the offset of the small link;

[0088] The fifth determining module 500 is used to determine the spatial position of the linkage wrist rotation joint by using a target ball installed at the end.

[0089] The sixth determining module 600 is used to determine the transformation relationship between the end tool coordinate system and the calibration end coordinate system by combining the second preset theoretical DH parameters.

[0090] Optionally, in one embodiment of this application, it further includes: an identification module, a seventh determination module, and an eighth determination module.

[0091] The identification module is used to identify the joint type of the joint;

[0092] The seventh determination module is used to install a laser tracker target ball at the distal end of the linkage joint when the joint type is a non-heterogeneous joint, and to determine the joint axis by fitting a circular axis using a single joint motion method.

[0093] The eighth determination module is used to determine the joint axis by fitting the circular axis through translation method when the joint type is a planar heterogeneous linkage joint.

[0094] Optionally, in one embodiment of this application, a fitting module is also included.

[0095] The fitting module is used to fit the axis of rotation and the axis of pitch by changing the direction of the quaternion when the joint type is a quaternion joint.

[0096] Optionally, in one embodiment of this application, the eighth determining module includes a fitting unit.

[0097] The fitting unit is used to acquire the position of the target ball from multiple angles, translate the target ball according to the rotation angle, fit the circumference of the translated set of points using the least squares method, and take the axis as the joint axis.

[0098] Optionally, in one embodiment of this application, the translated set of points is:

[0099]

[0100] Where i is the index of a set of points being measured, and X i " represents the coordinates of the translated point, X i ′ represents the coordinates of the end node of the linkage joint being measured, X oi The coordinates of the measured joint base end node are given. For X oi The average value.

[0101] It should be noted that the foregoing explanation of the embodiment of the DH parameter calibration method for the rope-driven agile space robot also applies to the DH parameter calibration device for the rope-driven agile space robot in this embodiment, and will not be repeated here.

[0102] The DH parameter calibration device for the rope-driven agile spatial manipulator proposed in this application can determine the spatial position of the shoulder joint axis by scanning a circle, determine the spatial positions of the linked elbow joint and wrist pitch joint by translating to eliminate small link offset, and determine the spatial position of the linked wrist rotation joint by using a first preset theoretical DH parameter combined with determining the spatial position of the virtual base under the condition of no actual base, and determine the spatial position of the linked wrist rotation joint by installing a target ball at the end effector. Then, it uses a second preset theoretical DH parameter combined with the determination of the transformation relationship between the end effector coordinate system and the calibration end effector coordinate system, thereby realizing the DH parameter calibration of the rope-driven agile spatial manipulator and improving the accuracy and efficiency of calibration. This solves the problems in related technologies, such as the difficulty in DH parameter calibration due to the linkage joints of the rope-driven agile spatial manipulator, which may lead to difficulty in accurately determining the position and attitude of the joints, increasing control difficulty, and reducing reliability and adaptability.

[0103] Figure 5 A schematic diagram of the structure of an electronic device provided in an embodiment of this application. The electronic device may include:

[0104] The memory 501, the processor 502, and the computer program stored on the memory 501 and capable of running on the processor 502.

[0105] When the processor 502 executes the program, it implements the DH parameter calibration method for the rope-driven agile space robot provided in the above embodiments.

[0106] Furthermore, electronic devices also include:

[0107] Communication interface 503 is used for communication between memory 501 and processor 502.

[0108] The memory 501 is used to store computer programs that can run on the processor 502.

[0109] The memory 501 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0110] If the memory 501, processor 502, and communication interface 503 are implemented independently, then the communication interface 503, memory 501, and processor 502 can be interconnected via a bus to complete communication between them. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. The bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 5 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0111] Optionally, in a specific implementation, if the memory 501, processor 502, and communication interface 503 are integrated on a single chip, then the memory 501, processor 502, and communication interface 503 can communicate with each other through an internal interface.

[0112] Processor 502 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of this application.

[0113] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for calibrating the DH parameters of a rope-driven agile space robot.

[0114] This application also provides a computer program product that can run computer instructions, which, when executed by a processor, implement the above-mentioned DH parameter calibration method for a rope-driven agile space robot.

[0115] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "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. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0116] 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 application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0117] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0118] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0119] It should be understood that the various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. If implemented in hardware, as in another embodiment, it can be implemented using any one or more of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0120] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0121] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0122] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of this application.

Claims

1. A method for calibrating the DH parameters of a rope-driven agile spatial robotic arm, characterized in that, Includes the following steps: The spatial position of the shoulder joint axis is determined by scanning a circle. The spatial position of the linked elbow joint is determined by using the first translation to eliminate the offset of the small link. Based on the first preset theoretical DH parameters, the spatial location of the virtual base is determined under the condition of no actual base. The spatial position of the wrist pitch joint is determined by using the second translation to eliminate the offset of the small link. The spatial position of the wrist rotation joint is determined by installing a target ball at the end of the wrist. The transformation relationship between the end tool coordinate system and the calibration end tool coordinate system is determined by combining the second preset theoretical DH parameters. Identify the joint type; In the case where the joint type is a non-heterogeneous joint, a laser tracker target ball is installed at the distal end of the link joint, and the joint axis is determined by fitting a circular axis using a single joint motion method. When the joint type is a planar heterogeneous linkage joint, the joint axis is determined by fitting the circular axis through a translation method using the linkage joint motion. The method of using linked joint motion to fit a circular axis through translation to determine the joint axis includes: The target ball's position is acquired from multiple angles, and the target ball is translated according to the rotation angle. The least squares method is used to fit a circle to a set of translated points, and the axis is taken as the joint axis. The translated set of points is: in, To measure the index of a set of points, The coordinates of the translated point are... The coordinates of the end node of the linkage joint are measured. The coordinates of the measured joint base end node are given. for The average value.

2. The method according to claim 1, characterized in that, Also includes: When the joint type is a quaternion joint, the axis of rotation and the axis of pitch are fitted by changing the direction of the quaternion.

3. A DH parameter calibration device for a rope-driven agile spatial robotic arm, characterized in that, include: The first determining module is used to determine the spatial position of the shoulder joint axis by scanning a circle; The second determining module is used to determine the spatial position of the linked elbow joint by using the first translation to eliminate the offset of the small connecting rod. The third determining module is used to determine the spatial location of the virtual base based on the first preset theoretical DH parameters and under the condition of no actual base. The fourth determining module is used to determine the spatial position of the linkage wrist pitch joint by using the second translation to eliminate the offset of the small link; The fifth determining module is used to determine the spatial position of the linkage wrist rotation joint by using a target ball installed at the end. The sixth determining module is used to determine the transformation relationship between the end-effector coordinate system and the calibration end-effector coordinate system using the second preset theoretical DH parameters. The identification module is used to identify the joint type of the joint; The seventh determining module is used to install a laser tracker target ball at the distal end of the linkage joint when the joint type is a non-heterogeneous joint, and to determine the joint axis by fitting a circular axis using a single joint motion method. The eighth determining module is used to determine the joint axis by fitting a circular axis through a translation method when the joint type is a planar heterogeneous linkage joint. The eighth determining module includes: The fitting unit is used to acquire the position of the target ball from multiple angles, translate the target ball according to the rotation angle, fit the circumference of the translated set of points using the least squares method, and take the axis as the joint axis. The translated set of points is: in, To measure the index of a set of points, The coordinates of the translated point are... The coordinates of the end node of the linkage joint are measured. The coordinates of the measured joint base end node are given. for The average value.

4. The apparatus according to claim 3, characterized in that, Also includes: The fitting module is used to fit the axis of rotation and the axis of pitch by changing the direction of the quaternion when the joint type is a quaternion joint.

5. An electronic device, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the program to implement the DH parameter calibration method for a rope-driven agile space robot as described in any one of claims 1-2.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that, The program is executed by the processor to implement the DH parameter calibration method for the rope-driven agile space robot as described in any one of claims 1-2.

7. A computer program product, comprising a computer program, characterized in that, The computer program is executed to implement the DH parameter calibration method for the rope-driven agile space robot as described in any one of claims 1-2.

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