Parameter deviation determination method and device, tool, storage medium and computer device

Abstract

The application discloses a parameter deviation determination method and device, tool, storage medium and computer equipment. The method comprises the following steps: determining that an adapter plate is fixed to the tail end of a robot, wherein a calibration needle and a camera are fixed to the adapter plate, and the robot is fixed to a base; controlling the robot to move, so that the calibration needle contacts a calibration plate, and a first relative position relationship between the calibration plate and the base is obtained; controlling the tail end to move to a calibration point, and controlling the camera to take a photo when the tail end moves to the calibration point, wherein the photo comprises the calibration plate; determining a second relative position relationship between the camera and the base when the photo is taken according to the photo and the first relative position relationship; and determining the kinematic parameter deviation of the robot according to the second relative position relationship and ideal kinematic parameters of the robot. The application solves the technical problems that the robot kinematic parameter calibration process is high in cost and low in efficiency, and the calibration equipment is inconvenient to carry.

Description

Technical Field

[0001] This invention relates to the field of program control, and more specifically, to a method, apparatus, tooling, storage medium, and computer equipment for determining parameter deviations. Background Technology

[0002] Industrial robots play an irreplaceable role in manufacturing, demonstrating remarkable expertise in improving production efficiency, ensuring product quality, and reducing production costs. Industrial robots possess high precision and stability, enabling them to efficiently execute repetitive and tedious tasks, thereby significantly improving the overall efficiency of the production line. Robot precision is primarily reflected in two aspects: absolute precision and repeatability. Absolute precision describes the accuracy of the robot's actual position relative to the global coordinate system when performing a task; while repeatability assesses the consistency with which the end effector or tool returns to the same relative position when the robot performs the same task multiple times. While robots typically guarantee good repeatability but struggle to maintain high absolute precision, in precision manufacturing fields such as aerospace, automotive, and electronics manufacturing, robots require high absolute precision to complete tasks.

[0003] The absolute accuracy of a robot is primarily affected by deviations in its kinematic parameters, with approximately 80% of errors attributable to inaccuracies in these parameters. Therefore, kinematic parameter identification is crucial. Robot manufacturers typically perform kinematic parameter identification upon delivery, but if a robot is damaged in the field and requires repair, the kinematic parameters often change after on-site maintenance, leading to inaccuracies and poor absolute accuracy, thus preventing the robot from performing its intended tasks. Common calibration equipment, such as laser trackers and coordinate measuring machines (CMMs), offers high-precision calibration, but their high cost and bulky size limit their flexible application in the field. Therefore, developing a portable, efficient, and cost-effective on-site calibration device is essential.

[0004] There is currently no effective solution to the above problems. Summary of the Invention

[0005] This invention provides a method, apparatus, tooling, storage medium, and computer equipment for determining parameter deviations, in order to at least solve the technical problems of high cost, low efficiency, and inconvenient calibration equipment in the process of calibrating robot kinematic parameters.

[0006] According to one aspect of the present invention, a method for determining parameter deviation is provided, comprising: determining that an adapter plate is fixed to the end effector of a robot, wherein a calibration pin and a camera are fixed to the adapter plate, and the robot is fixed to a base; controlling the robot to move such that the calibration pin contacts the calibration plate, thereby obtaining a first relative positional relationship between the calibration plate and the base; controlling the end effector to move toward a calibration point, and controlling the camera to take a photograph when the end effector moves to the calibration point, wherein the photograph includes the calibration plate; determining a second relative positional relationship between the camera and the base when the photograph is taken based on the photograph and the first relative positional relationship; and determining the kinematic parameter deviation of the robot based on the second relative positional relationship and the ideal kinematic parameters of the robot.

[0007] Optionally, determining the kinematic parameter deviation of the robot based on the second relative positional relationship and the robot's ideal kinematic parameters includes: acquiring the camera physical parameters and the adapter plate physical parameters; acquiring the robot's first motion control parameters when the end effector moves to the calibration point; determining the third relative positional relationship between the end effector and the base when taking the photograph based on the first motion control parameters and the ideal kinematic parameters; and determining the kinematic parameter deviation based on the second relative positional relationship, the third relative positional relationship, the camera physical parameters, and the adapter plate physical parameters.

[0008] Optionally, determining the kinematic parameter deviation based on the second relative position relationship, the third relative position relationship, the camera physical parameters, and the adapter plate physical parameters includes: constructing a forward kinematic model of the robot; determining a first position deviation of the camera in the calibration plate coordinate system based on the first relative position relationship, the second relative position relationship, the third relative position relationship, the adapter plate physical parameters, and the camera physical parameters; determining a first constraint equation between the first position deviation and the parameter deviation to be identified based on the forward kinematic model, the adapter plate physical parameters, and the camera physical parameters, wherein the parameter deviation to be identified includes: the kinematic parameter deviation, the deviation of the first relative position relationship, and the deviation of the positional relationship between the camera and the end effector; and solving the first constraint equation based on the first position deviation to obtain the parameter deviation to be identified.

[0009] Optionally, determining the first positional deviation of the camera in the calibration plate coordinate system based on the first relative positional relationship, the second relative positional relationship, the third relative positional relationship, the physical parameters of the adapter plate, and the physical parameters of the camera includes: determining a fourth relative positional relationship between the end and the calibration plate when taking the photo based on the first and third relative positional relationships; determining a fifth relative positional relationship between the camera and the calibration plate when taking the photo based on the fourth relative positional relationship, the physical parameters of the adapter plate, and the physical parameters of the camera; determining a sixth relative positional relationship between the camera and the calibration plate when taking the photo based on the photo; and determining the first positional deviation based on the deviation between the fifth and sixth relative positional relationships.

[0010] Optionally, the step of solving the first constraint equation based on the first position deviation to obtain the deviation of the parameter to be identified includes: substituting the first position deviation into the first constraint equation to obtain the equation to be solved; and solving the equation to be solved using the global least squares method to obtain the deviation of the parameter to be identified.

[0011] Optionally, determining the kinematic parameter deviation based on the second relative positional relationship, the third relative positional relationship, the camera physical parameters, and the adapter plate physical parameters includes: constructing a forward kinematics model of the robot; determining a seventh relative positional relationship between the end effector and the base when taking the photograph based on the second relative positional relationship, the camera physical parameters, and the adapter plate physical parameters; determining a second positional deviation of the end effector based on the deviation between the third relative positional relationship and the seventh relative positional relationship; determining a second constraint equation between the second positional deviation and the kinematic parameter deviation based on the forward kinematics model; and solving the second constraint equation based on the second positional deviation to obtain the kinematic parameter deviation.

[0012] Optionally, controlling the robot's movement to make the calibration needle contact the calibration plate and obtain a first relative positional relationship between the calibration plate and the base includes: acquiring the physical parameters of the adapter plate and the physical parameters of the calibration needle; controlling the robot's movement to make the calibration needle contact the calibration plate and recording the robot's second motion control parameters; and determining the first relative positional relationship based on the second motion control parameters, the physical parameters of the calibration needle, and the physical parameters of the adapter plate.

[0013] Optionally, controlling the robot's movement so that the calibration needle contacts the calibration plate and recording the robot's second motion control parameters includes: selecting multiple position points on the calibration plate; controlling the robot's movement so that the calibration needle contacts the multiple position points respectively, and recording the second motion control parameters corresponding to each of the multiple position points; determining the first relative positional relationship based on the second motion control parameters, the calibration needle's physical parameters, and the adapter plate's physical parameters includes: determining an eighth relative positional relationship between the end of the calibration needle and the base when the calibration needle contacts the multiple position points respectively, based on the second motion control parameters; determining a ninth relative positional relationship between the calibration needle and the base when the calibration needle contacts the multiple position points respectively, based on the eighth relative positional relationship, the calibration needle's physical parameters, and the adapter plate's physical parameters; and determining the first relative positional relationship based on the ninth relative positional relationship.

[0014] According to another aspect of the present invention, a parameter deviation determination device is also provided, comprising: a first determination module, configured to determine that an adapter plate is fixed to the end effector of a robot, wherein a calibration pin and a camera are fixed to the adapter plate, and the robot is fixed to a base; a first control module, configured to control the movement of the robot such that the calibration pin contacts the calibration plate, thereby obtaining a first relative positional relationship between the calibration plate and the base; a second control module, configured to control the end effector to move toward a calibration point, and when the end effector moves to the calibration point, control the camera to take a photograph, wherein the photograph includes the calibration plate; a second determination module, configured to determine a second relative positional relationship between the camera and the base when the photograph is taken based on the photograph and the first relative positional relationship; and a third determination module, configured to determine the kinematic parameter deviation of the robot based on the second relative positional relationship and the ideal kinematic parameters of the robot.

[0015] According to another aspect of the present invention, a parameter deviation determination fixture is also provided, comprising: a camera, an adapter plate, a calibration needle, and a calibration plate; wherein the camera and the calibration needle are fixed on the adapter plate, the adapter plate is used to fix the end effector of a robot, and the calibration plate is disposed in a position such that the movement of the robot is controlled so that the calibration needle can contact the calibration plate.

[0016] According to another aspect of the present invention, a non-volatile storage medium is also provided, the non-volatile storage medium including a stored program, wherein, when the program is executed, the device where the non-volatile storage medium is located is controlled to perform the parameter deviation determination method described in any one of the above embodiments.

[0017] According to another aspect of the present invention, a computer device is also provided, the computer device including a memory and a processor, the memory being used to store a program, and the processor being used to run the program stored in the memory, wherein the program, when running, executes the parameter deviation determination method described in any one of the above embodiments.

[0018] In this embodiment of the invention, an adapter plate is fixed to the end effector of a robot, wherein a calibration needle and a camera are fixed to the adapter plate, and the robot is fixed to a base. The robot is controlled to move so that the calibration needle contacts the calibration plate, thus obtaining a first relative positional relationship between the calibration plate and the base. The end effector is controlled to move towards the calibration point, and when the end effector moves to the calibration point, the camera is controlled to take a picture, wherein the picture includes the calibration plate. Based on the picture and the first relative positional relationship, a second relative positional relationship between the camera and the base is determined when the picture is taken. Based on the second relative positional relationship and the ideal kinematic parameters of the robot, the kinematic parameter deviation of the robot is determined, thereby achieving the goal of accurately determining the kinematic parameter deviation of the robot. This achieves the technical effect of efficiently and cost-effectively measuring the kinematic parameter deviation of the robot, and solves the technical problems of high cost, low efficiency, and inconvenient calibration equipment in the robot kinematic parameter calibration process. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0020] Figure 1 A hardware structure block diagram of a computer terminal for implementing a parameter deviation determination method is shown.

[0021] Figure 2 This is a flowchart illustrating the parameter deviation determination method provided in an embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of a tooling for determining parameter deviations according to an optional embodiment of the present invention;

[0023] Figure 4 This is a schematic diagram of the coordinate system in the tooling for determining parameter deviations according to an optional embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of the robot kinematic parameter identification process provided by an optional embodiment of the present invention;

[0025] Figure 6 This is a schematic diagram of the overall least squares solution process provided by an optional embodiment of the present invention;

[0026] Figure 7This is a schematic diagram of the kinematic parameter accuracy verification results of robot 1 according to an optional embodiment of the present invention;

[0027] Figure 8 This is a schematic diagram of the kinematic parameter accuracy verification results of robot 2 according to an optional embodiment of the present invention;

[0028] Figure 9 This is a structural block diagram of the parameter deviation determination device provided in an embodiment of the present invention. Detailed Implementation

[0029] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0030] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0031] According to an embodiment of the present invention, a method embodiment for determining parameter deviation is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0032] The methods and embodiments provided in this application can be executed on mobile terminals, computer terminals, or similar computing devices. Figure 1 A hardware block diagram of a computer terminal for implementing a parameter deviation determination method is shown. Figure 1As shown, the computer terminal 10 may include one or more processors (shown as processors 102a, 102b, ..., 102n in the figure) (the processor may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.) and a memory 104 for storing data. In addition, it may also include: a display, an input / output interface (I / O interface), a universal serial bus (USB) port (which may be included as one of the ports of a BUS bus), a network interface, a power supply, and / or a camera. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the aforementioned electronic device. For example, computer terminal 10 may also include... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0033] It should be noted that the aforementioned one or more processors and / or other data processing circuits are generally referred to herein as "data processing circuits". These data processing circuits may be implemented wholly or partially as software, hardware, firmware, or any other combination thereof. Furthermore, the data processing circuits may be a single, independent processing module, or may be wholly or partially integrated into any other element in the computer terminal 10. As involved in the embodiments of this application, the data processing circuits serve as processor control (e.g., selection of a variable resistor termination path connected to an interface).

[0034] The memory 104 can be used to store software programs and modules of application software, such as the program instructions / data storage device corresponding to the parameter deviation determination method in this embodiment of the invention. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory 104, thereby implementing the parameter deviation determination method of the application program described above. The memory 104 may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor, and these remote memories can be connected to the computer terminal 10 via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0035] The display may be, for example, a touchscreen liquid crystal display (LCD) that allows the user to interact with the user interface of the computer terminal 10.

[0036] To address the problem of high manpower, financial resources, and time costs in the process of calibrating robot kinematic parameters, this invention proposes a low-cost, high-efficiency method and apparatus for identifying robot kinematic parameters based on a camera. Figure 2 This is a flowchart illustrating the parameter deviation determination method provided in an embodiment of the present invention, as shown below. Figure 2 As shown, the method includes the following steps:

[0037] Step S201: Determine that the adapter plate is fixed to the end of the robot, wherein the calibration needle and the camera are fixed to the adapter plate, and the robot is fixed to the base.

[0038] The adapter plate is a rigid connecting component used to connect the calibration pin and camera to the robot's end effector, allowing the calibration pin and camera to move with the robot's end effector. The robot is fixed to the base, and the coordinate position of the robot's end effector can be called the Tool Center Point (TCP). To complete various tasks, different tools, such as spray guns, grippers, and welding torches, can be installed on the end effector of industrial robots. Because the shapes and sizes of tools vary, the actual working point of the robot relative to the end effector will change after the tool is changed or adjusted. Currently, the commonly used method is to establish a tool coordinate system on the robot tool, with its origin being the Tool Center Point (TCP). The robot is programmed within this coordinate system, and when the tool is adjusted, only the pose of the working coordinate system needs to be recalibrated to put the robot back into use.

[0039] The calibration probe can be either pointed or non-pointed. The non-pointed probe is rigidly fixed to the adapter plate, while the pointed probe faces outward to indicate position. The camera can be a 2D vision camera for taking photographs.

[0040] Step S202: Control the robot to move so that the calibration needle contacts the calibration plate, and obtain the first relative positional relationship between the calibration plate and the base.

[0041] In this step, controlling the robot's movement refers to controlling the robot's joint movements while keeping the robot fixed to the base, thereby changing the robot's end-effector pose. The calibration pin contacts the calibration plate; the tip of the calibration pin touches the calibration plate.

[0042] A calibration plate can be a flat plate with a fixed-spacing pattern array, typically including solid circle arrays and chessboard patterns, such as TI-TIMES' solid circle array pattern CG-100-D and chessboard pattern CG-076-T. Calibration plates can be used in machine vision, image measurement, photogrammetry, and 3D reconstruction applications to correct lens distortion; determine the conversion relationship between physical dimensions and pixels; and determine the relationship between the 3D geometric position of a point on the surface of a spatial object and its corresponding point in the image, establishing a geometric model of camera imaging.

[0043] Since the physical parameters of the calibration needle, adapter plate, and robot are known and will not change, by controlling the robot's movement to bring the calibration needle into contact with the calibration plate, the first relative positional relationship between the calibration plate and the base can be quantitatively measured. This first relative positional relationship can be represented using the calibration plate coordinate system {W}. b The description is given in the base coordinate system {B}.

[0044] As an optional embodiment, controlling the robot's movement to make the calibration needle contact the calibration plate and obtain a first relative positional relationship between the calibration plate and the base includes the following steps: obtaining the physical parameters of the adapter plate and the physical parameters of the calibration needle; controlling the robot's movement to make the calibration needle contact the calibration plate and recording the robot's second motion control parameters; determining the first relative positional relationship based on the second motion control parameters, the calibration needle physical parameters, and the adapter plate physical parameters.

[0045] The physical parameters of the adapter plate and the calibration pin can be used to describe the physical dimensions of the adapter plate and the calibration pin, respectively. Therefore, based on the physical parameters of the adapter plate and the calibration pin, the coordinates of the adapter plate and the calibration pin in the robot's end effector coordinate system {TCP} can be determined. The end effector coordinate system {TCP} is a coordinate system established with the center of the robot's end effector flange as the origin. The coordinates of the calibration pin in {TCP} can characterize the relative positional relationship between the calibration pin and the robot's end effector.

[0046] The robot's second motion control parameters characterize how the robot moves its end effector to a position where the calibration pin contacts the calibration plate. These parameters may include, for example, data such as the robot's joint angles and rotation angles. Based on these parameters, the coordinates of the robot's end effector in the base coordinate system of the robot's base can be calculated, thus obtaining the relative positional relationship between the end effector and the base. Furthermore, given the relative positional relationship between the end effector and the base, the relative positional relationship between the calibration pin and the end effector, and the calibration pin contacting the calibration plate, a coordinate system transformation can be performed to obtain the description of the calibration plate in the base coordinate system, thus obtaining the aforementioned first relative positional relationship.

[0047] As an optional embodiment, controlling the robot's movement to make the calibration needle contact the calibration plate and recording the robot's second motion control parameters includes: selecting multiple position points on the calibration plate; controlling the robot's movement to make the calibration needle contact the multiple position points respectively, and recording the second motion control parameters corresponding to each of the multiple position points; determining a first relative positional relationship based on the second motion control parameters, the calibration needle's physical parameters, and the adapter plate's physical parameters, including: determining an eighth relative positional relationship between the end of the calibration needle and the base when the calibration needle contacts the multiple position points respectively based on the second motion control parameters; determining a ninth relative positional relationship between the calibration needle and the base when the calibration needle contacts the multiple position points respectively based on the eighth relative positional relationship, the calibration needle's physical parameters, and the adapter plate's physical parameters; and determining the first relative positional relationship based on the ninth relative positional relationship.

[0048] This optional embodiment provides a method for determining the first relative positional relationship. Optionally, a three-point teaching method can be used. The number of multiple position points can be three: the origin of the calibration plate coordinate system, a point on one coordinate axis of the calibration plate coordinate system, and a point in a quadrant of the coordinate system. The second motion control parameters of the robot are recorded when the calibration needle contacts each of these three points. The robot's pose when contacting these three points can be calculated, and the pose can represent the eighth relative positional relationship. Then, by combining the physical parameters of the adapter plate and the calibration needle for coordinate system transformation, the representation of the calibration needle tip in the base coordinate system when the calibration needle contacts multiple position points can be determined, i.e., the ninth relative positional relationship. This is equivalent to representing the multiple position points on the calibration plate in the base coordinate system. Therefore, the position of the calibration plate in the base coordinate system can be determined based on this, thus obtaining the first relative positional relationship.

[0049] Step S203: Control the end effector to move towards the calibration point. When the end effector moves to the calibration point, control the camera to take a picture, wherein the picture includes the calibration plate. The calibration point can be a position in space. The movement of the end effector towards the calibration point can be understood as changing the position of the end effector in space. The position of the calibration point does not have special requirements, as long as the calibration plate can be included in the picture when the camera takes a picture when the end effector moves to that position.

[0050] Step S204: Based on the photograph and the first relative positional relationship, determine the second relative positional relationship between the camera and the base when taking the photograph.

[0051] Since the photograph includes a calibration plate, its spatial position relative to the camera can be determined by its shape within the photograph. For example, the position of the calibration plate can be represented in the camera coordinate system {C}. Simultaneously, since the first relative positional relationship clarifies the relative position between the calibration plate and the base, the camera's pose can be represented in the base coordinate system {B} through coordinate system transformation, thus obtaining the second relative positional relationship.

[0052] Step S205: Determine the kinematic parameter deviation of the robot based on the second relative position relationship and the ideal kinematic parameters of the robot.

[0053] The ideal kinematic parameters of the robot are its default kinematic parameters, which may be determined based on product specifications before the robot leaves the factory. However, due to tolerances in the robot's mechanical structure, slight deviations from the default working state may occur during on-site use due to installation or usage conditions. This may lead to differences between the robot's actual and ideal kinematic parameters. Therefore, this application identifies the deviation of the robot's kinematic parameters using the above method, which is the deviation between the robot's actual and ideal kinematic parameters. Based on this deviation, the robot's kinematic parameters can be revised to make the robot's subsequent operations more accurate. In this step, the second relative positional relationship can characterize the relative positional relationship between the camera and the base at the calibration point. This position can be called the actual position of the camera. The process of moving the camera to the calibration point can be calculated using the ideal kinematic parameters. Therefore, based on the ideal kinematic parameters, the theoretical position of the camera relative to the base at the calibration point can be calculated. Thus, the difference between the actual and theoretical positions can be used to estimate the deviation of the robot's kinematic parameters.

[0054] As an optional embodiment, the kinematic parameter deviation of the robot can be determined based on the second relative positional relationship and the robot's ideal kinematic parameters by: acquiring the camera's physical parameters and the adapter plate's physical parameters; acquiring the robot's first motion control parameters when the end effector moves to the calibration point; determining the third relative positional relationship between the end effector and the base when taking a picture based on the first motion control parameters and the ideal kinematic parameters; and determining the kinematic parameter deviation based on the second relative positional relationship, the third relative positional relationship, the camera's physical parameters, and the adapter plate's physical parameters.

[0055] In this optional embodiment, based on the first motion control parameters and ideal kinematic parameters, a third relative positional relationship between the end effector and the base can be calculated. This third relative positional relationship can be considered as the theoretical position of the end effector in the base coordinate system, since this theoretical position is not actually measured but calculated based on the ideal kinematic parameters. It is understood that the second relative positional relationship is the position of the camera in the base coordinate system obtained through coordinate system transformation based on the image of the calibration board taken from the photograph. Therefore, the second relative positional relationship can be considered as the actual position of the camera in the base coordinate system. The determination of the second relative positional relationship includes a certain component of actual measurement. Furthermore, the camera physical parameters and the adapter plate physical parameters can be used to determine the relative positional relationship between the camera and the end effector. Therefore, based on the second relative positional relationship and combining the camera physical parameters and the adapter plate physical parameters, the coordinates of the end effector in the base coordinate system, i.e., the actual position of the end effector in the base coordinate system, can be calculated.

[0056] As an optional embodiment, determining the kinematic parameter deviation based on the second relative positional relationship, the third relative positional relationship, the camera physical parameters, and the adapter plate physical parameters includes: constructing a forward kinematic model of the robot; determining a first positional deviation of the camera in the calibration plate coordinate system based on the first relative positional relationship, the second relative positional relationship, the third relative positional relationship, the adapter plate physical parameters, and the camera physical parameters; determining a first constraint equation between the first positional deviation and the deviation of the parameter to be identified based on the forward kinematic model, the adapter plate physical parameters, and the camera physical parameters, wherein the deviation of the parameter to be identified includes: kinematic parameter deviation, deviation of the first relative positional relationship, and deviation of the positional relationship between the camera and the end effector; solving the first constraint equation based on the first positional deviation to obtain the deviation of the parameter to be identified; and determining the kinematic parameter deviation based on the deviation of the parameter to be identified.

[0057] This optional embodiment provides a method for solving kinematic parameter deviations, wherein the robot's positive kinematic model is a relational model that describes the relationship between the position and orientation of the robot's end effector and the robot's joint angles. That is, given the robot's joint angles, the position and orientation of the robot's end effector can be calculated.

[0058] The first position deviation of the camera in the calibration plate coordinate system is the deviation between the actual position and the theoretical position of the camera in the calibration plate coordinate system. The actual position can be calculated from the photo, and the theoretical position can be calculated based on the ideal kinematic parameters. Therefore, the deviation between the actual position and the theoretical position can reflect the deviation between the ideal kinematic parameters and the actual kinematic parameters of the robot. Then, the actual kinematic parameters of the robot can be calculated based on this deviation, and the calibration of the actual kinematic parameters of the robot can be completed.

[0059] In this optional embodiment, the first constraint equation can include kinematic parameter deviation, deviation of the first relative position relationship, and deviation of the position relationship between the camera and the end effector as variables to be solved. By comprehensively solving the above three types of deviations, the solution result of the kinematic parameter deviation is more accurate.

[0060] The first relative positional relationship is the relative positional relationship between the calibration plate and the base determined by the calibration work of the calibration needle. Since ideal kinematic parameters are required to calculate the first relative positional relationship, and ideal kinematic parameters are not accurate, the first relative positional relationship is not absolutely accurate and there is a certain deviation between it and the actual relative positional relationship between the calibration plate and the base. This deviation is denoted as the first relative positional relationship deviation.

[0061] The positional relationship between the camera and the end effector is the relative positional relationship between the camera and the robot's end effector. This relationship can be determined by coordinate system substitution based on the camera's physical parameters and the adapter plate's physical parameters. These parameters describe the ideal dimensions of the camera and adapter plate. However, due to certain tolerances in the manufacturing process of the camera and adapter plate, the actual dimensions of the camera and adapter plate in use deviate from their physical parameters. This results in a certain deviation between the calculated positional relationship between the camera and the end effector and the actual positional relationship in the real scene. This deviation is the positional relationship deviation between the camera and the end effector.

[0062] As an optional embodiment, determining the first positional deviation of the camera in the calibration plate coordinate system based on the first relative positional relationship, the second relative positional relationship, the third relative positional relationship, the adapter plate physical parameters, and the camera physical parameters includes: determining the fourth relative positional relationship between the end and the calibration plate when taking a picture based on the first and third relative positional relationships; determining the fifth relative positional relationship between the camera and the calibration plate when taking a picture based on the fourth relative positional relationship, the adapter plate physical parameters, and the camera physical parameters; determining the sixth relative positional relationship between the camera and the calibration plate when taking a picture based on the picture; and determining the first positional deviation based on the deviation between the fifth and sixth relative positional relationships.

[0063] Since the first relative positional relationship characterizes the spatial relationship between the calibration plate and the base, and the third relative positional relationship characterizes the spatial relationship between the end effector and the base when taking a picture, the spatial relationship between the end effector and the calibration plate when taking a picture can be determined by using the base coordinate system as the intermediate coordinate system for coordinate transformation; this is the fourth relative positional relationship. At this point, the spatial relationship between the camera and the end effector can be determined by the physical parameters of the adapter plate and the camera. Therefore, based on the fourth relative positional relationship, the fifth relative positional relationship can be obtained, which is the theoretical position of the camera in the calibration plate coordinate system when taking a picture.

[0064] Since the actual image of the calibration board taken in the photograph is used, the sixth relative positional relationship between the calibration board and the camera can be directly calculated from the image of the calibration board in the photograph based on the imaging physics principle of the camera lens. The sixth relative positional relationship can be regarded as the actual position of the camera in the calibration board coordinate system when the photograph is taken. Therefore, based on the deviation between the fifth and sixth relative positions, the first deviation mentioned above can be determined. The first positional deviation of the camera in the calibration board coordinate system is the deviation between the actual position and the theoretical position of the camera in the calibration board coordinate system.

[0065] As an optional embodiment, the method of solving the first constraint equation based on the first position deviation to obtain the deviation of the parameter to be identified includes: substituting the first position deviation into the first constraint equation to obtain the equation to be solved; and solving the equation to be solved using the overall least squares method to obtain the deviation of the parameter to be identified.

[0066] The overall least squares method is a least squares approach that simultaneously considers the errors and perturbations in both the coefficient matrix A and the vector b to find the least squares solution for Ax = b. This method takes into account potential interference factors in the regression matrix. Since the parameters to be identified include three types of deviations, and only the kinematic parameter deviations are the deviations actually needed in this application, the overall least squares method can treat the other two types of deviations as errors and perturbations, ultimately improving the accuracy of the kinematic parameter deviation solution.

[0067] As an optional embodiment, the kinematic parameter deviation is determined based on the second relative positional relationship, the third relative positional relationship, the camera physical parameters, and the adapter plate physical parameters. This includes: constructing a forward kinematic model of the robot; determining a seventh relative positional relationship between the end effector and the base when taking a picture based on the second relative positional relationship, the camera physical parameters, and the adapter plate physical parameters; determining a second positional deviation of the end effector based on the deviation between the third and seventh relative positional relationships; determining a second constraint equation between the second positional deviation and the kinematic parameter deviation based on the forward kinematic model; and solving the second constraint equation based on the second positional deviation to obtain the kinematic parameter deviation.

[0068] This optional embodiment also provides a method for solving kinematic parameter deviations. The solution process proposed in this optional embodiment does not require consideration of the deviations in the first and second relative positional relationships, and can directly solve for the kinematic parameter deviations. Therefore, it improves the solution efficiency and is more suitable for application scenarios where the accuracy requirements for kinematic parameter deviations are moderate, but the solution speed requirements are high. Specifically, the second constraint equation constructed in this optional embodiment is the constraint relationship between the second position deviation of the robot's end effector and the kinematic parameter deviation. The second position deviation characterizes the deviation between the actual and theoretical positions of the robot's end effector. Since the determination of the seventh relative positional relationship utilizes photographs taken by a camera, the seventh relative positional relationship can characterize the actual position of the robot's end effector. Furthermore, the determination of the third relative positional relationship uses ideal kinematic parameters in the calculation, thus the third relative positional relationship can characterize the theoretical position of the robot's end effector.

[0069] Optionally, the process of solving the second constraint equation can be carried out using the least squares method. The second position deviation is introduced into the second constraint equation, and the kinematic parameter deviation is obtained based on the least squares method. This calculation process is fast and efficient.

[0070] Through the above steps, the following can be achieved: a calibration pin and a camera are fixed to the robot's end effector via an adapter plate, and the robot is fixed to a base. The robot is then controlled to move, causing the calibration pin to contact the calibration plate, thus establishing a first relative positional relationship between the calibration plate and the base. The end effector is then controlled to move towards the calibration point, and when it reaches the calibration point, the camera is controlled to take a photograph, which includes the calibration plate. Based on the photograph and the first relative positional relationship, a second relative positional relationship between the camera and the base is determined. Based on the second relative positional relationship and the robot's ideal kinematic parameters, the robot's kinematic parameter deviation is determined. This achieves the goal of accurately determining the robot's kinematic parameter deviation, thus realizing a high-efficiency and low-cost method for measuring the robot's kinematic parameter deviation, and solving the technical problems of high cost and low efficiency in robot kinematic parameter calibration.

[0071] Figure 3 This is a schematic diagram of a parameter deviation determination fixture provided by an optional embodiment of the present invention, as shown below. Figure 3 As shown, the tooling for determining parameter deviation may include: a camera, an adapter plate, a calibration needle, and a calibration plate. The camera and calibration needle are fixed to the adapter plate, which can be fixed to the end effector of the robot. The calibration plate is positioned such that the robot's movement allows the calibration needle to contact the calibration plate. To prevent the camera from shifting relative to the adapter plate, a camera reinforcement tool can be used to reinforce the connection between the camera and the adapter plate. Figure 4 This is a schematic diagram of the coordinate system in the tooling for determining parameter deviations according to an optional embodiment of the present invention, as shown below. Figure 4 As shown, {B} represents the base coordinate system, {TCP} represents the end effector coordinate system, {C} represents the camera coordinate system, {Tool} represents the calibration needle coordinate system, and {W} represents the calibration needle coordinate system. b} represents the coordinate system of the calibration plate.

[0072] The parameter deviation determination fixture provided in this application embodiment can efficiently determine the deviation of robot kinematic parameters. At the same time, the camera, adapter plate, calibration pin and calibration plate are all lightweight and readily available components. Therefore, the fixture has the advantages of low cost and easy portability, making it convenient for testers to carry to the robot's work site to calibrate the deviation of robot kinematic parameters.

[0073] based on Figure 3 and Figure 4 The tooling for determining parameter deviations provided in this invention offers the following optional embodiments for determining the kinematic parameters of the robot to be identified. Figure 5 This is a schematic diagram of the robot kinematic parameter identification process provided by an optional embodiment of the present invention, such as... Figure 5 As shown, the operation steps of this optional embodiment are as follows:

[0074] Step 1:

[0075] Mount the camera and calibration pin onto the adapter plate, then mount the adapter plate onto the end of the robot. Place the calibration plate within the robot's reach, then drive the robot so that the end of the robot, carrying the calibration pin, moves to the position of the calibration plate. Secure the camera with the securing tools and connect the necessary cables.

[0076] Step 2:

[0077] In robot control, the calibration needle coordinate system {Tool} is set under the tool center point TCP. That is, the pose of the calibration needle coordinate system {Tool} is described under the robot end coordinate system {TCP}. Since the physical parameters (geometric parameters) of the calibration needle are known, the {Tool} coordinate system can be obtained directly.

[0078] Step 3:

[0079] The robot is operated to determine the coordinate system {W} of the calibration plate using the three-point teaching method. b}

[0080] 1. The first teaching point is the origin P of the calibration board coordinate system. o ;

[0081] 2. The second teaching point is point P on the X-axis of the calibration board coordinate system. x ;

[0082] 3. The third teaching point is point P in the first quadrant of the XY plane of the calibration board coordinate system. xy .

[0083] The calibration plate coordinate system {W b The origin of the robot in the coordinate system {B} is P. o The x-axis is {W} can be obtained through the cross product of vectors. b The y and z axes of}.

[0084]

[0085]

[0086] The coordinate system {W} of the calibration plate is now established. b The description in the robot base coordinate system {B} is obtained, which is equivalent to determining the first relative position relationship.

[0087] Step 4:

[0088] In robot control, a camera coordinate system {C} is set up, which is the description of the pose of the camera coordinate system {C} in the robot's end effector coordinate system {TCP}. Since the physical parameters (geometric parameters) of the camera and the adapter plate are known, this coordinate system can be obtained directly.

[0089] Step 5:

[0090] The robot data acquisition program is run to drive the robot to automatically move the camera to the calibration point, capture images of the calibration board, and record the positions of each joint of the robot at the time of the camera's capture via communication, thus obtaining the first motion control parameters. After capturing images at the last calibration point, the program sends a data acquisition completion command to the robot controller.

[0091] Step 6:

[0092] Upon receiving the data acquisition completion command, the robot kinematic parameter identification software identifies the robot's actual kinematic parameters based on the robot's kinematic error model and sends a kinematic parameter identification completion command to the robot.

[0093] The process of establishing the kinematic error model is as follows:

[0094] 1. Robot kinematics modeling:

[0095] To address the problem that the traditional Denavit-Hartenberg (DH) modeling method cannot describe the deviations caused by assembly and manufacturing when two adjacent joints are parallel, this invention adopts the M-DH modeling method (modified DH model), which adds a rotation parameter β around the Y-axis compared to the traditional DH modeling method.

[0096] In M-DH, the coordinate transformation from link coordinate system {i-1} to link coordinate system {i} can be achieved using a homogeneous transformation matrix.

[0097]

[0098]

[0099] In the formula Trans(x) i-1 ,a i-1 ) indicates along x i-1 Axis translation a i-1 Rot(x) i-1 ,α i-1 ) indicates along x i-1 Axis rotation α i-1 ,Trans(z i ,d i ) indicates along z i Axis translation d i Rot(z) i ,θ i ) indicates along z i Axis rotation θ i Rot(y) i ,β i ) indicates along y i Axis rotation β i ,cθ i =cos(θ) i ), sθ i =sin(θ) i ), and the rest of the symbols are similar.

[0100] Therefore, the forward kinematics model of the robot can be obtained:

[0101] 2. Establishment of the kinematic error model:

[0102] The actual transformation relationship between two adjacent links of a robot can be obtained by using micro-translation and micro-rotation transformations. Described as: In the formula This represents the actual transformation relationship between the two theoretical links. The differential homogeneous matrix between adjacent coordinate systems obtained from micro-translation and micro-rotation transformations:

[0103]

[0104] Therefore, the actual kinematic model of the robot can be obtained as follows:

[0105]

[0106] Expanding and simplifying the actual kinematic model yields the constraint equation (i.e., the second constraint equation) between the robot's end-effector position deviation and the robot's kinematic parameter deviation:

[0107]

[0108] Where d n The deviation value representing the robot's end effector position (i.e., the second position deviation):

[0109]

[0110] In the formula P R P represents the actual position of the robot's end effector (described in the base coordinate system, equivalent to a third relative positional relationship); N The theoretical end position of the robot (described in the base coordinate system, equivalent to the seventh relative position relationship) can be calculated by the robot's forward kinematics theory.

[0111] M a M α M d M θ M β The simplified 3×6 matrix is ​​the coefficient matrix of the robot's kinematic parameter deviations; Δa, Δα, Δd, Δθ, and Δβ refer to the parameter deviations of the robot's kinematic model, describing the translational error along the X-axis, the rotational error around the X-axis, the translational error along the Z-axis, the rotational error around the Z-axis, and the rotational error around the Y-axis, respectively.

[0112] Δa=[Δa1 Δa2 Δa3 Δa4 Δa5 Δa6] T

[0113] Δα=[Δα1 Δα2 Δα3 Δα4 Δα5 Δα6] T

[0114] Δd=[Δd1 Δd2 Δd3 Δd4 Δd5 Δd6] T

[0115] Δθ=[Δθ1 Δθ2 Δθ3 Δθ4 Δθ5 Δθ6] T

[0116] Δβ=[Δβ1 Δβ2 Δβ3 Δβ4 Δβ5 Δβ6]T

[0117] Δa, Δα, Δd, Δθ, and Δβ are the deviations of the robot's kinematic parameters.

[0118] This optional embodiment can also provide a method for determining kinematic parameter deviations, namely, the robot's calibration plate coordinate system {W} b The errors in the camera coordinate system {C} (i.e., the deviation in the first relative positional relationship) and the errors in the camera coordinate system {C} (i.e., the deviation in the second relative positional relationship) are used as parameters to be identified, in order to improve the accuracy of solving for the kinematic parameter deviations. The robot's actual {0} link coordinate system is located in {W}. b The description below is:

[0119]

[0120] The actual camera coordinate system {C} in the actual link coordinate system {6} ({6} is the same as {TCP} above) is described as follows:

[0121]

[0122] The actual pose transformation of the camera in the calibration plate coordinate system can be expressed as:

[0123]

[0124] Let the theoretical position of the camera in the calibration plate coordinate system be... (i.e., the fifth relative positional relationship), the actual position of the camera in the calibration plate coordinate system is... (i.e., the sixth relative position relationship) yields the deviation between the theoretical and actual positions of the camera in the calibration plate coordinate system. (i.e., the first positional deviation) is:

[0125]

[0126] In the above formula, M Wb M C To simplify the resulting 3×6 matrix, ΔW b ΔC represents the deviation of the calibration plate coordinate system, and ΔC represents the deviation of the camera coordinate system.

[0127]

[0128] ΔC=[Δa C Δg C Δd C Δα C Δβ C Δθ C ] T

[0129] Where Δg represents the position error along the Y-axis. The actual position of the camera in the calibration plate coordinate system. It can be obtained directly from taking a picture with a camera. It can be calculated from ideal kinematic parameters; at this point, only the parameter to be identified [ΔW] needs to be solved. b ΔaΔα Δd Δθ Δβ ΔC] T This allows us to obtain the deviation of the kinematic parameters to be identified in the robot's kinematic model, thereby obtaining the robot's kinematic parameter deviation. Based on the robot's ideal kinematic parameters, we can then determine the robot's true kinematic parameters and improve the robot's absolute accuracy.

[0130] The above process of solving for the deviation of the parameter to be identified can be determined using the least squares method, as follows:

[0131] Let matrix

[0132] The parameter vector to be identified, b = [ΔW] b Δa Δα Δd Δθ Δβ ΔC] T ;

[0133] Multiple groups Let the error vector be e, then e = Ab. The above equation can be directly solved for b using the least squares method: b = (A... T A) -1 A T e.

[0134] The least squares method has high computational efficiency, but it is greatly affected by data sampling errors. To further improve the computational accuracy and reduce the impact of data sampling errors, this invention can also use the overall least squares method to solve for b.

[0135] The overall least squares method considers the errors of both dependent and independent variables, thus handling the errors in the data more comprehensively. It also has a certain robustness to outliers and can better adapt to data containing outliers.

[0136] Figure 6 This is a schematic diagram of the overall least squares solution process provided by an optional embodiment of the present invention, such as... Figure 6 As shown, the specific process of the overall least squares method is as follows:

[0137] (1) Calculate the singular value decomposition (SVD) of the augmented matrix A and store the matrix V.

[0138]

[0139] (2) Determine the number p of the principal singular values, i.e., use σ p >σ n+1 +ε>σ p+1 ≥…≥σ n+1Determine p, where ε is a very small positive number.

[0140] (3) Let V1 = [v p+1 v p+2 …v n+1 Let ] be a column block matrix of V, and calculate the Householder transformation matrix Q such that: Here, α is a scalar, and × represents a block whose value has no effect.

[0141] (4) If α≠0, then calculate If α = 0, then there is no global least squares solution for the originally set p. p should be reduced, and the above steps should be repeated to recalculate until a unique global least squares solution is found.

[0142] Step 7:

[0143] After receiving the instruction that kinematic parameter identification is complete, the robot controller writes the identified kinematic parameters into the code. This completes the kinematic parameter identification process.

[0144] In the above optional embodiments, a camera is mounted on the robot's end effector. The robot, driven by a calibration board coordinate system, an end effector coordinate system, and a preset program, carries the camera to a sampling point and takes a photograph including the calibration board. This process is equivalent to collecting the coordinate information necessary for identifying kinematic parameters. Simultaneously, the joint coordinate values ​​of the robot at the sampling point are recorded. Then, a robot kinematic error model is constructed based on micro-translation and micro-rotation transformations. The deviations of each kinematic parameter of the robot are obtained using the overall least squares method. Finally, the corrected robot kinematic parameters are written into the robot controller, thus achieving the goal of improving robot accuracy. In this optional embodiment, the data sampling device is a visual 2D camera. This type of camera is inexpensive, and in multiple experimental verifications, combined with the method of this invention, it can effectively improve the robot's absolute accuracy. Furthermore, this camera-based data acquisition scheme ensures the need for non-contact data acquisition; automated data acquisition can be completed solely through a program, resulting in high efficiency and eliminating reliance on technical personnel.

[0145] The hardware components of this invention include: a camera-to-robot adapter board, a 2D vision camera, and a vision calibration board. These hardware components are small in size and weight, making them highly portable. Extensive experimental verification shows that calibrating a six-axis collaborative robot with this invention takes only about 30 minutes, and the absolute accuracy of the robot can be improved by more than 70% after calibration. Therefore, the solution provided by this invention has the following technical advantages: non-contact data acquisition, low cost, portability, high efficiency, and high calibration accuracy.

[0146] Based on the above-described embodiments or optional embodiments provided by this invention, the kinematic parameters of a six-DOF collaborative robot were calibrated to verify the kinematic parameter correction effect. Fifty verification points were collected from the calibrated robot using a laser tracker to verify the improvement in the robot's absolute accuracy after calibration. The verification method is as follows:

[0147] The laser tracker can obtain the actual position P of the robot's end effector by changing the target sphere and the coordinate system. R The laser tracker has high precision, and the position P it obtains is... R This can be considered the actual position of the robot's end effector. The end effector position P before kinematic parameter calibration can be obtained through robot kinematic calculations. B The end-effector position P after the robot's kinematic parameters are calibrated A The absolute accuracy of the robot before calibration is E. B =||P R -P B ||, The absolute accuracy of the robot after calibration is E A =||P R -P A ||, in contrast to E B With E A The size is sufficient to verify the calibration effect.

[0148] Figure 7 This is a schematic diagram of the kinematic parameter accuracy verification results of robot 1 according to an optional embodiment of the present invention. The final accuracy verification effect of robot 1 is as follows: Figure 7 As shown, Figure 7 The calibration curve represents the absolute accuracy E of robot 1 after calibration using the device of this invention. A1 The curve before calibration represents the absolute positioning accuracy E of robot 1 before calibration. B1 , unit mm.

[0149] Calculate the average value with absolute precision In the formula, E represents the absolute accuracy of the robot at a single verification point, and num p To verify the number of points, the final average absolute accuracy of robot 1 after calibration using the device of this invention is: E A_avg1 = 0.743664 mm. The average absolute accuracy of robot 1, which was not calibrated using the device of this invention, is: E B_avg1 =18.998708mm. Analyzing the above experimental data, the absolute accuracy of robot 1 improved by 96.8581% after calibration of its kinematic parameters using the device and process proposed in this invention.

[0150] Figure 8This is a schematic diagram of the kinematic parameter accuracy verification results of robot 2 according to an optional embodiment of the present invention. The final accuracy verification effect of robot 2 is as follows: Figure 8 As shown, robot 2 analyzes data after calibration using the device and process proposed in this invention:

[0151] After calibration using the device of this invention, the average absolute accuracy of robot 2 is: E A_avg2 = 1.174933mm, while the average absolute accuracy of the robot not calibrated by the device of this invention is: E B_avg2 = 5.012296 mm. Analyzing the above experimental data, the absolute accuracy of Robot 2 improved by 76.55% after its kinematic parameters were calibrated using the device and process proposed in this invention.

[0152] The table below summarizes the improvement in absolute accuracy after calibrating the robot's kinematic parameters using the device and process proposed in this invention.

[0153] <![CDATA[E B_avg ]]> 18.998708mm 5.012296mm <![CDATA[E A_avg ]]> 0.743664mm 1.174933mm Improved accuracy 96.8581％ 76.55％

[0154] Furthermore, extensive experimental data has verified that the absolute accuracy of various robot models can be improved by 70% after calibration of the robot's kinematic parameters using the device and process proposed in this invention. This achieves the high-precision requirements of on-site calibration equipment. The total operation time for calibrating a single robot using the device and process proposed in this invention is approximately 30 minutes, meeting the requirement for high efficiency. Camera photography is a non-contact measurement method, meeting the requirement for non-contact data acquisition. The entire device is low-cost and small in size, meeting the requirements for portability and low cost.

[0155] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, because according to the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0156] Through the above description of the embodiments, those skilled in the art can clearly understand that the parameter deviation determination method according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platform. Of course, it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods of the various embodiments of the present invention.

[0157] According to embodiments of the present invention, a parameter deviation determination apparatus for implementing the above-described parameter deviation determination method is also provided. Figure 9 This is a structural block diagram of the parameter deviation determination device provided in an embodiment of the present invention, such as... Figure 9 As shown, the parameter deviation determination device includes: a first determination module 91, a first control module 92, a second control module 93, a second determination module 94, and a third determination module 95. The parameter deviation determination device will be described below.

[0158] The first determining module 91 is used to determine that the adapter plate is fixed to the end of the robot, wherein the calibration needle and the camera are fixed to the adapter plate, and the robot is fixed to the base;

[0159] The first control module 92 is connected to the first determination module 91 and is used to control the robot's movement so that the calibration needle contacts the calibration plate and obtains the first relative positional relationship between the calibration plate and the base.

[0160] The second control module 93 is connected to the first control module 92 and is used to control the end effector to move toward the calibration point. When the end effector moves to the calibration point, it controls the camera to take a picture, wherein the picture includes the calibration plate.

[0161] The second determining module 94 is connected to the second control module 93 and is used to determine the second relative position relationship between the camera and the base when taking a photo based on the photo and the first relative position relationship.

[0162] The third determining module 95, connected to the second determining module 94, is used to determine the kinematic parameter deviation of the robot based on the second relative position relationship and the ideal kinematic parameters of the robot.

[0163] It should be noted that the first determining module 91, the first control module 92, the second control module 93, the second determining module 94, and the third determining module 95 mentioned above correspond to steps S201 to S205 in the embodiments. Multiple modules implement the same instances and application scenarios as their corresponding steps, but are not limited to the content disclosed in the above embodiments. It should also be noted that the above modules, as part of the device, can run on the computer terminal 10 provided in the embodiments.

[0164] Embodiments of the present invention may provide a computer device. Optionally, in this embodiment, the computer device may be located in at least one of a plurality of network devices in a computer network. The computer device includes a memory and a processor.

[0165] The memory can be used to store software programs and modules, such as the program instructions / modules corresponding to the parameter deviation determination method and apparatus in this embodiment of the invention. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory, thereby realizing the aforementioned parameter deviation determination method. The memory may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory may further include memory remotely located relative to the processor, and these remote memories can be connected to a computer terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0166] The processor can access information and application programs stored in the memory via a transmission device to perform the following steps: determining that an adapter plate is fixed to the end effector of the robot, wherein a calibration pin and a camera are fixed to the adapter plate, and the robot is fixed to a base; controlling the robot to move so that the calibration pin contacts the calibration plate, obtaining a first relative positional relationship between the calibration plate and the base; controlling the end effector to move towards the calibration point, and controlling the camera to take a photograph when the end effector reaches the calibration point, wherein the photograph includes the calibration plate; determining a second relative positional relationship between the camera and the base when the photograph was taken based on the photograph and the first relative positional relationship; and determining the robot's kinematic parameter deviation based on the second relative positional relationship and the robot's ideal kinematic parameters.

[0167] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing the hardware related to the terminal device. The program can be stored in a non-volatile storage medium, which may include: flash drive, read-only memory (ROM), random access memory (RAM), magnetic disk or optical disk, etc.

[0168] Embodiments of the present invention also provide a non-volatile storage medium. Optionally, in this embodiment, the aforementioned non-volatile storage medium can be used to store the program code executed by the parameter deviation determination method provided in the above embodiments.

[0169] Optionally, in this embodiment, the non-volatile storage medium may be located in any computer terminal in a group of computer terminals in a computer network, or in any mobile terminal in a group of mobile terminals.

[0170] Optionally, in this embodiment, the non-volatile storage medium is configured to store program code for performing the following steps: determining that the adapter plate is fixed to the end effector of the robot, wherein the calibration pin and the camera are fixed to the adapter plate, and the robot is fixed to the base; controlling the robot to move such that the calibration pin contacts the calibration plate, thereby obtaining a first relative positional relationship between the calibration plate and the base; controlling the end effector to move towards the calibration point, and controlling the camera to take a picture when the end effector moves to the calibration point, wherein the picture includes the calibration plate; determining a second relative positional relationship between the camera and the base when the picture is taken based on the picture and the first relative positional relationship; and determining the kinematic parameter deviation of the robot based on the second relative positional relationship and the ideal kinematic parameters of the robot.

[0171] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0172] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0173] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some interfaces; indirect couplings or communication connections between units or modules may be electrical or other forms.

[0174] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0175] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0176] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a non-volatile storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0177] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for determining parameter deviation, characterized in that, include: The adapter plate is fixed to the end of the robot, wherein the calibration pin and the camera are fixed to the adapter plate, and the robot is fixed to the base; Controlling the robot's movement causes the calibration needle to contact the calibration plate, thereby obtaining a first relative positional relationship between the calibration plate and the base; The end effector is controlled to move toward the calibration point. When the end effector moves to the calibration point, the camera is controlled to take a picture, wherein the picture includes the calibration plate. Based on the photograph and the first relative positional relationship, a second relative positional relationship between the camera and the base is determined when the photograph was taken; Based on the second relative position relationship and the ideal kinematic parameters of the robot, the kinematic parameter deviation of the robot is determined; The step of determining the kinematic parameter deviation of the robot based on the second relative positional relationship and the ideal kinematic parameters of the robot includes: acquiring the camera physical parameters and the adapter plate physical parameters; acquiring the first motion control parameters of the robot when the end effector moves to the calibration point; determining the third relative positional relationship between the end effector and the base when the photo is taken based on the first motion control parameters and the ideal kinematic parameters; and determining the kinematic parameter deviation based on the second relative positional relationship, the third relative positional relationship, the camera physical parameters, and the adapter plate physical parameters.

2. The method according to claim 1, characterized in that, The step of determining the kinematic parameter deviation based on the second relative position relationship, the third relative position relationship, the camera physical parameters, and the adapter plate physical parameters includes: Construct the forward kinematics model of the robot; Based on the first relative position relationship, the second relative position relationship, the third relative position relationship, the physical parameters of the adapter plate, and the physical parameters of the camera, the first position deviation of the camera in the calibration plate coordinate system is determined; Based on the forward kinematics model, the physical parameters of the adapter plate, and the physical parameters of the camera, a first constraint equation is determined between the first position deviation and the deviation of the parameter to be identified, wherein the deviation of the parameter to be identified includes: the kinematic parameter deviation, the deviation of the first relative position relationship, and the deviation of the position relationship between the camera and the end effector; The first constraint equation is solved based on the first position deviation to obtain the deviation of the parameter to be identified; The kinematic parameter deviation is determined based on the deviation of the parameter to be identified.

3. The method according to claim 2, characterized in that, The step of determining the first position deviation of the camera in the calibration plate coordinate system based on the first relative position relationship, the second relative position relationship, the third relative position relationship, the physical parameters of the adapter plate, and the physical parameters of the camera includes: Based on the first relative positional relationship and the third relative positional relationship, a fourth relative positional relationship between the end and the calibration plate is determined when the photograph is taken; Based on the fourth relative positional relationship, the physical parameters of the adapter plate, and the physical parameters of the camera, the fifth relative positional relationship between the camera and the calibration plate is determined when the photo is taken; Based on the photograph, determine the sixth relative positional relationship between the camera and the calibration plate when the photograph was taken; The first positional deviation is determined based on the deviation between the fifth relative positional relationship and the sixth relative positional relationship.

4. The method according to claim 2, characterized in that, The step of solving the first constraint equation based on the first position deviation to obtain the deviation of the parameter to be identified includes: Substituting the first position deviation into the first constraint equation, we obtain the equation to be solved; The equation to be solved is obtained by using the overall least squares method, and the deviation of the parameter to be identified is obtained.

5. The method according to claim 1, characterized in that, The step of determining the kinematic parameter deviation based on the second relative position relationship, the third relative position relationship, the camera physical parameters, and the adapter plate physical parameters includes: Construct the forward kinematics model of the robot; Based on the second relative positional relationship, the camera physical parameters, and the adapter plate physical parameters, a seventh relative positional relationship between the end and the base is determined when the photo is taken. The second position deviation of the end is determined based on the deviation between the third relative position relationship and the seventh relative position relationship; Based on the positive kinematics model, determine the second constraint equation between the second position deviation and the kinematic parameter deviation; The kinematic parameter deviation is obtained by solving the second constraint equation based on the second position deviation.

6. The method according to any one of claims 1 to 5, characterized in that, Controlling the robot's movement to cause the calibration needle to contact the calibration plate, thereby obtaining a first relative positional relationship between the calibration plate and the base, includes: Obtain the physical parameters of the adapter plate and the physical parameters of the calibration needle; Control the robot's movement so that the calibration needle contacts the calibration plate, and record the robot's second motion control parameters; The first relative positional relationship is determined based on the second motion control parameters, the physical parameters of the calibration needle, and the physical parameters of the adapter plate.

7. The method according to claim 6, characterized in that, The process of controlling the robot's movement so that the calibration needle contacts the calibration plate and recording the robot's second motion control parameters includes: selecting multiple position points on the calibration plate; controlling the robot's movement so that the calibration needle contacts the multiple position points respectively; and recording the second motion control parameters corresponding to each of the multiple position points when the calibration needle contacts each of the multiple position points respectively. Determining the first relative positional relationship based on the second motion control parameters, the calibration needle physical parameters, and the adapter plate physical parameters includes: determining an eighth relative positional relationship between the end of the calibration needle and the base when the calibration needle contacts the plurality of position points respectively, based on the second motion control parameters; determining a ninth relative positional relationship between the calibration needle and the base when the calibration needle contacts the plurality of position points respectively, based on the eighth relative positional relationship, the calibration needle physical parameters, and the adapter plate physical parameters; and determining the first relative positional relationship based on the ninth relative positional relationship.

8. A parameter deviation determination device, characterized in that, include: The first determining module is used to determine that the adapter plate is fixed to the end of the robot, wherein the calibration needle and the camera are fixed to the adapter plate, and the robot is fixed to the base; The first control module is used to control the movement of the robot so that the calibration needle contacts the calibration plate and obtains a first relative positional relationship between the calibration plate and the base. The second control module is used to control the end effector to move toward the calibration point, and when the end effector moves to the calibration point, it controls the camera to take a picture, wherein the picture includes the calibration plate; The second determining module is used to determine a second relative positional relationship between the camera and the base when the photo was taken, based on the photo and the first relative positional relationship; The third determining module is used to determine the kinematic parameter deviation of the robot based on the second relative position relationship and the ideal kinematic parameters of the robot; The third determining module is further configured to acquire the camera physical parameters of the camera and the adapter plate physical parameters of the adapter plate; acquire the first motion control parameters of the robot when the end effector moves to the calibration point; determine the third relative positional relationship between the end effector and the base when the photo is taken based on the first motion control parameters and the ideal kinematic parameters; and determine the kinematic parameter deviation based on the second relative positional relationship, the third relative positional relationship, the camera physical parameters, and the adapter plate physical parameters.

9. A non-volatile storage medium, characterized in that, The non-volatile storage medium includes a stored program, wherein, when the program is executed, it controls the device containing the non-volatile storage medium to perform the parameter deviation determination method according to any one of claims 1 to 7.

10. A computer device, characterized in that, The computer device includes a memory and a processor, the memory being used to store a program, and the processor being used to run the program stored in the memory, wherein the program, when running, executes the parameter deviation determination method according to any one of claims 1 to 7.

Images