Mechanical arm precision verification method, device, equipment and medium

Abstract

The invention relates to a mechanical arm precision verification method, device and equipment and a medium, the mechanical arm precision verification method comprises the steps that a first image of the initial position of the tail end of a mechanical arm is acquired, and a calibration plate comprising a plurality of calibration circles is fixed to the tail end of the mechanical arm; acquiring a second image of the tail end of the mechanical arm at the final position of the motion track; the actual pose variation of the tail end of the mechanical arm is obtained based on the pose variation of the calibration circle on the calibration plate in the first image and the second image; based on the position relation between the TCP of the tail end of the mechanical arm and the calibration plate, the theoretical pose variation of the tail end of the mechanical arm is determined; whether precision verification or recalibration needs to be carried out or not is determined on the basis of the difference value between the actual pose variable quantity and the theoretical pose variable quantity, therefore, precision verification of the mechanical arm can be achieved through the calibration plate arranged at the tail end of the mechanical arm, the complexity of precision verification of the mechanical arm is reduced, meanwhile, the calibration plate is provided with a plurality of calibration circles, and the calibration accuracy is improved. A large amount of image data does not need to be collected, and the precision verification efficiency is improved.

Description

Technical Field

[0001] The present disclosure relates to the field of computer vision technology, and in particular to a method, device, equipment and medium for calibrating the accuracy of a robotic arm. Background Art

[0002] With the continuous improvement of industrial intelligence, the use of robotic arms has become more and more extensive, and robotic arm precision calibration has also become an indispensable task. Among them, robotic arm precision calibration refers to verifying the values ​​of the robotic arm's repeatability and absolute accuracy through calibration, as well as whether the accuracy requirements are met. Of course, the accuracy of the robotic arm precision calibration is also crucial to the production accuracy of industrial products.

[0003] At present, the method for calibrating the accuracy of a robotic arm is mainly to first install targets and other markers on the robotic arm, then measure the different posture data of the robotic arm in space through high-precision measuring instruments, compare the obtained different posture data with the theoretical posture data, and then evaluate the accuracy of the robotic arm end.

[0004] However, the existing robotic arm accuracy calibration method requires special calibration equipment such as targets, laser trackers, optical locators, etc. as well as a calibration environment, which has problems such as complex calibration process and low calibration efficiency. Summary of the invention

[0005] In order to solve the above technical problems, the present disclosure provides a method, device, equipment and medium for calibrating the accuracy of a robotic arm.

[0006] A first aspect of an embodiment of the present disclosure provides a method for calibrating the accuracy of a robotic arm, the method comprising:

[0007] A first image of a starting position of the end of the robotic arm is acquired by using an image sensor, wherein a calibration plate is fixed on the end of the robotic arm, a plurality of calibration circles are fixed on the calibration plate, and a positional relationship between the image sensor and a base of the robotic arm is relatively fixed;

[0008] Controlling the end of the robotic arm to move along a preset motion trajectory, and using an image sensor to obtain a second image of the end of the robotic arm at an end position of the motion trajectory;

[0009] The actual position and posture change of the end of the robot arm is obtained based on the position and posture change of the calibration circle on the calibration plate in the first image and the second image;

[0010] Based on the positional relationship between the TCP at the end of the robot arm and the calibration plate, the theoretical position change of the end of the robot arm is determined;

[0011] Based on the difference between the actual pose change and the theoretical pose change, it is determined whether accuracy verification or recalibration is required.

[0012] A second aspect of an embodiment of the present disclosure provides a robotic arm accuracy calibration device, the device comprising:

[0013] A first acquisition module, used for acquiring a first image of a starting position of the end of the robot arm by using an image sensor, wherein a calibration plate is fixed on the end of the robot arm, a plurality of calibration circles are fixed on the calibration plate, and a positional relationship between the image sensor and a base of the robot arm is relatively fixed;

[0014] A second acquisition module is used to control the end of the robot arm to move along a preset motion trajectory, and use an image sensor to acquire a second image of the end of the robot arm at the end position of the motion trajectory;

[0015] An actual posture calculation module is used to obtain an actual posture change of the end of the robot arm based on the posture change of the calibration circle on the calibration plate in the first image and the second image;

[0016] Theoretical posture calculation module, used to determine the theoretical posture change of the end of the robot arm based on the position relationship between the TCP of the end of the robot arm and the calibration plate;

[0017] The accuracy determination module is used to determine whether accuracy verification or recalibration is required based on the difference between the actual posture change and the theoretical posture change.

[0018] A third aspect of an embodiment of the present disclosure provides an electronic device, the device comprising:

[0019] Memory;

[0020] Processor; and

[0021] A computer program, wherein the computer program is stored in a memory and is configured to be executed by a processor to implement the robot arm accuracy calibration method as described in the first aspect above.

[0022] A fourth aspect of an embodiment of the present disclosure provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the robot arm accuracy calibration method as described in the first aspect above is implemented.

[0023] Compared with the prior art, the technical solution provided by the embodiments of the present disclosure has the following advantages:

[0024] The robot arm accuracy calibration method, device, equipment and medium provided by the embodiments of the present disclosure can use an image sensor to obtain a first image of the starting position of the end of the robot arm, wherein a calibration plate is fixed on the end of the robot arm, and a plurality of calibration circles are fixed on the calibration plate. The positional relationship between the image sensor and the base of the robot arm is relatively fixed, and the end of the robot arm is controlled to move along a preset motion trajectory, and a second image of the end of the robot arm at the end position of the motion trajectory is obtained by using the image sensor, and the actual posture change of the end of the robot arm is obtained based on the posture change of the calibration circle on the calibration plate in the first image and the second image, and based on the end of the robot arm The positional relationship between TCP and the calibration plate is used to determine the theoretical posture change of the end of the robot arm. Based on the difference between the actual posture change and the theoretical posture change, it is determined whether accuracy verification or recalibration is needed. Therefore, the accuracy verification of the robot arm can be achieved through the calibration plate set on the robot arm, which reduces the complexity of the accuracy verification of the robot arm. At the same time, since multiple calibration circles are set on the calibration plate, when the end of the robot arm moves, the calibration circle will produce multiple spatial movements, and the spatial movement postures of multiple calibration circles can be obtained by collecting them once, without the need to collect a large amount of image data, thereby improving the efficiency of accuracy verification. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0027] Figure 1 is a flow chart of a method for calibrating the accuracy of a robotic arm provided by an embodiment of the present disclosure;

[0028] Figure 2 is a structural schematic diagram of a calibration board provided in an embodiment of the present disclosure;

[0029] Figure 3 is a flow chart of another method for calibrating the accuracy of a robotic arm provided by an embodiment of the present disclosure;

[0030] Figure 4 It is a structural schematic diagram of a mechanical arm precision calibration device provided by an embodiment of the present disclosure;

[0031] Figure 5 It is a structural schematic diagram of an electronic device provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0032] In order to more clearly understand the above-mentioned objectives, features and advantages of the present disclosure, the scheme of the present disclosure will be further described below. It should be noted that the embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0033] In the following description, many specific details are set forth to facilitate a full understanding of the present disclosure, but the present disclosure may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present disclosure, rather than all of the embodiments.

[0034] It should be understood that the various steps described in the method embodiments of the present disclosure may be performed in different orders and / or in parallel. In addition, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present disclosure is not limited in this respect.

[0035] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0036] It should be noted that the modifications of "one" and "plurality" mentioned in the present disclosure are illustrative rather than restrictive, and those skilled in the art should understand that unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0037] Generally speaking, the existing robot arm precision calibration method requires special calibration equipment such as targets, laser trackers, optical locators, etc. and calibration environments, which have the problems of complex calibration process and low calibration efficiency. To address this problem, the present disclosure provides a robot arm precision calibration method, which is introduced below in conjunction with specific embodiments.

[0038] Figure 1It is a flow chart of a robot arm precision verification method provided by an embodiment of the present disclosure. The method can be executed by a robot arm precision verification device. The robot arm precision verification device can be implemented in software and / or hardware. The robot arm precision verification device can be configured in an electronic device, such as a server or a terminal or a server cluster, wherein the terminal can specifically include a mobile phone, a computer or a tablet computer, or can be any device that can be used to process the robot arm precision verification method.

[0039] like Figure 1 As shown, the robot arm accuracy calibration method provided by the embodiment of the present disclosure includes the following steps.

[0040] S110. Acquire a first image of the starting position of the end of the robot arm using an image sensor, wherein a calibration plate is fixed on the end of the robot arm, a plurality of calibration circles are fixed on the calibration plate, and a positional relationship between the image sensor and the base of the robot arm is relatively fixed.

[0041] In the disclosed embodiment, the positional relationship between the image sensor (generally a binocular camera) and the base of the robot arm is fixed, and the position of the image sensor can capture an image of the end of the robot arm during its movement, which image is an image containing a calibration plate. Since the positional relationship between the image sensor and the base of the robot arm is relatively fixed, the positional relationship between the robot arm coordinate system and the image sensor coordinate system is also fixed, and thus there is a fixed coordinate conversion relationship between the robot arm coordinate system and the image sensor coordinate system, which can be determined based on the position of the robot arm and the external parameters of the image sensor and pre-stored in the electronic device.

[0042] Furthermore, the calibration plate is provided with a plurality of calibration circles for determining the spatial position of the calibration plate. Each calibration circle can be captured by the image sensor device, and the specific coordinates of the calibration circle in the image sensor coordinate system can be obtained by using the existing algorithm. In addition, the coordinate conversion relationship between the robot arm coordinate system and the image sensor coordinate system is also known, and then the coordinates of each calibration circle in the robot arm coordinate system can be determined, and this coordinate is used as the initial coordinate. Afterwards, since the coordinates of the robot arm end TCP in the robot arm coordinate system are known, and the calibration plate is fixed on the robot arm end, the positional relationship or coordinate difference between the robot arm end TCP and each calibration circle is also determined.

[0043] Optionally, the TCP of the end of the robot arm may be the location of the center point of the end of the robot arm, or may be any pre-set point at the end of the robot arm, which is not limited here.

[0044] In an embodiment of the present disclosure, when the electronic device needs to perform accuracy verification on the robotic arm or receives an accuracy verification instruction for the robotic arm, the electronic device acquires a first image of the starting position of the robotic arm.

[0045] The first image is an image including a calibration plate, wherein the calibration plate is fixed to the end of the robotic arm and does not move relative to the end of the robotic arm. The calibration plate is provided with a plurality of calibration circles, and the number, size and positional relationship between the calibration circles can be set according to requirements and are not limited here.

[0046] Figure 2 is a schematic diagram of the structure of a calibration board provided by an embodiment of the present disclosure, such as Figure 2 As shown in the figure, the white circle is the calibration circle, the calibration circles are arranged in a certain order, and the calibration plate has a black background.

[0047] In some embodiments of the present disclosure, when an electronic device receives a robotic arm precision verification instruction, it can parse the robotic arm precision verification instruction, obtain a robotic arm identification corresponding to the robotic arm precision verification instruction, control an image acquisition device such as an image sensor to capture an image of the robotic arm, and obtain a first image of the starting position of the robotic arm.

[0048] In some embodiments of the present disclosure, the robot arm accuracy verification instruction only includes a robot arm identification. When the electronic device receives the robot arm accuracy verification instruction, it can parse the robot arm accuracy verification instruction and obtain a first image of the robot arm starting position corresponding to the robot arm identification from a preset memory according to the robot arm identification.

[0049] S120, controlling the end of the robotic arm to move along a preset motion trajectory, and using an image sensor to obtain a second image of the end of the robotic arm at a motion end position.

[0050] In the disclosed embodiment, the preset motion trajectory may be generated according to preset parameters, or may be a motion trajectory corresponding to the robot end TCP moving only along a straight line and rotating at a certain angle around the straight line as an axis.

[0051] Since the calibration circle is on a plane, TCP only needs to move along a straight line and rotate a certain angle around the straight line. In this way, the end of the robot arm only needs a very small movement or change to make the calibration circle produce multiple spatial movements, thereby reducing the time spent on a large number of movements of the robot arm during the inspection or verification process.

[0052] In an embodiment of the present disclosure, after acquiring a first image of the starting position of the robotic arm, the electronic device controls the robotic arm to move along a preset motion trajectory and acquires a second image of the end position of the robotic arm.

[0053] Specifically, after acquiring a first image of the starting position of the robotic arm, the electronic device acquires a preset motion trajectory of the robotic arm, and then controls the robotic arm to move along the preset motion trajectory. When the robotic arm runs to the end position of the preset motion trajectory, the image acquisition device is controlled to acquire a second image of the end position of the robotic arm's movement. The image acquisition device uploads the acquired second image to the electronic device, thereby enabling the electronic device to acquire a second image of the end position of the robotic arm's movement.

[0054] S130. Obtain an actual posture change amount of the end of the robotic arm based on the posture change amount of the calibration circle on the calibration plate in the first image and the second image.

[0055] In the embodiment of the present disclosure, it is first necessary to determine the coordinates of each calibration circle on the calibration plate in the first image and the second image in the robot arm coordinate system. Here, the determination of the coordinates of a calibration circle on the calibration plate in the first image in the robot arm coordinate system is described. Since the calibration circle can be collected by the image sensor device, the existing algorithm can be used to obtain the specific coordinates of the calibration circle in the image sensor coordinate system. In addition, the coordinate conversion relationship between the robot arm coordinate system and the image sensor coordinate system is also known. Therefore, the specific coordinates of the calibration circle in the image sensor coordinate system and the coordinate conversion relationship can be used to obtain the coordinates of the calibration circle in the robot arm coordinate system. In this way, the coordinates of each calibration circle on the calibration plate in the first image in the robot coordinate system (i.e., the initial coordinates) can be determined, and the coordinates of each calibration circle on the calibration plate in the second image in the robot coordinate system (i.e., the actual moving coordinates) can be determined, wherein the specific acquisition method is similar to the above-mentioned specific method of acquiring the coordinates of each calibration circle in the first image in the robot coordinate system, and will not be repeated here. Secondly, according to the coordinates of each calibration circle in the robot coordinate system in the first image and the second image, i.e., the initial coordinates and the actual moving coordinates, the actual position change of each calibration circle in the robot coordinate system can be obtained according to the difference between the actual moving coordinates and the initial coordinates.

[0056] S140, determining a theoretical position change of the end of the robot arm based on the position relationship between the TCP of the end of the robot arm and the calibration plate.

[0057] In the embodiment of the present disclosure, the robotic arm itself can obtain the coordinates of the TCP in the robotic arm coordinate system when it is at the end position of the motion trajectory through the changes in the translation and / or rotation of its own axes. Through the coordinates of the TCP in the robotic arm coordinate system when it is at the end position of the motion trajectory and the positional relationship between the TCP and the calibration circle on the calibration plate in the robotic arm coordinates, the coordinates of each calibration circle in the robotic arm coordinate system, that is, the theoretical moving coordinates, can be obtained. Then, the initial coordinates and the theoretical moving coordinates, that is, the difference between the theoretical moving coordinates and the initial coordinates, can be used to obtain the theoretical posture change of each calibration circle in the robotic arm coordinate system.

[0058] S150: Determine whether accuracy verification or recalibration is required based on the difference between the actual posture change and the theoretical posture change.

[0059] In the embodiment of the present disclosure, after obtaining the actual posture change and theoretical posture change of the end of the robotic arm, the electronic device calculates the difference between the actual posture change and the theoretical posture change, and determines whether accuracy verification or recalibration is needed based on the relationship between the difference between the actual posture change and the theoretical posture change and a preset threshold.

[0060] In the disclosed embodiment, an image sensor can be used to obtain a first image of the starting position of the end of the robot arm, wherein a calibration plate is fixed on the end of the robot arm, a plurality of calibration circles are fixed on the calibration plate, the positional relationship between the image sensor and the base of the robot arm is relatively fixed, the end of the robot arm is controlled to move along a preset motion trajectory, and a second image of the end of the robot arm at the end position of the motion trajectory is obtained by using the image sensor, the actual position and posture change of the end of the robot arm is obtained based on the positional change of the calibration circle on the calibration plate in the first image and the second image, the theoretical position and posture change of the end of the robot arm is determined based on the positional relationship between the TCP of the end of the robot arm and the calibration plate, and whether accuracy verification or recalibration is required is determined based on the difference between the actual position and posture change and the theoretical position and posture change. Thus, the accuracy verification of the robot arm can be realized by the calibration plate set on the robot arm, which reduces the complexity of the accuracy verification of the robot arm. At the same time, since a plurality of calibration circles are set on the calibration plate, when the end of the robot arm moves, the calibration circle will produce a variety of spatial movements, and the spatial movement position and posture of a plurality of calibration circles can be obtained by collecting once, thereby there is no need to collect a large amount of image data, thereby improving the efficiency of accuracy verification.

[0061] Based on the above embodiments of the present disclosure, before controlling the end of the robotic arm to move along a preset motion trajectory in S120, the robotic arm accuracy verification method may further include: acquiring a preset motion trajectory of the end of the robotic arm.

[0062] Wherein, obtaining the preset motion trajectory of the robot arm may specifically include: obtaining preset parameters, which are preset parameters for generating the motion trajectory; and automatically generating the preset motion trajectory based on the preset parameters.

[0063] In the embodiment of the present disclosure, the preset parameters are pre-set according to the accuracy type of the robotic arm that needs to be verified and stored in the electronic device.

[0064] Specifically, the electronic device can obtain preset parameters corresponding to the robot arm identifier from the preset memory, and automatically generate a preset motion trajectory based on the preset trajectory generation program and the preset parameters.

[0065] In the disclosed embodiment, the electronic device can automatically generate a preset motion trajectory based on preset parameters, and the accuracy verification of the robotic arm can be achieved with only simple operations, which simplifies the operational process of the robotic arm accuracy verification and further reduces the complexity of the robotic arm accuracy verification. At the same time, it can perform accuracy verification more specifically for the operation and verification areas of the robotic arm.

[0066] In the embodiments of the present disclosure, the accuracy types of the robotic arm include absolute position accuracy, absolute posture accuracy and repeatable positioning accuracy; different preset parameters correspond to different accuracy types of the robotic arm. When the accuracy type of the robotic arm is absolute position accuracy, the preset parameters include the starting point coordinates and the end point coordinates of moving in any direction of the X-axis, Y-axis and Z-axis of the robotic arm coordinate system; when the accuracy type of the robotic arm is absolute posture accuracy, the preset parameters include the starting point angle and the end point angle of rotation along any axis of the X-axis, Y-axis and Z-axis of the robotic arm coordinate system. When the accuracy type of the robotic arm is repeatable positioning accuracy, the preset parameters include the number of repetitions.

[0067] Among them, when the accuracy type of the robot arm is repeated positioning accuracy, the accuracy type corresponding to the repeated positioning accuracy is performed as needed, and the preset parameters also include parameters corresponding to the accuracy type corresponding to the repeated positioning accuracy.

[0068] Exemplarily, it is necessary to verify the repeatable positioning accuracy corresponding to the absolute position accuracy of the robot arm, and the preset parameters of the repeatable positioning accuracy include the starting point coordinates and the end point coordinates of moving in any direction of the X-axis, Y-axis, and Z-axis of the robot arm coordinate system, as well as the number of repetitions; it is necessary to verify the repeatable positioning accuracy corresponding to the absolute posture accuracy of the robot arm, and the preset parameters of the repeatable positioning accuracy include the starting point angle and the end point angle of rotation along any axis of the X-axis, Y-axis, and Z-axis of the robot arm coordinate system, as well as the number of repetitions.

[0069] In the disclosed embodiment, the preset motion trajectories can be flexibly combined according to the project requirements and site conditions corresponding to the robotic arm to achieve flexibility in the accuracy calibration of the robotic arm.

[0070] Specifically, the electronic device can respond to the user's combined operations based on preset parameters, and based on the combined operations of the preset parameters, generate a combined motion trajectory, and simultaneously calibrate the different precision types of the robotic arm according to the combined motion trajectory to ensure that the robotic arm can meet project requirements.

[0071] Exemplarily, the project that the robotic arm needs to perform is to transport an item from point A to point B, and the item needs to be transported from point A to point B repeatedly. At this time, the robotic arm involves absolute position accuracy and repeat positioning accuracy. At this time, the electronic device can generate a combined motion trajectory based on the preset parameters corresponding to the absolute position accuracy and the preset parameters corresponding to the repeat positioning accuracy, and then verify the absolute position accuracy and repeat positioning accuracy of the robotic arm according to the combined motion trajectory. Similarly, the electronic device can also generate a combined motion trajectory based on the preset parameters corresponding to the absolute position accuracy and the preset parameters corresponding to the absolute posture accuracy, and perform accuracy verification on the absolute position accuracy and absolute posture accuracy of the robotic arm.

[0072] In the embodiment of the present disclosure, obtaining the actual change of the end of the robotic arm based on the posture change of the calibration circle on the calibration plate in the first image and the second image in S130 may specifically include: performing posture calculations on the calibration circle on the calibration plate in the first image and the second image based on a multi-point transmission transformation algorithm to obtain a first posture of the calibration circle in the first image relative to the image sensor and a second posture of the calibration circle in the second image relative to the image sensor; calculating the difference between the first posture and the second posture, and determining the difference as the posture change of the calibration circle in the image sensor coordinate system; based on the conversion relationship between the image sensor coordinate system and the robotic arm coordinate system, converting the posture change in the image sensor coordinate system to the robotic arm coordinate system to obtain the actual posture change of the end of the robotic arm.

[0073] Among them, based on the multi-point transmission transformation algorithm, the posture calculation of the calibration circle on the calibration plate in the first image and the second image is respectively performed to obtain a first posture of the calibration circle in the first image relative to the image sensor and a second posture of the calibration circle in the second image relative to the image sensor, which can specifically include: obtaining the image sensor internal parameters and distortion coefficients, the three-dimensional space coordinates of the calibration circle, the first pixel coordinates of the calibration circle in the first image and the second pixel coordinates of the calibration circle in the second image; performing multi-point transmission transformation processing on the image sensor internal parameters and distortion coefficients, the three-dimensional space coordinates of the calibration circle and the first pixel coordinates to obtain the first posture; performing multi-point transmission transformation processing on the image sensor internal parameters and distortion coefficients, the three-dimensional space coordinates of the calibration circle and the second pixel coordinates to obtain the second posture.

[0074] In the embodiment of the present disclosure, the image sensor intrinsic parameters and distortion parameters are pre-acquired and stored in the memory of the electronic device. The electronic device can directly acquire the image sensor intrinsic parameters and distortion parameters according to the image sensor identifier, wherein the image sensor identifier can be acquired when acquiring the first image and the second image.

[0075] The three-dimensional spatial coordinates of the calibration circle are determined according to the rules of the calibration plate and pre-stored in the electronic device.

[0076] Among them, first, a corner of the calibration plate is taken as the origin, and the calibration plate coordinate system is established along the length and width directions of the calibration plate as the X-axis and Y-axis respectively. The X-coordinate and Y-coordinate in the three-dimensional space coordinates of the calibration circle can be determined according to the spacing between each calibration circle. The distance between each calibration circle and the origin is determined, and then the X-coordinate and Y-coordinate of each calibration circle in the calibration plate coordinate system are determined. At the same time, since the calibration plate coordinate system is established on the calibration plate plane, the Z coordinate of each calibration circle is 0, and then the three-dimensional space coordinates of each calibration circle are obtained.

[0077] In the embodiment of the present disclosure, the specific implementation method of performing multi-point transmission transformation processing on the image sensor internal parameters and distortion coefficients, the three-dimensional spatial coordinates of the calibration circle and the first pixel coordinates (or the second pixel coordinates) is similar to the existing transmission transformation processing implementation method based on the direct linear transformation algorithm and is not limited here.

[0078] In the disclosed embodiment, the first posture and the second posture obtained are both the postures of the calibration circle in the image sensor coordinate system. After obtaining the posture of the calibration circle in the image sensor coordinate system, the difference between the first posture and the second posture is determined as the posture change of the calibration circle in the image sensor coordinate system, and then based on the conversion relationship between the image sensor coordinate system and the robotic arm coordinate system, the posture change of the calibration circle in the image sensor coordinate system is converted to the robotic arm coordinate system to obtain the posture change of the calibration circle in the robotic arm coordinate system, that is, the actual posture change of the end of the robotic arm.

[0079] Furthermore, after obtaining the actual posture change of the end of the robotic arm, the electronic device calculates the difference between the actual posture change of the end of the robotic arm and the theoretical posture change of the end of the robotic arm, and determines whether accuracy verification or recalibration is needed based on the difference between the actual posture change and the theoretical posture change.

[0080] Determining whether accuracy check or recalibration is required based on the difference between the actual posture change and the theoretical posture change may specifically include: determining whether accuracy check or recalibration is required based on the size relationship between the difference and a preset threshold.

[0081] The preset threshold is a pre-set threshold for determining whether to perform accuracy verification or recalibration.

[0082] In the embodiment of the present disclosure, when the difference is greater than a preset threshold, it is determined that the accuracy of the end of the robot arm does not meet the requirements, and then based on the difference, the TCP of the end of the robot arm is subjected to accuracy compensation, i.e., accuracy verification or recalibration.

[0083] In some embodiments of the present disclosure, when the accuracy of the robot arm does not meet the requirements, but the accuracy error has a certain regularity, the accuracy of the TCP at the end of the robot arm can be compensated by the difference, so as to ensure the subsequent accuracy.

[0084] In other embodiments of the present disclosure, when the accuracy of the robotic arm does not meet the requirements and the accuracy error is too large and irregular, the accuracy verification result is fed back to the user, so that the user can contact the robotic arm manufacturer for accuracy compensation based on the accuracy verification result, and further perform accuracy verification and calibration.

[0085] In the embodiment of the present disclosure, when the difference is less than or equal to the preset threshold, it is determined that the accuracy of the end of the robotic arm meets the requirements, and there is no need to perform accuracy verification or recalibration on the TCP of the end of the robotic arm.

[0086] In the disclosed embodiment, when the accuracy of the robotic arm does not meet the requirements, the accuracy of the robotic arm can be compensated based on the accuracy verification result of the robotic arm, thereby improving the accuracy of the robotic arm and the working accuracy of the robotic arm and ensuring the success rate of the project corresponding to the robotic arm.

[0087] Figure 3 is a flow chart of another method for verifying the accuracy of a robotic arm provided by an embodiment of the present disclosure. Figure 3 As shown, the robot arm accuracy calibration method may include the following steps:

[0088] S310, using an image sensor to obtain a first image of the starting position of the end of the robot arm.

[0089] S320: Obtain preset parameters, and automatically generate a preset motion trajectory based on the preset parameters.

[0090] S330, controlling the end of the robotic arm to move along a preset motion trajectory, and using an image sensor to obtain a second image of the end of the robotic arm at an end position of the motion trajectory.

[0091] S340, performing posture calculations on the calibration circle on the calibration plate in the first image and the second image based on a multi-point transmission transformation algorithm, respectively, to obtain a first posture of the calibration circle in the first image relative to the image sensor and a second posture of the calibration circle in the second image relative to the image sensor.

[0092] S350, calculating the difference between the first posture and the second posture, and determining the difference as the position and posture change of the calibration circle in the image sensor coordinate system.

[0093] S360: Based on the conversion relationship between the image sensor coordinate system and the robotic arm coordinate system, the position and posture change in the image sensor coordinate system is converted to the robotic arm coordinate system to obtain the actual position and posture change of the end of the robotic arm.

[0094] S370. Determine the theoretical position change of the end of the robot arm based on the position relationship between the TCP of the end of the robot arm and the calibration plate.

[0095] S380: Determine whether accuracy verification or recalibration is required based on the difference between the actual posture change and the theoretical posture change.

[0096] S390: When the difference is greater than a preset threshold, the TCP at the end of the robot arm is precision-checked or recalibrated based on the difference.

[0097] S3010: When the difference is less than or equal to a preset threshold, it is determined that there is no need to perform accuracy verification or recalibration on the TCP at the end of the robot arm.

[0098] In the embodiment of the present disclosure, step S310 and step S320 may be performed simultaneously, or step S310 may be performed after step S320, which is not limited here.

[0099] It should be noted that the specific implementation of steps S310 to S3010 is similar to that of the above embodiment and will not be described in detail here.

[0100] In the disclosed embodiment, a first image of the starting position of the robot arm can be obtained, and preset parameters can be obtained, a preset motion trajectory can be automatically generated based on the preset parameters, the robot arm can be controlled to move along the preset motion trajectory, and a second image of the robot arm end at the motion international end position can be obtained, and the posture of the calibration circle in the first image and the second image is calculated based on the multi-point transmission transformation algorithm, respectively, to obtain a first posture of the calibration circle in the first image relative to the image sensor and a second posture of the calibration circle in the second image relative to the image sensor, calculate the difference between the first posture and the second posture, and determine the difference as the position and posture change of the calibration circle in the image sensor coordinate system. The amount of posture change in the image sensor coordinate system is converted to the robotic arm coordinate system based on the conversion relationship between the image sensor coordinate system and the robotic arm coordinate system, and the actual posture change of the end of the robotic arm is obtained. At the same time, based on the positional relationship between the TCP at the end of the robotic arm and the calibration plate, the theoretical posture change of the end of the robotic arm is determined. Based on the difference between the actual posture change and the theoretical posture change, it is determined whether accuracy verification or recalibration is needed. When the difference is greater than the preset threshold, it means that the accuracy of the robotic arm does not meet the requirements. Based on the difference, the accuracy compensation of the robotic arm is performed. Therefore, the complexity of the robotic arm accuracy verification can be reduced and the efficiency of the accuracy verification can be improved.

[0101] Figure 4: is a schematic diagram of the structure of a mechanical arm precision verification device provided by an embodiment of the present disclosure. The mechanical arm precision verification device in the embodiment of the present disclosure can be set in an electronic device, and the electronic device can be a server or a terminal or a server cluster, wherein the terminal can specifically include a mobile phone, a computer or a tablet computer, and can also be any device that can be used to process the mechanical arm precision verification method, etc., which is not limited here.

[0102] like Figure 4 As shown, the robotic arm accuracy verification device 400 may include a first acquisition module 410 , a second acquisition module 420 , an actual posture calculation module 430 , a theoretical posture calculation module 440 and an accuracy determination module 450 .

[0103] The first acquisition module 410 can be used to acquire a first image of the starting position of the robot arm using an image sensor, wherein a calibration plate is fixed on the end of the robot arm, a plurality of calibration circles are fixed on the calibration plate, and the positional relationship between the image sensor and the robot arm base is relatively fixed.

[0104] The second acquisition module 420 can be used to control the end of the robot arm to move along a preset motion trajectory, and use an image sensor to acquire a second image of the end of the robot arm at the end position of the motion trajectory.

[0105] The actual posture calculation module 430 can be used to obtain the actual posture change of the end of the robot arm based on the posture change of the calibration circle on the calibration plate in the first image and the second image.

[0106] The theoretical posture calculation module 440 can be used to determine the theoretical posture change of the end of the robot arm based on the positional relationship between the TCP of the end of the robot arm and the calibration plate.

[0107] The accuracy determination module 450 can be used to determine whether accuracy verification or recalibration is required based on the difference between the actual posture change and the theoretical posture change.

[0108] In the disclosed embodiment, an image sensor can be used to obtain a first image of the starting position of the end of the robot arm, wherein a calibration plate is fixed on the end of the robot arm, a plurality of calibration circles are fixed on the calibration plate, the positional relationship between the image sensor and the base of the robot arm is relatively fixed, the end of the robot arm is controlled to move along a preset motion trajectory, and a second image of the end of the robot arm at the end position of the motion trajectory is obtained by using the image sensor, the actual position and posture change of the end of the robot arm is obtained based on the positional change of the calibration circle on the calibration plate in the first image and the second image, the theoretical position and posture change of the end of the robot arm is determined based on the positional relationship between the TCP of the end of the robot arm and the calibration plate, and whether accuracy verification or recalibration is required is determined based on the difference between the actual position and posture change and the theoretical position and posture change. Thus, the accuracy verification of the robot arm can be realized by the calibration plate set on the robot arm, which reduces the complexity of the accuracy verification of the robot arm. At the same time, since a plurality of calibration circles are set on the calibration plate, when the end of the robot arm moves, the calibration circle will produce a variety of spatial movements, and the spatial movement position and posture of a plurality of calibration circles can be obtained by collecting once, thereby there is no need to collect a large amount of image data, thereby improving the efficiency of accuracy verification.

[0109] In some embodiments of the present disclosure, the robotic arm accuracy calibration device 400 may further include a third acquisition module.

[0110] The third acquisition module can be used to acquire the preset motion trajectory of the robotic arm before controlling the end of the robotic arm to move along the preset motion trajectory.

[0111] The third acquisition module may include a parameter acquisition unit and a trajectory generation unit.

[0112] The parameter acquisition unit may be used to acquire preset parameters, where the preset parameters are pre-set parameters for generating a motion trajectory.

[0113] The trajectory generating unit may be used to automatically generate a preset motion trajectory based on preset parameters.

[0114] In some embodiments of the present disclosure, the accuracy types of the robotic arm include absolute position accuracy, absolute posture accuracy and repeatable positioning accuracy; different preset parameters correspond to different accuracy types of the robotic arm. When the accuracy type of the robotic arm is absolute position accuracy, the preset parameters include the starting point coordinates and the end point coordinates of moving in any direction of the X-axis, Y-axis, and Z-axis of the robotic arm coordinate system; when the accuracy type of the robotic arm is absolute posture accuracy, the preset parameters include the starting point angle and the end point angle of rotation along any axis of the X-axis, Y-axis, and Z-axis of the robotic arm coordinate system. When the accuracy type of the robotic arm is repeatable positioning accuracy, the preset parameters include the number of repetitions.

[0115] In some embodiments of the present disclosure, the actual posture calculation module 430 may include a first calculation unit, a second calculation unit and a coordinate conversion unit.

[0116] The first calculation unit can be used to perform posture calculation on the calibration circle on the calibration plate in the first image and the second image based on the multi-point transmission transformation algorithm, respectively, to obtain a first posture of the calibration circle in the first image relative to the image sensor and a second posture of the calibration circle in the second image relative to the image sensor.

[0117] The second calculation unit can be used to calculate the difference between the first posture and the second posture, and determine the difference as the position and posture change of the calibration circle in the image sensor coordinate system.

[0118] The coordinate conversion unit can be used to convert the posture change in the image sensor coordinate system to the robotic arm coordinate system based on the conversion relationship between the image sensor coordinate system and the robotic arm coordinate system, so as to obtain the actual posture change of the end of the robotic arm.

[0119] In some embodiments of the present disclosure, the first computing unit can be specifically used to obtain the image sensor intrinsic parameters and distortion coefficients, the three-dimensional spatial coordinates of the calibration circle, the first pixel coordinates of the calibration circle in the first image, and the second pixel coordinates of the calibration circle in the second image; perform multi-point transmission transformation processing on the image sensor intrinsic parameters and distortion coefficients, the three-dimensional spatial coordinates of the calibration circle, and the first pixel coordinates to obtain a first posture; perform multi-point transmission transformation processing on the image sensor intrinsic parameters and distortion coefficients, the three-dimensional spatial coordinates of the calibration circle, and the second pixel coordinates to obtain a second posture.

[0120] In some embodiments of the present disclosure, the accuracy determination module 450 may be specifically used to determine whether accuracy verification or recalibration is required based on the size relationship between the difference value and a preset threshold.

[0121] In some embodiments of the present disclosure, the robotic arm accuracy calibration device 400 may further include an accuracy compensation module.

[0122] The accuracy compensation module can be used to determine whether accuracy verification or recalibration is required based on the size relationship between the difference and the preset threshold. When the difference is greater than the preset threshold, the robot arm is accuracy verified or recalibrated based on the difference.

[0123] It should be noted that Figure 4 The robotic arm accuracy calibration device 400 shown can execute each step in the above method embodiment and realize each process and effect in the above method embodiment, which will not be elaborated here.

[0124] Figure 5 A schematic structural diagram of an electronic device provided by an embodiment of the present disclosure is shown.

[0125] In the disclosed embodiment, Figure 5The electronic device shown can be a server or a terminal or a server cluster, wherein the terminal can specifically include a mobile phone, a computer or a tablet computer, a vehicle-mounted terminal, or any device that can be used for the robotic arm precision calibration method, etc., and is not limited here.

[0126] like Figure 5 As shown, the electronic device may include a processor 510 and a memory 520 storing computer program instructions.

[0127] Specifically, the processor 510 may include a central processing unit (CPU), or an application specific integrated circuit (ASIC), or may be configured to implement one or more integrated circuits of the embodiments of the present application.

[0128] The memory 520 may include a large capacity memory for information or instructions. By way of example and not limitation, the memory 520 may include a hard disk drive (HDD), a floppy disk drive, a flash memory, an optical disk, a magneto-optical disk, a tape, or a universal serial bus (USB) drive, or a combination of two or more of these. Where appropriate, the memory 520 may include a removable or non-removable (or fixed) medium. Where appropriate, the memory 520 may be inside or outside the integrated gateway device. In a particular embodiment, the memory 520 is a non-volatile solid-state memory. In a particular embodiment, the memory 520 includes a read-only memory (ROM). Where appropriate, the ROM may be a mask-programmed ROM, a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (Electrically Erasable Programmable ROM, EEPROM), an electrically rewritable ROM (EAROM), or a flash memory, or a combination of two or more of these.

[0129] The processor 510 reads and executes the computer program instructions stored in the memory 520 to perform the steps of the robot arm accuracy calibration method provided in the embodiment of the present disclosure.

[0130] In one example, the electronic device may further include a transceiver 530 and a bus 540. Figure 5 As shown, the processor 510, the memory 520 and the transceiver 530 are connected via a bus 540 and communicate with each other.

[0131] The bus 540 includes hardware, software, or both. For example, but not limitation, the bus may include an Accelerated Graphics Port (AGP) or other graphics bus, an Extended Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), a Hyper Transport (HT) interconnect, an Industrial Standard Architecture (ISA) bus, an InfiniBand interconnect, a Low Pin Count (LPC) bus, a Memory bus, a MicroChannel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local Bus (VLB) bus, or other suitable buses or a combination of two or more of these. Where appropriate, the bus 540 may include one or more buses.

[0132] The embodiments of the present disclosure also provide a computer-readable storage medium, which may store a computer program. When the computer program is executed by a processor, the processor implements the robot arm accuracy calibration method provided by the embodiments of the present disclosure.

[0133] The above-mentioned storage medium may, for example, include a memory 520 of computer program instructions, and the above-mentioned instructions may be executed by the processor 510 of the electronic device to complete the robot arm accuracy calibration method provided in the embodiment of the present disclosure. Optionally, the storage medium may be a non-temporary computer-readable storage medium, for example, the non-temporary computer-readable storage medium may be a ROM, a random access memory (Random Access Memory, RAM), a compact disc read-only memory (Compact Disc ROM, CD-ROM), a magnetic tape, a floppy disk, and an optical data storage device, etc.

[0134] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the term "comprising" is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0135] The above description is only a specific embodiment of the present disclosure, so that those skilled in the art can understand or implement the present disclosure. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to the embodiments described herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for calibrating the accuracy of a robotic arm, characterized in that: The method comprises: Acquire a first image of the starting position of the end of the robotic arm by using an image sensor, wherein a calibration plate is fixed on the end of the robotic arm, a plurality of calibration circles are fixed on the calibration plate, and the positional relationship between the image sensor and the base of the robotic arm is relatively fixed; Controlling the end of the robotic arm to move along a preset motion trajectory, and using the image sensor to obtain a second image of the end of the robotic arm at an end position of the motion trajectory; Obtaining an actual position change of the end of the robotic arm based on the position change of the calibration circle on the calibration plate in the first image and the second image; Determine the theoretical position change of the end of the robotic arm based on the position relationship between the TCP of the end of the robotic arm and the calibration plate; Whether accuracy verification or recalibration is required is determined based on the difference between the actual position and posture change and the theoretical position and posture change.

2. The method according to claim 1, characterized in that Before controlling the end of the robotic arm to move along a preset motion trajectory, the method further includes: Obtaining a preset motion trajectory of the end of the robotic arm; Wherein, obtaining the preset motion trajectory of the end of the robotic arm includes: Obtaining preset parameters, where the preset parameters are pre-set parameters for generating a motion trajectory; The preset motion trajectory is automatically generated based on the preset parameters.

3. The method according to claim 2, characterized in that The accuracy types of the robotic arm include absolute position accuracy, absolute posture accuracy and repeated positioning accuracy; the preset parameters corresponding to different accuracy types of the robotic arm are also different. When the accuracy type of the robotic arm is the absolute position accuracy, the preset parameters include the starting point coordinates and the end point coordinates of moving in any direction of the X-axis, Y-axis, and Z-axis of the robotic arm coordinate system; when the accuracy type of the robotic arm is the absolute posture accuracy, the preset parameters include the starting point angle and the end point angle of rotation along any axis of the X-axis, Y-axis, and Z-axis of the robotic arm coordinate system. When the accuracy type of the robotic arm is the repeated positioning accuracy, the preset parameters include the number of repetitions.

4. The method according to claim 1, characterized in that: The obtaining of the actual posture change of the end of the robotic arm based on the posture change of the calibration circle on the calibration plate in the first image and the second image includes: Based on a multi-point transmission transformation algorithm, posture calculation is performed on the calibration circle on the calibration plate in the first image and the second image respectively, so as to obtain a first posture of the calibration circle in the first image relative to the image sensor and a second posture of the calibration circle in the second image relative to the image sensor; Calculating a difference between the first posture and the second posture, and determining the difference as a change in the position and posture of the calibration circle in the image sensor coordinate system; Based on the conversion relationship between the image sensor coordinate system and the robotic arm coordinate system, the position and posture change in the image sensor coordinate system is converted to the robotic arm coordinate system to obtain the actual position and posture change of the robotic arm end.

5. The method according to claim 4, characterized in that The method of performing posture calculation on the calibration circle on the calibration plate in the first image and the second image based on the multi-point transmission transformation algorithm to obtain a first posture of the calibration circle in the first image relative to the image sensor and a second posture of the calibration circle in the second image relative to the image sensor includes: Acquire the image sensor internal parameters and distortion coefficients, the three-dimensional space coordinates of the calibration circle, the first pixel coordinates of the calibration circle in the first image, and the second pixel coordinates of the calibration circle in the second image; Performing multi-point transmission transformation processing on the image sensor internal parameters and distortion coefficients, the three-dimensional space coordinates of the calibration circle, and the first pixel coordinates to obtain the first posture; The second posture is obtained by performing multi-point transmission transformation processing on the image sensor internal parameters and distortion coefficients, the three-dimensional space coordinates of the calibration circle and the second pixel coordinates.

6. The method according to claim 1, characterized in that The determining whether accuracy verification or recalibration is required based on the difference between the actual posture change and the theoretical posture change includes: Whether accuracy verification or recalibration is required is determined based on the magnitude relationship between the difference and a preset threshold.

7. The method according to claim 1, characterized in that After determining whether accuracy verification or recalibration is required based on the magnitude relationship between the difference and the preset threshold, the method further includes: When the difference is greater than the preset threshold, the robotic arm is precision checked or recalibrated based on the difference.

8. A mechanical arm precision calibration device, characterized in that: include: A first acquisition module, used for acquiring a first image of a starting position of a robot arm end by using an image sensor, wherein a calibration plate is fixed on the robot arm end, a plurality of calibration circles are fixed on the calibration plate, and a positional relationship between the image sensor and a robot arm base is relatively fixed; A second acquisition module, used for controlling the end of the robotic arm to move along a preset motion trajectory, and using the image sensor to acquire a second image of the end of the robotic arm at an end position of the motion trajectory; An actual posture calculation module, used to obtain an actual posture change of the end of the robotic arm based on the posture change of the calibration circle on the calibration plate in the first image and the second image; Theoretical posture calculation module, used for determining the theoretical posture change of the end of the robotic arm based on the positional relationship between the TCP of the end of the robotic arm and the calibration plate; The accuracy determination module is used to determine whether accuracy verification or recalibration is required based on the difference between the actual posture change and the theoretical posture change.

9. An electronic device, characterized in that: include: Memory; processor; as well as Computer programs; The computer program is stored in the memory and is configured to be executed by the processor to implement the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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