CN111546330B - An automatic workpiece coordinate system calibration method - Google Patents

An automatic workpiece coordinate system calibration method Download PDF

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CN111546330B
CN111546330B CN202010295372.7A CN202010295372A CN111546330B CN 111546330 B CN111546330 B CN 111546330B CN 202010295372 A CN202010295372 A CN 202010295372A CN 111546330 B CN111546330 B CN 111546330B
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workpiece
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CN111546330A (en
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庄睿
朱力军
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Zhejiang Wahaha Intelligent Robot Co ltd
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
    • B25J9/00—Programme-controlled manipulators
    • B25J9/16—Programme controls
    • B25J9/1674—Programme controls characterised by safety, monitoring, diagnostic
    • B25J9/1676—Avoiding collision or forbidden zones
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
    • B25J13/00—Controls for manipulators
    • B25J13/08—Controls for manipulators by means of sensing devices, e.g. viewing or touching devices
    • B25J13/088—Controls for manipulators by means of sensing devices, e.g. viewing or touching devices with position, velocity or acceleration sensors
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
    • B25J9/00—Programme-controlled manipulators
    • B25J9/10—Programme-controlled manipulators characterised by positioning means for manipulator elements
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
    • B25J9/00—Programme-controlled manipulators
    • B25J9/16—Programme controls
    • B25J9/1679—Programme controls characterised by the tasks executed
    • B25J9/1692—Calibration of manipulator

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Abstract

本发明涉及机器人技术领域，具体涉及一种自动化工件坐标系标定方法，包括以下步骤：1）在工装上制作标定部，在基坐标系内固定位移传感器；2）使标定部多次接触位移传感器，记录每个接触点的接触数据；3）根据接触数据确定接触点在法兰坐标系下的坐标值；4）获得标定部中的点标定部在法兰坐标系下的坐标值以及方向标定部在法兰坐标系下的法线向量，计算获得法兰坐标到工件坐标系的旋转矩阵；5）获得法兰坐标到工件坐标系的平移矩阵，完成工件坐标系的标定。本发明的实质性效果是：采样点更方便，提高了整套标定装置的使用寿命，大幅提高标定效率；该标定方法可方便在不同结构的产品上进行复用。

Figure 202010295372

The invention relates to the technical field of robotics, in particular to an automated workpiece coordinate system calibration method, comprising the following steps: 1) making a calibration part on a tool, and fixing a displacement sensor in a base coordinate system; 2) making the calibration part contact the displacement sensor for many times , record the contact data of each contact point; 3) Determine the coordinate value of the contact point in the flange coordinate system according to the contact data; 4) Obtain the coordinate value and direction calibration of the point calibration part in the calibration part under the flange coordinate system Calculate and obtain the rotation matrix from flange coordinates to workpiece coordinate system; 5) Obtain the translation matrix from flange coordinates to workpiece coordinate system, and complete the calibration of workpiece coordinate system. The substantial effect of the invention is that the sampling point is more convenient, the service life of the whole set of calibration devices is improved, and the calibration efficiency is greatly improved; the calibration method can be easily reused on products of different structures.

Figure 202010295372

Description

一种自动化工件坐标系标定方法An automatic workpiece coordinate system calibration method

技术领域technical field

本发明涉及机器人技术领域，具体涉及一种自动化工件坐标系标定方法。The invention relates to the technical field of robots, in particular to an automatic workpiece coordinate system calibration method.

背景技术Background technique

将机器人技术应用到自动化加工时，需要解决机器人所夹持工件的坐标标定问题。比如在磨抛机器人系统中，机器人末端夹持工件，操作工件靠近砂带机来进行工件打磨。由于装夹等误差，实际生产环境中需要通过标定来明确工件坐标系到机器人法兰坐标系的转换关系。现有的坐标标定方法之一是特征点法，首先在仿真环境下建立工件坐标系，在工件CAD模型上选择多个特征点，获取特征点在工件坐标系下的坐标值；在工件被机器人夹持后，依次找到对应点在机器人法兰坐标系下的坐标；找到两个点集间的坐标系变换关系，即完成工件坐标系的标定。另一种标定方案是模型点云匹配法，通过线激光对工件表面进行扫描，得到工件在机器人末端坐标系的点云数据；将工件CAD模型离散成点云；通过迭代近邻点法(ICP)匹配扫描点云与模型点云，得到两者坐标系关系，完成标定。但以上两种方法存在以下不足：特征点法需通过示教器手动对点，人为误差大，每次装夹需要重复操作，可复用性低。对特征点位选取有要求，比如需要是点等在实际工件中易定位的点。且由于点通常为尖端，操作过程易造成工件和辅助工具的损坏。另外特征点法需要明确的对应关系，专利CN 101097131A中采用ICP近邻查找方式，对点位构成及质量有要求，否则在采集点位对应关系不明的情况下易出现计算结果稳定性差的问题，影响整体标定结果的可靠性。模型点云匹配法精度高，但线激光扫描仪成本较高。When applying robot technology to automatic processing, it is necessary to solve the problem of coordinate calibration of the workpiece held by the robot. For example, in the grinding and polishing robot system, the end of the robot clamps the workpiece and operates the workpiece close to the belt sander to grind the workpiece. Due to errors such as clamping, calibration is required to clarify the conversion relationship between the workpiece coordinate system and the robot flange coordinate system in the actual production environment. One of the existing coordinate calibration methods is the feature point method. First, a workpiece coordinate system is established in the simulation environment, multiple feature points are selected on the workpiece CAD model, and the coordinate values of the feature points in the workpiece coordinate system are obtained; After clamping, find the coordinates of the corresponding points in the robot flange coordinate system in turn; find the coordinate system transformation relationship between the two point sets, that is, complete the calibration of the workpiece coordinate system. Another calibration scheme is the model point cloud matching method. The surface of the workpiece is scanned by a line laser to obtain the point cloud data of the workpiece in the coordinate system of the robot end; Match the scanned point cloud and the model point cloud to obtain the relationship between the two coordinate systems, and complete the calibration. However, the above two methods have the following shortcomings: the feature point method needs to be manually aligned through the teach pendant, the human error is large, and each clamping needs to be repeated, and the reusability is low. There are requirements for the selection of feature points, such as points that are easy to locate in the actual workpiece. And since the point is usually a sharp point, the operation process is easy to cause damage to the workpiece and auxiliary tools. In addition, the feature point method needs a clear corresponding relationship. The patent CN 101097131A adopts the ICP nearest neighbor search method, which has requirements on the composition and quality of the points. Otherwise, the problem of poor stability of the calculation results will easily occur when the corresponding relationship between the collection points is unclear. The reliability of the overall calibration results. The model point cloud matching method has high accuracy, but the cost of line laser scanner is high.

发明内容SUMMARY OF THE INVENTION

本发明要解决的技术问题是：目前工件坐标系标定方法精度低或成本高的技术问题。提出了一种以较低成本显著提升工件标定准确度的自动化工件坐标系标定方法。本方法摆脱了坐标系标定对工件构造上的依赖，对于需频繁更换工件的情行，本标定方法可以方便的进行复用。The technical problem to be solved by the present invention is the technical problem of low precision or high cost of the current workpiece coordinate system calibration method. An automatic workpiece coordinate system calibration method is proposed, which can significantly improve the accuracy of workpiece calibration at a lower cost. The method gets rid of the dependence of the coordinate system calibration on the structure of the workpiece, and can be easily reused in the case of frequent replacement of the workpiece.

为解决上述技术问题，本发明所采取的技术方案为：一种自动化工件坐标系标定方法，用于机器手夹持工件的坐标系标定，包括以下步骤：1)在工装上制作标定部，在机器手的基坐标系内固定安装位移传感器，所述标定部包括点标定部和方向标定部；2)使移动机器手使工装上的点标定部以及方向标定部分别多次接触位移传感器，记录每个接触点pi.i∈[1,m]的坐标值由基坐标系转换到机器手的法兰坐标系的齐次转换关系

Figure GDA0003130819600000021
以及位移传感器读数Δzi，其中，m为点标定部以及方向标定部与位移传感器的接触次数和，
Figure GDA0003130819600000022
为接触点pi.i∈[1,m]的坐标值由基坐标系转换到法兰坐标系的3×3旋转矩阵，
Figure GDA0003130819600000023
为接触点pi.i∈[1,m]的坐标值由基坐标系到法兰坐标系的3×1平移矩阵；3)根据齐次转换关系
Figure GDA0003130819600000024
以及位移传感器读数Δzi确定点标定部在法兰坐标系下的坐标值FP以及方向标定部在法兰坐标系下的法线向量FV；4)工装以及工件尺寸以及夹持关系已知，由此获得点标定部在工件坐标系下的坐标值WP以及方向标定部在工件坐标系下的法线向量WV，使用FV以及WV由罗德里格斯公式计算获得法兰坐标到工件坐标系的旋转矩阵FRW；5)由FP、WP以及旋转矩阵FRW获得法兰坐标到工件坐标系的平移矩阵FPW，FPW＝FP-FRW WP，由此完成工件坐标系的标定。机器手使标定部靠近位移传感器后沿位移传感器的运动向量的反方向运动，由于采样点并不直接在工件上，需保证工装夹具每次夹取工件时的一致性。每个接触点pi.i∈[1,m]的坐标值由基坐标系转换到机器手的法兰坐标系的齐次转换关系
Figure GDA0003130819600000025
由实现接触时的机器手的移动过程决定，记录机器手的移动过程即可获得接触点pi.i∈[1,m]的坐标值由基坐标系转换到机器手的法兰坐标系的齐次转换关系
Figure GDA0003130819600000026
方便快捷，能够快速计算获得工件坐标系的标定结果，提高工作效率。采用位移传感器结合机器手使标定部靠近位移传感器后沿位移传感器的运动向量的反方向运动的技术方案，能够提高接触点位置的准确度，避免接触时的撞击或压力导致接触点位置产生应变，导致接触点位置准确度下降，甚至造成元件损坏。In order to solve the above-mentioned technical problems, the technical solution adopted by the present invention is: an automatic workpiece coordinate system calibration method, which is used for the coordinate system calibration of the workpiece clamped by the robot, including the following steps: 1) making a calibration part on the tooling, A displacement sensor is fixedly installed in the base coordinate system of the robot hand, and the calibration part includes a point calibration part and a direction calibration part; 2) Make the mobile robot hand make the point calibration part and the direction calibration part on the tool contact the displacement sensor for many times, respectively, and record The homogeneous transformation relation of the coordinate value of each contact point p ii∈[1,m] is transformed from the base coordinate system to the flange coordinate system of the robot
Figure GDA0003130819600000021
and the displacement sensor reading Δzi , where m is the sum of the contact times between the point calibration part and the direction calibration part and the displacement sensor,
Figure GDA0003130819600000022
is a 3 × 3 rotation matrix that transforms the coordinate value of the contact point p ii∈[1,m] from the base coordinate system to the flange coordinate system,
Figure GDA0003130819600000023
is a 3×1 translation matrix from the base coordinate system to the flange coordinate system for the coordinate value of the contact point p ii∈[1,m] ; 3) According to the homogeneous transformation relationship
Figure GDA0003130819600000024
And the displacement sensor reading Δzi determines the coordinate value F P of the point calibration part under the flange coordinate system and the normal vector F V of the direction calibration part under the flange coordinate system; 4) The dimensions of the tooling and workpiece and the clamping relationship are known , thus obtain the coordinate value W P of the point calibration part under the workpiece coordinate system and the normal vector W V of the direction calibration part under the workpiece coordinate system, and use F V and W V to calculate the flange coordinates by the Rodrigues formula To the rotation matrix F R W of the workpiece coordinate system; 5) Obtain the translation matrix F P W from the flange coordinates to the workpiece coordinate system from F P, W P and the rotation matrix F R W , F P W = F P - F R W WP , thus completing the calibration of the workpiece coordinate system. The robot moves in the opposite direction of the motion vector of the displacement sensor after bringing the calibration part close to the displacement sensor. Since the sampling point is not directly on the workpiece, it is necessary to ensure the consistency of the fixture every time the workpiece is clamped. The homogeneous transformation relation of the coordinate value of each contact point p ii∈[1,m] is transformed from the base coordinate system to the flange coordinate system of the robot
Figure GDA0003130819600000025
It is determined by the movement process of the robot hand when the contact is realized, and the coordinate value of the contact point p ii∈[1,m] can be obtained by recording the movement process of the robot hand. conversion relationship
Figure GDA0003130819600000026
It is convenient and quick, can quickly calculate and obtain the calibration result of the workpiece coordinate system, and improve work efficiency. Using a displacement sensor combined with a robot hand to move the calibration part close to the displacement sensor in the opposite direction of the motion vector of the displacement sensor can improve the accuracy of the position of the contact point and avoid the impact or pressure during contact resulting in strain at the position of the contact point. This leads to a decrease in the accuracy of the contact point position and even damage to the components.

作为优选，所述点标定部为固定在工装上的标准球，步骤2)中，移动机器手使工装上的标准球多次接触位移传感器，步骤3)中，由计算式：Preferably, the point calibration part is a standard ball fixed on the tooling. In step 2), the robot hand is moved to make the standard ball on the tooling contact the displacement sensor for many times. In step 3), the calculation formula is:

Figure GDA0003130819600000027
Figure GDA0003130819600000027

代入计算式：Substitute into the formula:

(FPi-FPS)T(FPi-FPS)＝R2，i∈(1,n)( F P i - F P S ) T ( F P i - F P S )=R 2 , i∈(1,n)

得计算式：get the formula:

Figure GDA0003130819600000031
Figure GDA0003130819600000031

采用非线性最小二乘优化算法，获得位移传感器末端在基坐标系下的坐标BPΔ，位移传感器末端在基坐标系下的运动向量BV，以及标准球球心在法兰坐标系下的坐标FPS，进而获得每次的接触点i在法兰坐标系下的坐标值FPi,i∈[1,n]，其中R为标准球的半径，n为标准球接触位移传感器的次数，步骤4)中，标准球球心在工装上的位置为已知，即标准球球心在工件坐标系下的坐标已知，进而获得法兰坐标系到工件坐标系的平移矩阵FPW。标准球多次接触位移传感器即可求解获得标准球的球心位置，接触次数不少于待求解变量个数即可。且现有技术中球面加工技术能够实现的精度非常高，相对于直接接触一个点，采用接触球面求解球心的方式，能够提高点定位的准确度，进而提升工件坐标系标定的准确度。The nonlinear least squares optimization algorithm is used to obtain the coordinates B P Δ of the end of the displacement sensor in the base coordinate system, the motion vector B V of the end of the displacement sensor in the base coordinate system, and the center of the standard sphere in the flange coordinate system. Coordinate F P S , and then obtain the coordinate value F P i,i∈[1,n] of each contact point i in the flange coordinate system, where R is the radius of the standard ball, and n is the contact point of the standard ball. times, in step 4), the position of the center of the standard sphere on the tooling is known, that is, the coordinates of the center of the standard sphere in the workpiece coordinate system are known, and then the translation matrix F P from the flange coordinate system to the workpiece coordinate system is obtained W. The position of the center of the standard sphere can be obtained by contacting the displacement sensor for many times, and the number of contact times is not less than the number of variables to be solved. In addition, the spherical surface processing technology in the prior art can achieve very high precision. Compared with directly contacting a point, the method of finding the center of the sphere by contacting the spherical surface can improve the accuracy of point positioning, thereby improving the accuracy of workpiece coordinate system calibration.

作为优选，步骤2)中，移动机器手使工装上的标准球多次接触位移传感器，根据接触计算标准球的球心在法兰坐标系下的坐标FPS，并多次计算获得的标准球的球心在法兰坐标系下的坐标FPS，取均值作为标准球的球心在法兰坐标系下的坐标FPS。多次求解取均值能够提高球心位置坐标值的准确度。Preferably, in step 2), move the robot hand to make the standard ball on the tool contact the displacement sensor for many times, calculate the coordinates F P S of the center of the standard ball in the flange coordinate system according to the contact, and calculate the obtained standard multiple times. The coordinate F P S of the center of the sphere in the flange coordinate system, and the average value is taken as the coordinate F P S of the center of the standard sphere in the flange coordinate system. Multiple solutions to take the mean value can improve the accuracy of the coordinate value of the sphere center position.

作为优选，所述方向标定部为固定在工装上的另外两个标准球与点标定部一起构成的三个标准球，在步骤2)中，移动机器手使工装上的三个标准球均分别多次接触位移传感器，步骤3)中，由计算式：Preferably, the direction calibration part is three standard spheres formed by the other two standard spheres fixed on the tool and the point calibration part. In step 2), the robot hand is moved so that the three standard spheres on the tool are respectively Contact the displacement sensor multiple times, in step 3), by the calculation formula:

Figure GDA0003130819600000032
Figure GDA0003130819600000032

以及计算式：and the calculation formula:

Figure GDA0003130819600000033
Figure GDA0003130819600000033

采用非线性最小二乘优化算法，计算出获得标准球i,i∈[1,3]每次的接触点在法兰坐标系下的坐标值FPij,i∈[1,3],j∈[1,n]、标准球i的球心在法兰坐标系下的坐标

Figure GDA0003130819600000034
位移传感器末端在基坐标系下的坐标BPΔ以及位移传感器末端在基坐标系下的运动向量的单位向量BV，其中，n为每个标准球的接触次数，R为标准球的半径，步骤4)中，三个标准球球心在工装上的位置为已知，即标准球球心在工件坐标系下的坐标已知，进而获得法兰坐标系到工件坐标系的平移矩阵FPW，由计算式：Using nonlinear least squares optimization algorithm, calculate the coordinate value F P ij,i∈[1,3],j of each contact point of standard sphere i,i∈[1,3] in the flange coordinate system ∈[1,n] , the coordinates of the center of the standard sphere i in the flange coordinate system
Figure GDA0003130819600000034
The coordinate B P Δ of the end of the displacement sensor in the base coordinate system and the unit vector B V of the motion vector of the end of the displacement sensor in the base coordinate system, where n is the number of contacts of each standard sphere, R is the radius of the standard sphere, In step 4), the positions of the three standard ball centers on the tooling are known, that is, the coordinates of the standard ball centers under the workpiece coordinate system are known, and then the translation matrix F P from the flange coordinate system to the workpiece coordinate system is obtained. W , calculated by:

Figure GDA0003130819600000041
Figure GDA0003130819600000041

获得标准平板在法兰坐标系下的法线向量FV。三个点能够确定一个平面，进而确定一个法线向量。优选的，增加更多的接触次数，求出最终结果取均值。能提高标定准确度。相对于平板，三个标准球的加工精度更容易保证，标定结果精度也会提高，但会导致接触次数增加，略降低效率。每个标准球的接触次数n不小于待求解变量个数，即可完成上述计算式的求解，多次接触计算最终值并取均值，可提高结果准确性。Obtain the normal vector F V of the standard plate in the flange coordinate system. Three points can define a plane, which in turn defines a normal vector. Preferably, more contact times are added, and the final result is averaged. It can improve the calibration accuracy. Compared with the flat plate, the machining accuracy of the three standard balls is easier to ensure, and the accuracy of the calibration results will also be improved, but it will lead to an increase in the number of contacts and a slight decrease in efficiency. The number of contacts n of each standard ball is not less than the number of variables to be solved, and the solution of the above calculation formula can be completed. The final value of multiple contacts is calculated and the average value is taken, which can improve the accuracy of the result.

作为优选，所述方向标定部为固定在工装上的标准平板，在步骤2)中，移动机器手使工装上的标准平板三次接触位移传感器，步骤3)中，由计算式：Preferably, the direction calibration part is a standard plate fixed on the tooling, in step 2), move the robot hand to make the standard plate on the tooling contact the displacement sensor three times, in step 3), by the calculation formula:

Figure GDA0003130819600000042
Figure GDA0003130819600000042

获得每次的接触点在法兰坐标系下的坐标值FPi,i∈[1,3]，其中，BPΔ为位移传感器末端在基坐标系下的坐标，BV为位移传感器末端在基坐标系下的运动向量的单位向量，由计算式：Obtain the coordinate value F P i,i∈[1,3] of each contact point in the flange coordinate system, where B P Δ is the coordinate of the end of the displacement sensor in the base coordinate system, and B V is the end of the displacement sensor The unit vector of the motion vector in the base coordinate system is calculated by:

FV＝(FP2-FP1)×(FP3-FP2) F V = ( F P 2 - F P 1 )×( F P 3 - F P 2 )

获得标准平板在法兰坐标系下的法线向量FV。标准平板三次接触位移传感器就可以确定平面的法向量，进而实现旋转矩阵的计算，标定过程简洁快速。Obtain the normal vector F V of the standard plate in the flange coordinate system. The standard flat plate three-contact displacement sensor can determine the normal vector of the plane, and then realize the calculation of the rotation matrix, and the calibration process is simple and fast.

作为优选，在步骤2)中，移动机器手使工装上的标准平板多次接触位移传感器，记录每个接触点pi.i∈[1,k]的坐标值由基坐标系转换到机器手的法兰坐标系的齐次转换关系

Figure GDA0003130819600000043
以及位移传感器读数Δzi，k为标准平板接触位移传感器的次数，步骤3)中，由计算式：Preferably, in step 2), move the robot hand to make the standard plate on the tool contact the displacement sensor for many times, record the coordinate value of each contact point p ii∈[1,k] from the base coordinate system to the method of transforming the robot hand Homogeneous transformation relation of blue coordinate system
Figure GDA0003130819600000043
And the displacement sensor reading Δzi , k is the number of times the standard plate contacts the displacement sensor, in step 3), by the calculation formula:

Figure GDA0003130819600000044
Figure GDA0003130819600000044

获得每次的接触点在法兰坐标系下的坐标值FPi,i∈[1,k]，根据多个接触点均在法兰坐标系下的同一平面上的约束条件,由平面的截距式方程FV·FPi＝1获得计算式：Obtain the coordinate value F P i,i∈[1,k] of each contact point in the flange coordinate system. According to the constraint that multiple contact points are on the same plane in the flange coordinate system, the The intercept formula F V · F P i =1 obtains the calculation formula:

Figure GDA0003130819600000045
Figure GDA0003130819600000045

非线性最小二乘优化算法，获得标准平板在法兰坐标系下的法线向量FV。增加更多的接触次数，求出最终结果取均值，能够提高标准平板的法线向量的标定准确度，但会略降低标定的效率。The nonlinear least squares optimization algorithm is used to obtain the normal vector F V of the standard plate in the flange coordinate system. Adding more contact times and obtaining the average of the final results can improve the calibration accuracy of the normal vector of the standard plate, but it will slightly reduce the calibration efficiency.

作为优选，步骤2)中，示教时，使位移传感器末端的运动向量基本沿着工装的接触点处标定部表面的法线方向。能够降低标定部造成的位移传感器微小形变，提高位移传感器使用寿命并提高标定的精度。Preferably, in step 2), during teaching, the motion vector of the end of the displacement sensor is basically along the normal direction of the surface of the calibration part at the contact point of the tool. The micro deformation of the displacement sensor caused by the calibration part can be reduced, the service life of the displacement sensor can be improved, and the calibration accuracy can be improved.

作为优选，步骤1)中，所使用的位移传感器末端硬度低于工装硬度。位移传感器的末端更容易更换，工装的加工和更换成本更高，能够提高工装使用寿命，节省成本。Preferably, in step 1), the hardness of the end of the displacement sensor used is lower than the hardness of the tool. The end of the displacement sensor is easier to replace, and the processing and replacement costs of the tooling are higher, which can improve the service life of the tooling and save costs.

本发明的实质性效果是：1)采用可伸缩的位移传感器结合专用的标定部，采样点不需要像特征点法一样采用工件上易定位的尖锐角点，避免了操作过程中对工件及辅助装置的损坏，提高了整套标定装置的使用寿命；2)本发明只需要将采样点示教一次，通过程序记录下所有点位，后续通过程序控制机械臂自动运行，自动采集数据，计算完成后自动反馈标定结果，大幅提高标定效率；3)采样点不在工件上，取消了标定对工件构造的依赖，对于需频繁更换磨抛产品的情行，该标定方法可方便在不同结构的产品上进行复用。The substantive effects of the present invention are: 1) Adopting a retractable displacement sensor combined with a dedicated calibration part, the sampling point does not need to use sharp corner points on the workpiece that are easy to locate like the feature point method, which avoids the workpiece and auxiliary during the operation process. The damage of the device increases the service life of the whole set of calibration devices; 2) The present invention only needs to teach the sampling points once, record all the points through the program, and then control the automatic operation of the robotic arm through the program, and automatically collect data, after the calculation is completed Automatic feedback of the calibration results, greatly improving the calibration efficiency; 3) The sampling point is not on the workpiece, which cancels the dependence of the calibration on the structure of the workpiece. For the situation where the grinding and polishing products need to be replaced frequently, this calibration method can be easily carried out on products of different structures. reuse.

附图说明Description of drawings

图1为实施例一工件坐标系标定方法流程框图。FIG. 1 is a flow chart of a method for calibrating a workpiece coordinate system according to an embodiment.

图2为实施例一工件坐标系标定结构示意图。FIG. 2 is a schematic diagram of the calibration structure of the workpiece coordinate system according to the first embodiment.

其中：100、法兰，200、工装，300、工件，401、标准球，402、标准平板，501、直线位移机构，502、位移传感器，600、砂带机。Among them: 100, flange, 200, tooling, 300, workpiece, 401, standard ball, 402, standard plate, 501, linear displacement mechanism, 502, displacement sensor, 600, belt grinder.

具体实施方式Detailed ways

下面通过具体实施例，并结合附图，对本发明的具体实施方式作进一步具体说明。The specific embodiments of the present invention will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings.

实施例一：Example 1:

一种自动化工件坐标系标定方法，用于机器手夹持工件300的坐标系标定，如图1所示，包括以下步骤：An automatic workpiece coordinate system calibration method, which is used for the coordinate system calibration of the workpiece 300 clamped by a robot hand, as shown in FIG. 1 , includes the following steps:

1)在工装200上制作标定部，在机器手的基坐标系内固定安装位移传感器502，标定部包括点标定部和方向标定部。法兰100安装在机器手上，工装200由法兰100夹持，工件300固定安装在工装200上，砂带机600以及位移传感器502均位于机器手工作范围内。点标定部为固定在工装200上的标准球401，方向标定部为固定在工装200上的标准平板402，如图2所示。所使用的位移传感器502末端硬度低于工装200硬度。1) A calibration part is made on the tooling 200, and the displacement sensor 502 is fixedly installed in the base coordinate system of the robot hand. The calibration part includes a point calibration part and a direction calibration part. The flange 100 is installed on the robot, the tooling 200 is clamped by the flange 100, the workpiece 300 is fixedly installed on the tooling 200, and the belt sander 600 and the displacement sensor 502 are located within the working range of the robot. The point calibration part is a standard ball 401 fixed on the tooling 200 , and the direction calibration part is a standard flat plate 402 fixed on the tooling 200 , as shown in FIG. 2 . The end hardness of the displacement sensor 502 used is lower than the 200 hardness of the tool.

2)移动机器手使工装200上的标准球401以及标准平板402分别多次接触位移传感器502，位移传感器502末端的运动向量基本沿着工装200的接触点处标定部表面的法线方向，记录每个接触点pi.i∈[1,m]的坐标值由基坐标系转换到机器手的法兰坐标系的齐次转换关系

Figure GDA0003130819600000061
以及位移传感器502读数Δzi，其中，m为点标定部以及方向标定部与位移传感器502的接触次数和，
Figure GDA0003130819600000062
为接触点pi的坐标值由基坐标系转换到法兰坐标系的3×3旋转矩阵，
Figure GDA0003130819600000063
为接触点pi的坐标值由基坐标系到法兰坐标系的3×1平移矩阵。2) Move the robot hand to make the standard ball 401 and the standard plate 402 on the tooling 200 contact the displacement sensor 502 multiple times, respectively. The motion vector at the end of the displacement sensor 502 is basically along the normal direction of the surface of the calibration part at the contact point of the tooling 200, and record The homogeneous transformation relation of the coordinate value of each contact point p ii∈[1,m] is transformed from the base coordinate system to the flange coordinate system of the robot
Figure GDA0003130819600000061
and the displacement sensor 502 reading Δz i , where m is the sum of the contact times between the point calibration part and the direction calibration part and the displacement sensor 502,
Figure GDA0003130819600000062
is a 3×3 rotation matrix for the coordinate value of the contact point p i to be transformed from the base coordinate system to the flange coordinate system,
Figure GDA0003130819600000063
The coordinate value of the contact point pi is a 3×1 translation matrix from the base coordinate system to the flange coordinate system.

3)由计算式：3) By the calculation formula:

Figure GDA0003130819600000064
Figure GDA0003130819600000064

代入计算式：Substitute into the formula:

(FPi-FPS)T(FPi-FPS)＝R2，i∈(1,n)( F P i - F P S ) T ( F P i - F P S )=R 2 , i∈(1,n)

得计算式：get the formula:

Figure GDA0003130819600000065
Figure GDA0003130819600000065

获得位移传感器502末端在基坐标系下的坐标BPΔ，位移传感器502末端在基坐标系下的运动向量BV，以及标准球401球心在法兰坐标系下的坐标FPS，进而获得每次的接触点i在法兰坐标系下的坐标值FPi,i∈[1,n]，其中R为标准球401的半径，n为标准球401接触位移传感器502的次数；Obtain the coordinate B P Δ of the end of the displacement sensor 502 in the base coordinate system, the motion vector B V of the end of the displacement sensor 502 in the base coordinate system, and the coordinate F P S of the center of the standard sphere 401 in the flange coordinate system, and then Obtain the coordinate value F P i,i∈[1,n] of each contact point i in the flange coordinate system, where R is the radius of the standard sphere 401, and n is the number of times the standard sphere 401 contacts the displacement sensor 502;

由计算式：By the calculation formula:

FV＝(FP2-FP1)×(FP3-FP2) F V = ( F P 2 - F P 1 )×( F P 3 - F P 2 )

获得标准平板402在法兰坐标系下的法线向量FV。The normal vector F V of the standard plate 402 in the flange coordinate system is obtained.

4)工装200以及工件300尺寸以及夹持关系已知，由此获得点标定部在工件坐标系下的坐标值WP以及方向标定部在工件坐标系下的法线向量WV，使用FV以及WV由罗德里格斯公式计算获得法兰坐标到工件坐标系的旋转矩阵FRW。4) The dimensions of the tooling 200 and the workpiece 300 and the clamping relationship are known, thereby obtaining the coordinate value W P of the point calibration part under the workpiece coordinate system and the normal vector W V of the direction calibration part under the workpiece coordinate system, using F V And W V is calculated by Rodriguez formula to obtain the rotation matrix F R W of the flange coordinate to the workpiece coordinate system.

5)由FP、WP以及旋转矩阵FRW获得法兰坐标到工件坐标系的平移矩阵FPW，FPW＝FP-FRW WP，由此完成工件坐标系的标定。机器手使标定部靠近位移传感器502后沿位移传感器502的运动向量的反方向运动，由于采样点并不直接在工件300上，需保证工装200夹具每次夹取工件300时的一致性。每个接触点pi.i∈[1,m]的坐标值由基坐标系转换到机器手的法兰坐标系的齐次转换关系

Figure GDA0003130819600000071
由实现接触时的机器手的移动过程决定，记录机器手的移动过程即可获得接触点pi.i∈[1,m]的坐标值由基坐标系转换到机器手的法兰坐标系的齐次转换关系
Figure GDA0003130819600000072
方便快捷，能够快速计算获得工件坐标系的标定结果，提高工作效率。采用位移传感器502结合机器手使标定部靠近位移传感器502后沿位移传感器502的运动向量的反方向运动的技术方案，能够提高接触点位置的准确度，避免接触时的撞击或压力导致接触点位置产生应变，导致接触点位置准确度下降，甚至造成元件损坏。5) Obtain the translation matrix F P W from the flange coordinates to the workpiece coordinate system from F P, W P and the rotation matrix F R W , F P W = F P- F R W W P, thus completing the calibration of the workpiece coordinate system . The robot moves the calibration part close to the displacement sensor 502 in the opposite direction of the motion vector of the displacement sensor 502. Since the sampling point is not directly on the workpiece 300, it is necessary to ensure the consistency of the fixture 200 each time the workpiece 300 is clamped. The homogeneous transformation relation of the coordinate value of each contact point p ii∈[1,m] is transformed from the base coordinate system to the flange coordinate system of the robot
Figure GDA0003130819600000071
It is determined by the movement process of the robot hand when the contact is realized, and the coordinate value of the contact point p ii∈[1,m] can be obtained by recording the movement process of the robot hand. conversion relationship
Figure GDA0003130819600000072
It is convenient and quick, can quickly calculate and obtain the calibration result of the workpiece coordinate system, and improve work efficiency. Using the displacement sensor 502 combined with the robot hand to make the calibration part move in the opposite direction of the motion vector of the displacement sensor 502 after moving in the opposite direction of the displacement sensor 502 can improve the accuracy of the position of the contact point and avoid the impact or pressure during the contact causing the position of the contact point Strain is created, resulting in a loss of accuracy in the location of the contact points, and even damage to components.

本实施例具有以下改进实施方式：在步骤2)中，移动机器手使工装200上的标准球401接触位移传感器502的次数超过四次，任取其中的四次接触计算标准球401的球心在法兰坐标系下的坐标FPS，并多次计算获得的标准球401的球心在法兰坐标系下的坐标FPS，取均值作为标准球401的球心在法兰坐标系下的坐标FPS。多次求解取均值能够提高球心位置坐标值的准确度。This embodiment has the following improved implementation: in step 2), move the robot hand so that the standard ball 401 on the tooling 200 contacts the displacement sensor 502 more than four times, and any of the four contacts is taken to calculate the center of the standard ball 401 Coordinate F P S in the flange coordinate system, and calculate the coordinates F P S of the center of the standard sphere 401 in the flange coordinate system, and take the average value as the center of the standard sphere 401 in the flange coordinate system The coordinates below FPS . Multiple solutions to take the mean value can improve the accuracy of the coordinate value of the sphere center position.

在步骤2)中，移动机器手使工装200上的标准平板402多次接触位移传感器502，记录每个接触点pi.i∈[1,k]的坐标值由基坐标系转换到机器手的法兰坐标系的齐次转换关系

Figure GDA0003130819600000073
以及位移传感器502读数Δzi，k为标准平板402接触位移传感器502的次数，步骤3)中，由计算式：In step 2), move the robot hand to make the standard plate 402 on the tooling 200 contact the displacement sensor 502 for many times, and record the coordinate value of each contact point p ii∈[1,k] from the base coordinate system to the method of transforming the robot hand Homogeneous transformation relation of blue coordinate system
Figure GDA0003130819600000073
And the displacement sensor 502 reads Δzi , k is the number of times the standard plate 402 contacts the displacement sensor 502, in step 3), by the calculation formula:

Figure GDA0003130819600000074
Figure GDA0003130819600000074

获得每次的接触点在法兰坐标系下的坐标值FPi,i∈[1,k]，根据多个接触点均在法兰坐标系下的同一平面上的约束条件,由平面的截距式方程FV·FPi＝1获得计算式：Obtain the coordinate value F P i,i∈[1,k] of each contact point in the flange coordinate system. According to the constraint that multiple contact points are on the same plane in the flange coordinate system, the The intercept formula F V · F P i =1 obtains the calculation formula:

Figure GDA0003130819600000075
Figure GDA0003130819600000075

非线性最小二乘优化算法，获得标准平板402在法兰坐标系下的法线向量FV。能够提高标准平板402的法线向量的标定准确度，但会略降低标定的效率。The nonlinear least squares optimization algorithm is used to obtain the normal vector F V of the standard plate 402 in the flange coordinate system. The calibration accuracy of the normal vector of the standard plate 402 can be improved, but the calibration efficiency will be slightly reduced.

移动机器手使工装200上的标定部接触位移传感器502的方法包括：21)将位移传感器502安装在直线位移机构501上，使位移传感器502具有直线位移行程，所述直线位移机构501的位移可检测，直线位移机构501带动位移传感器502移动到行程起点，所述行程起点在基坐标系下的坐标已知；22)移动机器手使工装200上的标定部位于所述直线位移行程范围内，该位置通过示教确定；23)直线位移机构501带动位移传感器502从行程起点移动预设的距离，该预设距离使得位移传感器502末端触碰到工装200上的标定部，并产生位移传感器502读数Δzi。该方法能够避免机器手使工装200撞击到位移传感器502，导致位移传感器502的损坏。直线位移机构501可以使用电动推杆、液压机构、气动缸或者伺服电缸。The method of moving the robot hand to make the calibration part on the tooling 200 contact the displacement sensor 502 includes: 21) Installing the displacement sensor 502 on the linear displacement mechanism 501, so that the displacement sensor 502 has a linear displacement stroke, and the displacement of the linear displacement mechanism 501 can be adjusted. Detection, the linear displacement mechanism 501 drives the displacement sensor 502 to move to the starting point of the stroke, and the coordinates of the starting point of the stroke in the base coordinate system are known; 22) Move the robot so that the calibration part on the tooling 200 is located within the range of the linear displacement stroke, The position is determined by teaching; 23) The linear displacement mechanism 501 drives the displacement sensor 502 to move a preset distance from the starting point of the stroke, and the preset distance makes the end of the displacement sensor 502 touch the calibration part on the tooling 200, and the displacement sensor 502 is generated. Reading Δz i . This method can prevent the robot hand from striking the tool 200 against the displacement sensor 502 , resulting in damage to the displacement sensor 502 . The linear displacement mechanism 501 can use an electric push rod, a hydraulic mechanism, a pneumatic cylinder or a servo electric cylinder.

实施例二：Embodiment 2:

一种自动化工件坐标系标定方法，本实施例采用了与实施例一不同的方向标定部，本实施例中方向标定部为固定在工装200上的另外两个标准球401与点标定部一起构成的三个标准球401，在步骤2)中，移动机器手使工装200上的三个标准球401均分别多次接触位移传感器502，步骤3)中，由计算式：An automatic workpiece coordinate system calibration method. This embodiment adopts a direction calibration part different from that of the first embodiment. In this embodiment, the direction calibration part is composed of two other standard balls 401 fixed on the tooling 200 together with the point calibration part. The three standard spheres 401 of , in step 2), move the robot hand so that the three standard spheres 401 on the tooling 200 are in contact with the displacement sensor 502 multiple times respectively, in step 3), by the calculation formula:

Figure GDA0003130819600000081
Figure GDA0003130819600000081

以及计算式：and the calculation formula:

Figure GDA0003130819600000082
Figure GDA0003130819600000082

采用非线性最小二乘优化算法，计算出获得标准球401i,i∈[1,3]每次的接触点在法兰坐标系下的坐标值FPij,i∈[1,3],j∈[1,n]、标准球401i的球心在法兰坐标系下的坐标

Figure GDA0003130819600000083
位移传感器502末端在基坐标系下的坐标BPΔ以及位移传感器502末端在基坐标系下的运动向量的单位向量BV，其中，n为每个标准球401的接触次数，R为标准球401的半径，步骤4)中，三个标准球401球心在工装200上的位置为已知，即标准球401球心在工件坐标系下的坐标已知，进而获得法兰坐标系到工件坐标系的平移矩阵FPW，由计算式：Using nonlinear least squares optimization algorithm, calculate the coordinate value F P ij,i∈[1,3],j of each contact point of standard sphere 401i,i∈[1,3] in the flange coordinate system ∈[1,n] , the coordinates of the center of the standard sphere 401i in the flange coordinate system
Figure GDA0003130819600000083
The coordinate B P Δ of the end of the displacement sensor 502 in the base coordinate system and the unit vector B V of the motion vector of the end of the displacement sensor 502 in the base coordinate system, where n is the number of contacts of each standard sphere 401 , and R is the standard sphere The radius of 401, in step 4), the positions of the centers of the three standard spheres 401 on the tooling 200 are known, that is, the coordinates of the centers of the standard spheres 401 in the workpiece coordinate system are known, and then the flange coordinate system is obtained to the workpiece. The translation matrix F P W of the coordinate system is calculated by the formula:

Figure GDA0003130819600000084
Figure GDA0003130819600000084

获得标准平板402在法兰坐标系下的法线向量FV。三个点能够确定一个平面，进而确定一个法线向量，三个标准球401的加工精度更容易保证。其余步骤同实施例一。相对于实施例一，本实施例获得的标定结果精度更高，但会导致接触次数增加，计算过程也更复杂，会造成标定效率略有降低。The normal vector F V of the standard plate 402 in the flange coordinate system is obtained. Three points can determine a plane, and then determine a normal vector, and the machining accuracy of the three standard spheres 401 can be more easily guaranteed. The remaining steps are the same as those in the first embodiment. Compared with the first embodiment, the calibration result obtained in this embodiment has higher precision, but will lead to an increase in the number of contacts and a more complicated calculation process, which will result in a slight decrease in the calibration efficiency.

以上所述的实施例只是本发明的一种较佳的方案，并非对本发明作任何形式上的限制，在不超出权利要求所记载的技术方案的前提下还有其它的变体及改型。The above-mentioned embodiment is only a preferred solution of the present invention, and does not limit the present invention in any form, and there are other variations and modifications under the premise of not exceeding the technical solution recorded in the claims.

Claims (8)

1.一种自动化工件坐标系标定方法，用于机器手夹持工件的坐标系标定，其特征在于，1. an automatic workpiece coordinate system calibration method, for the coordinate system calibration of the robot gripping workpiece, it is characterized in that, 包括以下步骤：Include the following steps: 1)在工装上制作标定部，在机器手的基坐标系内固定安装位移传感器，所述标定部包括点标定部和方向标定部；1) A calibration part is made on the tooling, and a displacement sensor is fixedly installed in the base coordinate system of the robot hand, and the calibration part includes a point calibration part and a direction calibration part; 2)移动机器手使工装上的点标定部以及方向标定部分别多次接触位移传感器，记录每个接触点pi.i∈[1,m]的坐标值由基坐标系转换到机器手的法兰坐标系的齐次转换关系
Figure FDA0003273978490000011
以及位移传感器读数Δzi，其中，m为点标定部以及方向标定部与位移传感器的接触次数和，
Figure FDA0003273978490000012
为接触点pi的坐标值由基坐标系转换到法兰坐标系的3×3旋转矩阵，
Figure FDA0003273978490000013
为接触点pi的坐标值由基坐标系到法兰坐标系的3×1平移矩阵；2) Move the robot hand to make the point calibration part and the direction calibration part on the tool contact the displacement sensor for many times, record the coordinate value of each contact point p ii∈[1,m] and convert it from the base coordinate system to the flange of the robot hand Homogeneous transformation relation of coordinate system
Figure FDA0003273978490000011
and the displacement sensor reading Δzi , where m is the sum of the contact times between the point calibration part and the direction calibration part and the displacement sensor,
Figure FDA0003273978490000012
is a 3×3 rotation matrix for the coordinate value of the contact point p i to be transformed from the base coordinate system to the flange coordinate system,
Figure FDA0003273978490000013
is a 3×1 translation matrix from the base coordinate system to the flange coordinate system for the coordinate value of the contact point p i ; 3)根据齐次转换关系
Figure FDA0003273978490000014
以及位移传感器读数Δzi确定点标定部在法兰坐标系下的坐标值FP以及方向标定部在法兰坐标系下的法线向量FV；3) According to the homogeneous transformation relationship
Figure FDA0003273978490000014
And the displacement sensor reading Δzi determines the coordinate value F P of the point calibration part under the flange coordinate system and the normal vector F V of the direction calibration part under the flange coordinate system; 4)工装以及工件尺寸以及夹持关系已知，由此获得点标定部在工件坐标系下的坐标值WP以及方向标定部在工件坐标系下的法线向量WV，使用FV以及WV由罗德里格斯公式计算获得法兰坐标到工件坐标系的旋转矩阵FRW；4) The size of the tooling and the workpiece and the clamping relationship are known, thereby obtaining the coordinate value W P of the point calibration part under the workpiece coordinate system and the normal vector W V of the direction calibration part under the workpiece coordinate system, using F V and W V is calculated by the Rodrigues formula to obtain the rotation matrix F R W from the flange coordinates to the workpiece coordinate system; 5)由FP、WP以及旋转矩阵FRW获得法兰坐标到工件坐标系的平移矩阵FPW，FPW＝FP-FRW WP，由此完成工件坐标系的标定。5) Obtain the translation matrix F P W from the flange coordinates to the workpiece coordinate system from F P, W P and the rotation matrix F R W , F P W = F P- F R W W P, thus completing the calibration of the workpiece coordinate system . 2.根据权利要求1所述的一种自动化工件坐标系标定方法，其特征在于，2. a kind of automatic workpiece coordinate system calibration method according to claim 1, is characterized in that, 所述点标定部为固定在工装上的标准球，步骤2)中，移动机器手使工装上的标准球多次接触位移传感器，步骤3)中，由计算式：The point calibration part is a standard ball fixed on the tooling. In step 2), the robot hand is moved to make the standard ball on the tooling contact the displacement sensor for many times. In step 3), the calculation formula is:
Figure FDA0003273978490000015
Figure FDA0003273978490000015
 代入计算式：Substitute into the formula: (FPi-FPS)T(FPi-FPS)＝R2，i∈(1,n)( F P i - F P S ) T ( F P i - F P S )=R 2 , i∈(1,n) 得计算式：get the formula:
Figure FDA0003273978490000016
Figure FDA0003273978490000016
 采用非线性最小二乘优化算法，获得位移传感器末端在基坐标系下的坐标BPΔ，位移传感器末端在基坐标系下的运动向量BV，以及标准球球心在法兰坐标系下的坐标FPS，进而获得每次的接触点i在法兰坐标系下的坐标值FPi,i∈[1,n]，其中R为标准球的半径，n为标准球接触位移传感器的次数，步骤4)中，标准球球心在工装上的位置为已知，即标准球球心在工件坐标系下的坐标已知，进而获得法兰坐标系到工件坐标系的平移矩阵FPW。The nonlinear least squares optimization algorithm is used to obtain the coordinates B P Δ of the end of the displacement sensor in the base coordinate system, the motion vector B V of the end of the displacement sensor in the base coordinate system, and the center of the standard sphere in the flange coordinate system. Coordinate F P S , and then obtain the coordinate value F P i,i∈[1,n] of each contact point i in the flange coordinate system, where R is the radius of the standard ball, and n is the contact point of the standard ball. times, in step 4), the position of the center of the standard sphere on the tooling is known, that is, the coordinates of the center of the standard sphere in the workpiece coordinate system are known, and then the translation matrix F P from the flange coordinate system to the workpiece coordinate system is obtained W. 3.根据权利要求2所述的一种自动化工件坐标系标定方法，其特征在于，3. a kind of automatic workpiece coordinate system calibration method according to claim 2 is characterized in that, 步骤2)中，移动机器手使工装上的标准球多次接触位移传感器，根据接触计算标准球的球心在法兰坐标系下的坐标FPS，并多次计算获得的标准球的球心在法兰坐标系下的坐标FPS，取均值作为标准球的球心在法兰坐标系下的坐标FPS。In step 2), move the robot hand to make the standard ball on the tool contact the displacement sensor for many times, calculate the coordinates F P S of the center of the standard ball in the flange coordinate system according to the contact, and calculate the obtained standard ball many times. The coordinate F P S of the center in the flange coordinate system, and the average value is taken as the coordinate F P S of the center of the standard sphere in the flange coordinate system. 4.根据权利要求2或3所述的一种自动化工件坐标系标定方法，其特征在于，4. a kind of automatic workpiece coordinate system calibration method according to claim 2 or 3 is characterized in that, 所述方向标定部为固定在工装上的标准平板，在步骤2)中，移动机器手使工装上的标准平板三次接触位移传感器，步骤3)中，由计算式：The direction calibration part is a standard plate fixed on the tooling, in step 2), moving the robot hand to make the standard plate on the tooling contact the displacement sensor three times, in step 3), by the calculation formula:
Figure FDA0003273978490000021
Figure FDA0003273978490000021
 获得每次的接触点在法兰坐标系下的坐标值FPi,i∈[1,3]，其中，BPΔ为位移传感器末端在基坐标系下的坐标，BV为位移传感器末端在基坐标系下的运动向量的单位向量，由计算式：Obtain the coordinate value F P i,i∈[1,3] of each contact point in the flange coordinate system, where B P Δ is the coordinate of the end of the displacement sensor in the base coordinate system, and B V is the end of the displacement sensor The unit vector of the motion vector in the base coordinate system is calculated by: FV＝(FP2-FP1)×(FP3-FP2) F V = ( F P 2 - F P 1 )×( F P 3 - F P 2 ) 获得标准平板在法兰坐标系下的法线向量FV。Obtain the normal vector F V of the standard plate in the flange coordinate system. 5.根据权利要求4所述的一种自动化工件坐标系标定方法，其特征在于，5. a kind of automatic workpiece coordinate system calibration method according to claim 4, is characterized in that, 在步骤2)中，移动机器手使工装上的标准平板多次接触位移传感器，记录每个接触点pi.i∈[1,k]的坐标值由基坐标系转换到机器手的法兰坐标系的齐次转换关系
Figure FDA0003273978490000022
以及位移传感器读数Δzi，k为标准平板接触位移传感器的次数，步骤3)中，由计算式：In step 2), move the robot hand to make the standard plate on the tool contact the displacement sensor for many times, record the coordinate value of each contact point p ii∈[1,k] and convert it from the base coordinate system to the flange coordinate system of the robot hand Homogeneous transformation relation of
Figure FDA0003273978490000022
And the displacement sensor reading Δzi , k is the number of times the standard plate contacts the displacement sensor, in step 3), by the calculation formula:
Figure FDA0003273978490000023
Figure FDA0003273978490000023
 获得每次的接触点在法兰坐标系下的坐标值FPi,i∈[1,k]，根据多个接触点均在法兰坐标系下的同一平面上的约束条件,由平面的截距式方程FV·FPi＝1获得计算式：Obtain the coordinate value F P i,i∈[1,k] of each contact point in the flange coordinate system. According to the constraint that multiple contact points are on the same plane in the flange coordinate system, the The intercept formula F V · F P i =1 obtains the calculation formula:
Figure FDA0003273978490000024
Figure FDA0003273978490000024
 非线性最小二乘优化算法，获得标准平板在法兰坐标系下的法线向量FV。The nonlinear least squares optimization algorithm is used to obtain the normal vector F V of the standard plate in the flange coordinate system. 6.根据权利要求1或2所述的一种自动化工件坐标系标定方法，其特征在于，6. a kind of automatic workpiece coordinate system calibration method according to claim 1 and 2 is characterized in that, 步骤2)中，示教时，使位移传感器末端的运动向量基本沿着工装的接触点处标定部表面的法线方向。In step 2), during teaching, the motion vector of the end of the displacement sensor is basically along the normal direction of the surface of the calibration part at the contact point of the tooling. 7.根据权利要求1或2所述的一种自动化工件坐标系标定方法，其特征在于，7. a kind of automatic workpiece coordinate system calibration method according to claim 1 and 2 is characterized in that, 步骤1)中，所使用的位移传感器末端硬度低于工装硬度。In step 1), the hardness of the end of the displacement sensor used is lower than the hardness of the tool. 8.根据权利要求1或2所述的一种自动化工件坐标系标定方法，其特征在于，8. a kind of automatic workpiece coordinate system calibration method according to claim 1 and 2 is characterized in that, 步骤2)中，移动机器手使工装上的标定部接触位移传感器的方法包括：In step 2), the method of moving the robot hand to make the calibration part on the tool contact the displacement sensor includes: 21)将位移传感器安装在直线位移机构上，使位移传感器具有直线位移行程，所述直线位移机构的位移可检测，直线位移机构带动位移传感器移动到行程起点，所述行程起点在基坐标系下的坐标已知；21) Install the displacement sensor on the linear displacement mechanism, so that the displacement sensor has a linear displacement stroke, the displacement of the linear displacement mechanism can be detected, and the linear displacement mechanism drives the displacement sensor to move to the starting point of the stroke, and the starting point of the stroke is in the base coordinate system The coordinates are known; 22)移动机器手使工装上的标定部位于所述直线位移行程范围内，工装上的标定部位通过示教确定；22) Move the robot hand so that the calibration part on the tooling is within the range of the linear displacement stroke, and the calibration part on the tooling is determined by teaching; 23)直线位移机构带动位移传感器从行程起点移动预设的距离，该预设的距离使得位移传感器末端触碰到工装上的标定部，并产生位移传感器读数Δzi。23) The linear displacement mechanism drives the displacement sensor to move a preset distance from the starting point of the stroke, the preset distance makes the end of the displacement sensor touch the calibration part on the tooling, and generates a displacement sensor reading Δzi .
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