CN212445322U - Industrial Robot Accuracy Calibration Device - Google Patents

Abstract

Translated fromChinese

本实用新型公开了一种工业机器人精度标定装置，包括三球座机构、末端测量机构、计数器及计算机等；所述三球座机构相对于机器人的基座固定设置，所述末端测量机构通过机器人法兰与机器人连接；所述末端测量机构还经计数器与计算机连接，同时所述计算机与机器人连接，从而构成一闭环工作回路。本实用新型的工业机器人精度标定装置结构简单，具有便携、低成本、操作方便及测量精度可靠等优点。并且，利用本实用新型的工业机器人精度标定装置可以方便、准确地标定机器人基坐标系的位姿及机器人运动学参数，进而提高机器人绝对定位精度。

The utility model discloses an industrial robot precision calibration device, which comprises a three-ball seat mechanism, an end measurement mechanism, a counter, a computer, etc.; the three-ball seat mechanism is fixedly arranged relative to the The flange is connected with the robot; the end measurement mechanism is also connected with the computer through the counter, and at the same time the computer is connected with the robot, thus forming a closed-loop working circuit. The industrial robot precision calibration device of the utility model has the advantages of simple structure, portability, low cost, convenient operation, reliable measurement precision and the like. Moreover, the industrial robot precision calibration device of the utility model can conveniently and accurately calibrate the pose of the robot base coordinate system and the kinematic parameters of the robot, thereby improving the absolute positioning accuracy of the robot.

Description

Industrial robot precision calibration device

Technical Field

The utility model relates to a calibration equipment of robot, in particular to industrial robot precision calibration device, it can be used for demarcating basic coordinate system position appearance of robot and robot kinematics parameter belongs to the robot kinematics field of demarcation.

Background

With the development of the robot application technology, manufacturing enterprises have higher and higher application requirements on the industrial robot offline programming technology, especially in the industries of automobile manufacturing, aviation manufacturing and the like. At present, an industrial robot generally has higher repeated positioning accuracy, but the absolute positioning accuracy is lower, which is mainly caused by the problems that the kinematic parameters of the robot have errors and the robot base coordinate system is difficult to accurately position, thereby affecting the reliability and accuracy of some robot applications including offline programming operation. And the robot kinematics calibration can effectively improve the absolute positioning accuracy of the robot, and has great research significance.

The robot kinematics calibration can be divided into absolute calibration and relative calibration according to whether the conversion relation between the robot base coordinate system and the external physical environment is calibrated. And only the calibration of the kinematic parameter error of the robot body is considered in relative calibration. And the absolute calibration is carried out on the basis of calibrating the kinematic parameters, and simultaneously the pose of the robot base coordinate system is calibrated. The base coordinate system is a reference for describing the robot joint coordinate system and the tail end position, so that accurate calibration of the robot base coordinate system is an important premise for realizing accurate position control of the robot.

In a traditional robot calibration method, external measuring equipment is usually used for acquiring robot pose error information, such as instruments such as a laser tracker, but the traditional robot calibration method has the defects of high cost, heavy equipment and higher operation technology threshold. Therefore, a robot calibration method based on a novel low-cost calibration device is widely researched. For example, CN107042528A discloses a calibration system for an industrial robot, which mainly includes an end effector disposed on the robot and two movable target spheres with fixed sphere center distances, and a calibration algorithm is established by using an error between a nominal distance and an actual distance between the two spheres, so as to calibrate kinematic parameters of a robot body.

Disclosure of Invention

The utility model discloses a main aim at provides an industrial robot precision calibration device to overcome not enough among the prior art.

In order to achieve the above purpose, the present invention provides the following technical solutions:

an embodiment of the utility model provides an industrial robot precision calibration device, it includes: the device comprises a three-ball seat mechanism, a tail end measuring mechanism, a counter and a computer; the three-ball seat mechanism is fixedly arranged relative to a base of the robot, and the tail end measuring mechanism is connected with the robot through a robot flange; the tail end measuring mechanism is also connected with a computer through a counter, and the computer is connected with the robot at the same time, so that a closed loop working circuit is formed; the three ball seat mechanisms comprise three precise steel balls and three conical ball seats, the three precise steel balls are respectively installed on the three conical ball seats, the three conical ball seats are fixed on an equilateral triangle base plate, and the three precise steel balls are respectively distributed at three vertex angles of the equilateral triangle.

In some embodiments, the tapered ball seats are further coupled to a magnetic mechanism, and the precision steel balls are mounted on the respective tapered ball seats at least under the magnetic force of the magnetic mechanism.

In some embodiments, the precision steel ball is a steel ball with a G5 precision rating or greater.

In some embodiments, the magnetic mechanism includes a cylindrical permanent magnet and a connection screw, and the connection screw fixedly connects the permanent magnet with the bottom plate through a mounting hole on the permanent magnet.

In some embodiments, the three-ball seat mechanism and the base of the robot are both fixed to a table top of a workbench.

In some embodiments, the base plate is secured to the table top of the table by a plurality of threaded connections.

In some embodiments, the end measuring mechanism comprises a plurality of displacement sensors, wherein the measuring end of each displacement sensor is provided with a measuring needle with a spherical measuring head, and the spherical center of the spherical measuring head of the measuring needle can generate axial displacement when the measuring needle contacts the precision steel ball in the three-ball seat mechanism.

In some embodiments, the tip measurement mechanism comprises three displacement sensors arranged in a ring and spaced 120 ° apart from each other.

In some embodiments, the three-ball mount mechanism is mounted near a target workspace of the robot.

In some embodiments, the poses of the robot for measuring the three ball seat mechanisms are uniformly distributed in the robot working space around the three precise steel balls.

In some embodiments, the counter is connected with the terminal measuring mechanism and the computer through wired or wireless communication respectively, and the computer is connected with the robot through wired or wireless communication.

Compared with the prior art, the embodiment of the utility model provides an industrial robot precision calibration device simple structure has portablely, low-cost, convenient operation and the reliable advantage of measurement accuracy, and key component wherein all can select from current ripe commercial product like accurate steel ball, measuring pin and high accuracy displacement sensor etc. the source is extensive, and utilizes precision calibration device can make things convenient for, accurately mark position appearance and the robot kinematics parameter of robot basic coordinate system, and then improve the absolute positioning accuracy of robot.

Drawings

Fig. 1a is a schematic structural diagram of an industrial robot precision calibration device provided by an embodiment of the present invention.

Fig. 1b is a partially enlarged schematic view of a portion a of fig. 1 a.

Fig. 1c is a partially enlarged schematic view of portion B of fig. 1 a.

Fig. 1d is a cross-sectional view of the structure of the magnetic mechanism of fig. 1 a.

Fig. 2 is a schematic structural diagram of a three-ball seat mechanism and an end measuring mechanism according to an embodiment of the present invention.

Fig. 3 is a schematic view illustrating the installation of the precision steel ball and the conical ball seat in an embodiment of the present invention.

Description of reference numerals: the device comprises a tailend measuring mechanism 1, arobot 2, a three-ball seat mechanism 3, aprecision steel ball 4, aworkbench 5, acommunication cable 6, acommunication cable 7, acounter 8, acommunication cable 9, acomputer 10, aconical ball seat 11, apermanent magnet 12, abottom plate 13, ameasuring pin 14, adisplacement sensor 15, arobot flange 16 and a connectingscrew 17.

Detailed Description

As described above, in view of the defects of the prior art, such as the problems of expensive and heavy measuring equipment used in the existing robot calibration method, and incapability of calibrating the pose of the robot base coordinate system, the inventors of the present application have long studied and practiced to provide a robot absolute accuracy calibration system with the advantages of portability, low cost, reliable accuracy, and convenient operation, and an absolute calibration method with the functions of calibrating the kinematic parameters of the robot and calibrating the pose of the robot base coordinate system

The present invention will be described in further detail with reference to the following examples and drawings, which are not intended to limit the invention, but are intended to facilitate the understanding thereof.

As shown in fig. 1a to 1d, an embodiment of the present invention provides an industrial robot precision calibration device (hereinafter referred to as "calibration device") including a three-ball-seat mechanism 3, anend measuring mechanism 1, acounter 8, acomputer 10, and the like, which are fixedly disposed relative to a robot 2 (particularly, a robot base). Wherein theterminal measuring mechanism 1 is connected with therobot 2 through arobot flange 16; theend measuring mechanism 1 is also connected to a computer via acounter 8, and the computer is connected to therobot 2, thereby forming a closed loop.

Further, thecounter 8 may be connected to theterminal measuring mechanism 1 and the computer through wired or wireless communication, and the computer is connected to therobot 2 through wired or wireless communication. For example, referring to fig. 1 a-1 d, therobot 2, theend measuring mechanism 1, thecounter 8, and thecomputer 10 may be connected viacommunication cables 6, 7, 9.

Further, the threeball seat mechanisms 3 and the base of therobot 2 are fixed on the table top of aworkbench 5.

Further, referring to fig. 2, the three-ball seat mechanism 3 of the present embodiment includes an equilateraltriangle bottom plate 13, 3precision steel balls 4, and 3conical ball seats 11. Theconical ball seats 11 are fixed on thebottom plate 13, the threeprecise steel balls 4 are respectively installed on the threeconical ball seats 11, and the threeprecise steel balls 4 are respectively distributed at three vertex angles of the equilateral triangle.

Further, the three-ball seat mechanism 3 further comprises 3 magnetic mechanisms, theconical ball seats 11 are matched with the magnetic mechanisms, and eachprecise steel ball 4 is mounted on the correspondingconical ball seat 11 by means of the magnetic attraction force of the magnetic mechanisms.

Further, the precision steel ball is a steel ball with a G5 precision grade or above.

Further, the magnetic mechanism comprises a cylindricalpermanent magnet 12 with a countersunk mounting hole and a connectingscrew 17, and thepermanent magnet 12 is fixed on thebottom plate 13 through the connectingscrew 17. Thepermanent magnet 12 may be a neodymium magnet or the like.

Furthermore, thebottom plate 13 is in an equilateral triangle, so that the robot calibration is simpler and more accurate. Thebottom plate 13 can be fixed on the table top of theworkbench 5 through a plurality of threaded connectors arranged at intervals.

Further, the threeball seat mechanism 3 is installed near a target working space of therobot 2 to ensure the actual operation precision of the calibrated robot.

Further, the tail end measuring mechanism further comprises threedisplacement sensors 15, the threedisplacement sensors 15 are arranged in a ring shape and are separated by 120 degrees, ameasuring needle 14 with a spherical measuring head is installed at the measuring end of eachdisplacement sensor 15, and when themeasuring needle 14 contacts theprecision steel ball 4 in the three-ball seat mechanism 3, the spherical center of the spherical measuring head of themeasuring needle 14 can generate axial displacement.

When the industrial robot precision calibration device of the embodiment is used for working, an external world coordinate system { w } describing a robot base coordinate system {0} can be established based on the position arrangement relationship of eachprecision steel ball 4 in the three-ball seat mechanism, namely the position distribution of each ball center, and is used for describing all coordinate systems in a robot system. And, thedisplacement sensor 15 and theprobe 3 can be used to measure the position coordinates of the center of sphere of theprecision steel ball 4 with respect to the robot flange coordinate system { F }. And then, the tail end measuring mechanism can be used for measuring tail end position error information of the robot, and a computer is used for processing the position error information, the joint angle data of the robot and the like by an absolute precision calibration program to obtain an accurate kinematic model of the robot under a world coordinate system { w }. The above absolute accuracy calibration algorithm is known in the art, and the aforementioned information collection and processing processes can be performed by means known in the art, for example, by means of software such as Matlab, and thus will not be described in detail herein.

Further, when the industrial robot precision calibration device works, the pose of therobot 2 for measuring the threeball seat mechanisms 3 can be uniformly distributed in the robot working space around the threeprecision steel balls 4. The poses of therobot 2 for measuring thesteel ball 4 are different as much as possible, so that the diversity of the measuring structure of the robot is improved, and the reliability of a calibration result is improved.

In addition, in this embodiment, before the three-ball seat mechanism is put into use for the first time, the precise value of the actual center coordinates of eachsteel ball 4 can be measured by a precision measurement device such as an optical three-coordinate measuring instrument or a laser scanner, so as to further improve the calibration precision.

The industrial robot precision calibration device of the embodiment can improve the positioning precision of the robot body, can realize accurate positioning of the robot base coordinate system, and is favorable for improving the reliability and accuracy of applications such as robot off-line programming.

It should be understood that the technical solution of the present invention is not limited to the limitations of the above specific embodiments, and all technical variations made according to the technical solution of the present invention fall within the protection scope of the present invention without departing from the scope of the present invention.

Claims (10)

Translated fromChinese

1.一种工业机器人精度标定装置，其特征在于包括：三球座机构（3）、末端测量机构（1）、计数器（8）及计算机；所述三球座机构（3）相对于机器人（2）的基座固定设置，所述末端测量机构（1）通过机器人法兰（16）与机器人（2）连接；所述末端测量机构（1）还经计数器（8）与计算机连接，同时所述计算机与机器人（2）连接，从而构成一闭环工作回路；其中，所述三球座机构（3）包括三颗精密钢球（4）和三个锥形球座（11），所述三颗精密钢球（4）分别安装于三个锥形球座（11）上，所述三个锥形球座（11）固定在一等边三角形底板（13）上，所述三颗精密钢球（4）分别分布于所述等边三角形的三个顶角处。1. An industrial robot precision calibration device, characterized in that it comprises: a three-ball seat mechanism (3), an end measurement mechanism (1), a counter (8) and a computer; the three-ball seat mechanism (3) is relative to the robot ( 2) The base is fixedly arranged, the end measuring mechanism (1) is connected with the robot (2) through the robot flange (16); the end measuring mechanism (1) is also connected with the computer through the counter (8), and all the The computer is connected with the robot (2) to form a closed-loop working loop; wherein, the three-ball seat mechanism (3) includes three precision steel balls (4) and three conical ball seats (11), the three Precision steel balls (4) are respectively mounted on three conical ball seats (11), and the three conical ball seats (11) are fixed on an equilateral triangular base plate (13). The balls (4) are respectively distributed at the three vertex angles of the equilateral triangle.2.根据权利要求1所述的工业机器人精度标定装置，其特征在于：所述锥形球座（11）还与磁性机构配合，所述精密钢球（4）至少是在所述磁性机构的磁力作用下安装于相应的锥形球座（11）上；和/或，所述精密钢球为具有G5精度等级以上的钢球。2. The industrial robot precision calibration device according to claim 1, characterized in that: the conical ball seat (11) is also matched with a magnetic mechanism, and the precision steel ball (4) is at least in the position of the magnetic mechanism. Installed on the corresponding conical ball seat (11) under the action of magnetic force; and/or, the precision steel ball is a steel ball with a G5 precision grade or higher.3.根据权利要求2所述的工业机器人精度标定装置，其特征在于：所述磁性机构包括柱形永磁体（12）和连接螺钉，所述连接螺钉通过所述永磁体（12）上的安装孔将所述永磁体（12）与所述底板（13）固定连接。3. The industrial robot accuracy calibration device according to claim 2, wherein the magnetic mechanism comprises a cylindrical permanent magnet (12) and a connecting screw, and the connecting screw is installed on the permanent magnet (12). The holes fixedly connect the permanent magnet (12) with the bottom plate (13).4.根据权利要求1所述的工业机器人精度标定装置，其特征在于：所述三球座机构（3）和机器人（2）的基座均固定在一工作台（5）的台面上。4 . The industrial robot accuracy calibration device according to claim 1 , wherein the three-ball seat mechanism ( 3 ) and the base of the robot ( 2 ) are fixed on the table top of a workbench ( 5 ). 5 .5.根据权利要求4所述的工业机器人精度标定装置，其特征在于：所述底板（13）通过多个螺纹连接件固定在工作台（5）的台面上。5 . The industrial robot accuracy calibration device according to claim 4 , wherein the base plate ( 13 ) is fixed on the table top of the workbench ( 5 ) through a plurality of threaded connectors. 6 .6.根据权利要求1所述的工业机器人精度标定装置，其特征在于：所述末端测量机构包括多个位移传感器（15），其中每一位移传感器（15）的测量端安装有具有球形测头的测针（14），在所述测针（14）接触所述三球座机构（3）中的精密钢球（4）时，所述测针（14）的球形测头的球心能产生轴向位移。6. The industrial robot accuracy calibration device according to claim 1, characterized in that: the end measurement mechanism comprises a plurality of displacement sensors (15), wherein the measurement end of each displacement sensor (15) is installed with a spherical probe The stylus (14), when the stylus (14) contacts the precision steel ball (4) in the three-ball seat mechanism (3), the ball center of the spherical probe of the stylus (14) can produce axial displacement.7.根据权利要求6所述的工业机器人精度标定装置，其特征在于：所述末端测量机构包括三个位移传感器（15），所述三个位移传感器（15）成环形布局且彼此相隔120°。7. The industrial robot accuracy calibration device according to claim 6, characterized in that: the end measurement mechanism comprises three displacement sensors (15), and the three displacement sensors (15) are arranged in a ring and are separated from each other by 120° .8.根据权利要求1所述的工业机器人精度标定装置，其特征在于：所述三球座机构（3）安装在机器人（2）的目标工作空间附近。8 . The precision calibration device for an industrial robot according to claim 1 , wherein the three-ball seat mechanism ( 3 ) is installed near the target working space of the robot ( 2 ). 9 .9.根据权利要求1所述的工业机器人精度标定装置，其特征在于：所述机器人（2）对三球座机构（3）进行测量的位姿均匀分布于所述三颗精密钢球（4）周围的机器人工作空间。9. The industrial robot accuracy calibration device according to claim 1, characterized in that: the poses of the three-ball seat mechanism (3) measured by the robot (2) are evenly distributed on the three precision steel balls (4). ) around the robot workspace.10.根据权利要求1所述的工业机器人精度标定装置，其特征在于：所述计数器（8）通过有线或无线通信方式分别与末端测量机构（1）、计算机连接，所述计算机通过有线或无线通信方式与机器人（2）连接。10 . The industrial robot accuracy calibration device according to claim 1 , wherein the counter ( 8 ) is connected to the terminal measuring mechanism ( 1 ) and a computer through wired or wireless communication, respectively, and the computer is connected to the end measurement mechanism ( 1 ) and a computer through wired or wireless communication. 11 . The communication method is connected with the robot (2).

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