Industrial robot repeatable positioning accuracy testing method and testing device

Abstract

The present invention discloses a method and device for testing the repeatable positioning accuracy of an industrial robot, comprising a base, a support arm, and a test bench which are assembled into one piece in sequence from bottom to top; three position sensors are evenly distributed around the center of the test bench, and the detection directions of the detection parts of the three position sensors are inclined upward toward the center and intersected at one point in space. The position sensor is a micrometer, and the detection part is a measuring rod of the micrometer. The axes of the measuring rods of the three micrometers are arranged vertically in pairs. The testing method of the present invention is more convenient in application and measurement, and data can be obtained quickly; the testing device used in the present invention has a simple structure, and can use a micrometer that is widely used in factories, is easy and reliable to operate, and provides accurate data, thereby overcoming the defects and high cost of existing equipment, and can be widely used at work sites and workshops.

Description

Technical Field

[0001] The invention belongs to the technical field of industrial automation control, and in particular relates to a method and a device for testing the repeatability accuracy of an industrial robot. Background Art

[0002] With the rapid development of mechanical automation, mechanical automation is gradually being applied in industrial production. Various robots are the main equipment to replace manual workpiece transportation and processing. During the movement of the robot, in order to ensure the accuracy of workpiece processing, the repeated positioning accuracy of the robot movement is required to be high. Patent No. 201410101895 discloses an industrial robot repeated positioning test device to solve the problem that the laser tracker has limitations such as high speed and easy light loss in the repeated positioning accuracy measurement of industrial robots. However, the device uses laser sensors and a large number of position adjustment devices, which has high procurement costs, complex position adjustment, and reliability is difficult to guarantee. Patent No. 201410523191 proposes a device for measuring the repeated positioning accuracy of industrial robots using a visual method, which is much cheaper than the laser tracker. However, the high-precision visual measurement method has high hardware requirements, the cost is still relatively high, and there are also high requirements for software calculation. Patent No. 201510098569 provides a test system for measuring the repeatability of industrial robots. It uses laser sensors to improve measurement accuracy, has a high transmission rate, and a flexible communication method. It is not limited to the measurement of a single station and can be used to measure the repeatability of multi-station robots. However, the position of the sensor itself is not fixed, making it difficult for workers to operate during factory applications and difficult to achieve an orthogonal method. Summary of the invention

[0003] The purpose of the present invention is to provide an industrial robot repeatability accuracy testing method and testing device, which can accurately measure the repeatability accuracy of the industrial robot. By using a micrometer widely used in factories, the operation is simple and reliable, the data is accurate, and the defects and high cost of existing equipment can be overcome, and the method and testing device can be widely used at work sites and workshops.

[0004] The technical solution of the present invention is: a testing device for the repeatability of positioning accuracy of an industrial robot, comprising a base, a support arm, and a testing table which are assembled into one piece in sequence from bottom to top;

[0005] Three position sensors are evenly distributed on the test bench around its center. The detection directions of the detection parts of the three position sensors are inclined upward toward the center and are spatially intersected at one point.

[0006] As a preferred implementation of the above technical solution, the testing device for the repeatability of positioning accuracy of an industrial robot provided in an embodiment of the present invention further includes some or all of the following technical features:

[0007] As an improvement of the above technical solution, the position sensor is a dial gauge, and the detection part is a measuring rod of the dial gauge.

[0008] As an improvement of the above technical solution, the axes of the measuring rods of the three micrometers are arranged vertically in pairs.

[0009] As an improvement of the above technical solution, the test bench is in the shape of an inverted frustum, and its upper end surface is provided with an inner concave arc surface coaxial with the test bench;

[0010] The three micrometers are evenly distributed on the side of the test bench, and the measuring rods thereof extend out from the inner concave arc surface.

[0011] As an improvement of the above technical solution, three evenly distributed arc-shaped grooves are arranged on the side of the inverted truncated cone-shaped test bench, and through holes are arranged on the arc-shaped grooves;

[0012] The measuring rod of the micrometer passes through the through hole to fix the micrometer on the arc-shaped groove of the test bench.

[0013] As an improvement of the above technical solution, the support arm includes an upper inverted truncated cone shape and a lower regular truncated cone shape, which are connected by a truncated cone.

[0014] As an improvement of the above technical solution, the lower right truncated cone-shaped bottom is provided with a flange, and the flange is provided with four circular holes evenly distributed around the circumference of the flange.

[0015] As an improvement of the above technical solution, a bolt hole corresponding to the circular hole is provided on the base, and a bolt passes through the circular hole and is threadedly connected to the bolt hole to fix the support arm to the base.

[0016] A method for testing the repeatability of an industrial robot comprises the following steps:

[0017] S01. Install the measuring block on the test flange at the end of the industrial robot;

[0018] S02, move the industrial robot to a specified position, move the test device closer to it, and adjust the test device to ensure that the displayed value of each position sensor is near the mid-range position;

[0019] S03, return the position sensor to zero. At this time, the three sensors form a rectangular coordinate system, the measuring block is located at the origin of the coordinate system, and the directions of the position sensors are respectively X-axis, Y-axis and Z-axis;

[0020] S04. Each time the industrial robot repeats its operation, the three position sensors obtain the offsets △Xn, △Yn and △Zn of the measuring block in the X-axis, Y-axis and Z-axis directions respectively;

[0021] S05. After running N times, N groups of data are obtained. According to GB / T 12642-2013 Industrial Robot Performance Specification and Experimental Method, the consistency of the actual posture of the industrial robot after it repeatedly responds to the same command posture from the same direction N times is calculated by computer.

[0022] Compared with the prior art, the present invention has the following beneficial effects: the test method of the present invention is more convenient in application and measurement, and data can be obtained quickly; the test device used in the present invention has a simple structure, and a micrometer widely used in factories can be used, which is easy and reliable to operate, and the data is accurate, which solves the problem of light loss in the laser tracker in the repeated positioning accuracy measurement of industrial robots, overcomes the defects and high cost of the existing equipment, and can be widely used in work sites and workshops. The test method of the present invention refers to GB / T 12642-2013 Industrial Robot Performance Specification and Experimental Method, solves the problem of limitations of the laser tracker in the repeated positioning accuracy measurement of industrial robots, and overcomes the defects of the existing equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] 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, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0024] Figure 1 It is a three-dimensional structural schematic diagram of a testing device for repeated positioning accuracy of an industrial robot provided by the present invention;

[0025] Figure 2 This is a front view of a testing device for the repeatability of positioning accuracy of an industrial robot provided by the present invention;

[0026] Figure 3 It is a structural schematic diagram of a test bench in a test device for repeatable positioning accuracy of an industrial robot provided by the present invention;

[0027] Figure 4 It is a structural schematic diagram of a support arm in a testing device for repeated positioning accuracy of an industrial robot provided by the present invention;

[0028] Figure 5 The present invention provides a flow chart of a method for testing the repeatability of an industrial robot. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] A testing device for the repeatability of an industrial robot, such as Figure 1 As shown, it includes a base 10, a support arm 20, and a test bench 30 which are assembled into one piece from bottom to top;

[0031] Three position sensors are evenly distributed around the center of the test bench 30 . The detection directions of the detection parts of the three position sensors are inclined upward toward the center and intersect at one point in space.

[0032] Preferably, the position sensor is a dial gauge 40 , and the detection portion is a measuring rod of the dial gauge 40 .

[0033] Specifically, the axes of the measuring rods of the three micrometers 40 are arranged vertically in pairs. Figure 2 As shown, the angle α between the axis of any of the micrometers 40 and the axis of the test bench 30 is an acute angle.

[0034] The testing device for the repeatability of positioning accuracy of an industrial robot further comprises a computer analysis system and a measuring block 50 . The measuring block 50 is mounted on a testing flange 70 at the end of the industrial robot via a connecting rod 60 .

[0035] Preferably, the base is configured as a height-adjustable base, and the height of the test bench can be adjusted within a certain range by adjusting the height of the base. The micrometer uses a micrometer position sensor with data output, and the data output of the micrometer is connected to a computer analysis system to obtain the position data of the measuring block in the three-dimensional measurement coordinate system.

[0036] When used for specific measurements: the industrial robot drives the measuring block to move into the three-dimensional measuring coordinate system. The position data of the measuring block in the three-dimensional measuring coordinate system can be obtained through the computer analysis system. At the same time, the position value of the robot end can be obtained. By repeating the measurement and processing the data many times, the robot's repeated positioning accuracy value can be obtained.

[0037] like Figure 1 , Figure 3 As shown, the test bench 30 is in the shape of an inverted frustum, and its upper end surface is provided with an inner concave arc surface 31 coaxial with the test bench 30;

[0038] The three micrometers 40 are evenly distributed on the side of the test bench 30 , and the measuring rods thereof extend out from the inner concave arc surface 31 .

[0039] like Figure 3 As shown, three evenly distributed arc grooves 32 are arranged on the side of the inverted truncated cone-shaped test platform 30, and through holes 33 are arranged on the arc grooves 32;

[0040] The measuring rod of the micrometer 40 passes through the through hole 33 to fix the micrometer 40 on the arc groove 32 of the test bench 30 .

[0041] Specifically, Figure 4 As shown, the support arm 20 includes an upper inverted truncated cone 21 and a lower regular truncated cone 22, which are connected by a truncated cone 23. The upper inverted truncated cone and the lower regular truncated cone are connected by the truncated cone to achieve fixed connection between the adjacent upper inverted truncated cone and the lower regular truncated cone, thereby avoiding the situation where the repeatedly stacked truncated cones are tilted or even tilted due to external forces, thereby greatly reducing the harm caused by the tilting of the truncated cones, and also reducing the weight of the test equipment itself.

[0042] like Figure 4 As shown, the area of ​​the upper end surface of the upper inverted truncated cone 21 is larger than the area of ​​the lower end surface of the lower regular truncated cone 22.

[0043] Specifically, the area of ​​the upper end surface of the test table 30 is larger than the area of ​​the upper end surface of the upper frustum cone 21 .

[0044] like Figure 4 As shown, a flange 24 is disposed at the bottom of the lower right truncated cone 22 , and four circular holes 25 evenly distributed around the circumference of the flange 24 are disposed on the flange 24 .

[0045] Specifically, the base 10 is provided with a bolt hole corresponding to the circular hole 25, and the support arm 20 is fixedly connected to the base 10 by a bolt passing through the circular hole 25 and being threadedly connected to the bolt hole. This detachable connection method facilitates the disassembly and assembly of the base and the support arm.

[0046] like Figure 5 As shown, a method for testing the repeatability of an industrial robot includes the following steps:

[0047] S01. Install the measuring block on the test flange at the end of the industrial robot;

[0048] S02, move the industrial robot to a specified position, move the test device closer to it, and adjust the test device to ensure that the displayed value of each position sensor is near the mid-range position;

[0049] S03, return the position sensor to zero. At this time, the three sensors form a rectangular coordinate system, the measuring block is located at the origin of the coordinate system, and the directions of the position sensors are respectively X-axis, Y-axis and Z-axis;

[0050] S04. Each time the industrial robot repeats its operation, the three position sensors obtain the offsets △Xn, △Yn and △Zn of the measuring block in the X-axis, Y-axis and Z-axis directions respectively;

[0051] S05. After running N times, N groups of data are obtained. According to GB / T 12642-2013 Industrial Robot Performance Specification and Experimental Method, the consistency of the actual posture of the industrial robot after it repeatedly responds to the same command posture from the same direction N times is calculated by computer.

[0052] According to the national standard, different loads and different speeds are required for industrial robot testing. Regardless of whether the robot is loaded or not, the measuring block is installed on the test flange at the end of the industrial robot. Move the industrial robot to a specified position, move the test device closer, and adjust the test device to ensure that the display value of each sensor is near the mid-range position. Return the position sensor to zero. At this time, the three position sensors form a rectangular coordinate system, the measuring block is located at the origin of the coordinate system, and the directions of the position sensors are X, Y, and Z axes respectively; each time the industrial robot repeats the operation, the three position sensors obtain a value of a, b, and c respectively, which is the offset of the measuring block in each direction △Xn, △Yn, and △Zn. After running N times, N groups of data will be obtained. At this time, according to GB / T 12642-2013 Industrial Robot Performance Specification and Experimental Method, the consistency of the actual posture of the industrial robot after responding to the unified command posture repeatedly from the same direction N times can be obtained through computer calculation. At present, most position sensors with data output on the market can directly display the measured values ​​on the computer without the need for a dedicated data acquisition module.

[0053] The above is only a preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and changes can be made without departing from the principle of the present invention, and these improvements and changes are also regarded as the protection scope of the present invention.

Claims

1. A testing device for the repeatability of an industrial robot, characterized in that: It includes a base, a support arm, and a test bench which are assembled into one piece in sequence from bottom to top; The test bench is evenly distributed with three position sensors around its center, and the detection directions of the detection parts of the three position sensors are inclined upward toward the center and intersect at one point in space; The position sensor is a dial gauge, the detection part is a measuring rod of the dial gauge, and the axes of the measuring rods of the three dial gauges are arranged vertically in pairs; The test bench is in the shape of an inverted frustum, and its upper end surface is provided with an inner concave arc surface coaxial with the test bench; The three micrometers are evenly distributed on the side of the test bench, and their measuring rods extend out from the concave arc surface; The side surface of the inverted truncated cone-shaped test table is provided with three evenly distributed arc-shaped grooves, and the arc-shaped grooves are provided with through holes; The measuring rod of the micrometer passes through the through hole to fix the micrometer on the arc-shaped groove of the test bench; The support arm includes an upper inverted truncated cone shape and a lower regular truncated cone shape, which are connected by a truncated cone; The lower right truncated cone-shaped bottom is provided with a flange, and the flange is provided with four circular holes evenly distributed around the circumference of the flange; The base is provided with a bolt hole corresponding to the circular hole, and the support arm is fixedly connected to the base by a bolt passing through the circular hole and being threadedly connected to the bolt hole; The method for testing the repeatability of an industrial robot includes the following steps: S01. Install the measuring block on the test flange at the end of the industrial robot; S02, move the industrial robot to a specified position, move the test device closer to it, and adjust the test device to ensure that the displayed value of each position sensor is near the mid-range position; S03, return the position sensor to zero. At this time, the three sensors form a rectangular coordinate system, the measuring block is located at the origin of the coordinate system, and the directions of the position sensors are respectively X-axis, Y-axis and Z-axis; S04. Each time the industrial robot repeats its operation, the three position sensors obtain the offsets ΔXn, ΔYn and ΔZn of the measuring block in the X-axis, Y-axis and Z-axis directions respectively; S05. After running N times, N groups of data are obtained. According to GB / T 12642-2013 Industrial Robot Performance Specification and Experimental Method, the consistency of the actual posture of the industrial robot after it repeatedly responds to the same command posture from the same direction N times is calculated by computer.

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