TWI745205B - Device and method for measuring repeated positioning accuracy of mechanical arm - Google Patents

Abstract

The present invention provides a device for measuring repeat positioning accuracy of a mechanical arm. It uses the spot three-dimensional displacement sensor developed by the applicant and cooperates with the low thermal expansion spot image three-dimensional positioning base of the established spot coordinate database to establish a three-dimensional absolute spot position. Positioning space. Install the spot 3D displacement sensor on the end effector of the robot arm, move the robot arm to make the spot 3D displacement sensor enter the spot 3D absolute positioning space, and capture the spot image of the positioning point and the coordinate spot image of the spot coordinate database By comparison, the three-dimensional absolute positioning coordinates of the end effector of the robotic arm can be obtained at this time.

Description

Device and method for measuring repeated positioning accuracy of mechanical arm

The present invention relates to a device and method for measuring repeat positioning accuracy of a robotic arm, in particular to a robotic arm repetition that can not only repeatedly position the robotic arm at a single point, but also repeatedly locate the motion trajectory of the robotic arm in the three-dimensional absolute positioning space of the light spot Device and method for measuring positioning accuracy.

It has become a trend to replace humans with robots. Tractica estimates that in 2020, the global market value of robot revenue will exceed US$100 billion for the first time, and it will reach US$500 billion in 2025. That is to say, in the next six years, the global robotics industry revenue will grow by more than 500%, and the impact of robots on human life will increase day by day. The main technical parameters of the robot usually include the following seven: degree of freedom, resolution, accuracy, repeat positioning accuracy, working range, carrying capacity and maximum speed. When talking about the accuracy of a robot, the industry generally first considers whether its repeatable positioning accuracy meets the application requirements. Position repeatability is the only positioning performance index specified by industrial robot manufacturers.

The measurement methods of the repeatable positioning accuracy of traditional robotic arms include: using a laser tracker, using a three-axis laser displacement sensor, and using a three-dimensional probe. The measurement principle of the laser tracker is to use a reflector and a laser head. When the laser head emits laser light, the laser light is reflected in parallel through the reflector and then returned to the laser. For the shooting head, the tracker calculates the distance from the time difference between emission and reception (ADM mode), or uses the interference calculation distance of laser light waves (IFM mode) to measure the distance between the laser head and the reflector. Then calculate the three-dimensional position coordinates of the reflector from the horizontal angle and pitch angle parameters of the laser head and the distance parameter. When the laser tracker is applied to the positioning of the robot arm, it is to attach the mirror to the end effector of the robot arm, and then measure the three-dimensional position of the end effector from time to time. The conventional technology discloses the erection of three laser displacement sensors perpendicular to each other in space, which is analogous to a three-dimensional coordinate system in space. During measurement, the robot arm is controlled to reach the test center range of the three laser displacement sensors to ensure that the three laser displacement sensors are The road light is projected to the end effector of the robot arm, and the position of the end effector of the robot arm in the three coordinate axes can be measured by the principle of the diffuse reflection of the laser light.

When the laser tracker is used to verify the positioning accuracy of the robotic arm, there are three shortcomings: 1. Its positioning accuracy is poor, and it becomes larger as the tracking distance increases. The positioning accuracy performance depends on different brands. Generally speaking, it is about 25um at about 5 meters and about 80um at 80 meters. 2. The tracking and positioning speed of the laser tracker is slow, so the moving speed of the robotic arm will be limited. 3. This measurement and correction system is more expensive.

Use a three-dimensional laser displacement meter or a three-dimensional contact probe to measure the positioning accuracy of a robot arm. Generally, the measuring points in the three directions are not the same. The position coordinates of the measuring points can be obtained through calculation. This indirectness The measurement method will affect the positioning accuracy. In addition, the measurement can only be done within the preset range, and three mutually perpendicular measurement devices must be reconstructed for different positions. It is very troublesome.

The reason is that, in view of this, the inventor upholds many years of rich experience in design and development and actual production in the related industry, and has researched and improved the current traditional robotic arm repeat positioning accuracy measurement method to provide a robotic arm repeat positioning accuracy measurement. The device and method in order to achieve the purpose of better practical value.

In view of the shortcomings of the above-mentioned known technology, the main purpose of the present invention is to provide a device and method for measuring repeated positioning accuracy of a robotic arm. 0.1um, fast positioning speed, and the entire calibration module is very cheap.

In order to achieve the above objective, according to a solution proposed by the present invention, a device for measuring repeat positioning accuracy of a robotic arm is provided, which includes: a light spot three-dimensional displacement sensor with two mutually perpendicular non-deformable light spot imaging devices And a laser displacement sensor; a two-dimensional laser interferometer calibration platform, with a spot image three-dimensional positioning base and the spot three-dimensional displacement sensor, the spot three-dimensional displacement sensor three laser beams To the same position of the spot image three-dimensional positioning base, to capture the two spot images and a height value of the position, and to create a plurality of spot images and a plurality of height values of the plurality of positions of the spot image three-dimensional positioning base Two-coordinate spot image and one three-dimensional positioning coordinate and one spot coordinate database; a robotic arm repeat positioning accuracy test platform, which is composed of a three-dimensional positioning base for the spot image whose three sides are perpendicular to each other. Wherein each of the light spot image three-dimensional positioning base has established the light spot coordinate database; and a robotic arm, the end effector of the robotic arm is equipped with the light spot three-dimensional displacement sensor; wherein the light spot is made by moving the robotic arm The three-dimensional displacement sensor enters into a spot three-dimensional absolute positioning space of the robotic arm repeat positioning accuracy test platform to capture the spot image of a positioning point and compare the coordinate spot image of the spot coordinate database to obtain the The relative displacement of the positioning point relative to the X-axis and Y-axis of the coordinate image is matched with the Z-axis height parameter of the spot 3D displacement sensor and the 3D positioning coordinates of the coordinate spot image to obtain the robot arm at this time The three-dimensional absolute positioning coordinates of the end effector.

Preferably, the non-deformable spot imaging device is used to measure the displacement of any point on the surface of the object in the X-axis direction and the Y-axis direction, and is an X-axis displacement sensor and a Y-axis displacement sensor, respectively.

Preferably, the laser displacement sensor can be a laser confocal displacement sensor, a color confocal displacement sensor, a white light interference displacement sensor or a triangular measurement laser displacement sensor, which is a Z Axis displacement sensor.

Preferably, the detection laser beams of the X-axis displacement sensor, the Y-axis displacement sensor and the Z-axis displacement sensor all hit the same point on the surface of the spot image three-dimensional positioning base, and each mine The difference between the working wavelengths of the beams is at least 20nm, and a ±5nm interference filter is installed in front of the receiving lens of each displacement sensor to filter out the scattered light of the other two lasers so that the three laser beams do not interfere with each other.

Preferably, the three-dimensional absolute positioning space of the light spot is The spot image is positioned above the three-dimensional base, and the spot three-dimensional displacement sensor measures the three-dimensional space within the height.

Preferably, the light spot three-dimensional displacement sensor continuously captures images at more than 10 kHz.

In order to achieve the above objective, according to a solution proposed by the present invention, a method for measuring repeat positioning accuracy of a robotic arm, the steps are: (A) Establish a two-dimensional laser interferometer calibration platform to sense the three-dimensional displacement of a spot The three laser beams of the device hit the same position on the three-dimensional positioning base of a spot image to capture the two spot images and a height value of the position, and the multiple spot images of the multiple positions of the three-dimensional positioning base of the spot image And a plurality of height values to establish a spot coordinate database with two-coordinate spot images and one three-dimensional positioning coordinate; (B) to establish a robotic arm repeat positioning accuracy test platform, which consists of a three-dimensional positioning base for the spot images perpendicular to each other on three sides, Wherein each of the light spot image three-dimensional positioning base has established the light spot coordinate database; (C) installing the light spot 3D displacement sensor on the end effector of the robotic arm; and (D) by moving the robotic arm Make the spot 3D displacement sensor enter the spot 3D absolute positioning space of the robotic arm repeat positioning accuracy test platform to capture the spot image of a positioning point and compare it with the coordinate spot image of the spot coordinate database, To obtain the relative displacement of the positioning point relative to the X-axis and Y-axis of the coordinate image, and then cooperate with the Z-axis height parameter of the spot three-dimensional displacement sensor and the three-dimensional positioning coordinate of the coordinate spot image to obtain this time The three-dimensional absolute positioning coordinates of the end effector of the robotic arm.

The above summary, the following detailed description and the accompanying drawings are all intended to further illustrate the methods, means and effects adopted by the present invention to achieve the intended purpose. The other objectives and advantages of the present invention will be described in the following description and drawings.

1: Three-dimensional positioning base for spot image

2: Spot three-dimensional displacement sensor

3: X-axis interferometer

4: Y-axis interferometer

5: 3D displacement sensor base

6: Y-axis displacement sensor

7: Z axis displacement sensor

8: X-axis displacement sensor

9: Anchor point

10: Anchor point

11: anchor point

12: Positioning track

A, B, C: test surface

(x _i ,y _j ,z _k ): positioning coordinates

(I _p ,I _q ) _{X axis} , (I _p ,I _q ) _{Y axis} : coordinate spot image

S1-S5: steps

The first figure is a schematic diagram of the structure of the spot 3D displacement sensor of the present invention.

The second figure is a schematic diagram of the architecture of the two-dimensional laser interferometer calibration platform of the present invention.

The third diagram is a diagram of a light spot coordinate database with X-axis coordinate image, Y-axis coordinate image, and three-dimensional positioning coordinate established on the light spot image three-dimensional positioning base according to the present invention.

The fourth figure is a schematic diagram of the test platform for repeat positioning accuracy of the robotic arm of the present invention.

The fifth figure is a schematic diagram of the test platform for the repeated positioning accuracy of the robot arm relative to the test surface according to the present invention.

The sixth figure is a schematic diagram of the testing platform for the repeated positioning accuracy of the robotic arm relative to the test surface according to the present invention.

The seventh figure is a schematic diagram of the testing platform for the repeated positioning accuracy of the robotic arm relative to the test surface according to the present invention.

The eighth figure is the repeated positioning accuracy test of the robotic arm of the present invention in the three-dimensional absolute positioning space of the light spot on the test surface. Schematic diagram of the platform.

The ninth figure is a flow chart of a method for measuring repeat positioning accuracy of a robotic arm according to the present invention.

The following is a specific example to illustrate the implementation of the present invention. Those familiar with the art can easily understand the advantages and effects of the creation from the content disclosed in this specification.

Please refer to the first to the ninth figure. The present invention is to provide a device for measuring repeat positioning accuracy of a robotic arm, using the spot three-dimensional displacement sensor 2 developed by the applicant to cooperate with the low thermal expansion spot image three-dimensional positioning base 1 for which the spot coordinate database has been established, and Three-dimensional absolute positioning space of the light spot. Install the spot 3D displacement sensor 2 on the end effector of the robot arm, move the robot arm to make the spot 3D displacement sensor 2 enter the spot 3D absolute positioning space of the spot image 3D positioning base 1, and capture the positioning points 9, 10 and 11 of the spot image and height value, and then compare the real-time obtained spot image with the coordinate spot image (I _p ,I _q ) _{X axis} , (I _p ,I _q ) _{Y axis of the} spot coordinate database, then you can Obtain the three-dimensional absolute positioning coordinates of the end effector of the robotic arm at this time.

In detail, a device for measuring repeated positioning accuracy of a robotic arm of the present invention includes: a light spot three-dimensional displacement sensor 2, a two-dimensional laser interferometer calibration platform, and a testing platform for repeated positioning accuracy of the robotic arm.

The spot three-dimensional displacement sensor 2 has two mutually perpendicular non Deformed spot imaging device and laser displacement sensor. Please refer to the Applicant's Republic of China Invention No. I 340910 and US Patent 7,715,016 B2 for the non-deformable light spot imaging device disclosed in this case. Two non-deformable spot imaging devices and a laser displacement sensor are used to construct the spot 3D displacement sensor 2. Referring to the first figure, install two perpendicular non-deformation sensors on the base 5 of the 3D displacement sensor. The light spot imaging device is used to measure the displacement of any point on the surface of the object in the X-axis direction and the Y-axis direction. They are the X-axis displacement sensor 8 and the Y-axis displacement sensor 6, respectively. A displacement sensor that can accurately measure the Z-axis direction is installed directly above the three-dimensional displacement sensor base 5. It can be a laser confocal displacement sensor, a color confocal displacement sensor, and a white light interference displacement sensor. It is a Z-axis displacement sensor 7 such as a sensor or a triangulation laser displacement sensor. The detection laser beams of X-axis displacement sensor 8, Y-axis displacement sensor 6 and Z-axis displacement sensor 7 all hit the same point on the object surface, and the working wavelength of each laser beam differs by at least 20nm, and each displacement A ±5nm interference filter is installed in front of the receiving lens of the sensor to filter out the scattered light of the other two lasers so that all three laser beams do not interfere with each other.

The two-dimensional laser interferometer calibration platform is set up on the optical table with a high-rigidity low thermal expansion spot image three-dimensional positioning base 1, X-axis laser interferometer, Y-axis laser interferometer, X-axis translation stage, Y-axis translation In order to obtain accurate measurement value of the spot image displacement that does not change with the ambient temperature, we need to use a low thermal expansion coefficient (not easy to change the length), high stiffness coefficient (not easy to deform) of the spot image three-dimensional Positioning base 1 is used to establish the light spot coordinate database. This kind of positioning base that is not easy to deform and change the length is like a flower Rock positioning base, zero-expansion glass positioning base, zero-expansion ceramic plate positioning base, etc. Please refer to the second figure, the X-axis translation stage is erected on the Y-axis translation stage, and the two are perpendicular to each other; the X-axis interferometer 3's laser transmitting and receiving head and interferometer are installed on the side of the X-axis translation stage, and its mirror Installed on the slider of the X-axis translation stage to adjust the direction of the laser beam. When the slider is moved, the laser beam reflected by the reflector is stably projected into the laser receiving hole; the laser beam of the Y-axis interferometer 4 The transmitting and receiving head and the interferometer are installed on the side of the optical table, and the reflector is installed on the X-axis translation stage. Adjust the laser beam of the Y-axis interferometer 4 to be perpendicular to the laser beam of the X-axis interferometer 3. When the X-axis translation stage is moved, the laser beam reflected by its mirror is stably projected into the laser receiving hole; the beam spot 3D displacement sensor 2 is installed on the X-axis translation stage slider, and its three laser beams Hit the same position of the spot image three-dimensional positioning base 1, adjust the height of the spot three-dimensional displacement sensor 2, so that the X and Y two-axis displacement sensors 8, 6 can capture good real-time spot images, and the Z-axis displacement sense The detector 7 can measure the real-time height value of the three-dimensional positioning base 1 of the light spot image.

Then, the multiple spot images and the multiple height values of the multiple positions of the measured spot image three-dimensional positioning base 1 are created to have a coordinate spot image (I _p , I _q ) _{X axis} , (I _p , I _q ) _{Y Axis} and three-dimensional positioning coordinates (x _i , y _j , z _k ) of the spot coordinate database, in detail, move the X and Y-axis translation stage of the two-dimensional laser interferometer calibration platform to make the X-axis translation stage slide The spot three-dimensional displacement sensor 2 has three laser beams hitting the origin of the spot image three-dimensional positioning base 1, and the coordinate spot image (I _p , I _q ) of the _{X-axis displacement sensor 8 at this time is recorded 1 ,1-X axis, p=1-n, q=1-m} , Y-axis displacement sensor 6 coordinate spot image (I _p , I _q ) _{1, 1-Y axis, p=1-n, q =1-m and the height value (h 1,1} ) of the Z-axis displacement sensor 7 at this time, where the coordinate spot image (I _p ,I _q ) _{p=1-n, q=1-m} represents the spot image It is an image matrix of an n×m array; the coordinate spot image (I _p , I _q ) _{1,1-X axis} indicates that this is the spot image measured by the X-axis displacement sensor 8 at the position (1,1). Return the displacement output of the two laser interferometers on the X and Y axis to zero, then the spatial coordinates of this point are (x ₁ ,y ₁ ,h _1,1 )=(0,0,h _1,1 ), comprehensive measurement _{Record: The 3D positioning coordinates (0,0,h 1,1} ) of this point and the coordinates of the X-axis displacement sensor 8 (I _p , I _q ) _{1 are} recorded at the origin of the light spot image 3D positioning base 1. _{1-X axis, p=1-n, q=1-m} and Y-axis displacement sensor 6 coordinate spot image (I _p , I _q ) _{1, 1-Y axis, p=1-n, q= 1-m} .

The Y-axis displacement translation stage does not move, and the X-axis displacement stage is moved a fixed distance △, and the coordinate spot image of the X-axis displacement sensor 8 at this time is recorded (I _p , I _q ) _{2, 1-X axis, p=1-n ,q=1-m} , Y-axis displacement sensor 6's coordinate spot image (I _p , I _q ) _{2, 1-Y-axis, p=1-n, q=1-m} , Z-axis displacement sensor The height value of 7 (h _2,1 ), the displacement x _{2 of the X-axis interferometer 3 and the displacement y 1 of the} Y-axis interferometer 4 (in this case y ₁ =0), the comprehensive measurement record: in the light spot image 3D The (2,1) position of the positioning base 1, the three-dimensional positioning coordinates (x ₂ ,0,h _2,1 ) of this point, and the coordinate spot image of the X-axis displacement sensor 8 (I _p , I _q ) _{2 are recorded 2 ,1-X axis, p=1-n, q=1-m} and Y-axis displacement sensor 6 coordinate spot image (I _p ,I _q ) _{2,1-Y axis, p=1-n,q =1-m} . By analogy, the Y-axis displacement stage does not move, and the X-axis displacement stage moves (u-1) times, and the coordinate spot image of the X-axis displacement sensor 8 (I _p ,I _q ) _{u,1-X is recorded at this time Axis, p=1-n, q=1-m} , Y-axis displacement sensor 6 coordinate spot image (I _p , I _q ) _{u, 1-Y axis, p= 1-n, q=1-m} , The height value of the Z-axis displacement sensor 7 (h _u,1 ), the displacement x _{u of the X-axis interferometer 3 and the displacement y 1 of the} Y-axis interferometer 4 (in this case, y ₁ =0), the integrated value Measurement record: At the position of the three-dimensional positioning base (u,1) of the spot image, the three-dimensional positioning coordinates (x _u ,0,h _u,1 ) of this point and the coordinate spot image of the X-axis displacement sensor 8 (I _p ,I _q ) _{u,1-X axis, p=1-n, q=1-m} and Y-axis displacement sensor 6 coordinate spot image (I _p ,I _q ) _{u,1-Y axis, p= 1-n,q=1-m} , complete the first column of coordinate spot image (I _p ,I _q ) _{X axis} , (I _p ,I _q ) _{Y axis} and three-dimensional positioning coordinates (x _i ,y _j ,z _k ) The light spot coordinate database is established.

Use the X-axis interferometer 3 reading to locate, return the X-axis translation stage slider position to the origin (the X-axis interferometer 3 position reading value returns to 0), move the Y-axis translation stage a fixed distance △, and record the X axis at this time The coordinate spot image of the displacement sensor 8 (I _p , I _q ) _{1,2-X axis, p=1-n, q=1-m} , the coordinate spot image of the Y-axis displacement sensor 6 (I _p , I _q ) _{1,2-Y axis, p=1-n, q=1-m} , height value of Z-axis displacement sensor 7 (h _1,2 ), displacement of X-axis interferometer 3 x ₁ ( At this time x ₁ =0) and the displacement y _{2 of the} Y-axis interferometer 4, the comprehensive measurement record: at the position (1,2) of the light spot image three-dimensional positioning base 1, the three-dimensional positioning coordinates (0, y ₂ , h _1,2 ), X-axis displacement sensor 8 coordinate spot image (I _p , I _q ) _{1,2-X axis, p=1-n, q=1-m} and Y-axis displacement sensor The coordinate spot image of the detector 6 (I _p , I _q ) _{1,2-Y axis, p=1-n, q=1-m} . The Y-axis displacement translation stage does not move, and the X-axis displacement stage is moved a fixed distance △, and the coordinate spot image of the X-axis displacement sensor 8 at this time is recorded (I _p , I _q ) _{2,2-X axis, p=1-n ,q=1-m} , Y-axis displacement sensor 6's coordinate spot image (I _p , I _q ) _{2, 2-Y-axis, p=1-n, q=1-m} , Z-axis displacement sensor 7 of height values (h _2,2), X-axis interferometer displacement amount of 3 x ₂ and Y-axis laser interferometer 4 of the displacement amount y _2, integrated measurement record: the image spot in the three-dimensional positioning of the base 1 ( 2,2) position, recorded the three-dimensional positioning coordinates (x ₂ , y ₂ , h _2,2 ) of this point, the coordinate spot image of the X-axis displacement sensor 8 (I _p , I _q ) _{2,2-X axis , p=1-n, q=1-m} and the coordinate spot image of the Y-axis displacement sensor 6 (I _p , I _q ) _{2, 2-Y-axis, p=1-n, q=1-m} . By analogy, the Y-axis displacement stage does not move, the X-axis displacement stage moves (u-1) times, and the coordinate spot image of the X-axis displacement sensor 8 (I _p ,I _q ) _{u,2-X is recorded at this time Axis, p=1-n, q=1-m} , Y-axis displacement sensor 6 coordinate spot image (I _p , I _q ) _{u, 2-Y axis, p=1-n, q=1-m} , The height value of the Z-axis displacement sensor 7 (h _u,2 ), the displacement x _{u of the X-axis interferometer 3 and the displacement y 2 of the} Y-axis interferometer 4, comprehensive measurement records: three-dimensional positioning of the spot image The position (u,2) of the base 1, the three-dimensional positioning coordinates (x _u , y ₂ , h _{u, 2} ) of this point, and the coordinate spot image of the X-axis displacement sensor 8 (I _p , I _q ) _{u are recorded. ,2-X axis, p=1-n,q=1-m} and Y-axis displacement sensor 6 coordinate spot image (I _p ,I _q ) _{u,2-Y axis, p=1-n,q =1-m} , complete the second row of coordinate spot image (I _p , I _q ) _{X axis} , (I _p , I _q ) _{Y axis} and three-dimensional positioning coordinates (x _i , y _j , z _k ) of the spot coordinate database Establish.

Use the X-axis interferometer 3 reading value to locate, return the X-axis translation stage slider position to the original point (the X-axis interferometer 3 position reading value returns to 0), move the Y-axis translation stage a fixed distance △, and record X at this time The coordinate spot image of the axis displacement sensor 8 (I _p , I _q ) _{1, 3-X axis, p=1-n, q=1-m} , the coordinate spot image of the Y axis displacement sensor 6 (I _p ,I _q ) _{1,3-Y axis, p=1-n, q=1-m} , height value of Z-axis displacement sensor 7 (h _1,3 ), displacement of X-axis interferometer 3 x ₁ (At this time x ₁ =0) and the displacement y _{3 of the} Y-axis interferometer 4, the comprehensive measurement record: At the position (1,3) of the light spot image 3D positioning base 1, the 3D positioning coordinates of this point (0 ,y ₃ ,h _1,3 ), X-axis displacement sensor 8 coordinate spot image (I _p , I _q ) _{1, 3-X axis, p=1-n, q=1-m} and Y-axis displacement The coordinate spot image (I _p , I _q ) of the _{sensor 6 is 1, 3-Y axis, p=1-n, q=1-m} . By analogy, the Y-axis displacement stage does not move, and the X-axis displacement stage moves (u-1) times, and the coordinate spot image of the X-axis displacement sensor 8 is recorded at this time (I _p ,I _q ) _{u,3-X Axis, p=1-n, q=1-m} , Y-axis displacement sensor 6 coordinate spot image (I _p , I _q ) _{u, 3-Y axis, p=1-n, q=1-m} , The height value of the Z-axis displacement sensor 7 (h _u,3 ), the displacement x _{u of the X-axis interferometer 3 and the displacement y 3 of the} Y-axis interferometer 4, comprehensive measurement records: three-dimensional positioning of the spot image The position (u,3) of the base 1, the three-dimensional positioning coordinates (x _u , y ₃ , h _{u, 3} ) of this point, and the coordinate spot image of the X-axis displacement sensor 8 (I _p , I _q ) _{u are recorded ,3-X axis, p=1-n, q=1-m} and Y-axis displacement sensor 6 coordinate spot image (I _p , I _q ) _{u, 3-Y axis, p=1-n, q =1-m} , complete the third row of coordinate spot image (I _p , I _q ) _{X axis} , (I _p , I _q ) _{Y axis} and three-dimensional positioning coordinates (x _i , y _j , z _k ) of the spot coordinate database Establish.

By analogy, the Y-axis displacement platform moves (v-1) times, and the X-axis displacement platform moves (u-1) times. At this time, the coordinate spot image of the X-axis displacement sensor 8 (I _p , I _{q) is recorded.} ) _{u, vX axis, p=1-n, q=1-m} , Y axis displacement sensor 6 coordinate spot image (I _p , I _q ) _{u, vY axis, p=1-n, q=1 -m} , the height value of the Z-axis displacement sensor 7 (h _u,v ), the displacement x _{u of the X-axis interferometer 3 and the displacement y v of the} Y-axis interferometer 4, comprehensive measurement records: in the spot image The (u,v) position of the three-dimensional positioning base 1, the three-dimensional positioning coordinates (x _u , y _v , h _{u, v} ) of this point, and the coordinate spot image of the X-axis displacement sensor 8 (I _p , I _{q) are recorded} ) _{u, vX axis, p=1-n, q=1-m} and Y-axis displacement sensor 6 coordinate spot image (I _p , I _q ) _{u, vY axis, p=1-n, q=1 -m} , complete the u×v array of the light spot image 3D positioning base 1, X axis coordinate light spot image (I _p ,I _q ) _{X axis} , Y axis coordinate image (I _p ,I _q ) _{Y axis} and 3D positioning coordinates ( x _i , y _j , z _k ) database establishment. As shown in the third figure, an X-axis coordinate spot image (I _p , I _q ) _X-axis , Y-axis coordinate image (I _p , I _q ) _Y-axis and three-dimensional positioning coordinate (x _i ,y _j ,z _k ) database, each spot location point (u,v) on the granite three-dimensional positioning base contains location coordinates (x _i ,y _j ,z _k ) _u,v , X-axis coordinate spot Image (I _p , I _q ) _{u, vX axis, p=1-n, q=1-m} and Y-axis coordinate spot image (I _p , I _q ) _{u, vY axis, p=1-n, q= 1-m} .

In this embodiment, the X, Y, and Z three-axis displacement sensors 6, 7, and 8 on the spot 3D displacement sensor 2 have a certain measurement range on the Z axis, such as being too close to the measuring surface or If it is too far, the three-axis displacement sensors 6, 7, and 8 will not be able to measure the correct displacement. Therefore, above the spot image 3D positioning base 1, the spot 3D displacement sensor 2 can accurately and quickly obtain the 3D absolute positioning coordinates of the spot 3D displacement sensor 2 relative to the spot image 3D positioning base 1 within a certain amount of height measurement. Therefore, above the spot image 3D positioning base 1, the spot 3D displacement sensor 2 measures the 3D space within the height, which is defined as the spot 3D absolute positioning space. As long as the spot 3D displacement sensor 2 is moved to the spot 3D absolute position In the positioning space, the three-dimensional absolute positioning coordinates of the spot three-dimensional displacement sensor 2 can be accurately and quickly measured.

The testing platform for repeat positioning accuracy of the robotic arm is composed of three-sided perpendicular light spot image three-dimensional positioning base 1. Each light spot image three-dimensional positioning base 1 has established a light spot coordinate database. In this embodiment, it is tested according to the performance of the robotic arm. If necessary, the spot image three-dimensional positioning base 1 can be combined arbitrarily. As shown in the fourth figure, the three-sided positioning coordinates (x _i , y _j , z _k ) _{u, v} and the X-axis coordinate spot image (I _p , I _q ) _{u, vX axis, p=1-n, q=1-m} and Y axis coordinate spot image (I _p , I _q ) _{u, vY axis, p=1-n, q=1-m} spot coordinate The light spot image 3D positioning base 1 of the database is combined into a mutually perpendicular robotic arm to repeat positioning accuracy test platform, and the robotic arm installed with the light spot 3D displacement sensor 2 is moved to any 3D positioning base 1 surface of the test platform In the three-dimensional absolute positioning space of the spot, capture the X-axis spot image, the Y-axis spot image and the Z-axis real-time height, and the X, Y-axis spot image and its coordinate spot image (I _p , I _q ) _X-axis , (I _p , I _q ) The _Y-axis database comparison can obtain the 3D absolute positioning coordinates of the end effector of the robotic arm relative to the 3D positioning base 1 of the light spot image in real time.

In detail, the surface of the three-spot image 3D positioning base 1 of the robotic arm repeat positioning accuracy test platform is calibrated into three test surfaces A, B, and C. Each of the test surfaces A, B, and C is They are perpendicular to each other, as shown in the fifth figure. Install the spot 3D displacement sensor 2 on the end effector of the robot arm, move the robot arm to make the spot 3D displacement sensor 2 on the end effector enter the spot 3D absolute positioning space of the test surface A, and capture the positioning point 9 The X-axis spot image, the Y-axis spot image and the Z-axis real-time height. Compare these two real-time spot images with the spot coordinate database to obtain the three-dimensional absolute position of the end effector of the robot arm relative to the surface A of the test surface. Positioning coordinates, record the rotation angle of each axis of the robotic arm at this time and the positioning relative to the surface A of the test surface The three-dimensional absolute positioning coordinates of the base completed the first positioning test of the end effector of the robotic arm. Move the robot arm away or return it to its original position, and then issue instructions to each axis of the robot arm, and turn to the test recording angle in sequence. After the end effector of the robot arm is positioned, then capture the X-axis spot image and Y-axis of the positioning point 9 The spot image and the real-time height of the Z-axis. Compare these two real-time spot images with the spot coordinate database to obtain the second three-dimensional absolute positioning coordinates of the end effector of the robotic arm relative to the surface A of the test surface. The same method, Perform n times the 3D absolute positioning coordinates of the end effector of the robotic arm relative to the A surface of the test surface, and calculate the three-dimensional absolute positioning coordinate data of the n times of positioning to obtain the repeat positioning accuracy related parameters of the robot arm relative to the A surface of the test surface. .

In the same way, as shown in the sixth figure, move the robot arm actuator into the 3D absolute positioning space of the spot on the test surface B, and capture the X-axis spot image, Y-axis spot image and Z-axis real-time height of the positioning point 10. The two real-time spot images are compared with the spot coordinate database, and the three-dimensional absolute positioning coordinates of the end effector of the robot arm relative to the positioning base of surface B can be obtained in real time, and the rotation angle of each axis of the robot arm and the positioning relative to surface B can be recorded at this time The three-dimensional absolute positioning coordinates of the base. Repeatedly execute the three-dimensional absolute positioning coordinates of the end effector of the robotic arm relative to the B surface positioning base for n times, and count the three-dimensional absolute positioning coordinate data of the positioning n times to obtain the posture of the robotic arm relative to the B surface. Repeat positioning accuracy related parameters.

In the same way, as shown in the seventh figure, move the actuator of the robotic arm into the 3D absolute positioning space of the spot on the C surface, and capture the X-axis spot shadow of the positioning point 11. By comparing the two real-time spot images with the spot coordinate database of the image, Y-axis spot image and Z-axis real-time height, the three-dimensional absolute positioning coordinates of the end effector of the robotic arm relative to the C-plane positioning base can be obtained in real time, and the time is recorded. The rotation angle of each axis of the robotic arm and the three-dimensional absolute positioning coordinates relative to the C-plane positioning base. Repeatedly execute the three-dimensional absolute positioning coordinates of the robotic arm end effector relative to the C-plane positioning base, and count n times of positioning and three-dimensional absolute positioning. Coordinate data can be used to obtain the relevant parameters of the repeated positioning accuracy of the robot arm relative to the C-plane posture.

Above, by moving the robot arm, the spot 3D displacement sensor 2 enters the spot 3D absolute positioning space of the robot arm repeat positioning accuracy test platform to capture the spot images of the positioning points 9, 10, and 11 and the spot coordinate database. The coordinate facula image (I _p , I _q ) _{X axis} , (I _p , I _q ) _{Y axis are} compared to obtain the positioning points 9, 10, 11 relative to the coordinate image (I _p , I _q ) _{X axis} , (I _p, I _q) X-axis and _Y-axis of the Y-axis relative displacement amount, matched with the spot of the three-dimensional displacement sensors 2 and Z-axis coordinate spot image height parameter (I _p, I _{q) X-axis,} (I _p, I _q ) The three-dimensional positioning coordinates of the _{Y axis (x i} , y _j , z _k ) can obtain the three-dimensional absolute positioning coordinates of the end effector of the robotic arm at this time.

From the fifth to seventh pictures, it can be clearly seen that the postures of the robotic arm at different positioning points 9, 10, and 11 in space are very different. The three-dimensional absolute positioning space of the light spot can meet the repeated positioning accuracy test of various postures of the robotic arm. It is not only the repeated positioning accuracy test of a single point in space, but also the repeated positioning accuracy test of the positioning trajectory of the continuous movement of the robot arm. As shown in the eighth figure, the end effector of the robotic arm clamps the spot 3D displacement sensor 2 to position the base on the A side. Draw a square trajectory in the three-dimensional absolute positioning space of the light spot of the seat, draw a triangular trajectory in the three-dimensional absolute positioning space of the light spot on the B-side positioning base, and draw a circular trajectory in the three-dimensional absolute positioning space of the light spot on the C-side positioning base. Since the X and Y axis displacement sensors 8 and 6 of the light spot 3D displacement sensor 2 can continuously take images and compare positioning over 10kHz, the Z axis displacement sensor 7 can even be positioned continuously at 49kHz, for a 1m/sec movement speed The robot arm can be positioned correctly in the absolute positioning space of the light spot, so no matter any movement trajectory, as long as it is in the absolute positioning space of the light spot, the repeated positioning accuracy of the robot arm can be measured correctly.

Please refer to Figure 9, a flow chart of a method for measuring repeat positioning accuracy of a robotic arm. The steps are: Steps S1 and S2: Establish a two-dimensional laser interferometer calibration platform, using three beams of the spot three-dimensional displacement sensor 2 The beam hits the same position of the spot image three-dimensional positioning base 1 to capture the spot image and height value at that position, and the multiple spot images and the multiple height values of the multiple positions of the spot image three-dimensional positioning base 1 are created with Positioning coordinates (x _i , y _j , z _k ) _{u, v} , X-axis coordinate spot image (I _p , I _q ) _{u, vX axis, p=1-n, q=1-m} and Y-axis coordinate spot image (I _p ,I _q ) _{u, vY axis, p=1-n, q=1-m} light spot coordinate database; Step S3: Establish a test platform for repeated positioning accuracy of the robotic arm, and three-dimensionally position the light spot images perpendicular to each other The base 1 is composed of a light spot image three-dimensional positioning base 1 which has established a light spot coordinate database; Steps S4, S5: Install the light spot 3D displacement sensor 2 on the end effector of the robot arm, and move the machine The arm makes the spot 3D displacement sensor 2 enter the spot 3D absolute positioning space of the robotic arm repeat positioning accuracy test platform to capture the spot image of the positioning points 9, 10, 11 and the coordinate spot image of the spot coordinate database (I _p ,I _q ) _X-axis , (I _p ,I _q ) _Y-axis comparison to obtain the location points 9, 10, 11 relative to the coordinate spot image (I _p ,I _q ) _{X axis} , (I _p ,I _q ) _The relative displacement (△x, △y) of the X axis and the Y axis of the Y axis, coupled with the Z axis height parameter (△z) of the spot 3D displacement sensor 2 and the coordinate spot image (I _p , I _q ) _{X axis} , (I _p ,I _q ) _Y-axis three-dimensional positioning coordinates (x _i , y _j , z _k ), then the three-dimensional absolute positioning coordinates of the end effector of the robotic arm (x _i +△x, y _j) +△y, z _k +△z).

In summary, the most direct way to increase the value of robots is to improve the positioning accuracy of the robot arms. The present invention discloses a device and method for measuring repeat positioning accuracy of a robot, which cooperates with the precision measurement positioning technology of a multi-axis robotic arm that the inventor has developed (see: Patent Invention No. I 646305 of the Republic of China, US Patent US 10,632,622 B2, Japanese Patent No. 6666321), from the precise measurement of the angle error and deformation error of each rotation axis of the robotic arm, and the positioning error measurement data of the end effector of the robotic arm, we have the opportunity to develop a set that can be accurate The technology of compensating the positioning error of the robot arm effectively improves the quality of domestic robots and reaches the international first-class level. Therefore, it is estimated that this patented technology can increase the income of related industries by billions of yuan.

The above-mentioned embodiments are merely illustrative to illustrate the characteristics and effects of this creation, and are not intended to limit the scope of the essential technical content of the present invention. Anyone familiar with this technique can modify and change the above-mentioned embodiments without violating the spirit and scope of creation. Therefore, the protection scope of the present invention should be as The scope of patent application described later is listed.

S1-S5: steps

Claims (10)

A device for measuring repeat positioning accuracy of a mechanical arm, which includes: a light spot three-dimensional displacement sensor with two orthogonal non-deformable light spot imaging devices and a laser displacement sensor; a two-dimensional laser interference The instrument calibration platform has a spot image three-dimensional positioning base and the spot three-dimensional displacement sensor. The three laser beams of the spot three-dimensional displacement sensor hit the same position on the spot image three-dimensional positioning base to capture the Position two spot images and a height value, and create a spot coordinate database with a two-coordinate spot image and a three-dimensional positioning coordinate of the plurality of spot images and the plurality of height values of the plurality of positions of the three-dimensional positioning base of the spot image ; A robotic arm repeat positioning accuracy test platform is composed of three-sided perpendicular to the light spot image three-dimensional positioning base, wherein each of the light spot image three-dimensional positioning base has established the light spot coordinate database; and a mechanical arm, the machine The spot 3D displacement sensor is installed on the end effector of the arm; the spot 3D displacement sensor is moved into the spot 3D absolute positioning space of the repeat positioning accuracy test platform by moving the robot arm to capture Compare the spot image of an anchor point with the coordinate spot image of the spot coordinate database to obtain the relative displacement of the anchor point relative to the X-axis and Y-axis of the coordinate spot image, and then match the spot's three-dimensional displacement sense The Z-axis height parameter of the detector and the coordinate The three-dimensional positioning coordinates of the light spot image can obtain the three-dimensional absolute positioning coordinates of the end effector of the robotic arm at this time. For example, the device for measuring the repeat positioning accuracy of the robotic arm described in the first item of the scope of patent application, wherein the non-deformable light spot imaging device is used to measure the displacement of any point on the surface of the object in the X-axis direction and the Y-axis direction. They are an X-axis displacement sensor and a Y-axis displacement sensor. The device for measuring repeated positioning accuracy of a robotic arm as described in the second item of the scope of patent application, wherein the laser displacement sensor is a laser confocal displacement sensor, a color confocal displacement sensor, and a white light interference displacement The sensor or triangulation laser displacement sensor is a Z-axis displacement sensor. For example, the device for measuring repeat positioning accuracy of a robotic arm described in item 3 of the scope of patent application, wherein the X-axis displacement sensor, the Y-axis displacement sensor, and the Z-axis displacement sensor have detection laser beams. Hit the same spot on the surface of the three-dimensional positioning base for the spot image, and each laser beam has a working wavelength difference of at least 20nm. Each displacement sensor is equipped with a ±5nm interference filter before the receiving lens to filter out the other two mines. Scattered light is emitted so that the three laser beams do not interfere with each other. The device for measuring repeat positioning accuracy of a robotic arm as described in the first item of the scope of patent application, wherein the spot 3D absolute positioning space is above the spot image 3D positioning base, and the spot 3D displacement sensor measures Three-dimensional space within height. The device for measuring repeat positioning accuracy of a robotic arm as described in the first item of the scope of patent application, wherein the spot three-dimensional displacement sensor continuously captures images at more than 10kHz. A method for measuring repeated positioning accuracy of a robotic arm. The steps are as follows: (A) Establish a two-dimensional laser interferometer calibration platform, and use three laser beams from a spot three-dimensional displacement sensor to hit a spot image three-dimensional positioning base Set the same position to capture the two spot images and a height value of the position, and create a two-coordinate spot image and a three-dimensional image with the multiple spot images and the multiple height values of the multiple positions of the three-dimensional positioning base of the spot image A spot coordinate database of one of the positioning coordinates; (B) Establish a robotic arm repeat positioning accuracy test platform composed of three-dimensional positioning bases of the spot image that are perpendicular to each other on three sides, and each of the three-dimensional positioning bases of the spot image has established the spot Coordinate database; (C) install the spot 3D displacement sensor on the end effector of the robot arm; and (D) move the robot arm so that the spot 3D displacement sensor enters the robot arm to repeat positioning One of the accuracy test platforms is a beam spot in the three-dimensional absolute positioning space to capture the spot image of a positioning point and compare the coordinate spot image of the spot coordinate database to obtain the X axis of the positioning point relative to the coordinate spot image And the relative displacement of the Y-axis, and then cooperate with the Z-axis height parameter of the spot three-dimensional displacement sensor and the coordinate light The three-dimensional positioning coordinates of the spot image can obtain the three-dimensional absolute positioning coordinates of the end effector of the robotic arm at this time. The method for repeating positioning accuracy measurement of a robotic arm as described in item 7 of the scope of patent application, wherein the spot three-dimensional displacement sensor is provided with two orthogonal non-deformable spot imaging devices and a laser displacement sensor , And the non-deformable spot image capturing device is used to measure the displacement of any point on the surface of the object in the X-axis direction and the Y-axis direction. They are an X-axis displacement sensor and a Y-axis displacement sensor, respectively. The method for measuring repeat positioning accuracy of a robotic arm as described in item 8 of the scope of patent application, wherein the laser displacement sensor is a laser confocal displacement sensor, a color confocal displacement sensor, and a white light interference displacement The sensor or triangulation laser displacement sensor is a Z-axis displacement sensor. For example, the method for measuring the repeated positioning accuracy of a robotic arm described in item 9 of the scope of patent application, wherein the X-axis displacement sensor, the Y-axis displacement sensor, and the Z-axis displacement sensor have detection laser beams. Hit the same spot on the surface of the three-dimensional positioning base for the spot image, and each laser beam has a working wavelength difference of at least 20nm. Each displacement sensor is equipped with a ±5nm interference filter before the receiving lens to filter out the other two mines. Scattered light is emitted so that the three laser beams do not interfere with each other.

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