CN117719006A - Position accuracy precision assessment method for industrial robot - Google Patents
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Abstract
The invention relates to the technical field of industrial robots and computer application, and discloses a position accuracy and precision assessment method for an industrial robot, which comprises the steps of presetting a theoretical point O, measuring the pose of the robot moving to the point O, and obtaining a measuring point set {p i And optionally taking 4 measuring points which are not on the same plane, calculating the sphere center O of the outer sphere of the polyhedron formed by the 4 measuring points o Setting the coordinates as initial values of iterative calculation of the spherical center position; and calculating the number of the useful contact points, executing processing modes corresponding to different numbers, and performing corresponding cycle skip until the number meets the first criterion or the second criterion, and finally calculating the accuracy of the output position. The invention processes the repeatability error data of the point-to-point running position of the robot, calculates the movement direction and the translation fluctuation of the sphere center, obtains the global optimal value through linear operation in each iterative calculation, andthe iteration times are effectively reduced, and the calculation efficiency is high.
Description
Technical Field
The invention relates to the field of industrial robots and computer applications, in particular to a position accuracy and precision assessment method for an industrial robot.
Background
The accuracy of the position accuracy is one of important performance indexes of the industrial robot, and the accuracy is high or low and is used for directly reflecting the quality of a robot product, the assembly quality and the service life of the robot product; therefore, the accuracy and precision of the position of the robot can be rapidly and accurately assessed, and the method has important significance. The definition of the position accuracy of the robot and the test method thereof are given in the national standard (GB/T12642) and the ISO standard, but a method for calculating the optimal position accuracy of the robot by measuring the position data is not given. At present, the assessment method of the accuracy and precision of the position of the industrial robot is a research hotspot in academia, and is mainly divided into the following four assessment methods: least Square Method (LSM), convex hull method, target optimization method and geometric search method.
The first type, least Squares (LSM), is an approximation method that provides an error assessment in the International Standard (ISO) and national standard (GB) error assessment related standards, where the error calculated by the method does not meet the requirements of the error assessment standard. When the result evaluated by the least square method is disputed, other accurate methods are still needed to judge the accuracy of the position accuracy of the industrial robot.
And second, convex hull method. Firstly, acquiring useful measurement data of a position; then, a convex hull is constructed by utilizing a convex hull principle, a convex polygon can be quickly constructed by measuring certain points of data by a convex hull method, so that the measured data is contained exactly, and the size of the data to be measured is reduced; and finally, calculating an evaluation result meeting the national standard error evaluation standard by an enumeration method. The convex hull method has advantages in processing a medium or small amount of data, and for a test with a large data scale, the efficiency of the convex hull method needs to be improved.
And thirdly, a target optimization method is an error measurement evaluation method for researching mechanical product parts. The target optimization method specifically comprises the steps of establishing error functions of the traditional shapes of single elements of various parts, analyzing the characteristics of optimal solutions of the error functions, and providing a substitution method to solve the error functions. However, the principle of the displacement method is to construct an evaluation standard by using a plurality of reference points of measured data, and then evaluate the error of the component, wherein the error evaluation process is to replace one existing reference point by another measured point continuously, so that the error index of the evaluation is gradually increased or decreased; when the reference point is now used to meet the optimal solution of the error function, the error index assessed is the error result of the component. However, the proposed permutation method is computationally inefficient. Although the roundness error of the parts can be calculated by adopting a target optimization method such as a particle swarm algorithm, a genetic algorithm, a differential evolution algorithm and the like, the proper error model is generally lacking, and the target optimization problem is difficult to construct.
Fourth, geometric search method. The geometric search method is characterized in that geometric operation is carried out by a small amount of measurement data, more suitable measuring point data are gradually found to construct a circle, and the method generally has high error evaluation efficiency, and the method realizes a standard solution in a plurality of software at present, so that the method is easy to popularize. Errors for assessing other shapes have great advantages, such as cylindrical, spherical, planar, etc.; but is not well suited for use in the assessment of the accuracy of the position of an industrial robot, because the measured data shows a circular shape, and for the assessment of circular errors the "local optimum" of the objective function is the "global optimum".
In view of the above, a simple, rapid and stable method for evaluating the accuracy of the position of an industrial robot is still lacking at present.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a position accuracy and precision assessment method for an industrial robot.
In order to achieve the above purpose, the present invention adopts the following technical scheme: a position accuracy precision assessment method for an industrial robot comprises the following steps:
s1, presetting the coordinates of a theoretical point O as { X, Y, Z }, measuring the pose of the robot moving to the point O, and obtaining a measuring point set {p i }，p i ={x i ,y i ,z i }，p i Is the coordinate value of the robot base coordinate of the measuring point i; wherein i is the measuring point sequence number; i=1, 2, 3, …, N; n is the total number of measuring points;
in the measuring point set {p i Any 4 measuring points which are not on the same plane are taken, and the sphere center O of the outer sphere of the polyhedron formed by the 4 measuring points is calculated o Setting the coordinates as initial values of iterative calculation of the spherical center position;
s2, calculating a measurement point set {p i Each point in } is measured to the sphere center O o Obtain the maximum distance value T max By T max Setting the centre of sphere O for radius o Is a spherical containment region of (2); to the sphere center O o Distance T of (2) max The measurement points of (1) are useful contact points, and the measurement point set {p i The rest of the points in the set are non-contact points, and all the non-contact points are put into the set {r k }；
Wherein k is the number of the non-contact point; k=1, 2, 3, …, M; m is the total number of non-contact points;
s3, judging whether the number of the useful contact points is smaller than 3, if the number of the useful contact points is larger than or equal to 3, jumping to the step S4;
if the number of useful contact points is less than 3, calculating the direction vector of the spherical containment regionV T Setting the over-sphere center O o And the direction vector isV T The straight line of (2) is the straight line to be intersected;
selecting one of the useful contact points as a calibration contact point, and calculating a set {r k Each non-contact point in }r k Vertical bisection plane with nominal contact pointW k ，
The spherical containing area translates along the line to be intersected until the spherical surface of the spherical containing area is in non-contact with the non-contact pointr k Is contacted with the spherical center of the spherical containing area is O k o ，O k o Is a vertical median planeW k Coordinates of an intersection point with the line to be intersected, O k o With O o The distance between them is |O o O k o I, all i O o O k o The I constitutes the set { C };
culling direction vectors from the set { C }, andV T and vector O o O k o The translation fluctuation A of the spherical containing area is the minimum value in the set { C };
combining translational variation A and direction vectorV T Calculating the direction vector of the spherical containment areaV T Center of sphere O after translational movement with translational movement amount A v And assign the coordinates to the sphere center O o Jumping to step S2;
s4, if the number of the useful contact points is greater than 3, jumping to the step S5; if the number of useful contact points is equal to 3, the sphere center O is judged o Whether or not it lies in a plane defined by the 3 useful contact points;
if the sphere center O o Lying in the plane defined by the 3 useful contact points, then jump to step S7; if the sphere center O o Not in the plane defined by the 3 useful contact points, then jump to step S6;
s5, when the number of useful contact points is greater than 3, taking 3 useful contact points as 1 combination, taking 3 useful contact points in each combination as calculation objects, if the sphere center O o All lying in the plane defined by the 3 useful contact points in each combination, then go to step S7;
if at least one combination of the spherical centers O exists o Not in the plane defined by the 3 useful contact points, then determining whether each combination meets the remaining useful contact points and the center O except the useful contact points in the combination o Respectively positioned at two sides of a plane determined by the 3 useful contact points combined by the two sides; if both the two are in accordance, jumping to the step S7;
if at least one combination is not met, jumping to the step S6;
s6, selecting one combination from the combinations conforming to the step S5, selecting 1 useful contact points in the combination as calibration contact points, and calculating a set {r k Each non-contact point in }r k Vertical bisection plane with nominal contact pointW k The method comprises the steps of carrying out a first treatment on the surface of the The circle center of the circumcircle of the 3 useful contact points in the combination is O w ；
Calculating the direction vector of the spherical containment regionV T Setting the over-sphere center O o And the direction vector isV T The straight line of (2) is the straight line to be intersected;
the spherical containing area translates along the line to be intersected until the spherical surface of the spherical containing area is in non-contact with the non-contact pointr k Is contacted with the spherical center of the spherical containing area is O k o ，O k o Is a vertical median planeW k Coordinates of an intersection point with the line to be intersected, O k o With O o The distance between them is |O o O k o I, all i O o O k o The I constitutes the set { C };
culling direction vectors from the set { C }, andV T and vector O o O k o The translation fluctuation A of the spherical containing area is the minimum value in the set { C };
combining translational variation A and direction vectorV T Calculating the direction vector of the spherical containment areaV T Center of sphere O after translational movement with translational movement amount A v And assign the coordinates to the sphere center O o Jumping to step S2;
s7, calculating the sphere center O o The distance B from the theoretical point O is the accuracy of the output position.
Further described, when the number of useful contact points in step S3 is 2, the direction vector of the spherical containment regionV T Equal to the sphere center O o The coordinates of the midpoint of the line segment connected by the 2 useful contact points.
Further described, when the number of useful contact points in step S3 is 1, the direction vector of the spherical containment regionV T Equal to the sphere center O o The coordinates of the useful contact point are subtracted from the coordinates of the useful contact point.
Further elaborating, the direction vector in step S6V T Equal to the sphere center O o The coordinates of the circle center O are subtracted w Is defined by the coordinates of (a).
The invention has the beneficial effects that:
1. the method is used for evaluating the accuracy of the position of the industrial robot, is simple, quick and stable in form, and can provide guidance for improving the processing technology, assembly and error compensation of the industrial robot;
2. the invention processes the repeatability error data of the robot point-to-point running position, presents the geometric characteristics of the spherical error containing region, simplifies the assessment form of the spherical error, calculates the distance between the spherical center position and the actual point position to be the accuracy of the position, and compared with the first-class and second-class assessment methods, the invention is easier to carry out industrial popularization and application;
3. according to the geometric characteristics of the spherical error containing region, the movement direction and the translation fluctuation of the spherical center are calculated, the global optimal value is obtained through linear operation in each iterative calculation, and compared with the local optimal value result of the fourth type of assessment method, the result obtained by the method is more accurate;
4. the method solves the iteration problem of invalid measurement data, the invalid measurement data cannot be added into iteration, the iteration times are effectively reduced, only key measurement data are considered when the target optimizing direction is calculated, and the calculation efficiency is high.
Drawings
Fig. 1 is a schematic flow chart of steps S1 to S3 according to the present invention.
Fig. 2 is a flow chart of step S4 of the present invention.
Fig. 3 is a flow chart of step S5 of the present invention.
Fig. 4 is a schematic flow chart of steps S6 to S7 according to the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings, for the purpose of making the objects, technical solutions and advantages of the present invention more apparent.
A position accuracy precision assessment method for an industrial robot comprises the following steps:
s1, presetting the coordinates of a theoretical point O as { X, Y, Z }, measuring the pose of the robot moving to the point O, and obtaining a measuring point set {p i }，p i ={x i ,y i ,z i }，p i Is the coordinate value of the robot base coordinate of the measuring point i; wherein i is the measuring point sequence number; i=1, 2, 3, …, N; n is the total number of measuring points;
in the measuring point set {p i Any 4 measuring points which are not on the same plane are taken, and the sphere center O of the outer sphere of the polyhedron formed by the 4 measuring points is calculated o Setting the coordinates as initial values of iterative calculation of the spherical center position;
s2, calculating a measurement point set {p i Each point in } is measured to the sphere center O o Obtain the maximum distance value T max By T max Setting the centre of sphere O for radius o Is a spherical containment region of (2); to the sphere center O o Distance T of (2) max The measurement points of (1) are useful contact points, and the measurement point set {p i The rest of the points in the set are non-contact points, and all the non-contact points are put into the set {r k }；
Wherein k is the number of the non-contact point; k=1, 2, 3, …, M; m is the total number of non-contact points;
s3, judging whether the number of the useful contact points is smaller than 3, if the number of the useful contact points is larger than or equal to 3, jumping to the step S4;
if the number of useful contact points is less than 3, calculating the direction vector of the spherical containment regionV T Setting the over-sphere center O o And the direction vector isV T The straight line of (2) is the straight line to be intersected;
when the number of useful contact points in step S3 is 2, the direction vector of the spherical envelope regionV T Equal to the sphere center O o The coordinates of the midpoint of the line segment connected by the 2 useful contact points are subtracted;
when the number of useful contact points in step S3 is 1, the direction vector of the spherical envelope regionV T Equal to the sphere center O o Subtracting the coordinates of the useful contact point;
selecting one of the useful contact points as a calibration contact point, and calculating a set {r k Each non-contact point in }r k Vertical bisection plane with nominal contact pointW k ，
The spherical containing area translates along the line to be intersected until the spherical surface of the spherical containing area is in non-contact with the non-contact pointr k Is contacted with the spherical center of the spherical containing area is O k o ，O k o Is a vertical median planeW k Coordinates of intersection point with line to be intersected, O k o With O o The distance between them is |O o O k o I, all i O o O k o The I constitutes the set { C };
culling direction vectors from the set { C }, andV T and vector O o O k o The translation variation A of the spherical containing area is the minimum value in the set { C };
combining translational variation A and direction vectorV T Calculating the direction vector of the spherical containment regionV T Center of sphere O after translational movement with translational movement amount A v And assigning the coordinates of (a)Giving the sphere center O o Jumping to step S2;
s4, if the number of the useful contact points is greater than 3, jumping to the step S5; if the number of useful contact points is equal to 3, the sphere center O is judged o Whether or not it lies in a plane defined by the 3 useful contact points;
if the sphere center O o Is positioned in the plane determined by the 3 useful contact points, and belongs to the criterion I (note: the criterion I is the criterion of the sphere containing area), then the step S7 is skipped; if the sphere center O o Not in the plane defined by the 3 useful contact points, then jump to step S6;
s5, when the number of useful contact points is greater than 3, taking 3 useful contact points as 1 combination, taking 3 useful contact points in each combination as calculation objects, if the sphere center O o All located in the plane defined by the 3 useful contact points in each combination, which also belongs to the criterion one, and jumps to step S7;
if at least one combination of the spherical centers O exists o Not in the plane defined by the 3 useful contact points, then determining whether each combination meets the remaining useful contact points and the center O except the useful contact points in the combination o Respectively positioned at two sides of a plane determined by the 3 useful contact points combined by the two sides; if both the two criteria are met, the step S7 is skipped;
if at least one combination is not met, jumping to the step S6;
s6, selecting one combination from the combinations conforming to the step S5, selecting 1 useful contact points in the combination as calibration contact points, and calculating a set {r k Each non-contact point in }r k Vertical bisection plane with nominal contact pointW k The method comprises the steps of carrying out a first treatment on the surface of the The circle center of the circumcircle of the 3 useful contact points in the combination is O w ；
Calculating the direction vector of the spherical containment regionV T Setting the over-sphere center O o And the direction vector isV T The straight line of (2) is the straight line to be intersected; at this time, the direction vectorV T Equal to the sphere center O o The coordinates of the circle center O are subtracted w Coordinates of (c);
the spherical containing area translates along the line to be intersected until the spherical surface of the spherical containing area is in non-contact with the non-contact pointr k Is contacted with the spherical center of the spherical containing area is O k o ，O k o Is a vertical median planeW k Coordinates of intersection point with line to be intersected, O k o With O o The distance between them is |O o O k o I, all i O o O k o The I constitutes the set { C };
culling direction vectors from the set { C }, andV T and vector O o O k o The translation variation A of the spherical containing area is the minimum value in the set { C };
combining translational variation A and direction vectorV T Calculating the direction vector of the spherical containment regionV T Center of sphere O after translational movement with translational movement amount A v And assign the coordinates to the sphere center O o Jumping to step S2;
s7, calculating the sphere center O o The distance B from the theoretical point O is the accuracy of the output position. Sphere center O o Is { x } 0 ,y 0 ,z 0 The coordinate of the theoretical point O is { X, Y, Z }, and the calculation formula of the distance B is B= ((X-X) 0 )^2+(Y-y 0 )^2+(Z-z 0 )^2)^(1/2) 。
First embodiment: referring to fig. 1 to 4, a position accuracy assessment method for an industrial robot includes the following steps:
s1, presetting the coordinates of a theoretical point O as { X, Y, Z } = {1800,0, 1000}, measuring the pose of the robot moving to the point O by using laser tracker measuring equipment, and obtaining a measuring point set {p i }，p i ={x i ,y i ,z i }，p i Is the coordinate value of the robot base coordinate of the measuring point i; wherein i is the measuring point sequence number; i=1 and,2, 3, …, N; n is the total number of measuring points;
measuring point set { obtained by laser tracker measuring equipmentp i The acquisition table of the } is specifically shown in the following table.
| i | x i | y i | z i |
| 1 | 1799.818 | 1.0365 | 1000.172 |
| 2 | 1799.823 | 1.0324 | 1000.214 |
| 3 | 1799.833 | 1.0360 | 1000.220 |
| 4 | 1799.831 | 1.0365 | 1000.224 |
| 5 | 1799.834 | 1.0248 | 1000.220 |
| 6 | 1799.835 | 1.0252 | 1000.234 |
| 7 | 1799.835 | 1.0263 | 1000.233 |
| 8 | 1799.839 | 1.0256 | 1000.226 |
| 9 | 1799.844 | 1.0338 | 1000.231 |
| 10 | 1799.835 | 1.0274 | 1000.233 |
| 11 | 1799.837 | 1.0391 | 1000.229 |
| 12 | 1799.843 | 1.0341 | 1000.230 |
| 13 | 1799.844 | 1.0291 | 1000.234 |
| 14 | 1799.840 | 1.0293 | 1000.238 |
| 15 | 1799.838 | 1.0210 | 1000.239 |
| 16 | 1799.843 | 1.0206 | 1000.234 |
| 17 | 1799.839 | 1.0261 | 1000.247 |
| 18 | 1799.846 | 1.0240 | 1000.242 |
| 19 | 1799.846 | 1.0158 | 1000.245 |
| 20 | 1799.849 | 1.0418 | 1000.238 |
| 21 | 1799.847 | 1.0391 | 1000.236 |
| 22 | 1799.849 | 1.0333 | 1000.247 |
| 23 | 1799.841 | 1.0297 | 1000.235 |
| 24 | 1799.847 | 1.0327 | 1000.255 |
| 25 | 1799.848 | 1.0365 | 1000.242 |
| 26 | 1799.846 | 1.0302 | 1000.241 |
| 27 | 1799.845 | 1.0333 | 1000.248 |
| 28 | 1799.843 | 1.0369 | 1000.253 |
| 29 | 1799.848 | 1.0273 | 1000.242 |
| 30 | 1799.849 | 1.0394 | 1000.238 |
In the measuring point set {p i Any 4 measuring points which are not on the same plane are taken, and the sphere center O of the outer sphere of the polyhedron formed by the 4 measuring points is calculated o Coordinates of the sphere center O o = (1799.845,1.034, 1000.213), and this coordinate is set as an initial value of iterative calculation of the center position;
s2, calculating a measurement point set {p i Each point in } is measured to the sphere center O o Obtain the maximum distance value T max ，T max =0.085 mm, at T max Setting the centre of sphere O for radius o Is a spherical containment region of (2); to the sphere center O o Distance T of (2) max The measurement points of (1) are useful contact points, and the measurement point set {p i The rest of the points in the set are non-contact points, and all the non-contact points are put into the set {r k }；
Wherein k is the number of the non-contact point; k=1, 2, 3, …, M; m is the total number of non-contact points;
s3, calculating to obtain a sphere center O o 1 useful contact point with the distance of 0.085mm and the number of useful contact points is less than 3, and the direction vector of the spherical containing area is calculatedV T Setting the over-sphere center O o And the direction vector isV T The straight line of (2) is the straight line to be intersected;
since the number of useful contact points is 1,V T equal to the sphere center O o Subtracting the coordinates of the useful contact point to calculateV T =[0.858，-0.129，-0.497] T ；
The useful contact point is defined as a calibration contact point, and a set { is calculatedr k Each non-contact point in }r k Vertical bisection plane with nominal contact pointW k ，
The spherical containing area translates along the line to be intersected until the spherical surface of the spherical containing area is in non-contact with the non-contact pointr k Is contacted with the spherical center of the spherical containing area is O k o ，O k o Is a vertical median planeW k Coordinates of intersection point with line to be intersected, O k o With O o The distance between them is |O o O k o I, all i O o O k o The I constitutes the set { C };
culling direction vectors from the set { C }, andV T and vector O o O k o The translation fluctuation A of the spherical containing area is the minimum value in the set { C } corresponding to the measuring point in the opposite direction, and the translation fluctuation A=0.011 mm is obtained through calculation;
combining translational variation a=0.011 mm and direction vectorV T =[0.858，-0.129，-0.497] T Calculating the direction vector of the spherical containment regionV T Center of sphere O after translational movement with translational movement amount A v Is calculated to obtain the sphere center O v = (1799.854,1.033, 1000.207) and assign this coordinate to the sphere center O o Sphere center O o =sphere center O v = (1799.854,1.033, 1000.207), jump to step S2;
s2, calculating a measurement point set {p i Each point in } is measured to the sphere center O o Distance of = (1799.854,1.033, 1000.207), maximum distance value T is obtained max ，T max =0.051 mm, in T max Setting the centre of sphere O for radius o Is a spherical containment region of (2); to the sphere center O o Distance T of (2) max The measurement points of (1) are useful contact points, and the measurement point set {p i The rest of the points in the set are non-contact points, and all the non-contact points are put into the set {r k }；
Wherein k is the number of the non-contact point; k=1, 2, 3, …, M; m is the total number of non-contact points;
s3, calculating to obtain a sphere center O o The number of useful contact points with the distance of 0.051mm is 2, the number of useful contact points is less than 3, and the direction vector of the spherical containing area is calculatedV T Setting the over-sphere center O o And the direction vector isV T The straight line of (2) is the straight line to be intersected;
since the number of useful contact points is 2, the direction vector of the spherical containment regionV T Equal to the sphere center O o Subtracting the coordinates of the midpoints of the line segments connected by the 2 useful contact pointsV T =[0.684，-0.095， -0.723] T ；
The useful contact point is defined as a calibration contact point, and a set { is calculatedr k Each non-contact point in }r k Vertical bisection plane with nominal contact pointW k ，
The spherical containing area translates along the line to be intersected until the spherical surface of the spherical containing area is in non-contact with the non-contact pointr k Is contacted with the spherical center of the spherical containing area is O k o ，O k o Is a vertical median planeW k Coordinates of intersection point with line to be intersected, O k o With O o The distance between them is |O o O k o I, all i O o O k o The I constitutes the set { C };
culling direction vectors from the set { C }, andV T and vector O o O k o The translation fluctuation A of the spherical containing area is the minimum value in the set { C } corresponding to the measuring point in the opposite direction, and the translation fluctuation A=0.015 mm is obtained through calculation;
combining translational variation a=0.015 mm and direction vectorV T =[0.684，-0.095， -0.723] T Calculating the direction vector of the spherical containment regionV T Center of sphere O after translational movement with translational movement amount A v Is calculated to obtain the sphere center O v = (1799.865,1.031, 1000.195) and assign this coordinate to the sphere center O o Sphere center O o =sphere center O v = (1799.865,1.031, 1000.195), jump to step S2;
s2, calculating a measurement point set {p i Each point in } is measured to the sphere center O o Distance of = (1799.865,1.031, 1000.195), maximum distance value T is obtained max ，T max =0.0249 mm, at T max Setting the centre of sphere O for radius o Is a spherical containment region of (2); to the sphere center O o Distance T of (2) max The measurement points of (1) are useful contact points, and the measurement point set {p i The rest of the points in the set are non-contact points, and all the non-contact points are put into the set {r k }；
Wherein k is the number of the non-contact point; k=1, 2, 3, …, M; m is the total number of non-contact points;
s3, calculating to obtain a sphere center O o 4 useful contact points with the distance of 0.0249mm, the number of the useful contact points is more than 3, and the step S4 is skipped;
s4, jumping to the step S5, wherein the number of useful contact points is larger than 3;
s5, when the number of the useful contact points is more than 3, taking 3 useful contact points as 1 combination, taking 3 useful contact points in each combination as calculation objects,
calculated wherein at least one combination has a center of sphere O o = (1799.865,1.031, 1000.195) are not located in the plane defined by the 3 useful contact points, and each combination is then determinedWhether or not the other useful contact points except the useful contact point in the self-combination are matched with the sphere center O o Respectively positioned at two sides of a plane determined by the 3 useful contact points combined by the two sides; if the judgment result is met, jumping to the step S7;
s7, calculating the sphere center O o The distance B from the theoretical point O is the accuracy of the output position. Sphere center O o ={x 0 ,y 0 ,z 0 The theoretical point o= { X, Y, Z = {1800,0, 1000}, the calculation formula of the distance B is b= ((X-X) 0 )^2+(Y-y 0 )^2+(Z-z 0 ) 2) 1/2. Calculated, b=1.05 mm, i.e. the accuracy of the output position is 1.05mm.
In the description of the present invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," "outer," and the like indicate or are based on the orientation or positional relationship shown in the drawings, merely to facilitate description of the present invention and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention.
The above description should not be taken as limiting the scope of the invention, and any modifications, equivalent variations and modifications made to the above embodiments according to the technical spirit of the invention still fall within the scope of the technical solutions of the invention.
Claims (4)
1. A position accuracy precision assessment method for an industrial robot is characterized in that: the method comprises the following steps:
s1, presetting the coordinates of a theoretical point O as { X, Y, Z }, measuring the pose of the robot moving to the point O, and obtaining a measuring point set {p i }，p i ={x i ,y i ,z i }，p i Is the coordinate value of the robot base coordinate of the measuring point i; wherein i is the measuring point sequence number; i=1, 2, 3, …, N; n is the total number of measuring points;
at the measuring pointSet {p i Any 4 measuring points which are not on the same plane are taken, and the sphere center O of the outer sphere of the polyhedron formed by the 4 measuring points is calculated o Setting the coordinates as initial values of iterative calculation of the spherical center position;
s2, calculating a measurement point set {p i Each point in } is measured to the sphere center O o Obtain the maximum distance value T max By T max Setting the centre of sphere O for radius o Is a spherical containment region of (2); to the sphere center O o Distance T of (2) max The measurement points of (1) are useful contact points, and the measurement point set {p i The rest of the points in the set are non-contact points, and all the non-contact points are put into the set {r k }；
Wherein k is the number of the non-contact point; k=1, 2, 3, …, M; m is the total number of non-contact points;
s3, judging whether the number of the useful contact points is smaller than 3, if the number of the useful contact points is larger than or equal to 3, jumping to the step S4;
if the number of useful contact points is less than 3, calculating the direction vector of the spherical containment regionV T Setting the over-sphere center O o And the direction vector isV T The straight line of (2) is the straight line to be intersected;
selecting one of the useful contact points as a calibration contact point, and calculating a set {r k Each non-contact point in }r k Vertical bisection plane with nominal contact pointW k ，
The spherical containing area translates along the line to be intersected until the spherical surface of the spherical containing area is in non-contact with the non-contact pointr k Is contacted with the spherical center of the spherical containing area is O k o ，O k o Is a vertical median planeW k Coordinates of an intersection point with the line to be intersected, O k o With O o The distance between them is |O o O k o I, all i O o O k o The I constitutes the set { C };
culling direction vectors from the set { C }, andV T and vector O o O k o The translation fluctuation A of the spherical containing area is the minimum value in the set { C };
combining translational variation A and direction vectorV T Calculating the direction vector of the spherical containment areaV T Center of sphere O after translational movement with translational movement amount A v And assign the coordinates to the sphere center O o Jumping to step S2;
s4, if the number of the useful contact points is greater than 3, jumping to the step S5; if the number of useful contact points is equal to 3, the sphere center O is judged o Whether or not it lies in a plane defined by the 3 useful contact points;
if the sphere center O o Lying in the plane defined by the 3 useful contact points, then jump to step S7; if the sphere center O o Not in the plane defined by the 3 useful contact points, then jump to step S6;
s5, when the number of useful contact points is greater than 3, taking 3 useful contact points as 1 combination, taking 3 useful contact points in each combination as calculation objects, if the sphere center O o All lying in the plane defined by the 3 useful contact points in each combination, then go to step S7;
if at least one combination of the spherical centers O exists o Not in the plane defined by the 3 useful contact points, then determining whether each combination meets the remaining useful contact points and the center O except the useful contact points in the combination o Respectively positioned at two sides of a plane determined by the 3 useful contact points combined by the two sides; if both the two are in accordance, jumping to the step S7;
if at least one combination is not met, jumping to the step S6;
s6, selecting one combination from the combinations conforming to the step S5, selecting 1 useful contact points in the combination as calibration contact points, and calculating a set {r k Each non-contact point in }r k Vertical bisection plane with nominal contact pointW k The method comprises the steps of carrying out a first treatment on the surface of the The circle center of the circumcircle of the 3 useful contact points in the combination is O w ；
Calculating the direction vector of the spherical containment regionV T Setting the over-sphere center O o And the direction vector isV T The straight line of (2) is the straight line to be intersected;
the spherical containing area translates along the line to be intersected until the spherical surface of the spherical containing area is in non-contact with the non-contact pointr k Is contacted with the spherical center of the spherical containing area is O k o ，O k o Is a vertical median planeW k Coordinates of an intersection point with the line to be intersected, O k o With O o The distance between them is |O o O k o I, all i O o O k o The I constitutes the set { C };
culling direction vectors from the set { C }, andV T and vector O o O k o The translation fluctuation A of the spherical containing area is the minimum value in the set { C };
combining translational variation A and direction vectorV T Calculating the direction vector of the spherical containment areaV T Center of sphere O after translational movement with translational movement amount A v And assign the coordinates to the sphere center O o Jumping to step S2;
s7, calculating the sphere center O o The distance B from the theoretical point O is the accuracy of the output position.
2. A position accuracy assessment method for an industrial robot according to claim 1, characterized in that: when the number of useful contact points in step S3 is 2, the direction vector of the spherical containment regionV T Equal to the sphere center O o The coordinates of the midpoint of the line segment connected by the 2 useful contact points.
3. A position accuracy assessment method for an industrial robot according to claim 1, characterized in that: when the number of useful contact points in step S3 is 1, the direction vector of the spherical containment regionV T Equal to the sphere center O o The coordinates of the useful contact point are subtracted from the coordinates of the useful contact point.
4. A position accuracy assessment method for an industrial robot according to claim 1, characterized in that: direction vector in step S6V T Equal to the sphere center O o The coordinates of the circle center O are subtracted w Is defined by the coordinates of (a).
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20080188986A1 (en) * | 2004-10-25 | 2008-08-07 | University Of Dayton | Method and System to Provide Improved Accuracies in Multi-Jointed Robots Through Kinematic Robot Model Parameters Determination |
| CN103063213A (en) * | 2013-01-04 | 2013-04-24 | 上海交通大学 | Calibration method of position relationship between welding robot and position changer |
| CN103278126A (en) * | 2013-06-11 | 2013-09-04 | 陈磊磊 | Sphericity error assessment method for part based on minimum area |
| CN103292674A (en) * | 2013-06-11 | 2013-09-11 | 陈磊磊 | Method for calculating function size of sphere part |
| CN103895023A (en) * | 2014-04-04 | 2014-07-02 | 中国民航大学 | Mechanical arm tail end tracking and measuring system and method based on coding azimuth device |
| CN109465826A (en) * | 2018-11-13 | 2019-03-15 | 南京工程学院 | One kind being based on the equally distributed industrial robot TCP scaling method of posture |
| CN114083534A (en) * | 2021-11-11 | 2022-02-25 | 浙江大学 | Mechanical arm kinematics MDH parameter calibration method based on adaptive gradient descent |
| CN114770517A (en) * | 2022-05-19 | 2022-07-22 | 梅卡曼德（北京）机器人科技有限公司 | Method for calibrating robot through point cloud acquisition device and calibration system |
| CN115533893A (en) * | 2022-08-25 | 2022-12-30 | 浙江工业大学 | Robot TCP calibration method using floatable standard sphere |
-
2024
- 2024-02-07 CN CN202410172058.8A patent/CN117719006A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20080188986A1 (en) * | 2004-10-25 | 2008-08-07 | University Of Dayton | Method and System to Provide Improved Accuracies in Multi-Jointed Robots Through Kinematic Robot Model Parameters Determination |
| CN103063213A (en) * | 2013-01-04 | 2013-04-24 | 上海交通大学 | Calibration method of position relationship between welding robot and position changer |
| CN103278126A (en) * | 2013-06-11 | 2013-09-04 | 陈磊磊 | Sphericity error assessment method for part based on minimum area |
| CN103292674A (en) * | 2013-06-11 | 2013-09-11 | 陈磊磊 | Method for calculating function size of sphere part |
| CN103895023A (en) * | 2014-04-04 | 2014-07-02 | 中国民航大学 | Mechanical arm tail end tracking and measuring system and method based on coding azimuth device |
| CN109465826A (en) * | 2018-11-13 | 2019-03-15 | 南京工程学院 | One kind being based on the equally distributed industrial robot TCP scaling method of posture |
| CN114083534A (en) * | 2021-11-11 | 2022-02-25 | 浙江大学 | Mechanical arm kinematics MDH parameter calibration method based on adaptive gradient descent |
| CN114770517A (en) * | 2022-05-19 | 2022-07-22 | 梅卡曼德（北京）机器人科技有限公司 | Method for calibrating robot through point cloud acquisition device and calibration system |
| CN115533893A (en) * | 2022-08-25 | 2022-12-30 | 浙江工业大学 | Robot TCP calibration method using floatable standard sphere |
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