WO2019114631A1

WO2019114631A1 - Method and device for acquiring tcp coordinates of robot

Info

Publication number: WO2019114631A1
Application number: PCT/CN2018/119789
Authority: WO
Inventors: 宫明波; 刘达
Original assignee: 北京柏惠维康科技有限公司
Priority date: 2017-12-13
Filing date: 2018-12-07
Publication date: 2019-06-20
Also published as: CN109909999A; CN109909999B

Abstract

An embodiment of the present application provides a method for acquiring TCP coordinates of a robot, comprising the following steps: marking a point, which can be recognized by a sensor, on a tool at an end of a robot arm as a TCP, and obtaining k adjustment coordinates from the theoretical coordinates of the TCP; utilizing the coordinates of the marked point in a robot arm coordinate system and in a sensor coordinate system to establish k coordinate conversion relationships between the robot arm coordinate system and the sensor coordinate system; in accordance with m positions, in a sensor recognition range, of the marked point, obtaining the maximum conversion error in the conversion errors of each coordinate conversion relationship at the m positions and/or the average error of the conversion errors of each coordinate conversion relationship at the m positions; and setting the adjustment coordinates corresponding to the minimum of the obtained k maximum conversion errors and/or the minimum of k average errors as the actual coordinates of the TCP. Said method reduces the range of error generated during the operation task of the robot, improving the operation precision of the robot.

Description

Method and device for acquiring robot TCP coordinates

Technical field

Embodiments of the present invention relate to the field of artificial intelligence, and in particular, to a method and apparatus for acquiring TCP coordinates of a robot.

Background technique

With the development of technology, the field of application of robots has become more and more extensive. For the robots in the two application fields of high-precision machining and surgery, the tasks that need to be completed have high requirements for precision.

In general, high-precision machining robots and surgical robots need to add tools to their own robotic arms to perform related tasks when performing work tasks. Since the coordinate conversion relationship between the end coordinate system of the arm and the coordinate system of the arm can be calculated by the DH parameter, and the error is small, how to accurately obtain the tool's own coordinate system origin (Tool Center Point, TCP) in the machine The coordinates in the arm end coordinate system are the key factors that affect the accuracy of its work. At present, the coordinates of TCP in the end coordinate system of the robot arm can be calculated or measured by the theoretical size of the robot arm end coordinate system in combination with the tool itself, which is called the theoretical coordinate of TCP. That is to say, when the tool is assembled to the end of the robot arm, the theoretical coordinates of TCP can only be used to perform the work task.

However, dimensional errors usually occur during the processing of the tool according to the design drawings. Assembly errors may occur during the assembly of the tool to the end of the robot arm. The tool may be affected by the environment and may also cause deformation errors. The measurement process may also occur. Generate measurement errors, etc. These errors will cause the actual coordinates of TCP in the end coordinate system of the arm to deviate from the theoretical coordinates of TCP. If the TCP is calibrated with the theoretical coordinates of TCP, it will inevitably result in the position of the calibrated TCP. There is an error between the actual TCP positions, which affects the working accuracy of the robot.

Summary of the invention

One of the technical problems solved by the embodiments of the present application is to provide a method and device for acquiring the TCP coordinates of a robot. When measuring or calculating the coordinates of the TCP in the coordinate system of the end of the arm, the theoretical coordinates of the TCP are adjusted multiple times, and The adjustment coordinate that produces the minimum conversion error or the most stable error fluctuation is taken as the actual coordinate of TCP, which reduces the range of errors generated by the robot during the execution of the work task, thereby improving the working precision of the robot.

In a first aspect, an embodiment of the present application provides a method for acquiring a TCP coordinate of a robot, including:

A point on the tool marking the end of the arm that can be recognized by the sensor is TCP, and k adjustment coordinates TCP _k are obtained from the theoretical coordinates of TCP; where k is an integer and k ≧ 1;

According to the k coordinate adjustment TCP _k and the coordinate transformation relationship between the robot arm end coordinate system and the robot arm coordinate system, and the coordinates of the marked point in the sensor coordinate system, the relationship between the robot arm coordinate system and the sensor coordinate system is established. k coordinate transformation relationships

Obtaining each coordinate transformation relationship according to the m positions in the identified range of the marked points

Maximum conversion error and/or each coordinate conversion relationship among the conversion errors of the m positions

The average error of the conversion error at the m locations; where m is an integer and m ≧ 1;

The adjustment coordinate TCP _k corresponding to the minimum of the k maximum conversion errors and/or the minimum of the k average errors is set as the actual coordinates of the TCP.

Optionally, the robot arm coordinate system and the sensor coordinates are established according to the coordinate transformation relationship between the _k coordinate adjustment TCP _k and the robot arm end coordinate system and the robot arm coordinate system, and the coordinates of the marked point in the sensor coordinate system. k coordinate transformation relationships between systems

The steps include:

Obtaining at least three non-collinear spatial reference points for establishing a coordinate conversion relationship between the robot arm coordinate system and the sensor coordinate system according to the movement of the marked point within the sensor recognition range;

Converting a coordinate relationship between a robot arm end coordinate system corresponding to a position of each of the spatial reference points and a robot arm coordinate system, and combining with k adjustment coordinates TCP _k to obtain each of the spatial reference points on the robot arm k coordinates in the coordinate system;

Obtaining k coordinates between the robot arm coordinate system and the sensor coordinate system according to k coordinates of each of the spatial reference points in the robot arm coordinate system and coordinates of each of the spatial reference points in the sensor coordinate system Conversion relationship

Optionally, each coordinate transformation relationship is obtained according to the m locations of the marked points within the sensor identification range.

The steps of the maximum conversion error in the conversion errors of the m locations include:

According to the coordinates Rm _j in the robot arm coordinate system and the coordinates Sm _j in the sensor coordinate system, the coordinate conversion relationship is obtained according to the coordinates of the points marked under each position m _j in the m positions and the coordinates Sm _j in the sensor coordinate system.

Conversion error at each position of m _j err _j;

Conversion relationship according to coordinates

The conversion error err _j at each position m _j gives each coordinate transformation relationship

The maximum conversion error in the conversion errors of the m locations;

Wherein, the conversion error err _j is the Euclidean distance after converting the coordinate Rm _{j of} the marked point in the robot arm coordinate system and the coordinate Sm _j in the sensor coordinate system to the same coordinate system, where m is an integer and m ≧ 1 , 1≦j≦m.

Optionally, the step of obtaining the k adjustment coordinates TCP _k from the theoretical coordinates of the TCP is: setting the theoretical coordinate of the TCP as the first item, and setting the constant difference to the tolerance series of the tolerance to the k adjustment coordinates TCP _k , or ,

A point in the coordinate range centered on the theoretical coordinate of TCP is set as k adjustment coordinates TCP _k .

In a second aspect, the embodiment of the present application further provides an apparatus for acquiring a TCP coordinate of a robot, where the apparatus includes:

Marking and adjusting the coordinate module, a point on the tool for marking the end of the arm that can be recognized by the sensor is TCP, and k adjustment coordinates TCP _k are obtained from the theoretical coordinates of the TCP; wherein k is an integer and k ≧ 1;

A coordinate transformation relationship establishing module is configured to establish a robot arm coordinate according to k coordinate adjustment TCP _k and a coordinate conversion relationship between the robot arm end coordinate system and the robot arm coordinate system, and coordinates of the marked point in the sensor coordinate system. k coordinate transformation relationships between the system and the sensor coordinate system

a deviation obtaining module, configured to obtain each coordinate conversion relationship according to m positions of the marked points within the sensor identification range

The actual coordinate determination module of the TCP is configured to set the adjustment coordinate TCP _k corresponding to the minimum value of the k maximum conversion errors and/or the minimum value of the k average errors to the actual coordinates of the TCP.

Optionally, the coordinate transformation relationship establishing module is specifically configured to:

Optionally, the deviation obtaining module is specifically configured to:

Conversion error at each position of m _j err _j;

Conversion relationship according to coordinates

a maximum conversion error among the conversion errors of the m positions; wherein the conversion error err _j is a conversion of the coordinate Rm _{j of} the marked point in the robot coordinate system and the coordinate Sm _j in the sensor coordinate system to the same The Euclidean distance after the coordinate system, m is an integer and m≧1,1≦j≦m.

Optionally, the marking and adjusting coordinate module is specifically configured to:

Taking the theoretical coordinate of TCP as the first item, an arithmetic constant with the adjustment constant to the tolerance is set to k adjustment coordinates TCP _k , or,

In a third aspect, the embodiment of the present application further provides a system for acquiring TCP coordinates of a robot, including a memory, a processor, an external communication interface, a bus, and a computer program stored on the memory and operable on the processor. The memory, the processor and the external communication interface are connected by the bus, and the processor executes the computer program to perform the acquisition of the TCP coordinates of the robot according to any one of claims 1 to 4. The steps of the method.

In a fourth aspect, the embodiment of the present application further provides a computer readable storage medium, where the computer readable storage medium stores a computer program, wherein the computer program is executed by a processor to implement claims 1 to 4. The step of the method of acquiring the TCP coordinates of the robot.

It can be seen from the above technical solution that the method and device for acquiring the TCP coordinates of the robot, the system and the computer readable storage medium provided by the embodiment of the present application first mark a point on the tool at the end of the robot arm that can be recognized by the sensor as TCP. By adjusting the theoretical coordinates of the calculated TCP to obtain k adjustment coordinates, and using k coordinate adjustment coordinates and the coordinate transformation relationship between the robot arm end coordinate system and the robot arm coordinate system, the marked points are obtained at the robot arm coordinates. The coordinates in the system, combined with the coordinates of the marked points in the sensor coordinate system, establish k coordinate transformation relationships between the robot arm coordinate system and the sensor coordinate system, and further move the marked points to m within the sensor recognition range. Position, obtain the maximum conversion error and/or average error of the conversion error of each coordinate transformation relationship at m positions, and finally the minimum of the k maximum conversion errors and/or the minimum of k average errors The corresponding adjustment coordinates are set to the actual coordinates of the TCP, which reduces the range of errors that the robot generates when performing tasks. The accuracy of the robot work.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are only It is a few embodiments described in the embodiments of the present invention, and other drawings can be obtained according to the drawings for those skilled in the art.

FIG. 1 is a flowchart of a method for acquiring a TCP coordinate of a robot according to an embodiment of the present application;

2 is a schematic structural diagram of an apparatus for acquiring a TCP coordinate of a robot according to an embodiment of the present application;

FIG. 3 is a schematic diagram of a mechanical arm and a sensor according to an embodiment of the present application.

Detailed ways

Of course, implementing any of the technical solutions of the embodiments of the present invention does not necessarily require all the above advantages to be achieved at the same time.

For a better understanding of the technical solutions in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. The embodiments are only a part of the embodiments of the embodiments of the invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art should be within the scope of protection of the embodiments of the present invention based on the embodiments in the embodiments of the present invention.

For the prior art, the coordinates of the tool's own coordinate system origin (Tool Center Point, TCP) in the end coordinate system of the arm and the actual coordinates of the TCP are calculated or measured by the theoretical coordinate of the robot arm end coordinate system and the tool itself. There may be a problem that a large error may occur. The embodiment of the present application provides a method for acquiring the TCP coordinates of the robot. As shown in FIG. 1 , the method includes steps S100-S400, specifically:

S100: A point on the tool marking the end of the robot arm that can be recognized by the sensor is TCP, and k adjustment coordinates TCP _k are obtained from the theoretical coordinates of the TCP; wherein k is an integer and k ≧ 1.

In the actual operation, find a point on the tool at the end of the robot that can be recognized by the sensor, or select a point from the points on the tool at the end of the arm that can be recognized by the sensor, and will find or select this The dot is marked as TCP. It should be noted that when the sensor is a camera, the marked point can be set as an optical marker point; when the sensor is an electromagnetic sensor, the marked point can be set as an electromagnetic marker point; when the sensor is an ultrasound probe, it can be set The marked points are ultrasonic marking points; when the sensor is an infrared sensor, the marked points can be set as infrared marking points, or other sensors and corresponding marking points. The actual coordinates of the TCP in the robot arm end coordinate system are not determined in step S100. The embodiment of the present application determines the actual coordinates of the TCP according to the marked points.

According to the theoretical size of the tool itself and the end coordinate system of the arm, the theoretical coordinates of TCP are calculated by the measuring tool or according to the coarse calibration algorithm, and the calculated theoretical coordinates are adjusted to obtain k adjustment coordinates, where k is an integer and k ≧1. It should be noted that the adjustment coordinate TCP _k can be equal to the theoretical coordinate of TCP.

In the actual operation process, there are various ways to obtain k adjustment coordinates by adjusting the theoretical coordinates of TCP. Here, two adjustment methods are specifically described.

On the one hand, an adjustment value can be set, and then based on the theoretical coordinates of TCP, the coordinates of the TCP are adjusted successively according to the adjustment value to obtain TCP _k . Specifically, the theoretical coordinate of TCP is taken as the first item, and the arithmetic constant with the constant is the tolerance is set to k adjustment coordinates TCP _k . In the actual operation, the theoretical coordinate of TCP can be set to (x, y, z). The tolerance is the adjustment constant d, then the adjustment coordinate TCP _k is: TCP _k (x+(k-1)d, y+(k-1)d, z+(k-1)d).

To make the adjustment coordinate TCP _k equal to the theoretical coordinate of TCP, the value of k can be taken as 1. If the adjustment coordinate TCP _{k is} not equal to the theoretical coordinate of TCP, k can be a value greater than or equal to 2.

On the other hand, it is also possible to define an adjustment range of coordinate values, and the coordinates of the points in the adjustment range are used as the adjustment coordinates TCP _k . Specifically, the coordinates of the partial points within the adjustment range centered on the theoretical coordinates of the TCP can be used. Or the coordinates of all points are set to k adjustment coordinates TCP _k . In the actual operation process, the coordinate of the partial point in the circular range with the radius of r (r>0) or the coordinates of all the points with the theoretical coordinate of TCP as the center of the circle can be used as the adjustment coordinate TCP _k , or The theoretical coordinate of TCP is the center. The coordinates of the partial points in the square range with D (D>0) as the side length or the coordinates of all the points are used as the adjustment coordinates TCP _k . It is also possible to center on the theoretical coordinate of TCP. The coordinates of the partial points in the range of the irregular pattern or the coordinates of all the points are used as the adjustment coordinates TCP _k , and may not be centered on the theoretical coordinates of the TCP, but will be bounded by the theoretical coordinates of the TCP, on the tool at the end of the arm. The other points are the coordinates of the partial points in the graphic range of the center or the coordinates of all the points as the adjustment coordinate TCP _k , which is not specifically limited here, as long as k adjustment coordinates TCP _k can be obtained by the theoretical coordinates of TCP, it is necessary to explain In this adjustment mode, the adjustment coordinate TCP _k can also be equal to the theoretical coordinate of TCP.

In addition to the above two adjustment methods, the adjustment coordinate TCP _k can also be obtained by random adjustment. In summary, the manner in which the coordinate TCP _k is adjusted is various, and the present application will not be described in detail herein.

S200: establishing a robot arm coordinate system and a sensor coordinate system according to k coordinate adjustment coordinates TCP _k and a coordinate conversion relationship between the robot arm end coordinate system and the robot arm coordinate system, and coordinates of the marked point in the sensor coordinate system. k coordinate transformation relationship

There are many ways to establish the coordinate transformation relationship between two coordinate systems by using the coordinates of the same point in two coordinate systems. A preferred solution is described below.

In actual operation, when step S200 is performed, the coordinate transformation relationship between the robot arm coordinate system and the sensor coordinate system may be firstly obtained according to the movement of the marked point (ie, TCP in S100) within the sensor recognition range. At least three non-collinear spatial reference points; and then combined with k adjustment coordinates TCP _k according to the coordinate conversion relationship between the robot arm end coordinate system and the robot arm coordinate system corresponding to the position of each of the spatial reference points Obtaining k coordinates of each of the spatial reference points in the robot arm coordinate system; finally, k coordinates in the robot arm coordinate system according to each of the spatial reference points, and each spatial reference point in the sensor coordinate system The coordinate in the middle, the k coordinate transformation relationship between the robot arm coordinate system and the sensor coordinate system is obtained.

Specifically, the moving point of the robot arm can be used to move the marked point on the tool at the end of the arm to at least three non-collinear positions, and at least a coordinate conversion relationship between the robot arm coordinate system and the sensor coordinate system can be obtained. Three non-collinear spatial reference points.

The coordinate conversion relationship between the end coordinate system of the arm and the coordinate system of the robot arm can be calculated by the DH parameter. According to the schematic diagram of the robot arm and the sensor shown in FIG. 3, the coordinate system between the end of the arm and the coordinate system of the arm is obtained. The coordinate conversion relationship, combined with the k adjustment coordinates TCP _k , can obtain _k coordinates of the marked point in the robot arm coordinate system; in the embodiment of the present application, the marked point is recorded as TCP and is marked by The position of the point in the real space to obtain the spatial reference point, so the coordinates of the marked point in the robot arm coordinate system can be used as the coordinates of the spatial reference point in the robot arm coordinate system, and since the marked point moves to At least three non-collinear positions obtain at least three non-collinear spatial reference points, and at least three non-zero can be obtained by using the obtained k-coordinates of the marked points in the robot arm coordinate system. The k coordinate of each of the spatial reference points in the collinear spatial reference point in the robot arm coordinate system.

Since the marked points can be recognized by the sensor, the coordinates of each of the at least three non-collinear spatial reference points in the sensor coordinate system can be obtained, and then the mechanical reference point is in the mechanical The k coordinate transformations between the arm coordinate system and the sensor coordinate system can be obtained from the k coordinates in the arm coordinate system and the coordinates of each spatial reference point in the sensor coordinate system.

Taking three non-collinear spatial reference points for establishing a coordinate conversion relationship between the robot arm coordinate system and the sensor coordinate system as an example to obtain a robot arm coordinate system and moving in the sensor recognition range according to the marked points. k coordinate transformation relationship between sensor coordinate systems

Be explained.

When the mobile robot arm obtains three non-collinear spatial reference points, the robot arm is in three poses of position 1, position 2, and position 3.

When the arm moves to the posture 1, the DH parameter can be used to obtain the coordinate conversion relationship between the end coordinate system of the arm and the coordinate system of the arm when the current arm is in the pose 1, and the origin of the end coordinate of the arm is in the machine. The coordinate p1 in the arm coordinate system can be used to obtain the coordinate t1 of TCP in the end coordinate system of the robot arm through the machining drawing of the tool. Therefore, the coordinates of the current TCP in the robot arm coordinate system are represented by p1+t1 (note that The coordinates of the current TCP in the robot arm coordinate system are not the sum of the coordinates of p1 and the coordinates of t1. Here, only the expression "p1+t1" is used to present the current TCP when the arm is in pose 1. The coordinates in the robot arm coordinate system are explained, as in the similar description below, so that the coordinates p1+t1 of the point marked by the manipulator in the pose 1 in the robot arm coordinate system can be obtained. By identifying the marked point by the sensor, it is also possible to obtain the coordinate s1 of the point marked by the robot arm in the pose 1 in the sensor coordinate system.

When the arm moves to the posture 2, the DH parameter can be used to obtain the coordinate conversion relationship between the arm end coordinate system and the arm coordinate system when the current arm is in the pose 2, and the origin of the arm end coordinate system is in the machine. The coordinate p2 in the arm coordinate system, because the obtained TCP coordinates t1 in the end coordinate system of the arm, the coordinates of the current TCP in the robot arm coordinate system are represented by p2+t1, that is, the robot arm is in the posture. The point marked at 2 o'clock is the coordinate p2+t1 in the robot arm coordinate system. By identifying the marked point by the sensor, it is also possible to obtain the coordinate s2 of the point marked by the robot arm in the pose 2 in the sensor coordinate system.

When the arm moves to the posture 3, the DH parameter can be used to obtain the coordinate conversion relationship between the arm end coordinate system and the arm coordinate system when the current arm is in the pose 3, and the origin of the arm end coordinate system is in the machine. The coordinate p3 in the arm coordinate system, plus the obtained coordinate t1 of the TCP in the end coordinate system of the arm, so here the p3+t1 is used to represent the current coordinate p3+t1 of the TCP in the robot arm coordinate system, that is, the robot arm is obtained. The point marked in pose 3 is the coordinate p3+t1 in the robot coordinate system. By identifying the marked point by the sensor, it is also possible to obtain the coordinate s3 of the point marked by the robot arm in the pose 3 in the sensor coordinate system.

In the embodiment of the present application, p1+t1 and s1, p2+t1 and s2, p3+t1 and s3 can be utilized, that is, the coordinates of the three non-collinear spatial reference points in the robot arm coordinate system and the sensor coordinate system are respectively used. The coordinates below establish the coordinate transformation relationship between the robot arm coordinate system and the sensor coordinate system

Similarly, when the coordinate t1 of the TCP in the end coordinate system of the arm is adjusted to obtain the coordinate t2 of the TCP in the end coordinate system of the arm, the coordinate conversion relationship between the robot coordinate system and the sensor coordinate system is established.

The process is:

When the robot arm moves to the posture 1, the coordinates p1+t2 of the marked point in the robot arm coordinate system and the coordinate s1 of the marked point in the sensor coordinate system are obtained.

When the robot arm moves to the pose 2, the coordinates p2+t2 of the marked point in the robot arm coordinate system and the coordinate s2 of the marked point in the sensor coordinate system are obtained.

When the robot arm moves to the pose 3, the coordinates p3+t2 of the marked point in the robot arm coordinate system and the coordinate s3 of the marked point in the sensor coordinate system are obtained.

In the embodiment of the present application, p1+t2 and s1, p2+t2 and s2, p3+t2 and s3 can be utilized, that is, the coordinates of the three non-collinear spatial reference points in the robot arm coordinate system and the sensor coordinate system are respectively used. The coordinates below establish the coordinate transformation relationship between the robot arm coordinate system and the sensor coordinate system

By analogy, k coordinate transformation relationships between the robot arm coordinate system and the sensor coordinate system can be obtained. It should be noted that when the adjusted coordinate of TCP is not equal to the theoretical coordinate of TCP, the coordinate conversion relationship between the robot arm coordinate system and the sensor coordinate system may be calculated without using the theoretical coordinate of TCP; when the adjusted coordinate of TCP can be equal to TCP In theoretical coordinates, the coordinate transformation relationship between the robot arm coordinate system and the sensor coordinate system can be calculated using the theoretical coordinates of TCP.

S300: obtaining each coordinate conversion relationship according to the m positions in the range of the sensor identification

The average error of the conversion error at the m locations; where m is an integer and m ≧ 1.

Specifically, each coordinate transformation relationship is obtained.

The steps of the maximum conversion error in the conversion errors of the m locations are:

Conversion error at each position of m _j err _j;

Conversion relationship according to coordinates

The maximum conversion error in the conversion errors of the m locations;

Get each coordinate transformation relationship

The steps of the average error of the conversion errors at the m locations are:

Conversion error at each position of m _j err _j;

Conversion relationship according to coordinates

The conversion error err _j at each position m _j , the coordinate conversion relationship is obtained according to the calculation formula of the average error

The average error of the conversion error at the m locations.

For example, assume that the marked point moves to 10 positions within the sensor's identification range, ie m equals 10. When the adjusted coordinate of TCP is TCP ₁ , the corresponding coordinate conversion relationship is

At the time, the robot arm coordinates Rm _{j of} the marked points at the 10 positions can be obtained by the conversion relationship of the joints of the robot arm, and the marked points and the movement of the marked points can be recognized by the sensor to obtain the marked Point the sensor coordinates Sm _j at these 10 positions, where 1≦j≦10. Further through the previously established coordinate transformation relationship

You can find the conversion error at these 10 positions.

or

From these 10 conversion errors err ₁ , err ₂ , err ₃ ... err ₁₀ , the maximum conversion error can be selected as err _{Max_1} , and the average error of the conversion errors at these 10 positions can be calculated as err _{aver_1} .

Similarly, through the previously established coordinate transformation relationship

And the adjustment coordinate of TCP is TCP ₂ , the conversion error of these 10 same positions can be obtained.

or

From these 10 conversion errors, the largest conversion error can be selected as err _{Max_2} , and the average error of the conversion errors at these 10 positions can be calculated as err _{aver_2} .

If there are 3 adjustment coordinates TCP ₁ , TCP ₂ and TCP ₃ , and the corresponding coordinate conversion relationship

Then, according to the above method of obtaining the maximum conversion error and the average error, three maximum conversion errors err _{Max_1} , err _{Max_2} , err _{Max_3} and three average errors err _{aver_1} , err _{aver_2} , err _{aver_3 can be obtained} .

It should be noted that, in the embodiment of the present application, a movement program may be set for the robot arm, so that the robot arm automatically moves to m positions within the sensor recognition range, and the number of movements, the movement path, and the movement distance can be Implemented using existing methods, and is looking for each coordinate transformation relationship

In the case of conversion errors at m positions, the same m positions are utilized.

It should be noted that, in the embodiment of the present application, each coordinate conversion relationship is obtained except for m positions within the sensor identification range according to the marked points.

In addition to the average error of the conversion errors of the m positions as a reference for setting the actual coordinates of the TCP, each coordinate conversion relationship obtained according to the m positions within the sensor identification range of the marked points may be obtained.

The standard deviation of the conversion errors at the m positions is used as a reference for setting the actual coordinates of the TCP, or both the obtained average error and the standard deviation are used as references for setting the actual coordinates of the TCP.

S400: The minimum value of the k largest error in the conversion and / or adjustment of the k corresponding to the minimum average error of coordinate _k TCP TCP is set to the actual coordinates.

There are still three adjustment coordinates TCP ₁ , TCP ₂ and TCP ₃ as an example. Specifically, since three maximum conversion errors err _{Max_1} , err _{Max_2} , err _{Max_3} have been obtained, one of the three maximum conversion errors is selected. The minimum value, if err _{Max_1} is the minimum value, set the TCP adjustment coordinate TCP ₁ corresponding to err _{Max_1} to the actual coordinate of TCP; if err _{Max_2} is the minimum value, set the TCP adjustment coordinate TCP ₂ corresponding to err _{Max_2} to The actual coordinate of TCP; if err _{Max_3} is the minimum value, the adjusted coordinate TCP ₃ of TCP corresponding to err _{Max_3 is} set to the actual coordinate of TCP.

Alternatively, a minimum value is selected from the three average errors err _{aver_1} , err _{aver_2} , err _{aver_3} that have been obtained, and the adjusted coordinate TCP _k of the TCP corresponding to the minimum value of the average error is set as the actual coordinate of the TCP.

Or when err _{Max_1} is the minimum maximum conversion error, the corresponding average error err _{aver_1} is also the smallest average error, and the TCP adjustment coordinate TCP ₁ corresponding to err _{Max_1} and err _{aver_1 is taken} as the actual coordinate of TCP.

Each coordinate transformation relationship obtained when m points will be within the sensor identification range according to the marked points

When the standard deviation of the conversion errors at the m positions is used as a reference for setting the actual coordinates of the TCP, the adjustment coordinate TCP _k corresponding to the minimum value of k standard deviations may be set as the actual coordinates of the TCP; the average error and standard to be obtained When the difference is used as a reference for setting the actual coordinates of the TCP, the adjustment coordinate TCP _k corresponding to the minimum value of the obtained average error and/or the minimum value of the standard deviation may be set as the actual coordinate of the TCP, or when the plurality of adjustment coordinates are TCP _When the average error of _k is the same, the adjustment coordinate corresponding to the minimum value of the standard deviation is taken as the actual coordinate of TCP. For example, if TCP ₁ , TCP ₂ , TCP ₃ ... TCP ₁₀ are obtained according to the theoretical coordinates of TCP 10 adjustment coordinates, and the average error of the 10 adjustment coordinates are the same, and the standard deviation of the conversion error corresponding to TCP ₃ is the smallest, then TCP ₃ is set as the actual coordinate of TCP.

In the embodiment of the present application, first, a point on the tool at the end of the robot arm that can be recognized by the sensor is marked as TCP. At this time, the theoretical coordinate of the TCP can be obtained by the design drawing of the tool combined with the coordinate system of the end of the arm, but the TCP The actual coordinates are not determined. In the process of determining the actual coordinates of TCP, k adjustment coordinates are obtained by adjusting the theoretical coordinates of TCP, and k adjustment coordinates and the coordinate system between the end of the arm and the coordinate system of the robot arm are used. Coordinate transformation relationship, obtain the coordinates of the marked point in the robot arm coordinate system, and combine the coordinates of the marked point in the sensor coordinate system to establish k coordinate transformation relationship between the robot arm coordinate system and the sensor coordinate system, further By moving the marked points to m positions within the sensor recognition range, the maximum conversion error and/or the average error of the conversion errors of each coordinate transformation relationship at m positions are obtained, that is, each adjustment coordinate is obtained through the coordinate conversion relationship. The maximum range of errors between the converted arm coordinates and the corresponding sensor coordinates and/or the level of error The average level, and finally the adjustment coordinate corresponding to the minimum value of the k maximum conversion errors and/or the minimum value of the k average errors is set as the actual coordinate of the TCP, thereby reducing the range of errors generated by the robot when performing the task, and improving The working precision of the robot.

Based on the same inventive concept, as shown in FIG. 2, the embodiment of the present application further provides an apparatus for acquiring TCP coordinates of a robot, including:

The marking and adjusting coordinate module 201 is configured to mark a point on the tool end of the robot arm that can be recognized by the sensor as TCP, and obtain k adjustment coordinates TCP _k from the theoretical coordinates of the TCP; wherein k is an integer and k ≧ 1;

The coordinate transformation relationship establishing module 202 is configured to establish a mechanical arm according to the coordinate transformation relationship between the k coordinate adjustment TCP _k and the robot arm end coordinate system and the robot arm coordinate system, and the coordinates of the marked point in the sensor coordinate system. k coordinate transformation relationship between coordinate system and sensor coordinate system

The deviation obtaining module 203 is configured to obtain each coordinate transformation relationship according to the m positions in the sensor identification range of the marked points.

The actual coordinate determination module 204 of the TCP is configured to set the adjustment coordinate TCP _k corresponding to the minimum value of the k maximum conversion errors and/or the minimum value of the k average errors to the actual coordinates of the TCP.

In the embodiment of the present application, the marking and adjusting coordinate module 201, the coordinate conversion relationship establishing module 202, the deviation obtaining module 203, and the actual coordinate determining module 204 of the TCP may perform corresponding preferred steps in the foregoing method embodiments.

Optionally, the coordinate transformation relationship establishing module 202 is specifically configured to:

According to the coordinate conversion relationship between the robot arm end coordinate system and the robot arm coordinate system corresponding to the position of each of the spatial reference points, combined with k adjustment coordinates TCP _k , each of the spatial reference points is obtained on the robot arm k coordinates in the coordinate system;

.

Optionally, the deviation obtaining module 203 is specifically configured to:

Conversion error at each position of m _j err _j;

Conversion relationship according to coordinates

The maximum conversion error in the conversion errors of the m locations;

Optionally, the marking and adjusting coordinate module 201 is specifically configured to:

Based on the same inventive concept, the embodiment of the present application further provides a system for acquiring TCP coordinates of a robot, including a memory, a processor, an external communication interface, a bus, and being stored on the memory and operable on the processor. a computer program, wherein the memory, the processor and the external communication interface are connected by the bus, and when the processor runs the computer program, the step of implementing the method for acquiring the TCP coordinates of the robot in the above method embodiment is performed .

Based on the same inventive concept, the embodiment of the present application further provides a computer readable storage medium, where the computer readable storage medium stores a computer program, and when the computer program is executed by the processor, the method is obtained in the foregoing method embodiment. The steps of the method of robot TCP coordinates.

In the several embodiments provided by the present application, it should be understood that the disclosed system, apparatus, and method may be implemented in other manners. For example, the device embodiments described above are merely illustrative. For example, the division of cells is only a logical function division. In actual implementation, there may be another division manner. For example, multiple units or components may be combined or integrated. Go to another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be in an electrical, mechanical or other form.

The units described as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units, i.e., may be located in one place, or may be distributed over multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may be processed separately, or two or more units may be integrated into one unit. The above integrated unit can be implemented in the form of hardware or in the form of hardware plus software functional units.

The above-described integrated unit implemented in the form of a software functional unit can be stored in a computer readable storage medium. The software functional units described above are stored in a storage medium and include instructions for causing a computer device (which may be a personal computer, server, or network device, etc.) to perform portions of the steps of various embodiments of the present invention. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and the like, and the program code can be stored. Medium.

Finally, it should be noted that the above embodiments are only used to explain the technical solutions of the embodiments of the present application, and are not limited thereto; although the present application is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that The technical solutions described in the foregoing embodiments may be modified, or some of the technical features may be equivalently replaced; and the modifications or substitutions do not deviate from the spirit of the technical solutions of the embodiments of the present application. range.

Claims

A method for acquiring TCP coordinates of a robot, comprising the steps of:

A point on the tool marking the end of the arm that can be recognized by the sensor is TCP, and k adjustment coordinates TCP k are obtained from the theoretical coordinates of TCP; where k is an integer and k ≧ 1;

According to the k coordinate adjustment TCP k and the coordinate transformation relationship between the robot arm end coordinate system and the robot arm coordinate system, and the coordinates of the marked point in the sensor coordinate system, the relationship between the robot arm coordinate system and the sensor coordinate system is established. k coordinate transformation relationships

Obtaining each coordinate transformation relationship according to the m positions in the identified range of the marked points
Maximum conversion error and/or each coordinate conversion relationship among the conversion errors of the m positions
The average error of the conversion error at the m locations; where m is an integer and m ≧ 1;

The adjustment coordinate TCP k corresponding to the minimum of the k maximum conversion errors and/or the minimum of the k average errors is set as the actual coordinates of the TCP.
The method for acquiring TCP coordinates of a robot according to claim 1, wherein the coordinate conversion relationship between the k coordinate adjustment coordinates TCP k and the robot arm end coordinate system and the robot arm coordinate system, and the marked points are K coordinate transformation relationship between the robot arm coordinate system and the sensor coordinate system is established in the coordinates of the sensor coordinate system
The steps include:

Obtaining at least three non-collinear spatial reference points for establishing a coordinate conversion relationship between the robot arm coordinate system and the sensor coordinate system according to the movement of the marked point within the sensor recognition range; each of the spatial reference points is The coordinate conversion relationship between the robot arm end coordinate system and the robot arm coordinate system corresponding to the position is combined with k adjustment coordinates TCP k to obtain k coordinates of each of the spatial reference points in the robot arm coordinate system;

Obtaining k coordinates between the robot arm coordinate system and the sensor coordinate system according to k coordinates of each of the spatial reference points in the robot arm coordinate system and coordinates of each of the spatial reference points in the sensor coordinate system Conversion relationship
The method for acquiring TCP coordinates of a robot according to claim 1, wherein the coordinate conversion relationship is obtained according to m positions in the sensor recognition range of the marked points.
The steps of the maximum conversion error in the conversion errors of the m locations include:

According to the coordinates Rm j in the robot arm coordinate system and the coordinates Sm j in the sensor coordinate system, the coordinate conversion relationship is obtained according to the coordinates of the points marked under each position m j in the m positions and the coordinates Sm j in the sensor coordinate system.
Conversion error at each position of m j err j;

Conversion relationship according to coordinates
The conversion error err j at each position m j gives each coordinate transformation relationship
The maximum conversion error in the conversion errors of the m locations;

Wherein, the conversion error err j is the Euclidean distance after converting the coordinate Rm j of the marked point in the robot arm coordinate system and the coordinate Sm j in the sensor coordinate system to the same coordinate system, where m is an integer and m ≧ 1 , 1≦j≦m.
A method for acquiring TCP coordinates of a robot according to claim 1 or 2 or 3, wherein the step of obtaining k adjustment coordinates TCP k from the theoretical coordinates of TCP is: taking the theoretical coordinates of TCP as the first item , an adjustment constant is the tolerance difference of the number of columns set to k adjustment coordinates TCP k , or,

A point in the coordinate range centered on the theoretical coordinate of TCP is set as k adjustment coordinates TCP k .
A device for acquiring TCP coordinates of a robot, characterized in that the device comprises:

Marking and adjusting the coordinate module, a point on the tool for marking the end of the arm that can be recognized by the sensor is TCP, and k adjustment coordinates TCP k are obtained from the theoretical coordinates of the TCP; wherein k is an integer and k ≧ 1;

A coordinate transformation relationship establishing module is configured to establish a robot arm coordinate according to k coordinate adjustment TCP k and a coordinate conversion relationship between the robot arm end coordinate system and the robot arm coordinate system, and coordinates of the marked point in the sensor coordinate system. k coordinate transformation relationships between the system and the sensor coordinate system

a deviation obtaining module, configured to obtain each coordinate conversion relationship according to m positions of the marked points within the sensor identification range
Maximum conversion error and/or each coordinate conversion relationship among the conversion errors of the m positions
The average error of the conversion error at the m locations; where m is an integer and m ≧ 1;

The actual coordinate determination module of the TCP is configured to set the adjustment coordinate TCP k corresponding to the minimum value of the k maximum conversion errors and/or the minimum value of the k average errors to the actual coordinates of the TCP.
The apparatus for acquiring the TCP coordinates of the robot according to claim 5, wherein the coordinate transformation relationship establishing module is specifically configured to:

Obtaining at least three non-collinear spatial reference points for establishing a coordinate conversion relationship between the robot arm coordinate system and the sensor coordinate system according to the movement of the marked point within the sensor recognition range; each of the spatial reference points is The coordinate conversion relationship between the robot arm end coordinate system and the robot arm coordinate system corresponding to the position, combined with the k adjustment coordinates TCP k to obtain k coordinates of each of the spatial reference points in the robot arm coordinate system;

Obtaining k coordinates between the robot arm coordinate system and the sensor coordinate system according to k coordinates of each of the spatial reference points in the robot arm coordinate system and coordinates of each of the spatial reference points in the sensor coordinate system Conversion relationship
The apparatus for acquiring TCP coordinates of a robot according to claim 5, wherein the maximum conversion error and/or average error acquisition module is specifically configured to:

According to the coordinates Rm j in the robot arm coordinate system and the coordinates Sm j in the sensor coordinate system, the coordinate conversion relationship is obtained according to the coordinates of the points marked under each position m j in the m positions and the coordinates Sm j in the sensor coordinate system.
Conversion error at each position of m j err j;

Conversion relationship according to coordinates
The conversion error err j at each position m j gives each coordinate transformation relationship
The maximum conversion error in the conversion errors of the m locations;

Wherein, the conversion error err j is the Euclidean distance after converting the coordinate Rm j of the marked point in the robot arm coordinate system and the coordinate Sm j in the sensor coordinate system to the same coordinate system, where m is an integer and m ≧ 1 , 1≦j≦m.
The error compensation device in the calibration of a robot tool according to claim 5 or 6 or 7, wherein the marking and adjusting coordinate module is specifically used for:

Taking the theoretical coordinate of TCP as the first item, an arithmetic constant with the adjustment constant to the tolerance is set to k adjustment coordinates TCP k , or,

A point in the coordinate range centered on the theoretical coordinate of TCP is set as k adjustment coordinates TCP k .
A system for acquiring TCP coordinates of a robot, the system comprising a memory, a processor, an external communication interface, a bus, and a computer program stored on the memory and operable on the processor, wherein The memory, the processor and the external communication interface are connected by the bus, and when the processor runs the computer program, the step of implementing the method for acquiring the TCP coordinates of the robot according to any one of claims 1 to 4 is performed.
A computer readable storage medium storing a computer program, wherein the computer program is executed by a processor, and the method for acquiring a TCP coordinate of the robot according to any one of claims 1 to 4 A step of.