CN113160326A - Hand-eye calibration method and device based on reconstructed coordinate system - Google Patents
Hand-eye calibration method and device based on reconstructed coordinate system Download PDFInfo
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Abstract
The invention provides a hand-eye calibration method and a hand-eye calibration device based on a reconstructed coordinate system, wherein the method comprises the following steps: determining clear characteristic points; establishing a transition tool coordinate system and a workpiece coordinate system; calculating the transformation relation between the image coordinate system and the workpiece coordinate system; calculating a feature point coordinate A on the first rotating image, a feature point coordinate B on the second rotating image and a midpoint C between the coordinate A and the coordinate B; calculating the coordinate of the midpoint C in the workpiece coordinate system and the deviation amount between the point C and the origin of the transition tool coordinate system; reconstructing a new tool coordinate system, wherein the origin of the new tool coordinate system is the origin of the transition tool coordinate system plus the deviation amount, and guiding the positioning of the mechanical arm according to the new tool coordinate system; and when the next guiding positioning is carried out, taking the new tool coordinate system as a transition tool coordinate system, and reestablishing the new tool coordinate system. The invention eliminates the error between the origin of the tool coordinate system and the rotation center of the workpiece and effectively improves the calibration precision of the hand and the eye.
Description
Technical Field
The invention relates to a hand-eye calibration method and device based on a reconstructed coordinate system.
Background
In high-precision and rapid operation, an industrial robot is often required to be assisted to perform accurate positioning through a visual guide technology. Visual guidance is the work of capturing an image of an objective object using an industrial camera instead of a human eyeball, processing the image by a correlation algorithm to obtain useful information, and finally controlling a robot. In the vision guide robot system, the transformation relation between a camera coordinate system and a robot basic coordinate system can be finally established through hand-eye calibration, and the transformation relation is a necessary condition for enabling a robot paw to accurately grab an object.
The existing hand-eye calibration method comprises a traditional nine-point hand-eye calibration method, wherein a mechanical arm TCP is used for touching a marker printed with nine characteristic points to record the pose of the mechanical arm, then the image coordinates of the nine points are shot and calculated, and the conversion relation between the mechanical arm and an image coordinate system is established through a calibration algorithm. However, the nine-point hand-eye calibration method needs to stick markers printed with nine feature points and needs to perform tip touch to perform coordinate unification, the operation is complicated, the result accuracy depends on the level of an operator to a greater extent, and more importantly, the origin of a tool coordinate system established by the method always has a certain error with the rotation center of a workpiece, and the error cannot be completely overlapped, so that displacement errors are introduced to influence the hand-eye calibration accuracy, and the error can be ignored when the operation is performed, and further the smooth operation is seriously influenced.
Disclosure of Invention
The invention aims to provide a hand-eye calibration method and device based on a reconstructed coordinate system, which aim to overcome the defects of the prior art, eliminate the error between the origin of a tool coordinate system and the rotation center of a workpiece, ensure that the result precision does not depend on the level of an operator any more, effectively improve the hand-eye calibration precision, and have simpler operation and improved operation efficiency.
The invention is realized by the following technical scheme:
a hand-eye calibration method based on a reconstructed coordinate system comprises the following steps:
A. determining a clear characteristic point on the surface of the shot workpiece;
B. establishing a transition tool coordinate system by a TCP calibration method of the mechanical arm, enabling the origin of the transition tool coordinate system to be basically superposed with the characteristic point, and establishing a workpiece coordinate system according to the transition tool coordinate system, wherein the direction of the workpiece coordinate system is consistent with the direction of a Base coordinate system of the mechanical arm;
C. controlling the mechanical arm to move nine positions on a plane with a workpiece coordinate system z being 0 by using a transition tool coordinate system, controlling a camera arranged on the mechanical arm to collect images containing characteristic points at the nine positions respectively, extracting the coordinates of the characteristic points on each image respectively, and calculating the conversion relation between the image coordinate system and the workpiece coordinate system through the coordinates of each position and the coordinates of each marker characteristic point;
D. controlling the mechanical arm to rotate around a first angle and a second angle with a difference value of 180 degrees respectively around (0,0) of a plane of a workpiece coordinate system z, controlling the camera to shoot a first rotation image and a second rotation image at the first angle and the second angle respectively, calculating a feature point coordinate A on the first rotation image and a feature point coordinate B on the second rotation image respectively, and calculating a coordinate of a midpoint C between the coordinate A and the coordinate B;
E. according to the conversion relation, calculating the coordinate (D) of the midpoint C in the workpiece coordinate systemx,Dy) Rotating the coordinate system of the workpiece to be consistent with the coordinate system of the transition tool in direction, and calculating the C point and the origin of the coordinate system of the transition toolAmount of deviation therebetween
Wherein, thetaxFor the Base coordinate x-axis Euler angle of the mechanical arm thetayIs the Base coordinate y-axis Euler angle of the mechanical arm thetazA Z-axis Euler angle is taken as a Base coordinate of the mechanical arm;
F. d, reconstructing a new tool coordinate system, wherein the origin of the new tool coordinate system is the origin of the transition tool coordinate system plus the deviation calculated in the step E, the new tool coordinate system is consistent with the direction of the flange tool coordinate system of the mechanical arm, and the mechanical arm is guided to be positioned according to the new tool coordinate system;
G. and D, when the next guiding positioning is carried out, taking the new tool coordinate system in the step F as a transition tool coordinate system, and entering the step C.
Further, in step C, the x and y coordinates of the nine positions are respectively: (-a, -a), (-a, 0), (-a, a), (0, -a), (0,0), (0, a), (a, -a), (a, 0), (a, a), wherein the value of a is related to the marker size and the camera field of view.
Further, in the step a, the feature point is a circle center or a cross line intersection.
Further, in the step a, a marker is pasted on the surface of the shot workpiece, a circular pattern or a cross line is printed on the marker, and the characteristic point is a center of the circular pattern or an intersection of the cross lines.
Further, in step D, the first angle is 90 ° clockwise, and the second angle is 270 ° clockwise.
Further, in the step C, the conversion relation [ R M ] is calculated by the following formula:
wherein, (x, y) is xy coordinates of each position on a workpiece coordinate system, (u, v) is row-column coordinates of an image coordinate system of each marker feature point, R is a rotation matrix, and M is a translation matrix.
Further, in the step B, a transition tool coordinate system is established by a TCP calibration four-point method of the mechanical arm.
Further, the camera field of view is 80mm, the marker size is 20mm, and the value of a is 20 mm.
The invention is also realized by the following technical scheme:
a hand-eye calibration device based on a reconstructed coordinate system, comprising:
a feature point determination module: the method comprises the steps of determining a clear characteristic point on the surface of a shot workpiece;
a transition tool coordinate system determination module: the method is used for establishing a transition tool coordinate system through a TCP calibration method of the mechanical arm, enabling the origin of the transition tool coordinate system to coincide with the characteristic point as much as possible, and establishing a workpiece coordinate system according to the transition tool coordinate system, wherein the direction of the workpiece coordinate system is consistent with the direction of a Base coordinate system of the mechanical arm;
a conversion relation determination module: the system comprises a control system, a transition tool coordinate system, a camera, a coordinate system and a coordinate system of a marker, wherein the control system is used for controlling the mechanical arm to move nine positions on a plane of a workpiece coordinate system z which is equal to 0 by using the transition tool coordinate system, controlling the camera arranged on the mechanical arm to respectively collect images containing characteristic points at the nine positions, respectively extracting the coordinates of the characteristic points on each image, and calculating the conversion relation between the image coordinate system and the workpiece coordinate system through the coordinates of each position and the coordinates of each marker characteristic point;
a deviation amount determination module: the system comprises a camera, a first angle and a second angle, a first rotating image and a second rotating image are respectively shot by the camera at the first angle and the second angle, a characteristic point coordinate A on the first rotating image and a characteristic point coordinate B on the second rotating image are respectively calculated, and the coordinate of a midpoint C between the coordinate A and the coordinate B is calculated, wherein the first angle and the second angle are respectively used for controlling the mechanical arm to rotate around a plane (0,0) with the workpiece coordinate system z being 0 and have the difference value of 180 degrees; according to the conversion relation, the coordinates of the midpoint C on the workpiece are calculatedCoordinates under the system (D)x,Dy) Rotating the workpiece coordinate system to be consistent with the direction of the transition tool coordinate system, and calculating the deviation between the C point and the origin of the transition tool coordinate system
Wherein, thetaxFor the Base coordinate x-axis Euler angle of the mechanical arm thetayIs the Base coordinate y-axis Euler angle of the mechanical arm thetazA Z-axis Euler angle is taken as a Base coordinate of the mechanical arm;
new tool coordinate system determination module: the tool coordinate system is used for reconstructing a new tool coordinate system, the original point of the new tool coordinate system is the original point of the transition tool coordinate system plus the deviation amount calculated in the step E, the new tool coordinate system is enabled to be consistent with the direction of the flange tool coordinate system of the mechanical arm, and the mechanical arm is guided to be positioned according to the new tool coordinate system;
a positioning update module: and the system is used for taking the new tool coordinate system used at the next guiding and positioning as a transition tool coordinate system, reestablishing a new tool coordinate system through the conversion relation determining module, the deviation amount determining module and the new tool coordinate system determining module, and guiding the positioning of the mechanical arm by using the new tool coordinate system.
The invention has the following beneficial effects:
1. before determining a tool coordinate system for the first time, determining a clear characteristic point on the surface of a shot workpiece, establishing a transition tool coordinate system with an origin basically coincident with the characteristic point, controlling a mechanical arm to collect images containing the characteristic point at nine specific positions, calculating the conversion relation between the image coordinate system and the workpiece coordinate system according to the images, controlling the mechanical arm to rotate to obtain a first rotating image and a second rotating image, obtaining the coordinates of the midpoint of the characteristic point coordinates on the first rotating image and the second rotating image, obtaining the deviation between the midpoint and the origin of the transition tool coordinate system by using the midpoint coordinates and the conversion relation, determining a new tool coordinate system by adding the deviation to the origin of the transition tool coordinate system, guiding the positioning of the mechanical arm according to the tool coordinate system, and when the next guiding positioning is needed, the tool coordinate system which is currently used is used as a transition tool coordinate system, the conversion relation and the deviation amount are calculated again to determine a new tool coordinate system again, so that the tool coordinate system and the workpiece rotation center can be kept consistent all the time in the operation process of the mechanical arm, the error between the original point of the tool coordinate system and the workpiece rotation center is eliminated, the result precision does not depend on the level of an operator any more, the hand-eye calibration precision is effectively improved, the operation is simpler, and the operation efficiency is improved.
Drawings
The present invention will be described in further detail with reference to the accompanying drawings.
FIG. 1 is a schematic diagram of coordinate systems according to the present invention.
FIG. 2 is a flow chart of the present invention.
Wherein, 1, a mechanical arm; 2. a tool coordinate system; 3. a workpiece coordinate system; 4. a camera coordinate system; 5. robot Base coordinate system.
Detailed Description
As shown in fig. 1 and fig. 2, the hand-eye calibration method based on the reconstructed coordinate system includes the following steps:
A. determining a clear characteristic point on the surface of the shot workpiece, wherein in the embodiment, a marker is stuck on the surface of the shot workpiece, a circular pattern is printed on the marker, and the characteristic point is the circle center of the circular pattern; in other embodiments, feature points, such as intersection points of crisscrossing lines, may also be determined directly on the surface of the tool being photographed;
B. establishing a transition tool coordinate system by a TCP four-point calibration method of the mechanical arm, enabling the origin of the transition tool coordinate system to be basically superposed with the characteristic point, and establishing a workpiece coordinate system according to the transition tool coordinate system, wherein the direction of the workpiece coordinate system is consistent with the direction of a Base coordinate system of the mechanical arm; the TCP four-point calibration method is the prior art, but the TCP four-point calibration method cannot completely coincide the origin of the coordinate system of the transition tool with the characteristic point, so the origin of the coordinate system of the transition tool can only coincide the characteristic point as much as possible, and moreover, the origin of the coordinate system of the transition tool does not need to coincide with the characteristic point, so that the origin can be achieved by a new tool coordinate system processed by subsequent steps, and the coordinate system of the transition tool is taken as a basis; the orientation of the Base coordinate system of the robot arm is known;
C. controlling the mechanical arm to move nine positions on a plane with a workpiece coordinate system z being 0 by using a transition tool coordinate system, controlling a camera arranged on the mechanical arm to collect images containing characteristic points at the nine positions respectively, extracting the coordinates of the characteristic points on each image respectively, and calculating the conversion relation between the image coordinate system and the workpiece coordinate system through the coordinates of each position and the coordinates of each marker characteristic point; wherein, the x, y coordinates of nine positions are respectively: (-a, -a), (-a, 0), (-a, a), (0, -a), (0,0), (0, a), (a, -a), (a, 0), (a, a), wherein a is related to the marker size and the camera field of view, in this example, the camera field of view is 80mm x 80mm, the marker size is 20mm x 20mm, and a is 20 mm; extracting the coordinates of the feature points of the image is the prior art, in this embodiment, extracting the coordinates of the circle center includes the steps of extracting the boundary, fitting the circle and obtaining the circle center, the image coordinate system is the image pixel coordinate system, and the coordinates of the feature points are the pixel coordinates of the feature points on the image;
calculating a transformation relationship [ R M]The concrete formula of (1) is as follows:
wherein, (x, y) is xy coordinates of each position on a workpiece coordinate system, (u, v) is row-column coordinates of an image coordinate system of each marker feature point, R is a rotation matrix, and M is a translation matrix;
D. controlling the mechanical arm to rotate around a first angle and a second angle with a difference value of 180 degrees respectively around (0,0) of a plane of a workpiece coordinate system z, controlling the camera to shoot a first rotation image and a second rotation image at the first angle and the second angle respectively, calculating a feature point coordinate A on the first rotation image and a feature point coordinate B on the second rotation image respectively, and calculating a coordinate of a midpoint C between the coordinate A and the coordinate B; in this embodiment, the first angle is 90 ° clockwise rotation, and the second angle is 270 ° clockwise rotation;
E. according to the conversion relation, calculating the coordinate (D) of the midpoint C in the workpiece coordinate systemx,Dy) Rotating the workpiece coordinate system to be consistent with the direction of the transition tool coordinate system, and calculating the deviation between the C point and the origin of the transition tool coordinate system
Wherein, TxFor the deviation in x-direction of the new tool coordinate system from the transition tool coordinate system, TyThe deviation in the y-direction of the new tool coordinate system from the transition tool coordinate system, TzTheta is the amount of deviation in the z-direction of the new tool coordinate system from the transition tool coordinate systemxFor the Base coordinate x-axis Euler angle of the mechanical arm thetayIs the Base coordinate y-axis Euler angle of the mechanical arm thetazA Z-axis Euler angle is taken as a Base coordinate of the mechanical arm;
in theory, the feature point coordinate a and the feature point coordinate B should be the same point, but because the origin of the transition tool coordinate system is not coincident with the workpiece rotation center, the feature point coordinate a and the feature point coordinate B both have a certain difference from (0,0), and because the difference between the first angle and the second angle is 180 °, the midpoint C of the coordinate a and the coordinate B is the actual workpiece rotation center and is also the origin of the new tool coordinate system;
F. d, reconstructing a new tool coordinate system, wherein the origin of the new tool coordinate system is the origin of the transition tool coordinate system plus the deviation calculated in the step E, the new tool coordinate system is consistent with the direction of the flange tool coordinate system of the mechanical arm, and the mechanical arm is guided to be positioned according to the new tool coordinate system; wherein the orientation of the robotic flange tool coordinate system is known;
G. and D, when the next guiding positioning is carried out, taking the new tool coordinate system in the step F as a transition tool coordinate system, and entering the step C.
Hand-eye calibration device based on reconstructed coordinate system includes:
a feature point determination module: the method comprises the steps of determining a clear characteristic point on the surface of a shot workpiece;
a transition tool coordinate system determination module: the method is used for establishing a transition tool coordinate system through a TCP calibration method of the mechanical arm, enabling the origin of the transition tool coordinate system to coincide with the characteristic point as much as possible, and establishing a workpiece coordinate system according to the transition tool coordinate system, wherein the direction of the workpiece coordinate system is consistent with the direction of a Base coordinate system of the mechanical arm;
a conversion relation determination module: the system comprises a control system, a transition tool coordinate system, a camera, a coordinate system and a coordinate system of a marker, wherein the control system is used for controlling the mechanical arm to move nine positions on a plane of a workpiece coordinate system z which is equal to 0 by using the transition tool coordinate system, controlling the camera arranged on the mechanical arm to respectively collect images containing characteristic points at the nine positions, respectively extracting the coordinates of the characteristic points on each image, and calculating the conversion relation between the image coordinate system and the workpiece coordinate system through the coordinates of each position and the coordinates of each marker characteristic point;
a deviation amount determination module: the system comprises a camera, a first angle and a second angle, a first rotating image and a second rotating image are respectively shot by the camera at the first angle and the second angle, a characteristic point coordinate A on the first rotating image and a characteristic point coordinate B on the second rotating image are respectively calculated, and the coordinate of a midpoint C between the coordinate A and the coordinate B is calculated, wherein the first angle and the second angle are respectively used for controlling the mechanical arm to rotate around a plane (0,0) with the workpiece coordinate system z being 0 and have the difference value of 180 degrees; according to the conversion relation, calculating the coordinate (D) of the midpoint C in the workpiece coordinate systemx,Dy) Rotating the workpiece coordinate system to be consistent with the direction of the transition tool coordinate system, and calculating the deviation between the C point and the origin of the transition tool coordinate system
Wherein, thetaxFor the Base coordinate x-axis Euler angle of the mechanical arm thetayIs the Base coordinate y-axis Euler angle of the mechanical arm thetazA Z-axis Euler angle is taken as a Base coordinate of the mechanical arm;
new tool coordinate system determination module: the tool coordinate system is used for reconstructing a new tool coordinate system, the original point of the new tool coordinate system is the original point of the transition tool coordinate system plus the deviation amount calculated in the step E, the new tool coordinate system is enabled to be consistent with the direction of the flange tool coordinate system of the mechanical arm, and the mechanical arm is guided to be positioned according to the new tool coordinate system;
a positioning update module: and the system is used for taking the new tool coordinate system used at the next guiding and positioning as a transition tool coordinate system, reestablishing a new tool coordinate system through the conversion relation determining module, the deviation amount determining module and the new tool coordinate system determining module, and guiding the positioning of the mechanical arm by using the new tool coordinate system.
The above description is only a preferred embodiment of the present invention, and therefore should not be taken as limiting the scope of the invention, which is defined by the appended claims and their equivalents and modifications within the scope of the description.
Claims (9)
1. A hand-eye calibration method based on a reconstructed coordinate system is characterized by comprising the following steps: the method comprises the following steps:
A. determining a clear characteristic point on the surface of the shot workpiece;
B. establishing a transition tool coordinate system by a TCP calibration method of the mechanical arm, enabling the origin of the transition tool coordinate system to be basically superposed with the characteristic point, and establishing a workpiece coordinate system according to the transition tool coordinate system, wherein the direction of the workpiece coordinate system is consistent with the direction of a Base coordinate system of the mechanical arm;
C. controlling the mechanical arm to move nine positions on a plane with a workpiece coordinate system z being 0 by using a transition tool coordinate system, controlling a camera arranged on the mechanical arm to collect images containing characteristic points at the nine positions respectively, extracting the coordinates of the characteristic points on each image respectively, and calculating the conversion relation between the image coordinate system and the workpiece coordinate system through the coordinates of each position and the coordinates of each marker characteristic point;
D. controlling the mechanical arm to rotate around a first angle and a second angle with a difference value of 180 degrees respectively around (0,0) of a plane of a workpiece coordinate system z, controlling the camera to shoot a first rotation image and a second rotation image at the first angle and the second angle respectively, calculating a feature point coordinate A on the first rotation image and a feature point coordinate B on the second rotation image respectively, and calculating a coordinate of a midpoint C between the coordinate A and the coordinate B;
E. according to the conversion relation, calculating the coordinate (D) of the midpoint C in the workpiece coordinate systemx,Dy) Rotating the workpiece coordinate system to be consistent with the direction of the transition tool coordinate system, and calculating the deviation between the C point and the origin of the transition tool coordinate system
Wherein, thetaxFor the Base coordinate x-axis Euler angle of the mechanical arm thetayIs the Base coordinate y-axis Euler angle of the mechanical arm thetazA Z-axis Euler angle is taken as a Base coordinate of the mechanical arm;
F. d, reconstructing a new tool coordinate system, wherein the origin of the new tool coordinate system is the origin of the transition tool coordinate system plus the deviation calculated in the step E, the new tool coordinate system is consistent with the direction of the flange tool coordinate system of the mechanical arm, and the mechanical arm is guided to be positioned according to the new tool coordinate system;
G. and D, when the next guiding positioning is carried out, taking the new tool coordinate system in the step F as a transition tool coordinate system, and entering the step C.
2. The hand-eye calibration method based on the reconstructed coordinate system as claimed in claim 1, wherein: in the step C, the x and y coordinates of the nine positions are respectively: (-a, -a), (-a, 0), (-a, a), (0, -a), (0,0), (0, a), (a, -a), (a, 0), (a, a), wherein the value of a is related to the marker size and the camera field of view.
3. The hand-eye calibration method based on the reconstructed coordinate system as claimed in claim 1, wherein: in the step A, the characteristic points are circle centers or cross intersection points.
4. The hand-eye calibration method based on the reconstructed coordinate system as claimed in claim 1, wherein: in the step A, a marker is pasted on the surface of the shot workpiece, a circular pattern or a cross line is printed on the marker, and the characteristic point is the center of the circle of the circular pattern or the intersection point of the cross line.
5. A hand-eye calibration method based on a reconstructed coordinate system according to claim 1, 2, 3 or 4, wherein: in the step D, the first angle is clockwise rotation of 90 degrees, and the second angle is clockwise rotation of 270 degrees.
6. A hand-eye calibration method based on a reconstructed coordinate system according to claim 1, 2, 3 or 4, wherein: in the step C, the conversion relation [ R M ] is calculated by the following formula:
wherein, (x, y) is xy coordinates of each position on a workpiece coordinate system, (u, v) is row-column coordinates of an image coordinate system of each marker feature point, R is a rotation matrix, and M is a translation matrix.
7. A hand-eye calibration method based on a reconstructed coordinate system according to claim 1, 2, 3 or 4, wherein: and in the step B, a transition tool coordinate system is established by a TCP calibration four-point method of the mechanical arm.
8. The hand-eye calibration method based on the reconstructed coordinate system as claimed in claim 2, wherein: the camera field of view is 80mm, the marker size is 20mm, and the value of a is 20 mm.
9. A hand-eye calibration device based on a reconstructed coordinate system is characterized in that: the method comprises the following steps:
a feature point determination module: the method comprises the steps of determining a clear characteristic point on the surface of a shot workpiece;
a transition tool coordinate system determination module: the method is used for establishing a transition tool coordinate system through a TCP calibration method of the mechanical arm, enabling the origin of the transition tool coordinate system to coincide with the characteristic point as much as possible, and establishing a workpiece coordinate system according to the transition tool coordinate system, wherein the direction of the workpiece coordinate system is consistent with the direction of a Base coordinate system of the mechanical arm;
a conversion relation determination module: the system comprises a control system, a transition tool coordinate system, a camera, a coordinate system and a coordinate system of a marker, wherein the control system is used for controlling the mechanical arm to move nine positions on a plane of a workpiece coordinate system z which is equal to 0 by using the transition tool coordinate system, controlling the camera arranged on the mechanical arm to respectively collect images containing characteristic points at the nine positions, respectively extracting the coordinates of the characteristic points on each image, and calculating the conversion relation between the image coordinate system and the workpiece coordinate system through the coordinates of each position and the coordinates of each marker characteristic point;
a deviation amount determination module: the system comprises a camera, a first angle and a second angle, a first rotating image and a second rotating image are respectively shot by the camera at the first angle and the second angle, a characteristic point coordinate A on the first rotating image and a characteristic point coordinate B on the second rotating image are respectively calculated, and the coordinate of a midpoint C between the coordinate A and the coordinate B is calculated, wherein the first angle and the second angle are respectively used for controlling the mechanical arm to rotate around a plane (0,0) with the workpiece coordinate system z being 0 and have the difference value of 180 degrees; according to the conversion relation, calculating the coordinate (D) of the midpoint C in the workpiece coordinate systemx,Dy) Rotating the workpiece coordinate system to be consistent with the direction of the transition tool coordinate system, and calculating the deviation between the C point and the origin of the transition tool coordinate system
Wherein, thetaxFor the Base coordinate x-axis Euler angle of the mechanical arm thetayIs the Base coordinate y-axis Euler angle of the mechanical arm thetazA Z-axis Euler angle is taken as a Base coordinate of the mechanical arm;
new tool coordinate system determination module: the tool coordinate system is used for reconstructing a new tool coordinate system, the original point of the new tool coordinate system is the original point of the transition tool coordinate system plus the deviation amount calculated in the step E, the new tool coordinate system is enabled to be consistent with the direction of the flange tool coordinate system of the mechanical arm, and the mechanical arm is guided to be positioned according to the new tool coordinate system;
a positioning update module: and the system is used for taking the new tool coordinate system used at the next guiding and positioning as a transition tool coordinate system, reestablishing a new tool coordinate system through the conversion relation determining module, the deviation amount determining module and the new tool coordinate system determining module, and guiding the positioning of the mechanical arm by using the new tool coordinate system.
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