CN108132648B - Robot bending precision compensation method based on sheet material tensile deformation - Google Patents

Robot bending precision compensation method based on sheet material tensile deformation Download PDF

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CN108132648B
CN108132648B CN201711469231.7A CN201711469231A CN108132648B CN 108132648 B CN108132648 B CN 108132648B CN 201711469231 A CN201711469231 A CN 201711469231A CN 108132648 B CN108132648 B CN 108132648B
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bending
coordinate system
robot
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point
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CN108132648A (en
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宋方方
敬淑义
王杰高
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Nanjing Estun Robotics Co Ltd
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    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B19/00—Programme-control systems
    • G05B19/02—Programme-control systems electric
    • G05B19/18—Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form
    • G05B19/404—Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form characterised by control arrangements for compensation, e.g. for backlash, overshoot, tool offset, tool wear, temperature, machine construction errors, load, inertia
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B2219/00—Program-control systems
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    • G05B2219/35—Nc in input of data, input till input file format
    • G05B2219/35362—Group similar operations, to select correction, compensation values

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Abstract

The invention discloses a robot bending precision compensation method based on sheet material stretching deformation, which comprises the steps of firstly establishing a compensation coordinate system S at a V-shaped notch of a bending machine, obtaining bending parameters set by a user, obtaining a user coordinate system CS (X, Y, Z, A, B, C) of a current robot system and a robot TCP point position P1(X, Y, Z, A, B, C) after bending following and matching are started, obtaining a bending target position P2(X, Y, Z, A, B, C), calculating stretching deformation of a sheet material in the bending process of the sheet material, compensating the compensation transformation user coordinate system CS in the compensation coordinate system S 'to a position point P2, and obtaining a new compensated target position P2'. The invention fully considers the tensile deformation generated in the bending process of the plate, compensates the deformation of the plate to the target position followed by the robot, eliminates the pulling or extrusion of the robot to the plate in the bending following process and improves the bending precision.

Description

Robot bending precision compensation method based on sheet material tensile deformation
Technical Field
The invention relates to a bending industrial robot, in particular to a bending precision compensation method of a bending robot.
Background
Along with the continuous reduction of labor resources and the continuous improvement of labor cost, the requirement on the bending application of the robot is more and more urgent in the bending field. At present, the precision of a robot meets the application of bending, but the plate is deformed due to stretching in the bending process, so that the robot pulls or extrudes the plate to a certain extent after the bending is finished, and the bending precision is influenced.
The invention discloses a real-time bending following method and a device thereof for a robot (CN 104475504A). The method is provided in the document of the Chinese invention patent application, namely the method for real-time bending following, and the method is characterized in that the displacement of a bending knife in a specific period is collected in advance by an external detection device, and then the position of the tail end of the robot is calculated according to the displacement of the bending knife, so that the real-time bending following effect of the robot is realized. The method only considers the position tracking of the plate in real time, does not consider the tensile deformation of the plate in the bending process, does not compensate in the extending direction of the plate, and cannot ensure the final bending precision.
Disclosure of Invention
The invention aims to overcome the defects in the prior art, provides a robot bending precision compensation method based on sheet material stretching deformation, solves the problem of low robot bending precision caused by sheet material stretching deformation in the bending process, and improves the robot bending precision.
In order to realize the purpose of the invention, the invention adopts the technical scheme that:
a robot bending precision compensation method based on plate material tensile deformation comprises the following steps:
step 1, establishing a compensation coordinate system S at a V-shaped notch of a bending machine in a three-point calibration mode, wherein a point, reaching the V-shaped notch surface of the bending machine, of the tail end of a mobile robot is an original point O, the original point O is located right above a bending line of the V-shaped notch, and a calibration point is PO(ii) a The central line of a V-shaped notch of a bending machine is taken as an X axis, and a calibration point is PAThe direction vertical to the V-shaped notch pointing to the robot is a Y axis, one point is selected in the notch plane, and the calibration point is PBThe direction perpendicular to the V-notch surface is the Z axis, so as to obtain a compensation coordinate system S (X, Y, Z, A, B, C), wherein X, Y, Z is the offset of the compensation coordinate system S relative to the robot base coordinate system, namely a calibration origin POX, Y, Z value of (a); A. b, C, the attitude rotation of the compensation coordinate system S relative to the robot base coordinate system is calculated as follows:
firstly, unit vectors of X axis, Y axis and Z axis of a compensation coordinate system are calculated according to three calibration points, and the formula is as follows:
Figure BDA0001531686630000021
Figure BDA0001531686630000022
Figure BDA0001531686630000023
from the unit vectors, a rotation matrix can be obtained, as shown in the following equation:
Figure BDA0001531686630000024
the value of A, B, C was found from the Z-Y-Z Euler transform equation, which is shown below:
Figure BDA0001531686630000025
A＝Atan2(YZ/sinB,XZ/sinB)
C＝Atan2(ZY/sinB，-ZX/sinB)
and 2, obtaining bending parameters set by a user from the robot system, wherein the bending parameters comprise a bending forming angle alpha, a bending radius R and a plate thickness T, V notch width W.
And 3, when the bending is started, acquiring a user coordinate system CS (X, Y, Z, A, B and C) of the current robot system and a TCP point position P1(X, Y, Z, A, B and C) of the robot, acquiring a bending target position P2(X, Y, Z, A, B and C), and compensating the position based on a bending target point P2 so as to ensure the relative position of the robot and the plate after the bending is finished.
Step 4, in the bending process of the plate, the material on the inner side of the bending fillet is compressed, the material on the outer side of the bending fillet is stretched, the material with the original length is distributed in an arc line, the position of the arc is a mechanical neutral line neutral layer of the plate, as shown by a dotted line L1 in FIG. 3, and the calculation formula of the arc length of the neutral line is as follows:
Figure BDA0001531686630000031
where pi is the circumferential ratio and K is the bending coefficient of the neutral layer, and the values are determined according to the plate thickness and the plate material, and there are empirical values, as shown in the following table:
R/T 0.5 0.6 0.7 0.8 1
K 0.23 0.24 0.26 0.28 0.31
the outer circular arc of the bending fillet is the stretched length L2 of the bent plate, the bending radius and the plate thickness are known, the corresponding radius of the outer circular arc is R + T, and the arc length is known
Figure BDA0001531686630000032
Tensile deformation of the sheet
Figure BDA0001531686630000033
And 5, the compensation coordinate system S is a variable coordinate system and changes along with the change of the bending angle and the change of the upper die knife edge in the bending process, wherein the attack distance of the upper die knife edge is the change of the Z axis of the compensation coordinate system, and half of the bending angle is the rotation change of the X axis, so that the XY plane of the compensation coordinate system S is always coincided with the plane of the plate. As shown in fig. 4 (the illustration shows an example of 90 ° bending), when the upper die blade of the bending machine reaches the clamping point, the upper die blade coincides with the X axis of the compensation coordinate system S, and P1 is the position of the robot TCP point before bending follows; after bending is finished, the upper die cutting edge descends for a distance H, the plate rotates for alpha/2 degrees along the X axis of the compensation coordinate system S, the compensation coordinate system is changed from S to S', and the target position of bending completion is P2 (uncompensated), as shown by the dotted line part in the figure. The tapping distance of the upper die knife edge can be obtained according to the known width and bending angle of the notch
Figure BDA0001531686630000041
Then the transformation matrix of S' relative to S is
Figure BDA0001531686630000042
The matrix of the modified compensated coordinate system S' with respect to the base coordinate system is thus obtained as:
Figure BDA0001531686630000043
wherein B is a symbol of a base coordinate system,
Figure BDA0001531686630000044
to compensate for the rotation matrix of the coordinate system S under the base marker B, the compensation coordinate system S is derived from the markers and is known.
In step 4, the deformation of the plate in the bending and stretching process is determined to be L, the deformation only occurs in the Y-axis direction of the compensation coordinate system S', and the compensated transformation matrix is
Figure BDA0001531686630000045
The position point P2 after the robot bending following is obtained from step 2, and since the point P2 is the position value in the user coordinate system CS, the compensation conversion of the compensation coordinate system S 'in the user coordinate system CS needs to be compensated to the position point P2, so as to obtain a new compensated target position P2', as shown in the figure, the specific formula is as follows:
Figure BDA0001531686630000046
according to the invention, the tensile deformation of the plate in the bending process is calculated, and the deformation of the plate is compensated through the target position of the robot, so that the relative stillness between the tail end of the robot and the plate in the bending following process is realized, the condition that the tail end of the robot pulls or extrudes the plate is avoided, and the bending precision is improved.
The invention fully considers the tensile deformation generated in the bending process of the plate, compensates the deformation of the plate to the target position followed by the robot, eliminates the pulling or extrusion of the robot to the plate in the bending following process and improves the bending precision.
Drawings
FIG. 1 is a flow chart of a robot bending precision compensation method based on sheet material tensile deformation.
Fig. 2 is a schematic diagram of a compensated coordinate system established by the bending machine notches.
Fig. 3 is a schematic diagram of deformation and stretching of the plate material in the bending process.
Fig. 4 is a diagram showing a change in position of the robot before bending starts and after bending is completed.
Detailed Description
The present invention will be described in detail with reference to the following examples and drawings.
The implementation steps are as follows:
step 1: three points on the notch are calibrated through the robot, and the coordinate value of the origin O is PO(1896.72-239.85,1033.50) for calibrating a point P in the X-axis direction of the compensation coordinate system in the notch directionA(1835.10, -1672.77, 1038.03) and calibrating a point P in the XY plane direction of the compensation coordinate systemB(1856.89, -1437.79, 1037.22), the unit vectors of X, Y, Z axes of the compensated coordinate system are obtained, and the rotation matrix is obtained as follows:
Figure BDA0001531686630000051
according to the Z-Y-Z Euler transformation formula, from the rotation matrix RSThe compensation is obtained by determining a ═ -92.46, B ═ 0, and C ═ 0The coordinate system is as follows:
S＝(1896.72，-239.85,1033.50,-92.46，0，0)
step 2: and obtaining bending parameters, wherein the bending forming angle alpha is 90 degrees, the bending radius R is 1mm, the plate thickness T is 1mm, and the V-shaped notch width W is 8 mm.
And step 3: before bending is started, a bending user coordinate system CS (856.236,0,556.571, 0,0,0) is obtained, bending starting point positions P1(189.216, -1306.607, 125.848, 170.996,1.793, -83.555) and bending end point positions P2(175.703, -1303.887,802.038, -2.235,43.219,89.611) are obtained, and plate deformation compensation is calculated based on the bending end points.
And 4, step 4: and (3) calculating the deformation length L of the plate material according to the bending parameters obtained in the step (2), and as follows:
Figure BDA0001531686630000061
and 5: the attack distance H of the upper die edge is determined from known parameters as follows:
Figure BDA0001531686630000062
then the transformation matrix of S' relative to S is
Figure BDA0001531686630000063
Due to the fact that
Figure BDA0001531686630000064
Is known, therefore
Figure BDA0001531686630000065
Can be obtained.
And 4, obtaining a compensated transformation matrix by taking the deformation of the plate material obtained in the step 4 in the bending and stretching process as L:
Figure BDA0001531686630000071
the above steps determine all unknowns to determine a new bend target position P2' after compensation, as shown below
Figure BDA0001531686630000072

Claims (1)

1. A robot bending precision compensation method based on plate material tensile deformation comprises the following steps:
step 1, establishing a compensation coordinate system S at a V-shaped notch of a bending machine in a three-point calibration mode, wherein a point, reaching the V-shaped notch surface of the bending machine, of the tail end of a mobile robot is an original point O, the original point O is located right above a bending line of the V-shaped notch, and a calibration point is PO(ii) a The central line of a V-shaped notch of a bending machine is taken as an X axis, and a calibration point is PAThe direction vertical to the V-shaped notch pointing to the robot is a Y axis, one point is selected in the notch plane, and the calibration point is PBThe direction perpendicular to the V-notch surface is the Z axis, so as to obtain a compensation coordinate system S (X, Y, Z, A, B, C), wherein X, Y, Z is the offset of the compensation coordinate system S relative to the robot base coordinate system, namely a calibration origin POX, Y, Z value of (a); A. b, C, the attitude rotation of the compensation coordinate system S relative to the robot base coordinate system is calculated as follows:
firstly, unit vectors of X axis, Y axis and Z axis of a compensation coordinate system are calculated according to three calibration points, and the formula is as follows:
Figure FDA0001531686620000011
Figure FDA0001531686620000012
Figure FDA0001531686620000013
from the unit vectors, a rotation matrix can be obtained, as shown in the following equation:
Figure FDA0001531686620000014
the value of A, B, C was found from the Z-Y-Z Euler transform equation, which is shown below:
Figure FDA0001531686620000015
A＝Atan2(YZ/sinB,XZ/sinB)
C＝Atan2(ZY/sinB，-ZX/sinB)
step 2, obtaining bending parameters set by a user from a robot system: bending forming angle alpha, bending radius R, plate thickness T, V notch width W;
step 3, after bending tracking is started, acquiring a user coordinate system CS (X, Y, Z, A, B, C) of the current robot system, a robot TCP point position P1(X, Y, Z, A, B, C), and a bending target position P2(X, Y, Z, A, B, C);
step 4, calculating the tensile deformation of the plate in the bending process:
Figure FDA0001531686620000021
wherein pi is the circumferential rate, and K is the bending coefficient of the neutral layer;
and 5, solving the attack distance of the upper die knife edge according to the known width and bending angle of the notch:
Figure FDA0001531686620000022
then the transformation matrix of S' relative to S is
Figure FDA0001531686620000023
Thereby obtaining a matrix of the modified compensated coordinate system S' relative to the base coordinate system
Figure FDA0001531686620000024
Wherein B is a symbol of a base coordinate system,
Figure FDA0001531686620000025
a rotation matrix of a compensation coordinate system S under a base mark B is obtained;
the compensated transformation matrix is
Figure FDA0001531686620000026
Compensating the compensation of the compensation coordinate system S 'to the position point P2 under the compensation transformation user coordinate system CS, thereby obtaining a new compensated target position P2', which has the following specific formula:
Figure FDA0001531686620000031
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Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102820844A (en) * 2012-09-20 2012-12-12 南京埃斯顿自动化股份有限公司 Vibration suppression method for flexible manipulators

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CN101644921B (en) * 2009-08-05 2011-07-20 无锡信捷电气有限公司 Improved method for designing numerical control bending of plate
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CN103707299B (en) * 2013-12-18 2016-01-13 南京埃斯顿机器人工程有限公司 A kind of method realizing the bending of bending robot and follow in real time
CN104438488B (en) * 2014-10-20 2016-07-27 上海新时达电气股份有限公司 The bearing calibration of robot bending blowing pose and device thereof
CN106295055A (en) * 2016-08-22 2017-01-04 南京埃斯顿自动化股份有限公司 A kind of bender bending method that upper mold depth is carried out bending springback compensation

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102820844A (en) * 2012-09-20 2012-12-12 南京埃斯顿自动化股份有限公司 Vibration suppression method for flexible manipulators

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