CN106737683A - The method of correction industrial robot off-line programing error in the field - Google Patents

Abstract

The method of correction industrial robot off-line programing error in the field belongs to industrial robot off-line programming technique field, the method is to carry out the off-line programing emulation of industrial robot in a computer, determine two particular locations of industrial camera and set up the new coordinate system of emulation, the position of two check points of determination and its coordinate value in new coordinate system, and determine in the range of two industrial cameras can be photographed, three characteristic points and its coordinate value on industrial robot；In the field, according to two industrial cameras of position of sound production of emulation, check point is shot, draws the coordinate and correction matrix of check point；Three characteristic points in the robot determined in emulation are shot, and draws coordinate of three characteristic points relative to industrial camera；Using the homogeneous transformation in coordinate transform, the related data that correction needs is obtained, then data are transmitted to computer, correct the off-line programing emulation of industrial robot.The present invention is simple and easy to apply, emulates robot off-line programming more accurate and accurate.

Description

The method of correction industrial robot off-line programing error in the field

Technical field

The invention belongs to industrial robot off-line programming technique field, and in particular to one kind correction industrial robot is compiled offline The method of journey error in the field.

Background technology

Robot Off-line Programming System (Robot off-line-programming System) is current robot research Most enliven the research direction of forefront in field.In recent years, it is quick with computer technology, microelectric technique and network technology etc. Development, robot technology is also developed rapidly.It collects mechanical engineering, electronic engineering, automatic control engineering and artificial intelligence In one, the robot input engineer applied of existing many types, creates the multi-disciplinary latest scientific research such as energy at present Huge economic and social benefit.Robot is a programmable mechanical device, the flexibility of its function and intelligent very big It is decided by the program capability of robot in degree.

Under ideal conditions, i.e., under conditions of enough smooth and smooth in six faces in whole space, industrial robot from Line programming simulation very can accurately lay industrial robot and carry out the path planning of industrial robot.But, in reality Cause error, and industrial robot size presence in itself are installed because the place for placing robot is likely to occur ground injustice The factors such as error, so, off-line programing simulate come result, be placed on scene have certain error, so as to cause emulation with Do not correspond actually.It is now artificial correction to the method majority that this phenomenon is corrected, individually using equipment calibration, calibration equipment It is very high in price, it is also very complicated in method.

The content of the invention

In order to solve the technical problem that calibration equipment price is high and bearing calibration is complicated that existing error calibration method is present, The present invention provides a kind of method for correcting industrial robot off-line programing error in the field.

The technical solution adopted for solving the technical problem of the present invention is as follows：

The method of correction industrial robot off-line programing error in the field, it is comprised the following steps：

(1) the off-line programing emulation of industrial robot is carried out in a computer, determines two particular locations of industrial camera, And the position of one of industrial camera is set as origin, the camera and another industrial camera line direction be X-axis just To, the direction of industrial camera optical axis is the forward direction of Y-axis, and the forward direction of Z axis is determined according to the right-hand rule, sets up the new coordinate system of emulation, In this new coordinate system of emulation, position and its coordinate value of two check points are determined, and determine in two industrial camera energy In the range of enough photographing, fixed three obvious characteristic points and its coordinate value on industrial robot；

(2) in the field, two industrial cameras of position of sound production for being emulated according to step (1), shoot check point, draw correction The coordinate and correction matrix of point；

(3) shoot step (1) emulation in determine robot on first characteristic point, and draw this feature point relative to The coordinate of industrial camera；

(4) shoot step (1) emulation in determine robot on second characteristic point, and draw this feature point relative to The coordinate of industrial camera；

(5) shoot step (1) emulation in determine robot on the 3rd characteristic point, and draw this feature point relative to The coordinate of industrial camera；

(6) using the homogeneous transformation in coordinate transform, the related data that correction needs is obtained；

(7) related data that step (6) is obtained is sent to computer, industrial robot is offline in amendment step (1) Programming simulation.

The particular location of two industrial cameras of determination described in step (1) refers to that industry is carried out in off-line programming software When the off-line programing of robot is emulated, in the layout of whole emulation, choose two and be easy to lay and can photograph industrial machine Two points of device people lay this two industrial cameras.

The position of two check points of determination described in step (1) refers to the scope that can be photographed in two industrial cameras It is interior, choose two fixations and visibility point.

The seat calibration method for drawing check point described in step (2) is：Coordinate system where check point with simulations The mode of check point establishment of coordinate system is identical, and two industrial cameras form triangular relationship with impact point, and it is base that impact point is solved In parallax, the acquisition of three-dimensional information is carried out by triangle principle, it is known that the position relationship between two industrial cameras, just can obtained The three-dimensional coordinate of object feature point in public view field；If the world coordinates of spatial point P is (X_W,Y_W,Z_W), in left side industrial camera Image coordinate be (u, v), on right side, the image coordinate of industrial camera isThen have：

I.e.：

Wherein, m₁~m₁₆、It is the projection matrix of industrial camera, is drawn by the inner parameter of industrial camera, k₁、 k₂、It is distortion factor, θ is stoichiometric factor；In above-mentioned formula, due under distortionless ideal conditions, m₁~ m₁₆、, it is known that θ is 0, above-mentioned equation can be solved with pseudoinverse technique, draw the coordinate value of check point.

The method for drawing correction matrix described in step (2) is：By the homogeneous transformation in coordinate transform, can obtain public Formula：

I.e.：

Wherein：

It is homogeneous transformation battle array；

For the coordinate that impact point determines in the field；

It is impact point identified coordinate in simulations；

It is the translation matrix of X, Y, Z axis variable quantity；

It is spin matrix；

In formula, f, q, j are the Eulerian angles of three-dimensional coordinate, and j is rotated to be around x-axis, and q is rotated to be around y-axis, and f is rotated to be around z-axis； Measured check point is two, therefore, eight formula being can obtain, it is necessary to solve six unknown numbers, can be solved with pseudoinverse technique, Obtain homogeneous transformation battle array, as correction matrix.

To drawing described in step (5), characteristic point refers to three characteristic points relative to the coordinate of industrial camera to step (3) New coordinate system is set up in coordinate under new coordinate system at the scene, setting up in mode and step (1) emulation for the new coordinate system in this scene Mode is identical, is to emulate the position of that selected industrial camera as coordinate origin with the off-line programing of industrial robot, Forward direction with this camera with another industrial camera line direction as X-axis, the direction of industrial camera optical axis is the forward direction of Y-axis, root The forward direction of Z axis is determined according to the right-hand rule, the new coordinate system in scene is set up.

The related data that needs are corrected described in step (6) refer in scene new coordinate system relative to new coordinate system in emulation Roll angle, yaw angle, the distance of the angle of pitch and origin translation.

The method for solving of the related data for correcting needs described in step (6) is to be multiplied by the homogeneous transform matrix of robot The correction matrix of step (2), draws the homogeneous transform matrix after correction, as corrects the related data of needs.

The beneficial effects of the invention are as follows：The method uses industrial camera, relatively cheap in price, simple and easy to apply in method； Using industrial camera, under given conditions, the error of off-line programing emulation is can be obtained by the field, then error is fed back Computer off-line programming software is given, parameter is remodified in software, make whole emulation more accurate and accurate, it is to avoid due to Industrial robot track caused by the natural conditions at scene it is inaccurate, it is to avoid manually carry out inaccurate school in the field Just, while decreasing the time of correction.

Brief description of the drawings

Fig. 1 is two industrial camera image-forming principle schematic diagrames.

Fig. 2 is the principle schematic that single industrial camera shoots characteristic point.

Fig. 3 is characterized the schematic diagram that coordinate is chosen after being a little imaged in phase plane.

Fig. 4 is the method flow diagram of present invention correction industrial robot off-line programing error in the field.

Specific embodiment

The present invention is described in further details below in conjunction with the accompanying drawings.

As shown in Figures 1 to 4, the method for present invention correction industrial robot off-line programing error in the field is as follows：

First, field layout is carried out in the emulation of industrial robot off-line programing, places industrial robot.Then whole Two points are chosen in individual layout and lays industrial cameras, and the two points need is special, convenient, be easy to two of placement Point, while also industrial robot (for example, two angles on station framework) can be photographed.Then, according to the two industry Camera sets up new coordinate system：Position with one of industrial camera as coordinate origin, with another industrial camera line Direction is the forward direction of X-axis, and the direction of industrial camera optical axis is the forward direction of Y-axis, and the forward direction of Z axis is then determined according to the right-hand rule, The new coordinate system of emulation of formation.

Then, more obvious two points in whole simulating area are chosen (for example, laying on industrial robot ground Hole) as check point, coordinate of the two check points in the case where new coordinate system is emulated is drawn by simulation software, by industry In the range of camera can take pictures, obvious three characteristic points fixed in robot are found (for example, on industrial robot base Three points that camera can be photographed), draw coordinate of these three characteristic points in the case where new coordinate system is emulated.

Process above is the preparation for needing to be carried out in industrial robot off-line programing simulation software.

In the field, the layout in simulation software, arranges whole scene.As shown in figure 1, two industrial cameras are used The mode of Fig. 1 is laid, and particular location is looked in the field then according to two industrial cameras of position of sound production in simulation software Two check points in emulation, are shot by industrial camera.

As shown in figure 1, two industrial camera vision systems are, based on parallax, obtaining for three-dimensional information to be carried out by triangle principle Take, it is known that the position relationship between two industrial cameras, just can obtain the three-dimensional dimension of object and space in public view field special Levy three-dimensional coordinate a little.

Fig. 2 is the schematic diagram that single industrial camera shoots characteristic point, and Fig. 3 is coordinate choosing after characteristic point is imaged in phase plane The mode for taking.Two industrial cameras are laid according to Fig. 1, if the world coordinates of spatial point P is (X_W,Y_W,Z_W), in left side industry phase The image coordinate of machine is (u, v), and on right side, the image coordinate of industrial camera isThen have：

I.e.:

Wherein, m₁~m₁₆、It is the projection matrix of industrial camera, is drawn by the inner parameter of industrial camera, k₁、 k₂、It is distortion factor, θ is stoichiometric factor.In above-mentioned formula, due to m₁~m₁₆、, it is known that θ is 0, I.e. under distortionless ideal conditions, just into 4 equations, 3 unknown numbers can be solved above-mentioned formula with pseudoinverse technique.With The method, it can be deduced that the actual coordinate value of check point.

The above-mentioned actual three-dimensional coordinate for drawing is made comparisons with the three-dimensional coordinate in industrial robot off-line simulation：If In error allowed band, then without correction；If outside the scope that error is allowed, needing correction.Because laying industrial phase When machine, can there is place, lay equal error, have difference with the position in emulation so as to cause the position laid.Want Go out accurate coordinate value, be just necessarily required to correction.Here draw correction matrix also for on post-equalization industrial robot Three characteristic points are prepared.

By the homogeneous transformation in coordinate transform, formula can be obtained

I.e.：

Wherein：

It is homogeneous transformation battle array

For the coordinate that impact point determines in the field

It is impact point identified coordinate in simulations,

It is the translation matrix of X, Y, Z axis variable quantity,

It is spin matrix,

F, q, j are the Eulerian angles of three-dimensional coordinate in formula, and j is rotated to be around x-axis, and q is rotated to be around y-axis, and f is rotated to be around z-axis. Measured check point is two, therefore, eight formula being can obtain, it is necessary to solve six unknown numbers, can be solved with pseudoinverse technique. Using the above method, homogeneous transformation battle array is can obtainAs correction matrix.

First characteristic point being fixed in robot in emulation is shot, characteristic point image coordinate is on two industrial cameras Respectively p_left=(X_left,Y_left), p_right=(X_right,Y_right)。

In approximately the same plane, the image coordinate Y-coordinate of first characteristic point is identical, i.e., for two images of industrial camera Y_left=Y_right=Y, the focal length of industrial camera is f, then obtained by triangle geometrical relationship：

Then parallax is：Disparity=X_left-X_right.In formula, B is baseline distance, i.e., the two projection centre lines of camera Distance.Thus three-dimensional coordinate of first characteristic point in the case where coordinate system is emulated can be calculated is：

According to above-mentioned method, second characteristic point and the 3rd characteristic point being fixed in robot of taking pictures successively, and Obtain its coordinate.

Then, roll angle, yaw angle, pitching of the site coordinate system relative to emulation coordinate system are drawn by following algorithm Angle, and origin translation distance, then spin matrix and translation matrix are multiplied with correction matrix respectively, draw required after correction Data.The algorithm is：

I.e.：

Wherein：

It is homogeneous transformation battle array

For the coordinate that impact point determines in the field

It is impact point identified coordinate in simulations,

It is the translation matrix of X, Y, Z axis variable quantity,

It is spin matrix,

In formula, f, q, j are the Eulerian angles of three-dimensional coordinate, and j is rotated to be around x-axis, and q is rotated to be around y-axis, and f is rotated to be around z-axis； Δ X, Δ Y, Δ Z are respectively increment, the increment of Y-direction, the increment of Z-direction of X-direction in translation matrix.Measured fixing point It is three, therefore, nine formula being can obtain, it is necessary to solve nine unknown numbers, can be solved with pseudoinverse technique.

Finally, related data is sent to computer, amendment off-line programing emulation.

Claims (8)

1. the method for correcting industrial robot off-line programing error in the field, it is characterised in that the method includes following step Suddenly：

(1) the off-line programing emulation of industrial robot is carried out in a computer, determines two particular locations of industrial camera, and will The position of one of industrial camera is set as origin, and the camera is the forward direction of X-axis, work with another industrial camera line direction The direction of industry camera optical axis is the forward direction of Y-axis, and the forward direction of Z axis is determined according to the right-hand rule, the new coordinate system of emulation is set up, at this In emulating new coordinate system, position and its coordinate value of two check points are determined, and determination can be photographed in two industrial cameras In the range of, fixed three obvious characteristic points and its coordinate value on industrial robot；

(2) in the field, two industrial cameras of position of sound production for being emulated according to step (1), shoot check point, draw check point Coordinate and correction matrix；

(3) first characteristic point in the robot determined in step (1) emulation is shot, and draws this feature point relative to industry The coordinate of camera；

(4) second characteristic point in the robot determined in step (1) emulation is shot, and draws this feature point relative to industry The coordinate of camera；

(5) the 3rd characteristic point in the robot determined in step (1) emulation is shot, and draws this feature point relative to industry The coordinate of camera；

(6) using the homogeneous transformation in coordinate transform, the related data that correction needs is obtained；

(7) related data that step (6) is obtained is sent to computer, the off-line programing of industrial robot in amendment step (1) Emulation.

2. the method for correcting industrial robot off-line programing error in the field as claimed in claim 1, it is characterised in that： The particular location of two industrial cameras of determination described in step (1) refers to that industrial robot is carried out in off-line programming software When off-line programing is emulated, in the layout of whole emulation, choose two and be easy to lay and can photograph the two of industrial robot Individual point lays this two industrial cameras.

3. the method for correcting industrial robot off-line programing error in the field as claimed in claim 1, it is characterised in that： The position of two check points of determination described in step (1) refers in the range of two industrial cameras can be photographed, to choose two Individual fixation and visibility point.

4. the method for correcting industrial robot off-line programing error in the field as claimed in claim 1, it is characterised in that： The seat calibration method for drawing check point described in step (2) is：Coordinate system where check point is sat with check point in simulations Mark is that the mode set up is identical, and two industrial cameras form triangular relationship with impact point, and it is to be based on parallax that impact point is solved, by Triangle principle carries out the acquisition of three-dimensional information, it is known that the position relationship between two industrial cameras, just can obtain public view field The three-dimensional coordinate of interior object feature point；If the world coordinates of spatial point P is (X_W,Y_W,Z_W), in left side, the image of industrial camera is sat (u, v) is designated as, the image coordinate of industrial camera is on right sideThen have：

$Z_w\left[\begin{array}{c}u\left(1+k_{1}J\right)\\ v\left(1+k_{2}J\right)\\ 1\end{array}\right]=\left[\begin{array}{cccc}{m}_1& m_2& m_3& m_4\\ m_5& m_6& m_7& m_8\\ m_9& m_{10}& m_{11}& m_{12}\\ m_{13}& m_{14}& m_{15}& m_{16}\end{array}\right]\left[\begin{array}{c}{X}_W\\ Y_W\\ Z_W\\ 1\end{array}\right]$

${\tilde{Z}}_w\left[\begin{array}{c}\tilde{u}\left(1+{\tilde{k}}_{1}J\right)\\ \tilde{v}\left(1+{\tilde{k}}_{2}J\right)\\ 1\end{array}\right]=\left[\begin{array}{cccc}{\tilde{m}}_1& {\tilde{m}}_2& {\tilde{m}}_3& {\tilde{m}}_4\\ {\tilde{m}}_5& {\tilde{m}}_6& {\tilde{m}}_7& {\tilde{m}}_8\\ {\tilde{m}}_9& {\tilde{m}}_{10}& {\tilde{m}}_{11}& {\tilde{m}}_{12}\\ {\tilde{m}}_{13}& {\tilde{m}}_{14}& {\tilde{m}}_{15}& {\tilde{m}}_{16}\end{array}\right]\left[\begin{array}{c}{X}_W\\ Y_W\\ Z_W\\ 1\end{array}\right]$

I.e.：

$\left[\begin{array}{ccc}{m}_1-u\left(1+k_1\mathrm{\θ}\right)m_9& m_2-u\left(1+k_1\mathrm{\θ}\right)m_{10}& m_3-u\left(1+k_1\mathrm{\θ}\right)m_{11}\\ m_5-u\left(1+k_2\mathrm{\θ}\right)m_9& m_6-u\left(1+k_1\mathrm{\θ}\right)m_{10}& m_3-u\left(1+k_2\mathrm{\θ}\right)m_{11}\\ {\tilde{m}}_1-\tilde{u}\left(1+{\tilde{k}}_1\mathrm{\θ}\right){\tilde{m}}_9& {\tilde{m}}_2-\tilde{u}\left(1+{\tilde{k}}_1\mathrm{\θ}\right){\tilde{m}}_{10}& {\tilde{m}}_3-u\left(1+{\tilde{k}}_1\mathrm{\θ}\right){\tilde{m}}_{11}\\ {\tilde{m}}_1-\tilde{u}\left(1+{\tilde{k}}_2\mathrm{\θ}\right){\tilde{m}}_9& {\tilde{m}}_2-\tilde{u}\left(1+{\tilde{k}}_2\mathrm{\θ}\right){\tilde{m}}_{10}& {\tilde{m}}_3-u\left(1+{\tilde{k}}_1\mathrm{\θ}\right){\tilde{m}}_{11}\end{array}\right]\×\left[\begin{array}{c}{X}_W\\ Y_W\\ Z_W\end{array}\right]=\left[\begin{array}{c}u\left(1+k_1\mathrm{\θ}\right)m_{12}-m_4\\ v\left(1+k_2\mathrm{\θ}\right)m_{12}-m_8\\ \tilde{u}\left(1+{\tilde{k}}_1\mathrm{\θ}\right){\tilde{m}}_{12}-{\tilde{m}}_4\\ \tilde{v}\left(1+{\tilde{k}}_2\mathrm{\θ}\right){\tilde{m}}_{12}-{\tilde{m}}_8\end{array}\right]$

Wherein, m₁~m₁₆、It is the projection matrix of industrial camera, is drawn by the inner parameter of industrial camera, k₁、k₂、It is distortion factor, θ is stoichiometric factor；In above-mentioned formula, due under distortionless ideal conditions, m₁~m₁₆、, it is known that θ is 0, above-mentioned equation can be solved with pseudoinverse technique, draw the coordinate value of check point.

5. the method for correcting industrial robot off-line programing error in the field as claimed in claim 1, it is characterised in that： The method for drawing correction matrix described in step (2) is：By the homogeneous transformation in coordinate transform, formula can be obtained

$A_{T_B}\left[\begin{array}{c}{B}_r\\ 1\end{array}\right]=\left[\begin{array}{c}{A}_r\\ 1\end{array}\right]$

I.e.：

Wherein：

It is homogeneous transformation battle array；

For the coordinate that impact point determines in the field；

It is impact point identified coordinate in simulations；

It is the translation matrix of X, Y, Z axis variable quantity；

It is spin matrix；

$A_{R_B}=\left[\begin{array}{ccc}\cos f& \cos f\sin q\sin j-\sin f& \cos f\sin q\sin j-\sin f\sin j\\ \sin f\cos q& \cos f\sin q\sin j+\sin f\cos j& \cos f\sin q\sin j+\cos f\sin j\\ -\sin q& \cos q\sin j& \cos q\cos j\end{array}\right];$

In formula, f, q, j are the Eulerian angles of three-dimensional coordinate, and j is rotated to be around x-axis, and q is rotated to be around y-axis, and f is rotated to be around z-axis；Surveyed The check point of amount is two, therefore, eight formula being can obtain, it is necessary to solve six unknown numbers, can be solved with pseudoinverse technique, obtain Homogeneous transformation battle array, as correction matrix.

6. the method for correcting industrial robot off-line programing error in the field as claimed in claim 1, it is characterised in that： To drawing described in step (5), characteristic point refers to that three characteristic points are new at the scene relative to the coordinate of industrial camera to step (3) Coordinate under coordinate system, the mode that the setting up during mode is emulated with step (1) of this new coordinate system in scene sets up new coordinate system is identical, Be the position with that selected industrial camera of the off-line programing of industrial robot emulation as coordinate origin, with this camera with Another industrial camera line direction is the forward direction of X-axis, and the direction of industrial camera optical axis is the forward direction of Y-axis, according to the right-hand rule Determine the forward direction of Z axis, set up the new coordinate system in scene.

7. the method for correcting industrial robot off-line programing error in the field as claimed in claim 1, it is characterised in that： The related data that needs are corrected described in step (6) refers to newly rolling of the coordinate system relative to new coordinate system in emulation in scene The distance of angle, yaw angle, the angle of pitch and origin translation.

8. the method for correcting industrial robot off-line programing error in the field as claimed in claim 7, it is characterised in that： The method for solving of the related data that the correction needs is the correction square that the homogeneous transform matrix of robot is multiplied by step (2) Battle array, draws the homogeneous transform matrix after correction, as corrects the related data of needs.