JPS60151712A - Calibration system for robot visual coordinate system - Google Patents

Abstract

PURPOSE:To calibrate the shift between a fixed visual coordinate system and a robot coordinate system and to secure the accurate working of a robot, by calculating a space error produced when a fixed sensor is attached to the robot coordinate system. CONSTITUTION:A robot 1 and a visual fixed tool 7 are attached to a robot attachment stage 2, and a fixed visual sensor 3 is attached to the tool 7. Then the robot 1 is moved in response to the position/posture command value given from a robot controller 6. The picture of the robot 1 obtained after movement of the robot is fetched by the sensor 3 and sent to a picture processor 4. The processor 4 measures the position and posture of the robot 1. While an error calculator 5 calculates the position and posture of the robot 1 in a fixed visual coordinate system based on said command value given from the controller 6. Based on this result of calculation and said measured value, an attachment error of the sensor 3 is calculated. Then the shift between the robot coordinate system and the fixed visual coordinate system is calibrated in accordance with said error.

Description

[Detailed description of the invention] [) Use of color light! 11].] The present invention is concerned with calibrating the spatial deviation between the visual coordinate system and the robot coordinate system when making Robono 1 perform all tasks using a fixed visual device. This invention relates to a visual coordinate system calibration method suitable for accurately performing dripping of objects with arbitrary positions and orientations.

[Background of the invention]

Conventionally, when making a robot perform a negative task using vision, the visual system recognizes a binary or multivalued image, and performs renog based on that. child. Therefore, Il'
fiU things Vl limited to flat things with a constant overflow j
I was there. At this point, the error between the robot's coordinate system and the visual tll< reference system is ・Fl− on the surface.
Movement: 1; 2 and rotation in the \do plane are all considered, and calibration of the j·1'-marker thread is relatively easy. In the plane visual device currently in practical use, this (Φ
Calibration of line 4: I am. However, as the number of nodding tasks by bots increases and the need to grasp complex objects increases, robots are able to recognize not only flat objects but also three-dimensional objects whose positions and orientations are not fixed. It has become necessary to do so. As a method for this purpose, a three-dimensional object recognition method using binocular vision or distance images is known. In the case of such three-dimensional vision, it is necessary to calibrate spatial errors between the robot coordinate system and the visual coordinate system, but such a technique has not yet been established.

[Purpose of the invention]

The purpose of the present invention is to calculate the spatial error that occurs when fixed vision is fixed to the robot coordinate system, correct the deviation between the fixed vision coordinate system and the robot coordinate system, and fix the fixed vision to the robot coordinate system. An object of the present invention is to provide a robot visual coordinate system calibration device that enables accurate work when the robot is used to perform work.

[Summary of the invention]

The robot visual coordinate system calibration method according to the present invention includes a robot, a fixed visual system fixed near the robot, an image processing device that processes the image data, and a robot control device that controls and processes each of the above parts. Under the control of the robot control device, 1) move the robot to the commanded position, and then use the fixed vision and image processing device to measure the position and orientation of the robot after the movement in a fixed visual coordinate system. Furthermore, the error calculation device calculates the position/orientation of the movement command for the robot in a fixed visual coordinate system, and from the division result and the measurement result, the error in installing the defined vision is calculated by s. -1 calculation [7, robot coordinate system
This is to calibrate the deviation between fixed visual coordinate systems.

In addition, the following is a supplement to this.

In order to handle an object with an arbitrary position and orientation, it is safe to measure the position and orientation of the object and direct the robot hand in the direction of the orientation of the object. To do this, the visual coordinate system for measuring position and orientation must be accurately compared with the robot coordinate system in which the robot moves. If there is a deviation between these coordinate systems, when the 1j robot is moved based on the position/orientation command values and the robot's position/orientation is visually determined, an error will occur between the two. Therefore, by using this fact in reverse, it is necessary to correct the error in the command value of the robot's position and orientation and the position and phlegm measured by the visual sense. becomes possible. By using this error, it is possible to calibrate the robot coordinate system and the visual coordinate system.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory diagram of an embodiment of the robot visual coordinate system calibration device according to the present invention, FIG. 2 is a conceptual diagram of the relative relationship between the robot coordinate system and the fixed visual coordinate system, and FIG. 4 is a conceptual diagram illustrating the installation error that occurs when fixing the fixed visual field to the robot coordinate system, and FIG. 4 is a functional block diagram of this system.

Here, 1 is the robot, 2 is the robot installation stand, and 3I
J, fixed vision; 4, image processing device; 5, error clearing device;
6 is a robot control device, and 7 is a visual fixation device.

As shown in Figure 2, the relationship between the robot coordinate system and the fixed visual coordinate system is as follows:
Letting the respective axes be xv, yv, and zv, it is expressed by the following equation.

Here, L=(L,,Ly,L7) is a vector representing the displacement with respect to the robot, i~I,,MfV.

M, is a 71-column representing three rotational displacements between both coordinate systems,
For example, if the rotation angles α, β, and z' are taken as shown in FIG. 3, the following is obtained (3).

] 1. [1] Give a command to the bot and set the robot coordinate system to position X - ("+ 3' + Z) + posture f, (f,).

f,,f,), the parameters JJK+, rJy
11.7. If α, β, and γ are as designed and there are no errors, then X-x xB -1-y y R-1-z zli +
oR・-(4) [-go x XR-tgo y yu + f
t Z I+ ・=(5)−・Dynamic<QLzu. This f〃position/posture is fixed visual 3-(-1j l [-
7) This confession is X Jin-'(X' + 3" + Z
' ) 1 f'-:y, ':: (1, / , (y
/, r, L) tea/In this case, \'=X'
Xv −t−y′ yv, l−z′zv +Ov −(
6) r' knee 1'%Xy 4fy"Jv l-F,'
ZV ”'(7)-C6/) o X+ 3' r Z
(!: X' + 3" + Z' and hir.

The I'A relationship between r,,f, and r,',f,',f,' is calculated using equations (1) to (3).

However, I got fixed vision 3! An error occurs when making one Kasuri.
C, the error is 17, etc., the error Δ1. ! .

ΔI) F・Δ1... Δα・Δβ, Δn゛.

In this case, each parameter in equations (1) to (3) is (l
.
．． "a.

Even if you command it to move f, )-\ and measure it with fixed vision 3, iiX' = (X' in the fixed visual coordinate system).

Y' + Z' )+ "' - (ff'+ f,',
f/), but the deviated values X// , -(x// ,
, // , z// ).

f // = ((Work//, (yIl, (tsu'')) 1, [-7 Therefore, X', y/, y/ and y'', y
″, Z″, f8′.

fy', "* fxll, fy", rz"' (1)
If each thread is determined, equations (J) to (3) are solved, and Δ1. Yo.

Δly+ ΔLz+ Δα Season Δβ, Δ7' can be calculated.

Be of Fig. 1 , 4. Based on Fig. 4, according to Fig. 4
:The configuration and operation of the embodiment will be explained.

The robot 1 moves based on the position/orientation command values Y, , 7 (Equations (4), (5)) from the robot control device 6, and the fixed vision 3 captures the image of the robot 1-1 after the movement. Send to image processing device 4. 1ijii image processing device 4
is the position/posture of the robot 1 as seen from the fixed visual field 3.

On the other hand, the error dividing device 7 calculates the equation (1) based on the command values X and r of the
), (2), and (3) when measuring position and figure in a fixed visual coordinate system, it is assumed that there is no parameter error, whereas X/J measured with fixed visual system 3, ：／／
includes parameter errors. [7 Therefore, stop X' (- can be done.

[Effect of investigation]

As explained above in ii1'ii+Il, according to the present invention, the 13-dimensional Installation errors can be reduced by moving the robot (-), so (1) 3-dimensional installation errors can be accounted for, and this error can be corrected by adjusting the tolerance. It is possible to handle not only physical objects, but also the position and posture of three-dimensional objects using fixed vision. -,Ill
071. i'52 'a i I' na i 乍 Y~ka eyes J'
ii ratio, 17, (2) Just by moving the robot I and measuring, there will be an error in the reading: Significant effects can be obtained in greatly simplifying the calibration work, improving the accuracy of robot work, and improving efficiency.

[Brief explanation of the drawing]

FIG. 1 shows i? of an embodiment of the robot visual coordinate thread 11iQ square according to the present invention. /Figure 1, Figure 2 shows 1, ``nU of the relative relationship between the jbot coordinate system and the fixed visual coordinate system (just in case,
Figure 3 &': 1. A conceptual diagram explaining the errors that occur when fixing fixed vision to the 11-point I/coordinate system. Figure 4 is a functional block diagram of Hongamin. Ruru 1, 1...Robot, 2...F1 Hot Station (1 piece,, 3.111
□1 constant vision, 4... image processing device, 5... error +'i
+ 3″）Device i/Obaya 1 Mekaya 2 Figure $3 Day 4th

Claims (1)

[Claims] 1. A robot, a fixed visual system fixed near it, an image processing device that processes the image data, and 1 error bar)
What about the facial expression device and each of the above parts? 1. rlJ ml+・
Processing [J-bot system f wholesale equipment R11, etc.]
According to the assignment 11 of the robot control device, the ``j-bot is moved to the commanded position, and the position and posture of the bot after the movement is determined by the fixed vision and image processing described in -1-''. -・Fixed crosspiece ij′ mouthpiece marker LIil
I determined that -1-recorded difference H13'1! Soso e (2, J-li, top 111-: ``Mobile phase 6 against bots
The position and position of the four-layered rib in a fixed visual coordinate system
') A11, Song Dynasty and 1-Measurement Results -1-Measurement Results 7
)l! Awakening no Toriage 1, 猾゛(wo・、il t'＞、
L, robot coordinate system/fixation, the deviation between the sensory coordinate system is axis 1
``Do'', ``)Nishida■] Pot celebration visual reference system axis 1L method.