JPH01312607A - Detection of deviated amount of robot - Google Patents

Abstract

PURPOSE:To improve work efficiency by detecting the conditions of a robot and a tool at the time of teaching and the conditions of the robot and the tool at the time of reproduction so as to correct a teaching program. CONSTITUTION:A data correction device 1 calculates the angle of in a basic direction F with respect to a teaching time space coordinate axis Y, namely, a teaching time declination THETA0. Next, an operator accesses a tool tip (b) to a reference point (q), and the data correction device 1 reads a turning angle theta1 from the basic direction (f) of an actual tool 40 and the coordinate value p1 (x1, y1) of an actual arm tip (a). Next, the operator accesses again the same reference point (q) from different angles. At that time, the data correction device 1 reads again a turning angle theta2 from the basic direction (f) and an arm tip coordinate p2 (x2, y2), and the data correction device 1 calculates the angle of the basic direction (f) with respect to the direction of the coordinate axis (y) in actual space, namely, a reproduction time declination theta0. Next, the data correction device 1 calculates the difference delta (=THETA0-theta0) of the teaching time declination THETA0 and the reproduction time declination theta0, and corrects the teaching program. Thus, work efficiency can be improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for detecting the amount of deviation of a robot. This invention relates to a method of detecting the amount of deviation.

[Conventional technology]

BACKGROUND OF THE INVENTION Conventionally, offline teaching systems are known that display an image of a robot on a display and teach the robot's operation using the image.

FIG. 8 shows an example of a display screen of such an offline teaching device, showing a robot model 30c, a tool model 40. is displayed.

This model is moved on the screen to teach work points.

At the time of reproduction, as shown in FIG. 9, the program is sent from the offline teaching device 10 to the robot control device 20,
Thereby, the control device 20 operates the actual robot 30 and tool 40.

[Problem to be solved by the invention]

The teaching robot model 30c and tool model 40c shown in FIG. 8 and the actual reproduction robot 30 and tool 40 shown in FIG. 9 should be basically equivalent.

However, it is impossible for the actual robot 30 and tool 40 to manufacture completely identical products, and there may be slight product errors.

Therefore, even if the teaching program is reproduced according to the teaching program, positional deviations occur in the work, and there is a limit to the accuracy of the work.

In order to improve accuracy, it is necessary to correct the deviation between the conditions of the robot and tool during teaching and the conditions of the robot and tool during playback, and the present invention provides a method for suitably detecting the amount of deviation. The purpose is to provide the following.

[Means to solve the problem]

The method of calculating the amount of deviation of a robot according to the present invention is that, during teaching, a tool attached to the tip of a robot arm and rotating around the arm tip is directed in a basic direction, and arm tip coordinates and tool tip coordinates are obtained. a teaching time argument calculation step, and a teaching time argument calculating step for calculating the argument of the basic direction with respect to the teaching spatio-temporal coordinate axis based on the arm tip coordinates and the tool tip coordinates.

Then, by changing the rotation angle from the basic direction of the tool that is attached to the end of the arm of the recycling robot and rotating around the arm end, accessing one reference point twice with the tool tip to calculate each rotation angle and each rotation angle. a reproduction condition detection step for obtaining arm tip coordinates;
a reproducing declination calculating step of calculating a declination of the basic direction of the reproducing robot with respect to a reproducing spatio-temporal coordinate axis based on each rotation angle and each arm tip coordinate; and a reproducing declination angle and a reproducing declination angle. The configuration is characterized in that it includes a shift distortion calculation step of calculating the difference between the two.

〔Example〕

Hereinafter, the present invention will be explained in more detail based on embodiments shown in the drawings. Here, FIG. 1 is a conceptual diagram of the configuration of a robot system that can implement the present invention, FIG. 2 is a schematic diagram showing the movement direction of each axis of the robot shown in FIG. 1, and FIG. FIG. 4 is a flowchart of main parts showing the teaching declination angle calculation process and the teaching declination calculation process; FIG. 5 is a schematic diagram explaining the reproduction condition detection process; FIG. The figure is a flowchart of the main part showing the reproduction condition detection process and the declination angle calculation process during reproduction, and FIG. 7 is the main part flowchart showing the deviation distortion calculation process and the correction process. Note that the present invention is not limited to this example.

11th i! ! As shown in FIG. 1, the robot 30 and tool 40 for reproduction are driven by a robot control device 20, and the robot control device 20 has a data correction device and a teaching program created by the offline teaching device 10. 1
It is given after being corrected by.

The robot 30 is a robot with three orthogonal axes, and a tool 40 is attached to the tip of the arm.
It can be rotated within the xy plane around .

Therefore, the movements of the robot 7) model and tool in the offline teaching device 10 are
The movement is along three orthogonal axes of y, and the tool tip B is rotated in a horizontal plane about a vertical axis that includes the arm tip A.

When the robot model and tool model are placed in the home position during teaching, the direction of the tool model at that time becomes the basic direction F, as shown in Fig. 3, and the arm tip coordinates Ao (Xa, Ya) of the robot model and the tool model The tool tip coordinates Bo (Xt, Yb) are detected,
be remembered. This stored arm tip coordinate A, (xa
, y□) and tool tip coordinates B0 (XI, , Yl,) are:
It is sent to the data correction device 1 together with the taught program at the time of playback.

As shown in FIG. 4, the data correction device 1 calculates arm tip coordinates Ao (Xa, Yi) and tool tip coordinates B.
o (Xb, YI,), then by the following formula,
The angular portion of the basic direction F with respect to the teaching spatio-temporal coordinate axis Y, that is, the teaching time argument e0 is calculated.

eo -Tai (Xi Xl,) / (Ya
YI,) Next, the operator drives the reproduction robot 30 and the tool 40 to access one reference point q with the tool light 4b, as shown in FIG.

Then, the data correction device 1 calculates the rotation angle θ1 of the actual tool 40 from the basic direction f and the coordinate value p of the actual arm tip a.
Read I (Xl, y+).

Next, the operator accesses the same reference point q from different angles.

At this time, the data correction device 1 again reads the rotation angle θt from the basic direction f and the arm tip coordinate p2 (X2.)'2).

Steps 31 to S4 shown in FIG. 6 show the procedure of the above operation.

Next, the data correction device 1 calculates the angular portion of the basic direction f with respect to the coordinate axis direction y in the actual space, ie, the playback deflection angle θ, using the following equation. Calculate.

C=sinθ+-5inθ2 DPartial θ1 Partial θri E! x2 −x(≠OG””/2 −3′l ≠0 1(scale DE−CG 1 −DG+GE θ.−■Note (H/I)) Next, the data correction device 1 performs the following as shown in FIG. Then, the difference δ (−θ.−〇.) between the teaching declination angle θ. and the reproducing declination angle θ.
Calculate. This difference δ is the amount of deviation.

Therefore, the teaching program is corrected using this deviation amount δ.

As described above, since the amount of deviation between the robot and tool conditions at the time of teaching and the conditions of the robot and tool at the time of regeneration is detected appropriately, work accuracy can be improved by correcting the teaching program based on this. .

〔Effect of the invention〕

According to the present invention, at the time of teaching, a teaching time declination angle calculation step of orienting a tool attached to the tip of the arm of the robot and rotating around the arm tip in a basic direction and obtaining arm tip coordinates and tool tip coordinates. , a teaching time declination calculation step of calculating a declination of the basic direction with respect to the teaching spatio-temporal coordinate axis based on the arm tip coordinates and tool tip coordinates; a regeneration condition detection step of changing the rotation angle from the basic direction of the rotating tool and accessing one reference point twice at the tool tip to obtain each rotation angle and each arm tip coordinate; a reproducing declination calculation step of calculating the declination of the basic direction of the reproducing robot with respect to the reproducing spatio-temporal coordinate axis based on the coordinates of each arm tip; and calculating the difference between the teaching declination and the reproducing declination; A method for detecting a robot deviation f is provided, which is characterized by including a step of calculating a deviation amount, whereby deviations between the conditions of the robot and tool at the time of teaching and the conditions of the robot and tool at the time of playback are easily detected. This means that it can be detected. Therefore, by correcting the teaching program based on this, it becomes possible to improve work accuracy.

[Brief explanation of the drawing]

Fig. 1 is a conceptual diagram of the configuration of a robot system capable of implementing the present invention, Fig. 2 is a schematic diagram showing the moving direction of each axis of the robot 7) shown in Fig. 1, and Fig. 3 is a yaw angle during teaching. FIG. 4 is a flowchart of main parts showing the teaching declination angle calculation process and the teaching declination calculation process; FIG. 5 is a schematic diagram explaining the reproduction condition detection process; FIG. The figure is a flowchart of the main part showing the regeneration condition detection step and the declination angle calculation step during playback, FIG. 7 is a flowchart of the main part showing the deviation amount calculation step and correction step, and FIG. 8 is an exemplary diagram showing the teaching screen of the offline teaching device. , FIG. 9 is a schematic perspective view showing a conventional regeneration robot system. [Explanation of symbols] l...Data correction device 10...Offline teaching device 20...Robot control equipment 30...Robot for reproduction 30e...Robot model 40...Tool for reproduction 40c ...Tool model a...Arm tip b of the robot for playback...Tool tip A of the tool for playback...Arm tip B of the robot model...Tool tip F of the tool model...Teaching Basic direction at time f...Basic direction θ during playback. ...Declination angle θ during teaching. ... Declination angle x, y, z during playback... Spatial coordinate axes during teaching x, y, z... Spatial coordinate axes during playback. Applicant Daihatsu Motor Co., Ltd.

Claims (1)

[Claims] 1. (a) During teaching, a teaching condition in which a tool attached to the tip of a robot arm and rotating around the arm tip is directed in a basic direction, and the arm tip coordinates and tool tip coordinates are obtained. (b) a teaching time deviation angle calculation step of calculating the deviation angle of the basic direction with respect to the teaching spatio-temporal coordinate axis based on the arm tip coordinates and tool tip coordinates; (c) the arm of the regeneration robot; Reproduction conditions for obtaining each rotation angle and each arm tip coordinate by accessing one reference point twice at the tool tip by changing the rotation angle from the basic direction of a tool that is attached to the tip and rotates around the arm tip. (d) Based on each rotation angle and each arm tip coordinate,
(e) a deviation amount calculation step of calculating a difference between the teaching argument and the reproduction argument; A method for detecting the amount of deviation of a robot, the method comprising: