JPS62172403A - Origin positioning device for rotary body - Google Patents

Abstract

PURPOSE:To shorten time for detection by providing at least two origin sensors that detect the position of origin in one member and providing an object of detection having width that extends over the distance of installation of the origin sensors in another member, and making positioning of the origin according to the result of detection of the origin sensors. CONSTITUTION:When the key of a microcomputer or the switch of a control box is operated, information of an L sensor and an R sensor is read, and it is examined that the n+1 arm 2 is in L direction or R direction within the movable range. When it is detected that the L sensor is on and R sensor is off, the n+1 arm 2 is turned in the direction that makes both L sensor 5 and R sensor 4 on. The n+1 arm 2 is turned by minute amount and information of the L sensor and R sensor is read again, and this procedure is repeated to a position where both sensors 4, 5 become on. To search for the boundary between positions where the L sensor, a reference sensor, becomes on and becomes off, the direction of turning is set to R direction and turned by minute amount to a position where off state of the L sensor 5 is confirmed. Thus, the positioning of the origin of a body that makes rotary motion can be made in a short time at high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an origin positioning device for a rotating body such as an industrial robot.

(Prior Art) Conventionally, the arms of industrial robots are configured to rotate around joints.

Figures 5 and 6 show the n-th arm 10 and the n+1-th arm 1.
In order to find the origin position in the rotation of the n+l arm 11, an origin sensor 13 is installed in one of the rotation directions of the right (R) direction and the left (L) direction (the L direction in the drawing). , an object to be detected 1 is placed on the n+1 arm 11 side.
4 is installed. Then, the n+l arm 11 is gradually moved in the L direction to a position where the origin sensor 13 is turned on, and then moved by a minimum distance to a position where the origin sensor 13 is once turned on and then turned off again. The origin is the boundary between ON and OFF of the sensor 13.

(Problem to be solved by the invention) However, in this origin positioning method, for example,
When the arm 11 is in the R direction, the origin sensor 13 is ON.
It takes time to move to the location.

On the other hand, when the width of the detected object 14 is increased, the sixth
As shown in the figure, when the origin sensor 13 is ON, the origin position is determined by moving in the R direction to the position where the origin sensor 13 is OFF, but if the origin sensor 13 is not moved little by little, the error in the origin position will be large. Therefore, it takes time to detect the detected object 14.

(Means for Solving the Problems) An origin positioning device for a rotating body according to the present invention detects at least two origin positions on one member of a rotating body consisting of a movable part and a fixed part. A sensor is provided, and the other member is provided with a detected object having a width spanning the installation interval of the origin sensor.

(Function) The detected object is moved to a position where at least two origin sensors are both ON, and then one origin sensor is turned OFF.
It is moved to the position F, and that position is determined as the origin position.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIGS. 2 to 4 show a case where the rotary body according to the present invention is applied to a joint part of a robot, and this joint part consists of two parts: the n-th arm 1, which is a fixed part, and the n+1-th arm 2, which is a movable part. It consists of two arms connected to each other so as to be rotatable around a rotation axis 3, and the n-th arm 1 has the right side (
R) sensor 4 and left (L) sensor 5 are provided at a predetermined interval, and these sensors 4 and 5 are provided on the n+1th arm 2.
An object to be detected 6 is provided with a width spanning the installation interval of .

FIG. 1 is a flowchart showing the procedure for locating the origin of a rotating body having such a configuration. The operation of this flowchart is controlled by a microcomputer (not shown) provided in the control device of the robot.

Now, suppose that the (n+1)th arm 2 is on the left side as shown in FIG. In this state, when a key operation on the microcomputer or a switch operation on the control box is performed, the information of the L sensor 5 and R sensor 4 is read in step (2) in FIG. 1, and from this information, the n+1 arm 2 is moved in step Check which side of the range, L direction or R direction. In the initial state illustrated in FIG. 2, the L sensor 5 is detected to be ON, and the R sensor 4 is detected to be OFF. Based on the result of this step ■, L sensor 5
Step (2) or (2), which is a direction setting step for rotating the (n+1)th arm 2 in the direction in which both the R sensor 4 and the R sensor 4 are turned on, is executed. In step ■, the nth
Rotate the +1 arm 2 by a minute amount, read the information of the L sensor 5 and R sensor 4 again in step ■, and repeat steps ■ and ■ until the position where both of these sensors 4 and 5 are ON (see Figure 3). repeat. In step (2), the rotation direction is set in the R direction in order to find the boundary between the ON position and the OFF position of the L sensor 5, which is the reference in this example. Then, in step (2), it is rotated by a minute amount in the direction set in step (2), and in step (2), it is rotated to a position where the OFF state of the L sensor 5 is confirmed, and the process ends.

In addition, in the step (2), the rotation direction may be set to the L direction with the R sensor 4 as a reference.

In addition, although the above-mentioned embodiments show examples in which the present invention is applied to industrial robots, the present invention is not limited to this, and can be applied to automatic machine tools, etc., for example.

(Effects of the Invention) As described above, according to the present invention, it is possible to accurately locate the origin of a rotating body in a short time.

[Brief explanation of drawings]

Fig. 1 is a flowchart showing the procedure for locating the origin of a rotary moving body according to the present invention, Figs. 2 to 4 are schematic configuration diagrams sequentially showing the stages of locating the origin, and Figs. FIG. 2 is a schematic configuration diagram illustrating an example. 1... nth arm 2... n+1 arm 4...
・R sensor 5...L sensor Fig. 2 Fig. 5

Claims (1)

[Claims] 1) In a rotating body consisting of a movable part and a fixed part, one member is provided with an origin sensor for detecting at least two origin positions, and the other member is provided with an object to be detected whose width straddles the installation interval of the origin sensors. An apparatus for locating an origin of a rotating body, characterized in that the origin is located based on the detection result of the origin sensor.