JPH03212704A - Method for restoring zero point of rotation axis in numerical controller - Google Patents

Abstract

PURPOSE:To quickly restore an origin without considering a mechanical error such as backlash by restoring the origin always in the same rotating direction within 360 deg. angle without reversing the rotation. CONSTITUTION:At first, a work coordinate system is set up to zero and allowed to coincide with the origin of a rotation axis which is the origin (0 deg.) of a mechanical coordinate system. Then a program is executed. Thereby, the rotation axis is rotated up to the angular position 13 of four revolutions or more. In parallel with the rotation control of the rotation axis, the mechanical coordinate system using a mechanical origin included in a numerical control device as its coordinate origin and a work coordinate system formed around a work are restored to zero in each 360 deg. unit. When the rotation axis arrives at the rotational angle position 13 and the origin restoration program is started, the current position of the work coordinate system is read out and the rotational angle 270 deg. up to the succeeding rotational angle zero position is calculated. The rotation axis is rotated by 270 deg. in the same rotating direction and positioned on a newly set rotation axis origin 9 and the completion of the positioning is displayed as zero display.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for returning a rotary axis to zero point in a numerical control device.

(Conventional technology) FIG. 3 shows a conventional rotary axis zero point return method.

In FIG. 3, 0゛ is the coordinate origin of the mechanical coordinate system possessed by the numerical control device, and 36o is based on this.

An angular position of 720° is specified. The numerical control device has the coordinate system of the workpiece, and prior to drive control of the rotary axis, the program G50 (YO;)
to zero the workpiece coordinate system, and set the origin of the machine coordinate system (
Then program GOI (for example F 1000Y 1530.;
). As a result, as shown in Figures 1 and 3, the rotating shaft is driven to rotate a little more than 4 times to the angular position 13 of 1530''.When the angular position 13 is reached, the return-to-origin program 053 (YO;) is started. Then, the rotating shaft is rotated in the opposite direction from the angular position 13 and returns to the rotating shaft origin 12 at an angle of 0°.

(Problem to be Solved by the Invention) In the above-mentioned method for returning the rotary axis to zero point in the conventional numerical control device, the rotary axis is reversely rotated by the amount of rotation angle from the rotary axis origin to return to the rotary axis origin. So,
As the amount of rotation angle increases, the time required for returning to the origin increases. Also, since it is rotated in the opposite direction,
When using a speed reduction mechanism, there is a problem in that mechanical errors such as backlash must be taken into account.

The present invention was made in view of such problems, and its purpose is to return the rotary axis to zero point in a numerical control device that can return to the origin in a short time in the same rotation direction regardless of the amount of rotation angle from the rotation axis origin. The purpose is to provide a method.

(Means for Solving the Problems) In order to achieve the above object, a rotary axis zero point return method in a numerical control device of the present invention has the following configuration.

That is, a rotary shaft zero point return method in a numerical control device of the present invention is a rotary shaft zero point return method in a numerical control device that returns the rotary shaft to a zero point position after rotating the rotary shaft in the same rotational direction; When controlling the rotational drive in the same direction of rotation, the rotation angle is set to zero for each rotation, and the rotation angle within one rotation is defined based on this; Rotation drive of the rotation axis In response to the end of the control, calculate the rotation angle from the rotation angle position at the end to the next rotation angle of zero degrees in the same rotation direction; rotate the rotation axis in the same rotation direction by the calculated rotation angle;
It is characterized by the following.

(Function) Next, the function of the rotary axis zero point return method in the numerical control device of the present invention configured as described above will be explained.

1 in parallel with the control to rotate the rotating shaft in the same rotational direction.
The rotation angle is set to zero degrees for each rotation, and when the rotational drive control of the rotary shaft is completed, the rotation angle from the rotation angle position at the end to the next rotation angle of zero degrees in the same rotation direction is calculated. Rotate the rotation shaft in the same rotation direction by the rotation angle.

That is, position the rotation axis at the next rotation angle of zero degrees,
It is a new starting point.

In this way, it is possible to always return to the origin within 360° without rotating backwards.

(Example) Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is an operation flowchart of a rotary axis zero point return method in a numerical control device according to an embodiment of the present invention, and FIG. 2 is a detailed explanatory diagram of the operation.

In the first step 1, it is determined whether the controlled object is a rotating shaft or not, and if the judgment result is affirmative (YES), proceed to the next step 2.0 As is well known, the controlled object of the numerical control device is In addition to the rotational axis, there is also a linear axis, so that linear axis is excluded.

Note that the rotational drive control of the rotating shaft is the same as before,
First, execute program G50 (YO;) to zero the workpiece coordinate system and make it coincide with the rotation axis origin 12, which is the origin (0°) of the machine coordinate system, and then, for example, program GO1 (F
l(100YI530.:). Therefore, in this embodiment as well, as shown in FIG. A process of returning the machine coordinate system with the machine origin of the control device as the coordinate origin and the workpiece coordinate system centered on the workpiece to zero degrees in units of 360° (referred to as r360° rounding process)
As shown in Figure 2, 360°→O@, 720°
°→o@, togo'→0″1440@→0°. This 3606 round process is repeatedly executed at the home where the origin return program G58 (YO,) according to the present invention is started (step 2→same). 3 → same 2).

When the rotation axis reaches the rotation angle position 13 and the return-to-origin program G58 (YO: ) is started, the judgment result in step 3 becomes affirmative (YES), and the current value (pos> in the workpiece coordinate system is read (step 4) Determine whether it is positive or negative (Step 5) The direction of rotation of the rotation axis is indicated by a positive or negative sign. If the current value (PO3) is positive,
In step 6, (360-POI is calculated, and if the current value (POS) is negative, in step 7, (-(360
-I PO3l ) Calculate l. That is, the rotation angle position 13 is at a position of 1530 degrees from the rotation axis origin 12, but it is at the previous zero degree i! Since it is at a position rotated 90 degrees from (1440'), the next rotation angle zero degree position (180
The rotation angle (270°) up to 0' is calculated.

Then, in the final step 8, the rotation axis is rotated by 27θ° in the same rotation direction, positioned at the newly set rotation axis origin 9, and a zero degree is displayed to indicate that the positioning is completed, and the rotation axis is returned to the origin position. A signal indicating that there is a condition is output to the outside, and the series of return operations is completed.

(Effects of the Invention) As explained above, according to the rotary axis zero point return method in the numerical control device of the present invention, it is possible to always return to the origin in the same rotational direction and within 360° without reverse rotation. This has the effect of returning to the origin in a short time without considering mechanical errors such as backlash.

[Brief explanation of drawings]

Fig. 1 is an operation flowchart of a rotary axis zero point return method in a numerical control device according to an embodiment of the present invention, Fig. 2 is a detailed explanatory diagram of the operation of the method of the present invention, and Fig. 3 is an explanatory diagram of the operation of the conventional method. It is. 9...Position moved by the method of the present invention (new rotation axis origin), 12...Rotation axis origin at the start of rotational drive control of the rotation axis, 13...Rotation Rotation angle position at the end of axis rotation drive control.

Claims (1)

[Claims] In a rotary shaft zero point return method in a numerical control device that returns the rotary shaft to the zero point position after controlling the rotary shaft in the same rotational direction; The rotation angle is set to zero for each rotation, and the rotation angle within one rotation is defined based on this; in response to the end of the rotational drive control of the rotary shaft, the rotation angle is adjusted from the rotation angle position at the end of the rotational drive control. A rotation axis zero point return method in a numerical control device, characterized in that: calculates the rotation angle up to the next rotation angle of zero degrees in the same rotation direction; and rotates the rotation axis in the same rotation direction by the calculated rotation angle;