JP3013998B2 - Rotary axis zero return method in numerical controller - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method of resetting a rotary shaft to zero in a numerical control device.

(Prior Art) FIG. 3 shows a conventional rotating shaft zero return method. In FIG. 3, 0 ° is the coordinate origin of the machine coordinate system of the numerical controller, and the angular positions of 360 °, 720 °,... Are defined based on this. Then, the numerical control device has a work coordinate system, and executes the program G50 (YO;) prior to drive control of the rotary axis to set the work coordinate system to zero, which is the origin (0 °) of the machine coordinate system. Align with the rotation axis origin 12.
Next, the program G01 (for example, F1000Y1530 .;) is executed. As a result, as shown in FIG. 3, the rotating shaft is rotationally driven to an angular position 13 of 1530 °, which is slightly more than four rotations. And
When the angular position 13 is reached, the home position return program G53 (Y
O;) is started, and the rotating shaft is driven to rotate in the reverse direction from the angular position 13 to return to the rotating shaft origin 12 at an angle of 0 °.

(Problems to be Solved by the Invention) In the above-described method of resetting the rotating shaft to the zero point in the conventional numerical control device, the rotating shaft is reversely rotated by the rotation angle amount from the rotating shaft origin to return to the rotating shaft origin. Therefore, as the rotation angle increases, the time required for returning to the origin increases. In addition, since the motor is rotated in the reverse direction, there is a problem that when a speed reduction mechanism is used, mechanical errors such as backlash must be considered.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a rotary shaft zero point return in a numerical control device capable of performing a home return in a short time in the same rotation direction irrespective of a rotation angle amount from the rotary shaft origin. It is to provide a method.

(Means for Solving the Problems) In order to achieve the above object, a method of resetting a rotary shaft to zero in a numerical controller according to the present invention has the following configuration.

That is, the rotation axis zero return method in the numerical control device of the present invention, after the rotation drive control of the rotation axis in the same rotation direction,
In a method of resetting a rotation axis to a zero point in a numerical control device for returning a rotation axis to a zero point position, a process of setting a rotation angle to zero degree for each rotation while performing rotation drive control of the rotation axis in the same rotation direction is performed. Based on this, a rotation angle within one rotation is defined; in response to the end of the rotation drive control of the rotation shaft, the rotation angle from the rotation angle position at the end to the next rotation angle zero degree in the same rotation direction. Is calculated; and the rotation shaft is rotated in the same rotation direction by the calculated rotation angle.

(Operation) Next, the operation of the rotating shaft zero return method in the numerical control device of the present invention configured as described above will be described.

In parallel with the control for driving the rotary shaft to rotate in the same rotational direction, a process is performed in which the rotation angle is set to zero for each rotation, and when the rotational drive control of the rotary shaft is completed, the rotation angle position at the end of the rotation is controlled in the same rotational direction. A rotation angle up to the next rotation angle of zero degree is calculated, and the rotation shaft is rotated in the same rotation direction by the calculated rotation angle. That is, the rotation axis is positioned at the position of the next rotation angle of zero degree, and is set as a new origin.

Thus, it is possible to always return to the original point within 360 ° without reverse rotation.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is an operation flowchart of a method of resetting a rotary shaft to zero in a numerical control device according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram of a specific operation.

In the first step 1, it is determined whether or not the control target is a rotating shaft. If the determination result is affirmative (YES), the process proceeds to the next step 2. As is well known, since the object to be controlled by the numerical controller includes a linear axis in addition to the rotary axis, the linear axis is excluded.

The rotation drive control of the rotary axis is the same as the conventional one. First, the program G50 (YO;) is executed to set the work coordinate system to zero, and the rotary axis origin (0 °) which is the origin of the mechanical coordinate system is set.
12 and then for example program G01 (F1000 Y1
530 .;). Therefore, also in this embodiment, as shown in FIG. 2, the rotating shaft is driven to rotate to an angular position 13 of 1530 °, which is slightly more than four rotations.

In step 2, in parallel with the rotation drive control of the rotating shaft,
A process (referred to as "360 ° rounding process") is performed in which the machine coordinate system having the machine origin as the coordinate origin and the workpiece coordinate system centering on the workpiece of the numerical controller are returned to zero in 360 ° units. As shown in FIG. 2, 360 ° → 0 °, 720 ° → 0
゜, 1080 ゜ → 0 ゜, 1440 ゜ → 0 ゜. This 360 ° rounding process is repeatedly executed until the origin return program G58 (YO;) according to the present invention is started (steps 2 → 3).
→ Same as 2).

When the rotation axis reaches the rotation angle position 13 and the home position return program G58 (YO;) is started, the determination result in step 3 becomes affirmative (YES), and the current value (PO
S) is read (step 4), and its sign is determined (step 5). The direction of rotation of the rotating shaft is indicated by positive and negative signs. If the current value (POS) is positive, {360-POS} is calculated in step 6, and if the current value (POS) is negative, {-(360- | POS |)} in step 7. Is calculated. That is, although the rotation angle position 13 is located at 1530 ° from the rotation axis origin 12, it is at a position rotated 90 ° from the previous zero-degree position (1440 °), so the next rotation angle zero-degree position (1800 °)
The rotation angle up to (270 °) is determined.

Then, in the last step 8, the rotating shaft is rotated 270 ° in the same rotating direction, positioned at the newly set rotating shaft origin 9, the completion of the positioning is displayed at zero degree, and the rotating shaft is moved to the origin position. A signal indicating the presence is output to the outside, and a series of return operations is completed.

(Effects of the Invention) As described above, according to the method of returning the rotating shaft to the zero point in the numerical controller of the present invention, the origin can always be returned in the same rotational direction without rotating in the reverse direction and within 360 °. There is an effect that the origin can be returned in a short time without considering mechanical errors such as backlash.

[Brief description of the drawings]

FIG. 1 is an operation flowchart of a method of resetting a rotary shaft to zero in a numerical control apparatus according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of a specific operation of the method of the present invention, and FIG. It is. 9: Position moved by the method of the present invention (new rotation axis origin), 12: Rotation axis origin at the start of rotation drive control of the rotation axis, 13 ... Rotation angle position at the end of rotation drive control of the rotation axis.

Claims (1)

(57) [Claims] 1. A method of resetting a rotating shaft to a zero point in a numerical control device for controlling the rotating shaft to rotate in the same rotational direction and then returning the rotating shaft to a zero point position. In this case, the rotation angle is set to zero degree for each rotation and the rotation angle within one rotation is defined based on the rotation angle; in response to the end of the rotation drive control of the rotation shaft, A rotation angle from the rotation angle position to a next rotation angle of zero degree in the same rotation direction; and rotating the rotation shaft in the same rotation direction by the calculated rotation angle. Axis zero return method.