JPS6145302A - Setting method for mechanical original point of numerically controlled moving object - Google Patents

Abstract

PURPOSE:To improve the setting labor and time for setting an original point by providing a detection means for arrival of the original point position of a moving object so that its position can be freely controlled and then controlling the detecting position of the original point to a place shifted by a prescribed distance from the oscillating position of a zero pulse. CONSTITUTION:The moving action of a moving object 5 is caught by an encoder 1 of an incremental system, and a zero pulse detection signal is oscillated at a zero point slit 3a decided by a slit 3 of a slit disk 1. Thus the moving action of the object 5 is controlled. Here a dog 13 is provided with free control of its position to detect that the object 5 arrives at a prescribed position near an original point. Then the shift of the object 5 toward the original point is detected by a limit switch LS provided to the object 5 at both ends 13a and 13b of the dog 13. At the same time, the number of pulses are counted until the oscillation of said zero pulse. This counted number of pulses is compared with the number of pulses equivalent to half rotation of the encoder 1. The dog 13 is controlled to a position where the difference is equal to zero between both pulse numbers. Then an original point is set.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for setting a mechanical origin of a moving object that is numerically controlled.

[Description of the Prior Art] A carriage of a numerically controlled machine tool, which is a moving object that is numerically controlled, is provided with an encoder that detects the movement m of the moving object. There are two types of encoders: absolute type encoders that allow you to know the movement position in absolute values over the entire range of movement, and incremental type encoders that oscillate a predetermined number of pulse signals for each unit of movement. Incremental encoders are often used for reasons of control and cost.

By the way, when an incremental encoder is used, the position of the object to be moved is detected by integrating the detection pulses with a counter, so the origin position is lost when the power is off. Furthermore, it is necessary to mechanically determine the origin position of the object to be moved in order to eliminate discrepancies in the count numbers.

The method for determining this mechanical origin and the grinding machine operation with respect to this origin are as follows.

(1) A dog is provided near the origin position on the base. On the other hand, on the side to be moved, a limit switch is provided that is turned on and off by contacting the pulley set on the base.

(2) The moving object is moved toward the origin in the origin return mode, and the moving object is decelerated from the position where the limit switch provided on the moving object first contacts one end of the dog. This deceleration slows down the moving object and produces a zero pulse (Zer), which will be described later.

This is to ensure the detection of pulse (pulse) and the stopping operation based on this detection.

? (3) The object to be moved further moves toward the origin, passes the other end of the dog, and turns off the limit switch. The moving object is further decelerated by this off signal, and further moves at a very slow speed toward the origin.

(4) The encoder slowly rotates as the moving object moves slowly, and the first zero pulse is detected. This detection position of the robot is set as the origin position, and the robot stops at this position.

Therefore, in this example, the mechanical origin is [the position of the dog, especially,
It can be said that the other end of the dog turns off the limit switch.

Here, the encoder is designed so that the zero pulse is oscillated once during one rotation, and the origin position determined as described above and the position of the other end of the dog (the position where the limit switch is turned off) ) is most preferably a distance corresponding to 1/2 rotation of the encoder.

The reason for this is that if the limit switch is installed on a moving object or the off position of the limit switch is too close to the zero pulse detection position, zero pulse detection may not be possible due to a difference in detection time of the limit switch. This is because the position where the next zero pulse is detected after rotation may be mistaken as the origin position. In fact, since the detection system of the numerical control device has a signal delay of 2QIllSeC to 50m5ec, such a situation can occur even if the system is operated at a low speed.

On the other hand, if the off position and the zero pulse detection position are too fast, it will be close to the previous zero pulse (which should have already passed), and the previous zero pulse may be lost due to machine vibration or other reasons. may be detected and the origin position may be incorrect.

For the above reasons, the distance between the zero pulse detection position and the other end (off position) of the dog is most commonly set to a distance equivalent to half a rotation of the encoder.

Under the above premise, the conventional origin setting method is as follows.

(1) Return the object to be moved to the origin position in the origin return mode (this movement direction is the minus (-) direction)
. At this time, since the dog position is a temporary position, the dog position is adjusted so that the actual stopping position becomes a preferable position.

This is to confirm the origin, and the following dog adjustment work is started.

The object to be moved remains at the origin.

(2) Set the CRT display to self-diagnosis mode. This makes it possible to determine whether the limit switch is on or off. That is, if the limit switch is on, the display area corresponding to the limit switch will be "1".
”, and if it is off, “0” will be displayed. Since it is currently off, rOJ is displayed. This is because the limit switch is currently away from the dog and is turned on only when the dog passes through.

(3) Switch the operation mode to manual, and while pressing the manual button, move the motor toward the home position (minus (G) direction) at very low speed.

(4) Since the limit 1 switch installed on the object to be moved moves from the origin position toward the other end of the dog, the operator should carefully observe the ON signal of the limit 1 switch displayed on the CRT, and in particular, At the position where the dog and limit switch are likely to come into contact, press the manual button slowly and search for a position where the display changes from "0" to "1".

(5) After finally finding the position where the CRT display is "1", the operator switches the CRT display mode to the current position display mode.

(6) The current position at that time is displayed as 12.34 mm, for example. This means that the other end of the dog is 12°34 md from the origin position (encoder zero pulse oscillation position).
L means being left.

(7) By the way, let us assume that the number of pulses emitted during one revolution of the encoder is 2000, and half of that number, 1000 pulses, is used to move the object of the machine. When converted to JJ ffi, it becomes 24n+m as 0.024n+i per one pulse.

Therefore, the position of the other end of the dog is 24 m from the origin position.
It is desirable that it be at position m. Therefore, since the above displayed value is 12.3411111, move the dog in the plus (+) direction (away from the origin) by 11.66 mm.
It turns out that all you have to do is move.

(8) Corrected distance calculated as above +11.66
Adjust the dog based on mm.

(9) From the above operations, the distance between the origin and the other end of the dog will approximately correspond to the distance equivalent to half a turn of the encoder, but to ensure greater accuracy, repeat the above operations several times. I will do it.

The above origin setting method is extremely troublesome and requires a lot of time and effort, and some kind of improvement has been desired.

[Object of the Invention] In view of the above-mentioned points, the present invention is an improvement thereof, and an object thereof is to provide a method for setting a mechanical origin of a numerically controlled moving object, which can be performed easily and accurately. .

[Object of the Invention] To achieve the above object, the present invention provides a method for setting a mechanical origin of a moving object, in which the moving movement of the moving object is captured by an incremental encoder and the moving movement is numerically controlled. , a predetermined position detecting means for detecting that the moving object has reached a predetermined position near the origin position is provided in a position adjustable manner, and the moving object is actually returned to the origin, and the predetermined position detecting means The number of oscillation pulses from when the encoder is activated until the first zero pulse of the encoder is oscillated is counted, and the counted number is compared with the number of pulses corresponding to half a rotation of the encoder to find the difference between the two. While displaying the converted movement m as appropriate, the detected position of the predetermined position detection means corresponds to, for example, half a rotation of the encoder from the position where the zero pulse was oscillated, based on the converted and displayed numerical value. A method for setting a mechanical origin of a numerically controlled moving object, characterized in that the detection position of the predetermined position detection means is adjusted to a position shifted by a distance.

[Explanation of Embodiment] Figure 1 does not show an embodiment of the method of this invention, but shows one flowchart of operation and control, Figure 2 is an explanatory diagram of the encoder, and Figure 3) to Figure 3). 4 is an explanatory diagram of the operation of the predetermined position detection means (dog and limit switch), and FIG. 4 is an explanatory diagram of the adjusted position of the dog.

As shown in Fig. 2, a slit disk 1 of an incremental type rotary encoder is provided with a large number of slits 3 in the radial direction, and one of these slits 3a is a zero point slit and is separated from C and others. be done. The slit disk 1 of the encoder is rotated in conjunction with a transfer roll 9 that rolls in sliding contact with the base 7 as the moving object 5 shown in FIG. 3(a) moves relative to the base 7. , the encoder receives light projected from one side of the slit disk at the other side and obtains a pulse signal using this optical d as an electrical signal. The Iζ arrow 11 shown in FIG. 2 indicates the current detection position, and when the zero point slit provided on the slit disk 1 comes to this position, a zero pulse detection signal is oscillated.

As shown in FIG. 3(a), the base 7 is provided with a dog 13. On the other hand, the moving object 5 is provided with a limit switch LS. Therefore, when the moving object 5 moves from the right side (plus direction) toward the origin (minus direction) in the figure, the limit switch LS is first turned on when it approaches one end 13a of the dog 13, and then the other end 4n 13 is turned on. b “C will be turned off. Dog 1
What is the position of the other end 13b of 3? Suppose that it is L1. On the other hand, the limit switch LS moves from the negative direction to the positive direction! When FJJ is turned on, the signal is moved from the other end 13b of the dog 13 to the one end 13a, so in this case, the other end 13b turns on and the one end 13a turns off.

After step 101 in FIG. 1, when a return-to-origin command is given in step 103, the moving object 5 moves in the negative direction (step 1o5).

Then, as shown in FIG. 3(b), the limit switch LS is turned on at one end 13a of the dog 13. In FIG. 1, this state is determined in step 107.

As shown in step 109, upon receiving the off signal from the limit switch LS shown in step 107, the numerical control device reduces the moving speed of the moving object 5. Then, the moving object 5 is further moved in the negative direction at the reduced moving speed, and the limit switch LS is turned off at the other end 13b of the dog 13, as shown in FIG. 3(C). The judgment shown in step 111 in FIG. 1 is to know that the limit switch S is turned off and tc.

As shown in step 113, when the off signal of the limit switch LS is determined, the moving speed of the moving object 5 is further reduced, and the moving object 5 moves at a very low speed in the negative direction. Further, as shown in step 115 in FIG. 1, a limit switch l-S off signal is obtained and the encoder detection pulses are counted from this point on.

If the first zero pulse is detected in step 117, the counting of the movement amount shown in step 115 is finished, and at the same time, in step 119, the moving object 5 is stopped at that position. As shown in FIG. 3(d), the position of the limit switch LS at that time is io.

Therefore, as shown in step 121, the number (11°i
The control device has limit switch LS off position history 1 (position of the other end 13b of dog 13) to relopulse detection position 0.
The distance to (shi 1 - 吏0) is shown. Further, in step 123, a distance L/2 corresponding to a half rotation of the encoder is subtracted from this difference (love+-no). DI this answer
! :do. As shown in FIG. 3(d), it is clear that the position of the dog 13 as well as D'a 13b is Dl, f* away from the stop position Lo (origin) of the limit switch LS.

By the way, as shown in the description of the prior art, the position of the other end 13b of the dog 13 is the history of the stop position of the limit switch LS. <FA point) Mustard/2 is desirable. That is, D
It is desirable that =0. Therefore, the following operations are performed based on the display shown in step 25.

That is, if D > O, the dog is shifted in the negative direction by the absolute value of D (a). On the other hand, if D < O, the dog is shifted in the positive direction by the absolute value of D.
As shown in the figure, the position of the other end 13b of the dog 13 is adjusted to a position where D=O.

However, since the adjustment operation of the h<-1- period dog 13 is performed manually, it is difficult to perform it accurately enough in - times. Therefore, try executing the program from step 103 onwards in FIG. 1 again.

As a result, if the display result in step 125 reports D=O, this is determined in step 127 and all operations of the stainless steel 7129r are completed.

As is clear from the above, what the operator must do in all of these operations is to press the return-to-origin button,
The only operation required is to adjust the position of the dog 13 based on the display result in step 125.

In other words, there is no need to perform troublesome operations during the process, such as checking the position of S by using a limit switch in diagnosis mode, or confusing calculations such as how far to move the dog. Work can be done extremely easily.

In addition, in the description of the above embodiment, the limit switch L
Although the predetermined positions of the base 7 and the movable object 5 are detected by the S and the dog 13, it is obvious that other optical or magnetic detection means can be used as these detection means. Their positional relationship is also relative; for example, it goes without saying that the dog may be placed as the moving object and the limit switch may be placed on the space side.

In addition, the display of the calculation result shown in step 125 can be done by simply displaying the numerical value for moving the dog (it is also possible to simply display 4 in the dirt, but the direction of adjustment can be indicated using a plus or minus sign, or an arrow, etc.). It will make the work even easier if you indicate it.

Furthermore, although the calculation work in the above embodiment may be performed by the numerical control device itself that numerically controls the object to be transferred, the calculation work is not limited to this, and may be performed by adding a calculation device for adjustment work. Of course.

[Effects of the Invention] As is clear from the above description, by using the method of the present invention, it is possible to extremely easily set the mechanical origin of a moving object whose a value is controlled.

[Brief explanation of the drawing]

The drawings all show embodiments, and FIG. 1 is a flowchart of operation and control showing one embodiment of the method of the present invention.
Figure 2 is an explanatory diagram of the encoder, Figures 3(a) to 3(
d) Predetermined position detection means (dog and limit switch)
FIG. 4 is an explanatory diagram of the adjustment position of the dog. 1...Encoder slit disk 5...Movement target 13...Dog LS...Limit switch agent Patent attorney Yasuo Miyoshi Engraving of drawing (no change in content) Diagram 1 Procedural amendment indentation Voluntary) 1982? Manabu Shiga, Commissioner of the Japan Patent Office on Mon-2Z, 1, Indication of the incident, Showa 2, Patent application no. rll 8 on the clock? (2) Roshi (1) Akira P41 Police El h

Claims (1)

[Claims] In a method for setting a mechanical origin of a moving object in which the movement movement of the moving object is captured by an incremental encoder and this movement movement is numerically controlled, it is detected that the moving object has reached a predetermined position near the origin position. A predetermined position detecting means is provided whose position can be adjusted freely, and the moving target is actually returned to its origin, and the number of oscillation pulses from when the predetermined position detecting means is activated until the first zero pulse of the encoder is oscillated is determined. The number of counts is compared with the number of pulses corresponding to half a revolution of the encoder, and the difference between the two is converted to the amount of movement as appropriate and displayed. Based on this, the detection position of the predetermined position detection means is adjusted so that the detection position of the predetermined position detection means is shifted from the position where the zero pulse is oscillated by a distance corresponding to, for example, half a rotation of the encoder. A method for setting a mechanical origin of a numerically controlled moving object, characterized in that: