JP3146482B2 - Home position return method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Industrial applications]

The present invention relates to an apparatus having a positioning table,
The present invention relates to a method of returning to the mechanical origin.

[0002]

[Prior art]

An example of a conventional positioning table will be described with reference to FIGS. FIG. 3 is a block diagram of a conventional example, and FIG. 4 is a flowchart of the origin return operation.

In FIG. 4, when the home position return operation is started (step 15), the motor 7 for driving the drive shaft starts rotating, and the table 24 starts to move. After that, the control device
In other words, the slow sensor 19 determines whether 24 has entered the slow area.
It is constantly monitored whether it is turned on (step 16). At the same time, the limit sensors 22 and 23 are also monitored to prevent the limit from being exceeded (step 20).

[0004] Next, after the slow sensor 19 is turned on, the table speed is switched to a low speed, and the origin sensor 18 is moved at a low speed.
It is monitored to be turned on (steps 17 and 18). Also at this time, it is monitored whether the limit sensors 22 and 23 are ON. Hereinafter, whether or not the limit sensors 22 and 23 are turned on continues until the origin return is completed. When the limit sensors 22 and 23 are turned on, the moving direction of the table 24 is reversed, and the home return operation is continued (step 21). When the origin sensor 18 is turned on, the signals of the encoders (not shown), A phase, B phase,
It waits for the AND condition of phase C to be met (step 19). Here, when the origin sensor 18 is ON, the A phase and B
When the phases C and C are turned ON, the origin return is completed (step 22).

In other words, it is assumed that the slow sensor 19 is a temporary origin, and that the true origin is present in the temporary origin, and the origin return operation is performed. In FIG. 3, reference numeral 20 denotes an origin sensing dog, and reference numeral 21 denotes a slow and limit sensing dog.

[0006]

[Problems to be solved by the invention]

The conventional origin return method has the advantage that the table can be moved at high speed until the slow sensor is turned on, even if the current position of the table is unknown, but all origin sensors, slow sensors and limit sensors are monitored. As well as mechanical accuracy. If the current position is unknown, the initial movement direction of the table is unknown, and if high-speed movement is started without knowing the direction, an accident may occur. In addition, when low-speed positioning is performed in consideration of this point, there is a problem that the value of the slow sensor is lost.

[0007]

[Means for Solving the Problems]

The present invention provides a positioning table movably supported, a driving unit for driving and positioning the table, an encoder for detecting an amount of movement of the table by the driving unit, and a table for solving the above problem. An origin sensor for determining the mechanical origin of the above, a + direction and-direction limit sensor for determining the moving range of the table, and a method of returning to the origin of the positioning table comprising a control device for controlling these systems. Based on the current position confirmation step for confirming the current position, which is the position to start the home position return, if the current position is found in the current position confirmation step, calculate the distance to the origin and calculate the distance to the origin For the high-speed movement process where the table is moved at high speed without monitoring either the limit sensor or the origin sensor. On the other hand, if the current position is unknown in the current position confirmation step, the process moves to the low-speed movement step of moving from the movement start position to the position where the origin sensor is turned on at a low speed while monitoring the limit sensor and the origin sensor. A determination step of determining which of the high-speed movement step and the low-speed movement step is to be selected based on whether or not the current position is known; and After turning on, move the table at low speed while confirming that the origin sensor is ON, and only while the origin sensor is ON while moving at low speed, all the A, B, and C phases of the encoder are ON. And confirming whether all the phases have been turned on, and returning to the home position when all the phases are turned on.

[0008]

[Action]

According to the present invention, according to the above-described method, when the current position is determined, a simple algorithm is used to quickly and quickly, and when the current position is unknown, an overrun can be avoided. It is possible to accurately judge whether to prioritize up-up or safety, and select an origin return suitable for the situation at that time. In other words, regardless of the position of the table at any time, including immediately after power-on, the maximum performance can be obtained with the minimum control load in accordance with the conditions for returning to the origin. In addition, the load on the control device and the production and adjustment of the table can be facilitated by reducing the number of the slow sensors.

[0009]

【Example】

An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a configuration diagram of an XY table using the present invention.
FIG. 2 is a flowchart of a method of returning the table to the origin in this configuration.

The XY table positioning control device 14 (hereinafter referred to as a controller) to which the home position return operation command has been input (Step 1) checks the current position (Step 2). The table 13 is moved at high speed by x-0 = Δx and y-0 = Δy by the difference toward the point 0, Y = 0 (step 3). If the current position is unknown here, the movement is started at a low speed (step 6). After the positioning is completed, the controller checks whether the X-axis origin sensor 8 and the Y-axis origin sensor 2 are ON (step 4). Here, the origin sensor 8 for each of the X axis and the Y axis,
2 is ON, the controller 14 confirms that the origin sensor is ON, and the controller 14 moves the X-axis encoder 11 and the Y-axis encoder 5 until the respective A-phase, B-phase, and C-phase are all ON. The motors 7, 1 for the axis and the Y axis are rotated (step 10). If the origin sensor is turned off before all of the phases A, B, and C are turned on, the direction of movement of the table of the axis that was turned off is reversed (steps 11 and 12). With these, the origin sensor is ON and the encoder's A phase, B phase,
Home return is completed when all C phases are turned on (step 13).

If the current position mentioned above is unknown, it moves at a low speed from the movement start position (step 6) and monitors whether the limit sensors 9, 10, 3 and 4 of the XY axes are turned on. (Step 7) The movement is continued until the origin sensor is turned on (Step 8).

Of course, if the limit sensor is turned on during this time, the moving direction of the table is reversed. When the origin sensor is turned on, as described above, move further until each of the encoder A phase, B phase, and C phase is turned on.
Home position return is completed when all phases, phase B and phase C are turned ON.

In FIG. 1, 6 is a Y-axis ball screw, 12 is an X-axis ball screw, 15 is a Y-axis sensing dog, and 16 is an X-axis sensing dog.

[0014]

【The invention's effect】

According to the present invention, only one origin sensor is required, and the width of the origin sensor is limited to the width within one rotation of the motor. In addition, the origin can be reliably set. Further, at the time of origin return, high-speed return by data is possible, so that there is no waste time and at the same time, the origin can be checked even in the case of return by data. Also, if the current position is unknown, the vehicle moves at a low speed to further secure safety, and also has the advantage that the load on the controller is reduced by the amount of the removal of the slow sensor.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is a flowchart of the embodiment.

FIG. 3 is a configuration diagram of a conventional example.

FIG. 4 is a flowchart of a conventional example.

[Explanation of symbols]

 1 Y-axis motor 2 Y-axis origin sensor 3 Y-axis limit sensor 4 Y-axis + limit sensor 5 Y-axis encoder 7 X-axis motor 8 X-axis origin sensor 9 … X-axis minus limit sensor 10 …… X-axis plus limit sensor 11 …… X-axis encoder 13 …… XY table 14 …… Control device

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G05D 3/12

Claims (3)

(57) [Claims] A positioning table movably supported; a drive unit for driving and positioning the table;
An encoder for detecting the amount of movement of the table by the drive unit, an origin sensor for determining the mechanical origin of the table, a + and-direction limit sensor for determining the range of movement of the table, and control for controlling these systems In the home position return method of the positioning table composed of a device, a current position check step for checking a current position which is a position to start the home position return based on a home position return operation command; and a case where the current position is found in the current position check step. To
Shift to the high-speed movement step of calculating the distance to the origin and performing high-speed movement of the table for the distance to the origin without monitoring any of the limit sensor and the origin sensor,
On the other hand, when the current position is unknown in the current position confirmation step, the process moves to the low-speed movement step of moving at a low speed from the movement start position to the position where the origin sensor is turned on while monitoring the limit sensor and the origin sensor. A determination step of determining which of the high-speed movement step and the low-speed movement step is to be selected depending on whether or not the current position is known; and after the origin sensor is turned on by any of the high-speed movement step and the low-speed movement step, Move the table at a low speed while checking whether the origin sensor is ON, and check that all the A, B, and C phases of the encoder are ON only while the origin sensor is ON while moving at a low speed. And returning to the home position when all of the phases are turned on. 2. The origin return method according to claim 1, wherein in the origin return step, when the origin sensor is turned off during the low-speed movement after the origin sensor is turned on, the moving direction of the table is reversed. 3. The origin returning method according to claim 1, wherein in the low-speed moving step, the direction of movement of the table is reversed when the limit sensor is turned on before the origin sensor is turned on.