JPS59102557A - Positioning device for moving material - Google Patents

Abstract

PURPOSE:To perform highly accurate positioning by moving on the basis of interface position data in each region of target stoppage, temporal stoppage and decelleration and current position data of moving material from a pulse generator. CONSTITUTION:Upon motion of X-Y table 2 in X and Y directions, pulse output from rotary encoders 12, 14 is provided to counters in position detection modules 22, 24 to produce current position data. When moving X-Y table 2 to target point, it will move with high speed upto position data stored in RAM and indicating deceleration region by means of a programmable controller 20 then move with low speed to reach to position data in temporal stoppage to stop each motor 6, 10 thereafter move slightly to stop at target position. Consequently highly accurate positioning is achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a moving object positioning device, and in particular to a moving object positioning device suitable for positioning a moving object used as a processing tool with respect to a workpiece in a machine tool or the like. The present invention relates to a positioning device.

A conventional positioning device for a moving object has a dog disposed on the moving object, and a limit switch that is turned on and off by the dog at a predetermined location on the workpiece, which is a fixed object. A method has been used in which a moving object is positioned by detecting a set point, which is a target stop position, and stopping an actuator for driving the moving object.

In such devices, the set point was determined by a limit switch and a dog, so if the number of set points increased, it would be foolish to have a large number of limit switches.
Variation in index detection points becomes a problem. Furthermore, even if the final positioning point fluctuates widely due to the inertia and frictional resistance of the positioning slide, it is impossible to determine whether the final positioning point is good or bad, making it impossible to perform highly accurate positioning.

In addition, in recent years, in order to cope with other types of workpieces, it has become necessary for a positioning device for a moving object to be able to perform positioning with respect to many positioning set points. Therefore, as a countermeasure to this problem, NC devices have come to be used. In the case of this device, position information is detected from a table drive device for moving a moving object, and position feedback is provided to a reversible control servo device, making it possible to perform variable yet reliable positioning. However, this device required complicated programming and operation, and was unsatisfactory in terms of operability and maintainability. It was also difficult to make the robot memorize location information through teaching. Furthermore, there was a drawback that υ was more expensive than conventional equipment.

Therefore, we developed a type of counter function that captures the amount of table movement as a pulse signal, counts the cumulative pulse signal, and stops the drive actuator when this number of pulses matches a preset number of position-corresponding pulses. What they had came to be used. However, even in the case of a device using such a counter, even if a large positioning error occurs due to friction or inertia of the moving object, it cannot be determined as abnormal, so the moving object is reliably indexed within the allowable range. I couldn't get a guarantee.

In addition, in a positioning device for a moving object that moves in two dimensions, the two axes are controlled at the same timing, which makes the device complicated, and there is a problem that it is not possible to set many positioning points due to the number of output points. was there.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to provide an inexpensive moving object positioning device that can perform highly accurate positioning of a moving object.

In order to achieve the above object, the present invention defines a movement area of a moving object in a reference coordinate system using position data indicating a distance along at least one or more reference coordinate axes (two reference coordinate axes), and determines a target stopping position of the moving object. In a moving object positioning device that is determined by the position data and moves the moving object to a target stop position based on the position data, a pulse generator outputs a pulse signal according to the amount of movement of the moving object along the reference coordinate axis. , position data of a target stopping area defined as a boundary of an area permitted as a target stopping position of the moving object, and a temporary stopping area including the target stopping area defined as a boundary of a temporary stopping area of the moving object. The position data and the position data of a deceleration area that includes the temporary stop area and is defined as the boundary of a deceleration area that decelerates the moving speed of the moving object are given, and the current position of the moving object in the moving area is determined from the pulse signal. A control unit that calculates data and outputs various commands based on this position data, and a drive that moves the moving object in a direction that increases or decreases the amount of movement of the moving object along the reference coordinate axis according to the drive command. the control unit determines the moving direction of the moving object along the reference coordinate axis based on the current position data and the position data with respect to the target stopping area;
Give a drive command in accordance with this regulation to the drive device, capture current position data of the moving object based on this drive command, and instruct the moving object to decelerate when the moving object moves within the deceleration area, The present invention is characterized in that a drive command to the drive device is stopped when the moving object moves to the temporary stop area, and a positioning completion command is output when the moving object reaches the target stop area.

Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

FIG. 1 shows a preferred embodiment of the present invention, in which a moving object moves in two dimensions.

In the figure, the X-Y table 2 that constitutes the moving object is
When the motor 6 is driven by a drive signal from the drive device 4 to move the X-Y table 2 along the Y-axis of the reference coordinate axes, it moves along the Y-axis, and the X-Y table 2 is moved along the Y-axis of the reference coordinate axes. When the motor 10 is driven by a drive signal from the drive device 8, the motor 10 moves along the Y axis, and can move in a two-dimensional coordinate system defined by the Y axis of the reference coordinate axis and the Y axis.

Y-axis, X-Y table 2 in reference coordinate system with Y-axis
In order to obtain movement information, the X-Y table 2 includes an X-axis rotary encoder 12 and a Y-axis rotary encoder 14.
is provided. The X-axis rotary encoder 12 and the Y-axis rotary encoder 14 each have a pair of photoelectric elements and a waveform shaping circuit, and the photoelectric elements of each pair are arranged at intervals such that the phase difference between the pulse trains produced by each photoelectric element is 90°. It is set up. When the X-Y table 2 moves along the Y-axis, it outputs pulse signals having different phases depending on the direction of movement, and supplies the pulse signals to the control section 16.

The control unit 16 includes a program module 18, a programmable controller 20, an X-axis position detection module 22, and an
It has an axis position detection module 24, and the programmable controller 20, the X-axis position detection module 22, and the X-axis position detection module 24 are connected by path lines 26, respectively.

As shown in FIG. 2, the programmable controller 20 includes a CPU 28, a power supply 30, a bit operation section 32, and
0 interface 34, etc., and constitutes a sequence circuit for controlling the drive devices 4 and 8. Based on commands from the X-axis position detection module 22 and the X-axis position detection module 24, the X-axis drive signal 100 and Y A shaft drive signal 102 is output.

As shown in FIG. 2, the X-axis position detection module 22 and the X-axis position detection module 24 include an input circuit 40, an output circuit 42, a display circuit 44, a direction discriminator 46, and a frequency divider 48.
, counter 50, comparator 52, CPU 5 as an arithmetic unit
4. Consists of ROM56, RAM58, etc.
The input circuit 40 is supplied with a signal from the X-axis rotary encoder 12. The output of the input circuit 40 is supplied to a direction discriminator 46, and the moving direction of the X-Y table 2 along the X-axis is discriminated from the pulse train of the pulse signal. The output signal of direction discriminator 46 is supplied to counter 50 via frequency divider 48 . The counter 50 adds and subtracts the frequency-divided pulse train according to the signal from the direction discriminator 46, and
The current position data (Xy, Yy) of the X-Y table 2 in the coordinate system is output. The output of counter 50 is supplied to comparator 52 and CPU 54. Comparator 52
The circuit 42 compares the output of the counter 50 with the position data of the provisional stop area defined for the boundary of the provisional stop area of the X-Y table 2 in the XY coordinate system, and outputs a comparison signal when these data match. supply to. The output circuit 42 supplies an X-axis drive stop signal to the drive device 4 based on the comparison signal.

Although the X-axis position detection module 22 has been described in this embodiment, the X-axis position detection module 24 is also configured in the same manner as the X-axis position detection module 22.

The AM 58 stores various position data indicated by coordinate values in the XY coordinate system. That is, as shown in FIG. 3, the target stopping position Pi(i
position data (xi, yi) i=1 of the target stopping position determined for the boundary of the allowable area for =1 to n)
~n are stored.

In addition, in this embodiment, when moving the X-Y table 2 to the target stop position Pi, it is moved at high speed to the target stop position Pi, and at the same time when the X-Y table 2 stops at the target stop position Fil. In order to reduce the influence of inertia of the X-Y table 2, a method is adopted in which the moving speed of the X-Y table 2 is varied. That is, as shown in FIG. 4, the X-Y table 2
When moving to , a system is adopted in which the vehicle moves at high speed to the speed variable point Qi, and moves at low speed after passing through the speed variable point Qi. Therefore, in this embodiment) LAM58
As shown in FIG. 3, position data (Llx, Lly) indicating a deceleration area defined as a boundary of a deceleration area in which the moving speed of the X-Y table 2 is reduced is stored. Position data of this deceleration area (ci, di; c
i=xi±LIX (+: when moving in the positive direction of X, -: when moving in the negative direction of X), d i=y i+Ll)
' (+ indicates movement in the positive direction of y, - indicates movement in the negative direction of y)) is compared with the current position data (Xy, Yy) of the counter 50 by the CPU 54, and these data are When it matches, programmable controller 2
0, a drive signal for decelerating and moving the X-Y table 2 is output.

In addition, in this embodiment, the X-Y
When stopping the table 2 within the target stopping area, two types of temporary stopping areas are defined: one where highly accurate positioning is required and one where highly accurate positioning is not required.

In other words, when the X-Y table 2 moves by ζ2 within the deceleration region, when the X-Y table 2 is stopped within the target stop region by highly accurate positioning (= is for stopping the X-Y table 2 As shown in FIG. 3, the position data (ei, fi) of the temporary stop area including the target stop area is set to correspond to the boundary of the temporary stop area of the X-Y table 2 as the point for outputting the command. ei=xi±II
X, f i=y i±11y).

On the other hand, when there is no need to stop the X-Y table 2 with high precision positioning, the position data of the temporary stop area is the third
As shown in the figure (=(2), the position data (gi, hl) of the temporary stop area defined for the boundary of the temporary stop area S including the temporary stop area R; (gi=xi±l 2x,
h i=y i±12y).

Temporary stop area JS position data (ei, fi entered (gj,
hi) is (xi, yi), (11x, 11y), (1
2X, 12y) is calculated by the CPU 54.
is supplied to the comparator 52 via the counter 50, and is compared with the current position data (Xy, Yy) by the counter 50. When each position data matches, the output circuit 42 outputs the
A drive stop signal for stopping the drive of the table 2 is issued.

Note that a command to stop the x-y table 2 by highly accurate positioning and a stop command that does not require highly accurate positioning are given in advance at the positioning position (xi).

yi) is stored in the RAM 58 at the same time, and depending on the command, one of the positions to be performed is selected.

This embodiment does not have the above-mentioned configuration.Next, the operation of the 7o-chart shown in FIGS. 5 and 6 will be explained.

First, in step 200, after confirming that all devices including peripheral devices are at the work origin, a predetermined program is set, and the process moves to step 202. In step 202, an address is set from the RAM 58 to the position data (ai, bi) (hereinafter referred to as target value) of the target stop area according to the program, and the process moves to step 204. When the operation start signal is output from the programmable controller 20 in the process of step 204, the process moves to step 206, where the target value whose address has been set is taken into the target value register of the CPU 54 for each axis. Next, the process moves to step 208, where the current position data (Xy) is determined by the counter 50.

Yy) (hereinafter referred to as the current value) is taken into the CPU 54 and the process moves to step 210. In step 210, a comparison operation is performed between the target value and the current value.

Note that since the same control is performed for both the Y-axis and Y-axis, the following
Only the drive along the axis will be discussed.

Reign 1>L! (coordinate values corresponding to the distance from the target stop position to the boundary of the target stop area shown in FIG. 3), the process moves to step 212, where a direction determination process is performed in the CPU 54, and the process moves to step 214. In step 214, based on the direction determination process of the CPU 54,
A drive signal that determines whether the amount of movement of the Y table 2 along the Y axis is increased or decreased is supplied from the programmable controller 20 to the drive device 4.

Next, the process moves to step 216 j5, and it is determined whether the X-Y table 2 is to be moved at a high speed or a low speed. That is, if it is determined that the current value of the X-Y table 2 is not included in the deceleration area Q, the process moves to step 218jl),
A drive signal for moving the XY table 2 at high speed is supplied to the drive device 4, and the process moves to step 220. In step 220, the shimotor 6 rotates at high speed in response to a signal from the drive device 4, and moves the X-Y table 2 at high speed.

On the other hand, if it is determined in step 216 that the current value of the X-Y table 2 has reached the deceleration region Q, the process moves to step 222, and j, drive for moving the X-Y table 2 at a low speed is performed. A signal is provided from the programmable controller 20 to the drive device 4 and the process moves to step 224 . In step 224, a signal from the drive device 4 (the second shim motor 6 is rotated at a low speed and the X-Y table 2 is moved at a low speed).

After processing steps 220 and 224, step 226
, 228, it is determined whether or not the motor 6 is rotating and the direction of rotation. Step 226 or Step 228
In the process, if the motor 6 does not rotate or the rotation direction is reversed, the process moves to step 230, and the CPU 5
4 outputs an abnormality command to the programmable controller 20, and the programmable controller 20 outputs a signal for safely operating the entire device to the drive device 4 and the like.

If it is determined in step 226 that there is no abnormality, the process moves to steps 232 and 234. That is, X-Y
Counter 50 until table 2 reaches within deceleration area Q
The current value is taken in, and it is determined whether the X-Y table 2 has reached the deceleration region Q or not. If it is determined in step 234 that the X-Y table 2 has reached the deceleration region Q, the process moves to step 236;
A drive signal for moving the XY table 2 at a low speed is supplied to the drive device 4 by the programmable controller 2o, and the process moves to step 238. Note that even if it is determined in step 228 that there is no abnormality, step 238 is performed.
Move on to processing.

In the process of step 238, it is determined whether the positioning of the X-Yf-pull 2 requires high precision. If it is determined that highly accurate positioning is required (second step, the process moves to step 242. In step 242, the current Compare the value with the target value.

If the X-Y table 2 has reached the temporary stop area S, the process moves to step 244, and the output circuit 42 supplies an X-axis drive stop signal to the drive device 4. In response to this signal, the drive of the motor 6 is stopped and the process moves to step 246.

In step 246, it is determined whether or not it is an end program. If the determination in this step is NO, the process moves to step 248, the timer count is set to T2, and the process moves to step 250.

In step 250, it is determined whether the X-Y table 2 is within the target stopping area P.

In other words, even if the drive of the X-Y table 2 is stopped, the X-Y
This process is performed because the table 2 may not stop within the target stopping area P. If the determination in this step is NO, the process moves to step 252, where the CPU 54 outputs an abnormality command to the programmable controller 20, and the programmable controller 20 outputs a control command to control the entire device safely to the drive device 4, etc. be done.

If YES is determined in steps 250 and 210, the process moves to step 2549, where a positioning completion command for the Y-axis is output to the programmable controller 20, and the process moves to step 256. In step 256, data of a plurality of switching signals corresponding to the target stop position Pi stored in advance in the auxiliary data memory of the programmable controller 20 is taken in, and these switching signals are independently supplied to the external machine sequence circuit. . Next, the process moves to step 258, where it is determined whether or not the control of the external mechanical sequence circuit has ended.

The processing of steps 260 and 262 performed when the determination is YES in step 246 is the same as that of step 25 described above.
6. The same processing as that of 258 is performed.

On the other hand, if it is determined in step 238 that highly accurate positioning is not required, the process moves to step 264, and 6. It is determined whether the x-y table 2 has reached the temporary stop area S or not.

When it is determined in step 264 that the X-Y table 2 has reached the temporary stop area S, the process moves to step 266, where a drive signal to stop driving the X-Y table 2 is supplied to the drive device 4. Ru.

This signal stops the drive of the motor 6, and step 26
Move on to 8. In step 268, Y of X-Y table 2
A determination is made whether movement along the axis has been stopped;
When the XY table 2 has stopped, the process moves to step 256, and the same process as described above is performed.

In step 258, when the sequence control for controlling the external machine sequence circuit is completed, an operation start signal is supplied from the programmable controller 20 to the X-axis position detection module 22, and the process moves to step 270. In step 270, the address of the RAJ 58 is incremented by one and the process moves to step 272. By the way, the processing up to this point is similarly performed for the Y-axis, so in step 272 it is determined whether or not the Y-axis and Y-axis addresses match. In step 272, the Y-axis address and Y
If the axis addresses match, the process returns to step 204, which is the initial state of the program. Note that if the determination in step 272 is NO, the process moves to step 274.
An abnormality command is outputted to the programmable controller 20, and then outputted to the drive device 4.8 etc. for controlling the entire device on the safe side.

After the above processing is executed a predetermined number of times and the position of the X-Y table 2 returns to the work origin, the X-axis position detection module 22 and the Y-axis detection module 24 issue a completion command to the programmable controller 20 to indicate that one cycle of one program has been completed. is supplied and all processing is completed.

In this embodiment, when confirming the positioning on the X-axis and Y-axis, the processing of the X-axis lateral output module 22 is set to be positioned higher than the Y-axis detection module x-7. There is. Further, if one of the coordinate values of the stop position of the X-Y table 2 is within the target stop area, a positioning abnormality signal indicating poor positioning is supplied to the programmable controller 20, The programmable controller 20 outputs a drive signal for safely controlling the drive device 4.8.

Further, the pulse generator in the above embodiment is not limited to a rotary encoder, but can be similarly implemented by a linear encoder, and a forward/reverse signal system may be used instead of the 90' phase difference system.

Further, in the above embodiment, the X-Y table 2 in which the moving object moves in two dimensions has been described, but the above embodiment can also be applied when the moving object moves along one or three or more reference coordinate axes. can do.

Furthermore, in the embodiment described above, since the moving object can be positioned with respect to a plurality of target stop positions, it is possible to flexibly respond to changes in the positioning points. Furthermore, if the moving object does not reach the target stopping area, an abnormality signal is output, so reliability can be improved. Furthermore, since all processing is performed by the control section, it can be operated without any special knowledge by an operator or the like. Furthermore, since the drive of the moving object can be controlled without using a servo mechanism, the drive device can be configured with an inexpensive actuator.

As explained above, according to the present invention, various types of control are performed based on the position data determined for the boundaries of the target stop area, provisional stop area, and deceleration area and the current position data of the moving object by the pulse generator. The control unit that performs calculations determines the moving direction of the moving object along the basic coordinate axes based on the current position data and the position data of the target stopping area, and sends a drive command according to this determination to the drive device to drive the moving object. Then, the current position data of the moving object based on this drive command is received, and when the moving object moves into the deceleration area, the moving object is commanded to decelerate, and when the moving object moves into the temporary stop area, the moving object is driven. Since the drive command to the device is stopped and the positioning completion command is output when the moving object reaches the target stopping area, there is an excellent effect that highly accurate positioning can be performed.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram showing one embodiment of the present invention, FIG. 2 is a configuration diagram for explaining the specific configuration of the control section shown in FIG. 1, and FIG. 3 is a diagram explaining the allocation of position data. Figure 4 is a velocity diagram for explaining changes in the velocity of a moving object, Figures 5 and 6 are diagrams for explaining the operation of the device shown in Figure 1. This is a simple flowchart. 2...X-Y table 4.8...Drive device 6.10...Motor 12...X-axis rotary encoder 14...Y-axis rotary encoder 16...Control unit 18...Program Module 20...Programmable controller 22...X-axis position detection module 24...Y-axis position detection module Fig. 3 YN 334- Fig. 4k Main beak 1 straight

Claims (1)

[Scope of Claims] (1) A movement area of a moving object in a reference coordinate system is determined using position data indicating a distance along at least one reference coordinate axis, and a target stopping position of the moving object is determined using the position data. A moving object positioning device that moves the moving object to a target stop position based on position data determined by the moving object, comprising: a pulse generator that outputs a pulse signal according to the amount of movement of the moving object along the reference coordinate axis; Position data of a target stopping area defined as a boundary of an area permitted as a target stopping position of an object, positional data of a temporary stopping area including the target stopping area and defined as a boundary of a temporary stopping area of the moving object, and the position data of a deceleration area defined as a boundary of a deceleration area that decelerates the moving speed of the moving object including a provisional stop area, and calculates current position data of the moving object in the moving area from the pulse signal. a control unit that outputs each plum command based on these position data (2); a drive device that moves the moving object in a direction in which the amount of movement of the moving object along the reference coordinate axis increases or decreases according to the drive command; The control unit determines the moving direction of the moving object along the reference coordinate axis based on the current position data and the position data with respect to the target stop area, and issues a drive command according to this determination to the drive device. and receives the current position data of the moving object based on this drive command, and when the moving object moves into the deceleration area, commands the moving object to decelerate, and the moving object moves into the temporary stop area. A positioning device for a moving object, characterized in that the drive command to the drive device is stopped when the moving object reaches the target stop area, and a positioning completion command is output when the moving object reaches the target stop area. (2) The pulse generator is , outputting pulse signals having different phases depending on an increase or decrease in the amount of movement of the moving object along the reference coordinate axes, and the control unit determining the moving direction of the moving object along the reference coordinate axes from the pulse signals and generating a discrimination signal. a counter that adds or subtracts the pulse signal according to the discrimination signal and outputs current position data of the moving object; position data of the target stop area, position data of the temporary stop area, and a counter that outputs the current position data of the moving object; a memory section in which position data of the deceleration area is stored in advance; a comparator that compares the position data of the temporary stop area stored in the memory section with the counter output; and a target stop area and the target stop area stored in the memory section. an arithmetic unit that compares and calculates the position data of the deceleration area and the counter output, and compares the current position data and the position data of the temporary stop area, and adjusts the speed of the moving object according to the magnitude of both position data. determines the moving direction of the moving object, compares the current position data and the position take of the deceleration area, and when both position data match, commands deceleration drive of the moving object, and compares the current position data and the temporary stop area. The drive command is stopped when both position data match, and the position data of the target stop area is compared with the position data of the local point, and when both position data match, positioning is performed. Output a completion command (3) The memory unit stores a plurality of position data regarding the target stop area, the provisional stop area, and the deceleration area, and the control unit outputs the positioning completion command and then outputs the position data to the memory unit. Claims (1) or (2) which receives new position data from each stop area (two) and outputs a command based on these position data.
A moving object positioning device as described in Section 1. (4) When the movement area of the moving object is defined by position data indicating distances along a plurality of reference coordinate axes, the control unit sends drive commands along each reference coordinate axis to the drive device and each reference coordinate axis. Claims (1) to (1) independently instructing to stop the drive command for each reference coordinate axis.
3) The moving object positioning device according to any one of the items.