JPH0348911A - Positioning device - Google Patents

Abstract

PURPOSE:To attain a sure positioning by updating the storage of a slip extent by performing the comparison via an incremental encoder between a real slip extent and a stored one after a shift command signal is cut off. CONSTITUTION:A set shift extent is decided by subtracting the slip extent set to a setting storage means 12 of a drive control circuit 10 from a target stop position. A shift command signal is outputted in accordance with the set shift extent. Then a mobile object moves and is controlled when the coincidence is obtained between the slip extent set via an incremental encoder 16 and that stored in the means 12. In this case, an actual slip extent is stored in an actual slip extent storage means 21 of an automatic slip extent correction means 20 and then compared with the slip extent read out to a set slip extent read/ storage means 22. Then a comparison deciding means 23 decides the presence or absence of difference between both slip extents. If the difference is recog nized, a rewriting means 24 updates the contents of the means 12 into the actual slip extent. This slip extent is automatically detected and corrected so that a sure positioning job is carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an open-loop control type positioning device using an incremental encoder.

[Prior Art] Positioning devices that move a movable body relative to a stationary body and stop it at a predetermined position are widely used.

One such positioning device is an oven loop control system formed from a drive control circuit 10 and a motor (not shown) as shown in FIG.

For example, it is used to adjust the slide of a press or adjust the inner width of a feed bar.

In the figure, reference numeral 11 denotes actual movement amount detection means, which is connected to an incremental encoder 16 that outputs one pulse per unit movement of the movable body relative to the stationary body.

It is often formed from a reversible counter. Reference numeral 12 denotes a setting storage means, which has the function of setting and storing a target stop position and a set amount of slippage, as well as determining a set amount of movement as a difference between the two. Comparison means 13 compares the set movement amount SS from the setting storage means 12 and the actual movement amount C from the actual movement amount detection means 11 and cuts off the movement command signal E when both movement amounts become equal. It is. On the other hand, 14
is a drive control means, which receives start and stop signals S from the outside.
Based on TT and STP, a control signal CNT is output to a stepping motor (not shown) or the like.

This control signal CNT is a pulse (No. It is formed to output a timing signal 1'1 for starting and stopping the actual movement amount detecting means 11 and the comparing means 13.

Therefore, as shown in FIG.
Once the target stop position ISO and the set slip amount SC shown by the solid line are set, the setting storage means 12 stores these and also determines and stores the set movement amount ss <5o-8C). Here, the drive control means 14 outputs a control signal CNT of a predetermined frequency to a motor (not shown) based on a starting signal STT and a movement command signal E from the outside to drive and control the movable body relative to the stationary body. At the same time, the actual movement amount detection means 11 counts the movement amount signal P from the incremental encoder 16. Further, the comparison means 13 compares the actual movement amount SS from the actual movement amount detection means 11 with the setting storage means 12.
Compare the set movement amount SS from . and rainfall amount C, S
When S becomes the same value, the movement command signal E is cut off. In addition,
The movement command signal E was output at the rising edge of the timing signal T1.

Therefore, the drive control means 14 uses the control signal CN
Block T. The movable body slides as shown by the solid line in FIG. 4 due to the existing inertia. This amount of slippage is S
It is C. Therefore, the movable body is positioned at the target stop position 'rtSO.

Problems to be Solved by the Invention] Incidentally, the slip amount SC set in the setting storage means 12 is determined by mechanical factors such as the moving speed and mass of the movable body, but when setting the specific value, it is determined by an appropriate value immediately corresponding to the actual machine. Not only is the setting work extremely troublesome, but
It is extremely difficult to set accurately.

On the other hand, from the i trl i configuration, the amount of slip changes due to changes in load, etc. even during the same stroke.

Furthermore, even if the load etc. is constant, it changes over time. Furthermore, when changing the movement stroke, for example from a short stroke to a long stroke, the slippage will increase or decrease due to deformation of the guide rail or the like. That is,
As shown in FIG. 4 by the 2-point gfiIl, the 1-point dotted line, and the dotted line, the amount of slippage <sc, , scl, 5C3) increases and decreases.

Here, in the conventional positioning device, the setting storage means 1
2, the desired amount of slip was selected from among the many slip amounts (parameters) stored in 2, or the desired slip amount was set each time, which not only made the setting work complicated and time-consuming, but also made it difficult to position accurately. There was a fear that this would not be guaranteed.

An object of the present invention is to provide a positioning device that automatically detects and automatically sets the amount of slippage, eliminates the conventional work of setting the amount of slippage, and performs accurate and reliable positioning.

[Means to solve the problem]

The present invention focuses on the existence of an inflation metal encoder that detects the amount of movement of a movable body, and automatically detects the actual amount of slippage after cutting off the movement command signal, and automatically sets and stores the actual amount of slippage. In the subsequent operation, the actual amount of slippage is used to control the drive.

Specifically, a movement command signal is issued when the set movement amount, which is determined as the difference between the target stop position stored in the setting storage means and the set slip amount, and the actual movement amount detected by the incremental encoder become equal. In a positioning device that performs positioning control by cutting off the movement command signal, the actual slip amount storage means detects and stores the actual slip amount by counting the signal output from the incremental encoder after the movement command signal is cut off; a comparison determination means for determining whether there is a quantitative difference by comparing the actual slip amount stored in the setting storage means with the set slip amount stored in the setting storage means; and an automatic slip amount correction means formed including a rewriting means for rewriting the set slip amount stored in the setting storage means to the actual slip amount stored in the actual slip amount storage means. Features.

A moving object stops after sliding by a certain amount due to inertia.

At this time, the actual slip amount detected and stored in the actual slip amount storage means is compared with the set slip amount initially set and stored in the setting storage means to determine whether there is a difference, and if there is a difference, it is written down. The changing means rewrites the set slip amount in the setting storage means to the actual slip amount. That is, the automatic slip amount correction means always automatically rewrites the set slip amount stored in the setting storage means of the drive control circuit to the immediately previous actual slip amount.

Therefore, since the second drive control is performed based on the actual amount of slippage, accurate positioning can be achieved at the target stop position. Furthermore, it is possible to automatically correct changes in the amount of slip due to stroke changes and increases and decreases in the amount of slip over time, thereby always achieving reliable positioning.

C action
[Example] In the present invention having the above configuration, the first drive control will be explained below with reference to the drawings.
do.

As shown in FIG. 1, this positioning device includes a drive control circuit 1
0 is provided with an automatic slip amount correction means 20.

The drive control circuit 10 has the same basic configuration as the conventional drive control circuit (10) shown in FIG. Setting and storing and postscript rewriting means 2'
4 so that it can be rewritten to a specific slip amount. Further, the drive control means 14 outputs a timing signal T2. Furthermore, as shown in FIG. 2, when the start signal STT is input, the drive control means 14 first outputs the control signal CNT of the low speed LS to the stepping motor (not shown), then switches to the high speed HS, and then outputs the control signal CNT of the low speed LS again. It is programmed so that it can be switched to This is to achieve high-speed movement beyond the self-starting frequency range. Switching between the low speed LS and the high speed H3 is managed based on the actual movement amount signal C' from the actual movement amount detection means 11.

Now, the automatic slip amount correction means 20 is also shown in FIG. This means automatically rewrites the set slip amount of No. 12 to the actual slip amount and corrects it.

First, the actual slip amount storage means 2-1 stores the actual amount of slippage in the drive control means 1.
The movement amount signal P is output from the incremental encoder 16 at the rising edge of the timing signal T2 output from 4.
It is a means of detecting and storing information.

The timing signal 'r2 is output when the comparison means 13 interrupts the movement command signal E. Therefore, the actual slip amount storage means 21 can automatically detect and store the actual slip amount of the movable body relative to the stationary body after the control signal CNT is cut off.

On the other hand, the set slip amount reading storage means 22 is a means for reading and storing the set slip amount R8 stored in the setting storage means 12 at the rising edge of the timing signal T2.

Note that the actual slip amount storage means 21 and the set slip amount reading storage means 22 are cleared at the fall of the timing signal T2.

Next, the comparison/judgment means 23 compares the set slip amount R3 from the hand Pi 22 and the actual slip amount OC from the means 21, and judges whether there is a difference between the two. This is executed after a predetermined period of time from the rise of T2, that is, after the movable body stops sliding due to inertia.

In this sense, a stop detector 25 connected to the incremental encoder 16 is provided as shown by the two-dot chain line in FIG. You may.

Then, when it is determined that there is a difference between both QC and R3, a rewrite signal DF is output. When there is no signal DF, the signal DF is not output.

The rewriting means 24 receives the rewriting signal DF from the comparing and determining means 23.
is input, reads the actual slip amount OC stored in the actual slip amount storage means 21, and automatically rewrites the set slip amount R3 stored in the setting storage means 12 to this actual slip amount OC. is formed.

Next, the effect will be explained.

First, the target stop position SO and the set slip amount SC are set and stored in the setting storage means 12, as shown by the solid line in FIG. Find this and remember it.

Here, when the start signal STT is input, the drive control means 14 outputs the timing signal T1, and based on the timing signal T1, the drive control means 14 sets the movement command signal E outputted from the comparison means 13 as a condition, as shown in FIG. A control signal CNT in the indicated mode (low speed LS - high speed H8 - low speed LS) is output to a stepping motor (not shown) to move the movable body. The low speed to high speed switching is managed by signal C'.

At this time, the comparison means 13 compares the set movement amount SS from the setting storage means 12 and the actual movement amount C from the actual movement amount detection means 11. When both plates SS and C become the same, the movement command signal E is cut off at time t1 shown in FIGS. 2 and 4.

Therefore, the control signal CNT is cut off (the motor is stopped) from the drive control means 14, and at the same time, the timing signal T disappears, and the timing signal T2 is output.

The disappearance of the timing signal T1 means that the actual movement amount detector 91
1 and comparison means 13 are cleared. On the other hand, when the timing signal T2 rises, the actual slip amount storage means 21. The set slip amount reading and storing means 22 and the comparing and determining means 23 operate.

In this case, movement command signal E (control signal CNT)
Even if the motor is stopped due to the interruption of
Sliding as shown by the dotted chain line is the amount of slippage (SCI, SC2
) increases, and the sliding shown by the dotted line is the case when the amount of slippage SC1 decreases.

Here, the actual slip amount storage means 21 receives the movement amount signal P of the incremental encoder 16 and records the movement Ji.
Detects SCx (SC, SCI, SC2, 5C1)
Remember. On the other hand, the set slip amount reading storage means 22 reads and stores the set slip amount R3 stored in the setting storage means 12.

Then, in the comparison and judgment means 23, after a predetermined time (time until the sliding stops) from the rise of the timing signal T2,
The actual slip i0C from the means 21 and the set slip amount R8 from the means 22 are compared to determine whether there is a difference between the two.

Note that when the stop detector 25 is provided, the stop signal ST
Judgment is made based on the timing of the utterance.

Then, as shown in FIG. 4, when the actual slip amount increases or decreases with respect to the set slip amount SC, as shown in SCI, SC2, and SC3, a rewriting signal DF is output.

When this rewriting signal DF is input, the rewriting means 24 automatically rewrites the set slip amount R3 stored in the setting storage means 12 to the actual slip amount OC.

Therefore, the amount of slippage stored in the setting storage means 12 is always the amount of slippage that has absorbed changes over time, etc. Also, the setting storage means 12 is stored in the one-dot chain line (△1), 2
As shown by the dot-dashed line (Δ2) and the one-dot line (Δ3), the set movement amount SS is calculated and corrected.

Note that, due to the fall of the timing signal T2, the actual slip amount memory hand Pi21. The set slip amount reading storage means 22 is cleared.

According to this embodiment, the automatic slip amount correction means 20 rewrites and corrects the set slip amount stored in the setting storage means 12 of the drive control circuit 10 to the actual slip amount based on the actual (sliding) operation. Even if the amount of slippage increases or decreases due to changes in the movement stroke (target stop position setting) of the movable body or changes over time, this can be automatically corrected and accurate positioning can be performed at the target stop position. . At the same time, the conventional setting work for the amount of slippage, which was performed every time, can be wiped out, and smooth operation without sacrificing productivity can be achieved.

Furthermore, since the automatic slippage amount correction means 20 is configured to calculate the actual slippage toe using the movement amount signal P from the essential incremental encoder 16, the drive control time r! can be achieved at low cost. Accuracy matching with @10 is easy.

Further, since the timing signal T2 for controlling the automatic slip amount correction means 20 can be outputted from the drive control means 14 of the drive control circuit 10 in a timely and easy manner, the correction work can be performed quickly and appropriately.

[Effects of the Invention] The present invention comprises a drive control circuit and an automatic slip amount correction means that rewrites and corrects the set slip amount stored in the setting storage means constituting the circuit into the detected actual slip amount each time. This configuration eliminates the complicated conventional setting change work associated with changes in the movement stroke of the movable body and changes in the amount of slippage over time, and provides a positioning device that can stably perform accurate positioning with high efficiency. can.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a timing chart for explaining the operation mode, FIG. 3 is a block diagram of a conventional positioning device, and FIG.
The figure is a diagram for comparing and explaining the change in the amount of slippage between the present invention and the conventional example. DESCRIPTION OF SYMBOLS 10... Drive control circuit, 12... Setting storage means, 16... Incremental encoder, 20... Automatic slip amount correction means, 21... Actual slip amount storage means, 23... Comparison judgment Means, 24... Rewriting means. Figure 2

Claims (1)

[Claims] (1) Cut off the movement command signal when the set movement amount found as the difference between the target stop position stored in the setting storage means and the set slip amount and the actual movement amount detected by the incremental encoder become equal. In a positioning device that performs positioning control by controlling the positioning, the actual slip amount storage means detects and stores the actual slip amount by counting the signal output from the incremental encoder after the movement command signal is cut off; a comparison and determination means for comparing the amount of slippage and the set amount of slippage stored in the setting storage means to determine whether there is a quantitative difference; and when the comparison and determination means determines that there is a difference, the The present invention is characterized by providing an automatic slip amount correction means including a rewriting means for rewriting the set slip amount stored in the setting storage means to the actual slip amount stored in the actual slip amount storage means. positioning device.