JPS5842082B2 - positioning control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a positioning control device for a transport table for transporting material from one processing line to the next processing line.

FIG. 1 shows an example of typical conveyance equipment to which this positioning control device is applied.

This conveyance equipment is used for conveying material 4 from processing line 1 to treatment line 2 through conveyance line (conveyance table) 3.

That is, when the material 4 is transferred from the processing line 1 to the transport line 3, the transport table 3 is activated to transport the material 4 to the right in the figure.

When the material 4 reaches the position of the material detector 5, this material detector 5 gives a deceleration instruction to the conveying table 3. Next, when the material 4 reaches the position of the material detector 6, the material detector 6 causes the conveying table 3 to decelerate. is given a stop instruction.

By giving this stop instruction, the material 4 is stopped in front of the processing line 2 and then taken into the processing line 2.

In the case of such conveyance equipment, the deceleration timing is given by the material detector 5, but the position of the material detector 5 for this deceleration timing depends on the weight per unit length of the material and the coefficient of friction between the material and the table. , material 4 even at line speed.
needs to be placed at a position where deceleration is completed before the position of the material detector 6 for the next stage stop timing.

Furthermore, in cases where slipping between material tables is avoided or in equipment where a relatively high stopping speed is required, constant deceleration rate control is usually used to control the deceleration rate at a constant level during deceleration. ing.

FIG. 2 shows the conveying speed of the conveying table 3, that is, the operating speed curve.

In Figure 2, a is an acceleration command, b is an acceleration command, C is a constant speed, d is a deceleration command, e is a deceleration, f is a deceleration completed, g is a constant speed, h is a stop command, i is a deceleration, and j is a stopping point. It is.

In this case, the deceleration rate is such that the material 4 completes deceleration before the stop timing material detector 6 even when the operating speed is the highest, the weight per unit length of the material is heavy, and the friction coefficient is small. It is necessary to select the deceleration rate.

However, depending on the equipment, when the material 4 is shorter and lighter than when it is long and heavy, it may be necessary to increase the number of materials that can be processed.

In this case, according to the control method described above, the transport table 3 may become a bottleneck in terms of throughput.

The present invention enables the conveyance table's conveyance speed and acceleration/deceleration rate to be set and variable, and is capable of adjusting the position of the conveyance table so as to correspond to the type of material to be conveyed, such as weight per unit length, and the coefficient of friction.Therefore, the processing capacity can be increased as required. The purpose is to provide a control device.

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 3, reference numeral 11 denotes a drive device for the conveyance table 3, and a speed reference signal for the conveyance speed to this drive device 11 is given from a speed reference generation circuit 12 through an input limiting circuit 13.

The input limit circuit 13 is a function generator that limits acceleration and deceleration during acceleration and deceleration, and its acceleration rate and deceleration rate are determined by the acceleration/deceleration rate setting circuit 1.
4, and these parts constitute a speed reference device.

Here, in the present invention, the following correction circuit is provided.

That is, the reference conveyance speed setting circuit 15 shown in the figure uses the standard material flowing on the conveyance table 3 (for example, the material that is the most common among the various materials flowing on the conveyance table 3) as the reference material,
The normal average friction coefficient between the conveyance table 3 and the material 4 is used as a reference friction coefficient to give the maximum speed at this time and the low speed after deceleration is completed, and the speed standard generation circuit 12 sets this standard conveyance speed. In addition to the signals from the circuit 15, signals from a friction coefficient setting circuit 16 and a weight per unit length setting circuit 17 for setting the weight per unit length based on the type of material are input. The signal from the reference transport speed setting circuit 15 is corrected based on the signal from the weight per unit length of material setting circuit 17 and is output to the input limiting circuit 13.

On the other hand, the acceleration/deceleration rate setting circuit 14 includes a reference acceleration/deceleration rate setting circuit 18 that sets the acceleration/deceleration rate when the friction coefficient of the standard material is obtained.
In addition to the signals of the setting circuits 15 and 17, the signals of the setting circuits 15 and 17 are input, and the signals of the reference acceleration/deceleration rate setting circuit 18 are corrected by the signals of the setting circuits 15 and 17, and the acceleration/deceleration rates are set depending on the material 4 to be conveyed. Input limit circuit 1 by setting
Output to 3.

The input limiting circuit 13 performs an integral operation so that its output is equal to the input from the speed reference generating circuit 12,
The output is increased or decreased with a constant integration time constant, and when the output becomes equal, the output is held at that value and the integration operation is stopped.

The integral time constant (increase/decrease rate) is determined by the acceleration/deceleration rate setting circuit 14.
is given by the output of

This input limiting circuit 13 allows the speed reference signal to the drive device 11 to smoothly follow the acceleration/deceleration rate set by the acceleration/deceleration rate setting circuit 14 so that it becomes the output of the speed reference generation circuit 12. This prevents slippage between the material 4 and the conveyance table 3, and allows the material 4 to be accelerated or decelerated at a required acceleration/deceleration rate.

In addition, reference numeral 19 is a deceleration/stop signal which generates the deceleration/stop timing of the conveying table 3 in response to the material detection signals from the deceleration timing position detector 5 and the stop timing position detector 6.
The stop timing generation circuit is shown.

With such a correction configuration, the conveying speed and acceleration/deceleration rate of the conveying table 3 can be varied to correspond to the weight per unit length and friction coefficient of the material to be conveyed.

FIG. 4 shows an example of the input signal to the drive device 11 in the positioning device, that is, the output of the input limiting circuit 13. When the weight per unit length of the material is small, G1, and when it is large, G2 (small approximately twice the weight per unit length)
In the case of material G1 with a small weight per unit length, the maximum speed of the transport table is set, and in the case of material G2 with a large weight per unit length, the speed is set to 1/2 of the maximum speed of the transport table, and its acceleration/deceleration rate This is also the case when the size is reduced to 1/4.

In this way, by setting the conveyance speed to be changed depending on the size of the weight per unit length, the conveyance table 3 and the material 4 can be
In addition, even when deceleration is performed using the same timing signal from the material detector 5 for deceleration timing, the time of low speed after deceleration can be kept to a substantially shortest time.

Moreover, if the conveyance speed is changed according to the weight per unit length of the material, a substantially constant power will be required from the drive motor regardless of the type of material, and the acceleration/deceleration rate will also be changed depending on the weight per unit length. This allows the power during acceleration and deceleration to be suppressed, allowing equipment to be used as efficiently as possible.

Next, using FIG. 4 as an example, processing contents in each setting circuit will be explained when changing the conveyance speed and acceleration/deceleration rate depending on the weight per unit length of the material 4 or the friction coefficient of the material 4.

In the figure, 01 is the reference material and the reference friction coefficient, the reference conveyance speed is Vmax, the deceleration rate during deceleration from this speed to the low speed before stopping from the point dl is αmax, and the low speed is V.

Then, the reference conveyance speed setting circuit 15 in FIG.
X and V6 are output to the speed reference generation circuit 12.

Further, the reference acceleration/deceleration rate setting circuit 18 for the reference material G1 outputs the deceleration rate αmax to the acceleration/deceleration rate setting circuit 14.

When the deceleration and stop detection signal is not output from the deceleration and stop timing generation circuit 19, the speed reference generation circuit 12 operates according to the above-mentioned (max) and (2).

Select and output VmaX from the standard transport speed VmaX
The reference material G1 is transported.

Next, when a deceleration signal is output from 19, the speed reference generation circuit 12 changes from VmaX to V.

to output VC.

At the same time, the acceleration/deceleration rate setting circuit 14 outputs the deceleration rate αmax.

In this way, from the point d1 in FIG. 4, the reference material G1 has a deceleration rate αmax and a speed VmaX less than VmaX.

is decelerated towards. Low speed V.

When the reference material G1 is decelerated to
2 switches to O output, and the material conveyance speed is V.

It is decelerated from 0 to speed and stops.

The above is the operation when the machine is operated at the normal standard conveyance speed and standard acceleration/deceleration rate.

However, the coefficient of friction between the material 4 and the conveyor belt 3 is μ.

Then, when αmax>lLog, g; When acceleration/deceleration is performed at the gravitational acceleration/deceleration rate αmax, the acceleration/deceleration is too large and slipping occurs between the material 4 and the conveying table 3.

Therefore, in order to prevent slipping, the acceleration/deceleration rate α
α=μ from α−amax.

It is necessary to change to 2.

Further, it is clear that acceleration/deceleration cannot be performed at an acceleration/deceleration rate that requires an acceleration/deceleration torque greater than the maximum output torque of the electric motor for driving the transport chiffle.

Therefore, when the weight per unit length of the material is W, the constant determined by the inertia of the machine is WM, and the maximum acceleration/deceleration rate determined by the maximum output torque of the drive motor is αM, αM- W + WM However, since it can be written as K constant number , the acceleration/deceleration rate α needs to be set to α.

W+WM From the above, the acceleration/deceleration rate α is)αmaX)μogsK/W+W
It is necessary to set the acceleration/deceleration rate to the smallest value of M.

Also, the lower speed V than the start of deceleration. Let l be the distance that material 4 travels until it reaches
In other words, it is desirable that the distance be equal to the distance between the deceleration timing device detector 5 and the stop timing position detector 6.

Letting this constant value of e be v = 2 a l! 6 + VC” However, V:
The relationship between the conveyance speed before deceleration holds true.

Therefore, acceleration/deceleration rate α=μ.

2, f7+v" K v-logo c 1 α=, then W+
WM v=7IJ□ + VC" 2 Conveying speed v wo W + WM If set, the distance from the start of deceleration to the slow speed will be approximately constant l.

It can be kept at Returning to Figure 3 from the above explanation,
In FIG. 3, the friction coefficient setting circuit 16 sets the friction coefficient μ.

uses a variable resistor or digital switch as a component,
Set in advance.

Similarly, in the material weight per unit length setting circuit 17, the material 4
The weight per unit length Bw is set in advance using a variable resistor or a digital switch as a component.

In the speed reference generation circuit 12, '/max + lLo y
W rV (from the information of JT sword; = 107 - "W + WM ""'" value is determined by calculation or polygonal line approximation, etc. Vma The smallest value is outputted to the input limiting circuit 13 as a transport speed setting standard.

Next, when the deceleration signal is output from 19, the output of the speed reference generation circuit 12 is the low speed reference V.

Switch to . At the same time, in the acceleration/deceleration rate setting circuit 14, αm
axsμO) From the information of W, α”a” ltO” W+
The WM is calculated and compared, and the smallest value is selected and output to the input limiting circuit 13 to limit the acceleration/deceleration rate.

As a result of the above, the distance of the material traveling during deceleration can be maintained substantially constant without causing any slippage between the material 4 and the conveying table 3.

Figure 5 shows material G with a small weight per unit length as material 4.
1 and the large material G2, the conveying speed is set to the maximum speed of the conveying table.

Then, the acceleration/deceleration rates of the two are made different, and with respect to the deceleration timing signal d of the material detector 5 for deceleration timing,
The actual deceleration signal is shifted after time T1 for material G1 with a small weight per unit length, and after time T2 for material G2 with a large weight per unit length.
Each finger ◆d1. d2 shows the output of the input limiting circuit 13.

In this way, the acceleration/deceleration rate is determined by the acceleration/deceleration rate setting circuit 14 shown in FIG. 3, based on the weight per unit length of the material 4 and the coefficient of friction, so that the material 4 does not slip on the conveying table.

Also, in the reference generation circuit 12, instead of correcting the signal of the reference conveyance speed setting circuit 15 based on the weight per unit length and the friction coefficient, the actual deceleration signal is adjusted by receiving the signal from the deceleration timing generation circuit 19. By doing so, the distance that the material travels from the actual deceleration to the completion of deceleration can be kept approximately constant even if the weight per unit length of the material and the coefficient of friction change.

That is, in FIG. 5, the actual deceleration timing time is T1 from the generation timing of the deceleration timing generation circuit 19 at the time of the reference material and the standard friction coefficient, and the distance traveled by the material from the actual start of deceleration to the completion of deceleration is 11, The actual timing for weight per unit length and coefficient of friction is T
2. The distance the material travels from the start of deceleration to the end of deceleration is 12
Then, T I V□ + 4 = T 2 V□
+12 stands.

As a result, T2=TI ’・−′・ O Vo: Material speed before start of deceleration From this, the actual deceleration timing is calculated.

In addition, when the acceleration/deceleration rate is changed depending on the weight per unit length of the material as shown in Figures 4 and 5, the distance from when the stop command is issued by the material detector 6 until the material actually stops changes as shown by the hatched area in FIG. 4, which may be inconvenient when high stopping accuracy is required.

To avoid this, use the stop finger ◆h1 as shown in Figure 6.
．． A distant relationship can be achieved by keeping the deceleration rate 11s12 constant from h2 to stop.

In this case, the deceleration rate from the stop command to the stop is the third
If the acceleration/deceleration rate calculated by the acceleration/deceleration rate setting circuit 14 in the figure is used, it will be the same as the acceleration/deceleration rate during deceleration, and the deceleration rate will not be constant depending on the material.

In order to keep the acceleration/deceleration rate constant when stopping, when a stop timing command is issued by the deceleration/stop timing generation circuit 19, the acceleration/deceleration rate setting circuit 14 switches to a fixed acceleration/deceleration rate, and inputs the fixed value to the input limit circuit 13. Output to .

This fixed acceleration/deceleration rate is set in advance as a fixed number in the acceleration/deceleration rate setting circuit 14.

This value is set so that no slippage occurs on any material.
The acceleration/deceleration rate at which no slipping occurs even when the weight per unit length of the material is the largest and the coefficient of friction is the smallest within the range of use is determined by calculation, and that value is set in advance.

According to the present invention described above, it is possible to provide a positioning control device that requires only a conventional material detector for deceleration/stop timing and can perform stop control relatively easily and accurately without using a special device detector. can do.

[Brief explanation of drawings]

FIG. 1 is a diagram explaining a processing process line using a conveyance table, FIG. 2 is a time-speed curve diagram of the conveyance table in FIG. 1, FIG. 3 is a block diagram of an embodiment of the present invention, and FIG. 6 through 6 are time-output curve diagrams showing different set outputs according to the same embodiment. 1.2...processing line, 3...conveyance table, 4.
...Material, 5...Position detector for deceleration timing, 6.
...Stop timing position detector, 11...1 drive device, 12...speed reference generation circuit, 13...input restriction circuit, 14...acceleration/deceleration rate setting circuit, 15...reference transport speed Setting circuit, 16...Friction coefficient setting circuit, 17.
... Weight setting circuit per unit length of material, 18 ... Reference acceleration/deceleration rate setting circuit, 19 ... Deceleration/stop timing generation circuit.

Claims (1)

[Claims] 1. A drive device that drives a conveyance table, a deceleration timing position detector and a stop timing position detector arranged along the conveyance table, and performs stop positioning of the material conveyed by the conveyance table. , a reference conveyance speed setting circuit provides the maximum speed and low speed after deceleration for the reference material and the reference friction coefficient, a reference acceleration/deceleration rate setting circuit sets the acceleration/deceleration rate, and sets the weight per unit length of the conveyed material. A weight per unit length setting circuit, a friction coefficient setting circuit that sets the friction coefficient between the material and the conveyance table, and normally output the values set by the reference conveyance speed setting circuit and the reference acceleration rate setting circuit, and at the same time output the values set by the reference conveyance speed setting circuit and the reference acceleration rate setting circuit. A speed reference generation circuit that predicts the slip between the material and the conveyance table from the settings of the material weight per unit length setting circuit and the friction coefficient setting circuit and sets the conveyance line speed, and an acceleration/deceleration rate setting that sets the acceleration/deceleration rate of the conveyance line. The circuit receives the outputs of the speed reference generation circuit and acceleration/deceleration rate setting circuit as input, generates a speed reference output corresponding to the output of the speed reference generation circuit, and when the output of this speed reference generation circuit changes, the acceleration/deceleration setting circuit sets the speed reference output. a positioning control device, comprising: an input limiting circuit that limits the speed reference output at a given acceleration/deceleration rate, and supplies the speed reference output to the drive device.