JPH08626B2 - Cutting amount control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is intended to cut out raw materials from a lower end opening of a storage tank such as a hopper, silo, bottle, bunker or the like for storing powdered raw materials such as ores. The present invention relates to a cutting amount control device in a cutting device including a gate and a feeder.

[Conventional technology]

A conventional general cut-out amount control device has a cut-out gate and a feeder arranged at the lower end opening of a storage tank, and has a motor for driving the feeder and a sliderac which is a variable voltage device for changing the primary voltage of the motor. It has. In this conventional general cut-out amount control device, the pressurization voltage to the motor is changed by the operation of the slidac, thereby changing the frequency of the feeder to change and adjust the cut-out amount of the raw material in the storage tank.

The conventional general cutting-out amount control device described above determines the cutting-out amount based on the measurement result of the transportation amount measuring device on the downstream side, and directly or remotely operates the sliderac via the pilot motor to control the motor. Since it is a manual control that the primary voltage, that is, the cutout amount is appropriately adjusted, there is a problem that the adjustment takes time and the control accuracy is poor.

FIG. 6 shows the relationship between the cutout amount for each material brand and the primary voltage of the motor with the gate opening kept constant. From FIG. 6, it can be seen that the primary voltage of the motor is constant. However, there is a problem that the amount cut out varies depending on the type of raw material, the humidity, the level of raw material in the storage tank, etc.When trying to keep this constant, it is necessary to constantly monitor the measured value, which is the transport amount in the transport amount measuring device. In addition, since the sliderac must be finely adjusted according to the change in the measured value, there is a problem that the operation becomes complicated.

As a means to solve these problems, as shown in FIG. 10, the feed tank 4 which is provided with the gate 3 at the lower end opening of the storage tank 1 storing the raw material 2 is cut out so as to measure the cut amount. A weighing signal detected by a transportation amount measuring device 7 provided in the middle of a belt conveyor 5 that conveys the raw material 2;
The subtractor 8 calculates the deviation from the cut-out amount setting signal set by the cut-out amount setting device 11, and PI is set to make this deviation zero.
A variable voltage variable frequency device which is a power supply device of the motor 6 as a drive source of the feeder 4 by performing a PID feedback control calculation by the D controller 9 and using the result as a feedback control signal.
There is a control means for inputting to 10 (JP-A-61-106334).

[Problems to be Solved by the Invention]

In the means disclosed in Japanese Patent Laid-Open No. 61-106334, although labor saving of the operation adjustment of the operator can be achieved to some extent, various settings of the PID feedback control can be made for the type of raw material 2 and the raw material 2. In addition to the harmful effect that fine tuning work must be performed in accordance with changes in humidity, raw material level in the storage tank 1, etc., the deposition state and flow state difference and change of the raw material 2 in the storage tank 1 due to the shape of the storage tank 1 and the feeder 4 It is not possible to exert effective controllability with respect to the difference in the cut-out characteristics and the change in the opening of the gate 3.

That is, in PID feedback control, the optimum control constant for minimizing the disturbance superimposed on the weighing signal does not always match the PID value that provides the optimum follow-up performance with respect to the change in the setting value. It is said that it is difficult to make an adjustment to satisfy the above conditions at the same time, and it is said that it is extremely difficult to obtain a high degree of control accuracy even when controlling the amount of cutting out from the storage tank 1 which is a first-order lag system with a large dead time.

Further, the opening degree of the gate 3 is appropriately adjusted according to the brand of the raw material 2 and the target cutting value, based on the operator's conventional experience and intuition, although this is a factor that greatly influences the cutting amount.

Taking the brand A in FIG. 6 and obtaining the change in cutting amount using the gate opening as a parameter, the characteristics are as shown in FIG. As is clear from the characteristics shown in FIG. 7, it is understood that the gate opening largely controls the change in the cutting amount, and the gate opening can be adjusted by changing the frequency of the feeder 4 if the opening is small. That is, in FIG. 7, the cutting amount
To obtain Wk, the gate opening may be 70% and the primary voltage of the motor 6 may be Vk.

However, it is not easy to find the optimum combination of the gate opening and the primary voltage. For the primary voltage
Although a certain degree of automatic adjustment can be made by forming a PID feedback system with the PID controller 9, the gate opening can be set by the operator by trial and error for a long time because there are 400 kinds of brands of raw material 2. Was to be required.

For example, in FIG. 7, assuming that the initial indication point was at the point with the gate opening of 90% in order to obtain the cutout amount Wk, after the indication point was lowered to the lower limit point by lowering the primary voltage, Since it is larger than the cutout amount WK, change the gate opening to 50% and move to the point while keeping the primary voltage.
Since the cutout amount W at this point is smaller than the cutout amount WK, the primary voltage is raised and shifted to the point, but since the cutout amount W at this point is still smaller than the cutout amount WK, the primary voltage is left as it is. The gate opening is changed to 70%, and the operation moves to a point where the primary voltage is lowered to find a point where the target cutting amount Wk can be obtained, which is an extremely troublesome operation.

Basically, the gate opening is determined by the brand of the raw material 2, but in the short term, fine adjustment is required due to changes in the water content of the raw material 2, the cutting characteristics of the feeder 4, and the like. It is extremely difficult to perform a determination process in a short time based on the experience and intuition of the operator. Even if the control of the gate opening is automated, the basic setting for each brand of the raw material 2 is easy, but the water content of the raw material 2 in the short term,
It is extremely difficult to reflect changes in the cutting characteristics of the feeder 4 and the like.

In other words, in controlling the amount of raw material cut out from the storage tank, there are process variations such as the type of raw material, the humidity of the raw material, and the raw material level in the storage tank. Correspondence with the shape of the storage tank, the difference in the cutting characteristics of the feeder, and the gate opening However, it is required to save labor in operation and tuning work and to obtain high control accuracy after overcoming the problem that it is possible to achieve flexible adjustment with respect to disturbance suppression and set value change followability. In addition to this, it is required that fine adjustment of the gate opening can be performed in response to short-term changes in the water content of the raw material, the cutting characteristics of the feeder, and the like.

Generally, the transient characteristics of material cutting by the feeder are
As shown in FIG. 8, it is possible to approximate with a system of a large dead time TL and a first-order delay time T. The PID calculation formula for optimally controlling this system by the PID feedback control method is m (t) = 100 / PB · {1 / TI · ∫e (t) dt + e (t) +
TDde (t) / dt}. Note that m (t) is an operation output, PB is a proportional term, TI is an integration time, TD is a differential time, and e (t) is a control deviation.

PID set values that are PB, TI, TD in the above equation are FP, F
If I and FD are functions that find the optimum values of PB, TI, and TD, they are expressed as follows.

In terms of differences in raw material brands, particle size, specific gravity, humidity, raw material level in storage tanks, storage tank shape, feeder cutting characteristics, and gate opening, process K, T , TL value changes. On the contrary, in order to be able to obtain flexible adjustments for both disturbance suppression and set value change followability, the PID set values PB, TL, T
It is necessary to change D.

From this, it is understood that in controlling the amount of raw material cut out by the feeder, it is necessary to directly change the PID set value in order to respond to the change in the characteristics of the process and for flexible adjustment.

In addition, it is very difficult to calculate and calculate the appropriate initial gate opening based on the difference between the target cutting value and the brand of raw material, the moisture content of the raw material, the change in the cutting characteristics of the feeder, etc. using a mathematical model. As mentioned above, if we look at one job from the start to the end of cutting from a given storage tank for one raw material brand by changing the fulcrum, there may have been trial and error control at the end of that cutting. Finally, the gate opening should be the optimum value.
Therefore, if the learning control for sequentially accumulating and reflecting the most effective experience value on the initial gate opening of the next job is performed, the effective gate opening can be controlled.

The present invention has been devised to solve the above-mentioned problems in the prior art and meet the demands of the prior art, and achieves labor saving of operation and tuning work,
The purpose is to significantly change the PID set value in order to respond to changes in process characteristics and to make flexible adjustments, and to obtain a high degree of control accuracy of the amount of raw material cut out by the feeder.

Another purpose is to calculate and control an appropriate initial gate opening corresponding to the cut-out target value by learning control, using the past experience of controlling the gate opening for each brand of raw material as the most effective experience value. .

Furthermore, another object is to obtain a higher degree of control accuracy of the amount of material cut out by giving arithmetic control of the initial gate opening in addition to PID setting control for the PID controller.

[Means for Solving the Problem] Means of the present invention for achieving this object, means for adjusting and setting the feedback control signal output from the PID controller, means for calculating and controlling an appropriate initial gate opening, There is a means that organically combines both means.

The means for adjusting and setting the feedback control signal from the PID controller is the amount of cutting out of the granular material stored in the storage tank through the gate and the feeder. It is a cutting amount control device that performs PID processing of the deviation value with a PID controller and inputs it as a feedback control signal to the drive source of the feeder.PID aptitude value registered in advance from the material brand and storage tank number is extracted and the PID basic setting is made. Value influence signal, a search signal that corrects the PID basic set value according to the process identification result at startup, and a temporary operation instead of the correction calculation by the search signal when the control value becomes unstable when the deviation value increases during control. Forcibly intervenes to generate a deviation signal that causes the PID basic established value to be calculated according to the deviation value, and forms a PID setting value that performs stepwise control and outputs this PID setting value to the PID controller. That PID
Providing a setting calculation device.

In addition, the means for calculating and controlling the appropriate initial gate opening, the cutting amount of the granular material stored in the storage tank through the gate and the feeder, the amount of raw material cut out and the set cutting amount The deviation value should be PID processed by the PID controller and input to the drive source of the feeder as a feedback control signal, and it should be installed together with the cutting amount control device.The gate opening ratio at the end of the job should be calculated. From the result and the initial gate opening ratio at the start of the job, the initial gate opening ratio of the same brand group of raw materials in the next job is calculated by exponential averaging and stored for each brand group of raw materials, and the bulk density and Based on the corners, each raw material is divided into multiple brand groups, the corresponding brand group is selected according to the brand designation of the raw material, and the stored initial gate opening ratio of this brand group is set. In addition to setting the initial gate opening degree for the next job from the extracted initial gate opening ratio, a gate control device is provided to perform the subsequent correction opening / closing control of the gate by the signal from the PID controller. is there.

The means that organically combines both means determines the amount of powdered granular material stored in the storage tank through the gate and feeder, and the deviation value between the amount of raw material cut out and the set amount of cutout. It is a cutting amount control device that performs PID processing by the PID controller and inputs it to the drive source of the feeder as a feedback control signal, extracts the preregistered PID aptitude value from the brand of the raw material and the tank number, and sets it as the PID basic set value. PI based on the influence signal that causes it and the process identification result at startup
D Search signal for correction calculation of basic set value and PI control depending on deviation value by temporarily intervening instead of correction calculation by search signal when control becomes unstable during deviation of control value
D Form a PID set value that emits a deviation signal to perform correction calculation of the basic set value and performs stepwise control, and then use this PID set value.
Providing a PID setting calculation device that outputs to the PID controller, calculates the gate opening ratio at the end of the job, and calculates the raw material for the next job from the calculation result and the initial gate opening ratio at the start of the job. The initial gate opening ratio of the same brand group is calculated by exponential averaging and stored for each brand group of raw materials, and each raw material is divided into multiple brand groups based on the bulk density and angle of repose, and the raw material brand is designated. Select the corresponding brand group according to the above to retrieve the stored initial gate opening ratio of this brand group, set the initial gate opening ratio of the next job from this retrieved initial gate opening ratio, and There is a gate control device for carrying out the correction opening / closing control of 1) by a signal from the PID controller.

[Action]

The means for adjusting and setting the feedback control signal from the PID controller is to establish the PID basic by extracting the optimum value from a large number of PID aptitude values registered in advance corresponding to the brand of the raw material and the tank number by the influence signal. This extracted PID basic set value is corrected and calculated as the PID set value according to the process identification result at startup obtained by the search signal, and only when the deviation becomes large during control Instead of the correction calculation according to the process identification result at startup obtained from the search signal, the deviation value obtained from the deviation signal is temporarily forcibly intervened to directly change the PID value and set the PID basic established value to PID. Since correction calculation is performed on the set value, the influence signal for the type of raw material, the humidity of the raw material, the search signal and the deviation signal for the raw material level in the storage tank are used to determine the storage tank shape, feeder cutting characteristics, and The respective differences impact signal for DOO opening and the search signal, and for flexible adjustment of the setting value changing followability of both a disturbance suppression and thus be controlled by the deviation signal, always high control accuracy. Moreover, since these controls are performed automatically, no operation or tuning work is required.

That is, setting the PID basic setting value by the influence signal,
The process identification process and the PID set value are performed by performing stepwise control that performs correction calculation of the PID basic set value to the PID set value by the search signal and forced change of the PID value in the PID basic set value by the deviation signal in stages. Perform the adjustment process in parallel,
The control system is set to work at all times, and the convergence process is performed so that the performance improves as the adaptation process progresses, and the convergence process is made as fast as possible.

Further, the means for calculating and controlling the appropriate initial gate opening is
At the time of stop, the gate opening ratio at stop is calculated from the time until the gate is fully opened at the end of the specific job of the target stock group and the target cutout amount, and this gate opening ratio at stop and the initial gate at the start of the same job The opening ratio and the initial gate opening ratio at the start of the next job are calculated by exponential averaging.

When a job of a specific brand group is specified, the initial gate opening ratio corresponding to this brand group is called, and the initial gate opening is obtained from the cutting amount target value from the cutting amount setting device. The specific initial gate control of the gate is performed according to the initial gate opening obtained as above.
Then, the final measurement result of the gate closing time is sequentially accumulated and learning control of the gate opening is performed.

That is, by calculating the initial gate opening ratio at the start of the next job by exponential averaging from the gate opening ratio at stop and the initial gate opening ratio at the start of the job, the cutting target value and the material brand It is possible to follow not only the difference in water content but also short-term changes in the water content of the raw material and changes in the characteristics of the feeder.

And, means for organically combining both means, that is, means for adjusting and setting the feedback control signal from the PID controller, and means for arithmetically controlling the proper initial gate opening,
The operation of both of the above-mentioned means is performed independently at the initial stage of driving when the control tends to become unstable, and the correction calculation of the PID basic set value to the PID set value by the search signal due to the gate opening setting error is always good. In this way, the control is stabilized early in the driving. Further, in the forced control by the deviation signal, the opening / closing of the gate is directly controlled to significantly improve the set value change followability.

〔Example〕

 Hereinafter, the present invention will be described with reference to the drawings.

FIG. 1 shows the basic circuit configuration of the means for adjusting and setting the feedback control signal from the PID controller. The raw material cutting device is the same as before, in the lower end opening of the storage tank 1 containing the granular raw material 2. A raw material cutting feeder 4 driven by a motor 6 via a gate 3 is provided, and a belt conveyor 5 is provided for conveying the cut raw material 2 to a desired location.

The cutting amount control device assembled to this cutting device is
A delivery amount measuring device 7 which is provided in the middle of the feed path of the raw material 2 formed by the belt conveyor 5 and directly measures the transport amount of the raw material 2 that has been cut and transported, and a cutout amount setting device including a CRT or the like. 11 and the target amount of cut SV set by the amount of cut setting device 11 and the transportation amount measuring device 7 which is the actual amount of cut.
Of the transport amount PV of the subtractor 8, a PID controller 9 for PID control by the output from the subtractor 8, and the PI
It is composed of a variable voltage variable frequency device 10 for controlling the motor 6 with a variable voltage variable frequency proportional to the control output MV by a control output MV which is the output of the D adjuster 9, and a PID setting arithmetic device 13. In the I / F section between each device, A / D or D /
A conversion etc. is performed, but this is omitted.

The PID setting calculation device 13 receives the brand of the raw material 2 and the tank number from the input device 12 and calculates the PID basic set value, and the influence signal calculation device 14 to the control output MV by the adder 19 from the search signal generation device 16 The search signal of is forcibly superimposed at startup, and the bounce for that process is identified by the transport amount PV, and according to this process identification result.
Search signal calculation device 15 for correction calculation of PID basic set value
And the subtractor 8 which is the deviation between the target cutting amount SV and the transport amount PV
Deviation signal calculation device 17 for performing the temporary forced intervention calculation to the PID basic set value when the deviation value becomes a certain value or more by taking in the output of the output signal, the influence signal calculation device 14 and the search signal calculation device 15 And PID value setting device 18 for stocking the operation results of the deviation signal operation device 17 and designating the PID set value which is the operation result to the PID controller 9.

Next, the operation of the embodiment shown in FIG. 1 will be described with reference to FIG.

From the input device 12, the brand of the raw material 2 (type and grain size of the raw material 2) and the storage tank number (the storage tank number also determines the characteristics of the feeder 4), which are the largest factors that determine the process characteristics according to the influence signal, are input. take in. That is, by designating the brand of the raw material 2, the corresponding brand group is selected from the brand groups divided into six according to the bulk density and the angle of repose of about 400 brands, and the selected brand group is input. The optimum PID set value that matches the specified brand and storage number is extracted from the stored storage number and the set value table registered in advance as the PID basic set value.

Then, with the search signal from the search signal generator 16 kept the gate 3 at a constant opening degree, the kick start with the control output MV forcibly set to the maximum value is taken for a certain time, and the process as shown in FIG. That is, process identification is performed by observing the rebound reaction of the transport amount PV. That is, every time it is started, the actual process dead time TL, the first-order lag time T, etc. are actually measured to obtain the process identification result, and the calculation based on the formula (1) previously determined based on the process identification result. The above PID basic set value is corrected and calculated to calculate the PID set value. In this way, the search signal forcibly maximizes the control output MV for a certain period of time t, and performs process identification from the transport amount PV corresponding to this, for example, the raw material 2 due to clogging of the gate 3 Is not discharged and dead time TL,
The first-order delay time T becomes an abnormally large value, and the correction calculation also outputs an abnormal value, which may cause the PID control to run away. Therefore, as shown in FIG. 4, a rationality check called process identification OK is performed, and a correction operation is performed only when the check result is valid. Needless to say, the PID feedback control with the calculated PID set value is promptly made after the lapse of a certain time t after the start-up, and the actual transport amount PV is slightly different as shown in FIG. After the overshoot of, the target cutout amount SV will match.

If the deviation value becomes large during the PID feedback control according to the PID setting value set by the influence signal and the search signal and it is determined that the control is unstable, the deviation signal is used instead of the correction by the search signal. The proportional term PB and the integration time TI are forcibly and strongly changed into a safe area by the direct correction of the PID basic set value by. If the deviation value enters the safe area, the PID corrected and calculated by the base search signal quickly to prevent the harmful effects such as continuous vibration.
Return to the set value.

That is, the principle of the PID setting calculation of the present invention is that even if the PID basic setting value is fixed by the influence signal and the process identification by the search signal fails and the correction calculation cannot be performed, almost stable control can be obtained. I am allowed to do so. Therefore, in the correction calculation using the search signal, each term of the PID basic set value is not changed significantly. On the other hand, in the deviation signal, each term of the PID basic set value is directly changed to a large extent, thereby achieving early stabilization of the system.

The setting values and coefficients for various calculations in the above embodiment are approximately 950.
Fine control is achieved by this, and the followability of the cut-out target value can be obtained for about 30 seconds, and the disturbance suppression has a control accuracy of about ± 1% or less (± 15T / H). I was able to.

FIG. 2 shows a basic circuit configuration of a means for calculating and controlling an appropriate initial gate opening. Suffixes "i" indicate each brand group, and 1 to 6 groups are provided. The suffix indicates a time-series job transition for each brand group.

The gate control device 20 assembled in the PID feedback control system includes a gate opening / closing control device 26, a stop gate opening ratio calculation device 22, an initial gate opening ratio calculation device 24, and an initial gate opening ratio storage device 25. And the initial gate opening calculation device 23
And a brand file device 21 having a built-in input section.

In the gate opening ratio calculation device 22 at the time of stop, the gate closing time Tcij until the gate is fully closed at the end of the job j of the brand group i is fetched from the gate opening / closing control device 26 and the target cutout at that time is taken out. The amount Wcij is taken in from the cut-out amount setting device 11, and the gate opening ratio tcij at stop is calculated by the following arithmetic expression. The target cutout amount Wcij may be a measured value from the transportation amount measuring device 7.

tcij = Tcij / Wcij That is, the gate opening ratio at stop is calculated as the gate closing time per target cutting amount. Gate opening ratio at stop
The target cutout amount was calculated from tcij from the gate closing time Tcij.
In order to obtain Wcij, it can be said that it is optimum to open the gate 3 on the contrary for Tcij time from full opening.

In the initial gate opening ratio calculation device 24, the gate opening ratio tcij at stop and the initial gate opening ratio to when the same job is started to
ij and ij are fetched from the initial stage gate opening ratio storage device 25 of the next stage, and the initial gate opening ratio toi (j + 1) at the start of the next job (j + 1) of the brand group called i is calculated by the following formula. .

toi (j + 1) = α · toij + (1-α) tcij The above formula is an exponential averaging operation, and it means that the latest stop gate opening ratio tcij and the initial gate opening ratio toij The initial gate opening ratio toi (j + 1) for the next job is determined based on the actual result. From this, it can be said that the initial gate opening ratio toij is the result of sequentially accumulating the cumulative learning calculation results up to now. α is
It is a coefficient to prioritize either the latest latest data or past cumulative data. By selecting a value from 0 to 1, short-term changes in the water content of the raw material 2, the characteristics of the feeder 4, etc. can be followed. be able to.

The initial gate opening ratio toi (j + 1), which is the result calculated by the initial gate opening ratio calculating device 24, is the initial gate opening ratio storage device for each brand group i until the next job of the same brand group i occurs. Stored at 25.

The brand group i of raw material 2 is selected by the brand file device.
This can be achieved by setting one of the 400 brands classified in the brand input section built into the 21.
Actually, the transmission is designated by the host computer. The brand classification of the raw material 2 in the brand file device 21 is performed by the brand group i having the same raw material properties according to the bulk density and the angle of repose.
Are summarized in. When the job of the next brand group called i is designated in this brand file device 21, this designation signal is transmitted to the initial gate opening ratio storage device 25 and the initial gate opening ratio toi (corresponding to the brand group i is stored. j +
1) is called and transmitted to the initial gate opening calculation device 23, and the cutting-out amount target value Woi (j + 1) of the next job (j + 1) from the cutting-out amount setting device 11 is separately sent from the initial gate opening calculation device 23. The initial gate opening Toi is transmitted to the arithmetic unit 23.
(J + 1) is calculated by Toi (j + 1) = toi (j + 1) × Woi (j + 1). This calculation is nothing but obtaining the actual initial gate opening time by multiplying the opening ratio by the cutout amount.

The gate opening / closing control device 26 includes an initial gate opening degree calculation device 23.
The specific initial gate opening control of the gate 3 is performed according to the initial gate opening Toi (j + 1) calculated in. This gate opening / closing control device 26 receives a command from the PID adjuster 9 when the transportation amount PV deviates from the appropriate adjustment range in the PID control and reaches the upper and lower limits of the adjustment range due to the subsequent change in the extraction amount target value. The gate 3 is controlled to open and close.

Therefore, as a matter of course, the gate opening time and the gate closing time are different at the start and end of the same job. Then, the final measurement result of the gate closing time is fed back to the stop gate opening ratio calculation device and sequentially accumulated to perform the gate opening learning control.

The gate opening / closing control device 26 can be given a manual correction command from the manual gate opening / closing setting device 27. Further, in the above embodiment, the gate opening degree control is controlled by the opening or closing time of the gate 3, but it may be directly performed by the opening degree position control of the gate 3.

FIG. 9 shows an example of a flow in which the gate control device 20 is repeatedly processed in sequence.

FIG. 3 shows a basic circuit configuration of means for organically combining means for adjusting and setting a feedback control signal from the PID controller and means for arithmetically controlling an appropriate initial gate opening. 2 and the configuration of the embodiment shown in FIG.
This is a combination of the configurations of the illustrated embodiment.

In the embodiment shown in FIG. 3, the control operations of the embodiments shown in FIGS. 1 and 2 are individually and combined to be carried out. In the state in which the gate 3 is forcibly and temporarily set to the constant opening degree by the search signal of, the kick start in which the control output MV is forcibly set to the maximum value is taken for a certain period of time, and then the initial gate opening calculation device 23 is set. Follow the gate opening. From this state, when the transport amount PV deviates from the proper adjustment range in the PID control and reaches the upper and lower limits of the adjustment range, the gate 3 is controlled to open and close by a command from the PID adjuster 9.

〔The invention's effect〕

Since the present invention has the above-mentioned configuration, the following effects can be obtained.

Correspondence between the amount of raw material cut out from the storage tank by the feeder, the type of raw material in the storage tank, the humidity of the raw material, the process variation such as the level of the raw material in the storage tank, the shape of the storage tank, the difference in the cutting characteristics of the feeder, and the gate opening. The cut-out amount can be adjusted with high accuracy by flexibly responding to both disturbance suppression and followability to change of set value.

The above-mentioned adjustment of the cutting amount can be achieved automatically and while maintaining high reliability.

Optimized adjustment values with high accuracy, such as response to changes in plant operation level due to social situation of resource saving and energy saving, demand for better control from operation that is stable, loop adjustment for difficult processes, etc. You can definitely achieve it.

Since it is difficult to use the optimal adjustment suppression theory in the field of process control, the adjustment work was trial and error, so it took a long time to make adjustments, and there were individual differences in the adjustment results.
Adjustments must be completed with room for improvement, and an automated system that can be used in the field to solve this problem was desired, but the above requirements must be met by achieving automation of control parameter adjustment work. You can

In a process in which the process characteristics change greatly depending on the operating condition level, etc., it is required to follow the changes and automatically adjust the parameters to maintain stable control performance. Accurate tracking can be achieved.

By implementing the present invention, the plant operation is not significantly disturbed, the tuning is not disturbed by the disturbance and noise added to the process, and the dynamic characteristics of the process are followed, so that the tuning can be performed quickly in a short time.

Since the initial gate opening is set to the optimum value calculated according to the past optimum value corresponding to the type of raw material and the target cutting value, it is possible to make the control in the initial stage of operation, which is prone to control instability, extremely stable. it can.

It is possible to flexibly cope with different brands of raw materials, different moisture contents of raw materials, changes in cutting characteristics of the feeder, and the like.

Together with PID control by process fluctuation and change of set value, the gate opening is directly controlled in the state of being driven by this PID control, so more stable operation of initial control can be obtained and large deviation can be prevented. It is possible to respond promptly, and thereby an extremely stable operation can be obtained.

In particular, according to claim 3, the correction calculation to the PID basic set value by the search signal due to the gate opening setting error can always be satisfactorily achieved at the early stage of driving when the control tends to be unstable, so that early stage of driving can be performed early. The control can be stabilized. Further, in the forced control by the deviation signal, the opening / closing of the gate is directly controlled to dramatically improve the followability to the change of the set value.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a basic circuit configuration of the first device of the present invention. FIG. 2 is a block diagram showing an example of the basic circuit configuration of the second device of the present invention. FIG. 3 is a block diagram showing an example of the basic circuit configuration of the third device of the present invention. FIG. 4 shows a flowchart of the operation in the embodiment shown in FIG. FIG. 5 is a characteristic diagram showing the change characteristic of the actual cut-out amount with respect to the search signal in the embodiment shown in FIGS. 1 and 3. FIG. 6 is a characteristic diagram showing the relationship between the primary voltage of a general feeder driving motor and the cutting amount of the feeder. FIG. 7 is a characteristic diagram showing the relationship between the primary voltage and the cut-out amount with a general gate opening as a parameter. FIG. 8 is a characteristic diagram showing transient characteristics of material cutting by a general feeder. FIG. 9 is a chart showing a processing example in the embodiment shown in FIGS. 2 and 3. FIG. 10 is a schematic diagram showing a circuit configuration of a conventional PID control device. DESCRIPTION OF SYMBOLS 1; Storage tank, 2; Raw material, 3; Gate, 4; Feeder, 5; Belt conveyor, 6; Motor, 7; Transport quantity meter, 8; Subtractor, 9; PID controller, 10; Variable voltage Variable frequency device, 11; Cutting amount setting device, 12; Input device, 13; PID setting calculation device, 14; Influence signal calculation device, 15; Search signal calculation device, 16; Search signal generation device,
17: Deviation signal calculation device, 18: PID value setting device, 19: Adder,
20; Gate control device, 21; Brand file device, 22; Stop gate opening ratio calculation device, 23; Initial gate opening calculation device, 2
4; initial gate opening ratio calculation device, 25; initial gate opening ratio storage device, 26; gate opening / closing control device, 27; manual gate opening / closing setter, MV; control output, PV; transportation amount, SV; target cutting amount , T;
Primary delay time, TL; dead time.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-60-79228 (JP, A) JP-A-57-13016 (JP, A) JP-B 63-10058 (JP, B2)

Claims (3)

[Claims] 1. A cutout amount of a powdery and granular raw material stored in a storage tank through a gate and a feeder, and a deviation value between the cutout raw material amount and a set cutout amount is determined by a PID controller by a PID controller. In the cutting amount control device for processing and inputting to the drive source of the feeder as a feedback control signal, an influence signal to extract a pre-registered PID suitability value from the brand of the raw material and the storage tank number and a PID basic set value, A search signal for correcting the PID basic set value according to the process identification result at start-up, and a temporary forced intervention instead of the correction calculation by the search signal when the control becomes unstable when the deviation value increases during control. Providing a deviation signal for correction calculation of the PID basic set value according to the deviation value, forming a PID set value for performing stepwise control, and providing a PID setting calculation device for outputting the PID set value to the PID controller hand That cut amount control device. 2. A cutting amount of the granular material stored in the storage tank through a gate and a feeder, and a deviation value between the cutting amount of the raw material and the set cutting amount is determined by a PID controller by a PID controller. In the cutting amount control device for processing and inputting as a feedback control signal to the drive source of the feeder, the gate opening ratio at the end of the job is calculated, and the calculation result and the initial gate opening ratio at the start of the job are calculated. From the next job, the initial gate opening ratio of the same brand group of raw materials in the next job is calculated by exponential averaging and stored for each brand group of raw materials, and each raw material is divided into multiple brand groups based on the bulk density and angle of repose. Divide, select the corresponding brand group according to the brand designation of the raw material, take out the stored initial gate opening ratio of the brand group, and execute the next job from the fetched initial gate opening ratio. It sets the initial gate opening, subsequent correction controls the opening and closing of the cut amount control device comprising providing a gate control carried out by a signal from the PID regulator gate. 3. A cutting amount of the granular raw material stored in the storage tank through a gate and a feeder, and a deviation value between the amount of the raw material cut and the set cutting amount is adjusted by a PID controller by a PID controller. In the cutting amount control device for processing and inputting to the drive source of the feeder as a feedback control signal, an influence signal to extract a pre-registered PID suitability value from the brand of the raw material and the storage tank number, and a PID basic set value, A search signal for correcting the PID basic set value according to the process identification result at start-up, and a temporary forced intervention instead of the correction calculation by the search signal when the control becomes unstable when the deviation value increases during control. A PID setting calculation device for forming a PID set value for performing stepwise control by issuing a deviation signal for performing a correction calculation of the PID basic set value according to a deviation value, and outputting the PID set value to the PID controller, The The gate opening ratio at the end of the job is calculated, and the initial gate opening ratio of the same brand group of raw materials in the next job is calculated by exponential averaging from the calculation result and the initial gate opening ratio at the start of the job. Calculated and stored for each raw material brand group, each raw material is divided into a plurality of brand groups based on the bulk density and angle of repose, and the corresponding brand group is selected according to the designation of the raw material brand, and the brand group is stored. A gate that takes out the initial gate opening ratio, sets the initial gate opening for the next job from the extracted initial gate opening ratio, and executes the subsequent correction opening / closing control of the gate by the signal from the PID controller. A cutout amount control device comprising: a control device.