JPH0215314A - Measure control device - Google Patents

Abstract

PURPOSE:To rapidly and surely attain highly accurate measure without using an expensive liquid control valve by adjusting air pressure in a tank on the basis of fuzzy inference. CONSTITUTION:When measure is started, a weight measuring part 10 in a control part 9 inputs a weight value outputted from a weighing machine 4. A fuzzy inference part 11 infers the control data of a control regulator 6 so that a flow rate corresponds to the time-flow rate limit function of liquid by fuzzy inference on the basis of measuring weight, a flow rate and a set value. An output control part 12 regulates the regulator 6 on the basis of the control data. Then, the measuring part 10 is returned to the reading operation of the output from the weighing machine 9. When the measuring weight value does not reach the set weight value yet, the fuzzy inference is started again, but at the time of arriving at the measuring weight value, the measure of the liquid feed is ended.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a metering control device particularly suitable for metering and supplying highly viscous fluids.

[Conventional technology]

When metering a highly viscous fluid from a tank to a metering container, it is difficult to control the flow due to its viscosity, making the flow rate unstable.Especially if the flow rate is set high for high-speed supply, the flow rate may become unstable when the supply is stopped. The flow rate fluctuates greatly. Therefore, the problem to be solved is to improve the measurement accuracy and at the same time shorten the measurement time. As a solution to this problem, for example, a large flow rate is supplied at the beginning of metering, and a small flow rate is reduced immediately before the end of metering.

Conventional metering and supply methods can be roughly divided into two types: pump type, in which the fluid to be measured is supplied from a tank to a measuring container using a liquid pump; There is an air pressure type that supplies the

For both the pump type and air pressure type, it is necessary to arrange a liquid control pulp in the fluid discharge pipe for highly accurate metering and supply.

[Problem to be solved by the invention]

The liquid control valves used in the conventional supply metering described above are expensive. In the case of mixing and metering, this pulp must be installed in each tank of each fluid, which increases equipment costs.

Furthermore, in the conventional air pressure type, the pressurizing force is constant, and even if controlled by a liquid control valve, the flow rate cannot be controlled according to the set value, resulting in errors. For this reason, it has been difficult to increase measurement accuracy.

SUMMARY OF THE INVENTION An object of the present invention is to provide a metering control device that can shorten the total ft time and improve metering accuracy without using control pulp for liquids, which causes high costs.

[Means to solve the problem]

The basic configuration of the metering control device provided by the present invention is: a fluid tank with a stop valve in the discharge pipe; a control regulator that adjusts the air pressure to pressurize the tank; and a container that receives fluid supply through the stop valve. Then, from the weighing machine that weighs the total weight of this container, the output of this weighing machine, and the current control data of the control regulator, fuzzy inference is performed to shorten the weighing time and improve weighing accuracy, and the control of the control regulator is calculated. The present invention is characterized by comprising a control section that opens and closes a stop valve to meter and supply a predetermined amount of fluid into the container.

In addition, when mixing and weighing multiple fluids, use multiple fluid tanks equipped with stop valves, use a single control regulator and weighing machine, and configure the control unit based on fuzzy reasoning (alternatives of stop valves). The opening/closing and control regulator may be controlled, and the fluid in each tank may be sequentially metered and supplied into the container for mixing and metering.

[Effect]

The control unit calculates the weight and flow rate of the fluid supplied to the container from the weight data output from the weighing machine and the rate of change thereof. Then, the target value of the current flow rate is determined based on a preset liquid time-flow rate function (larger at the start of flow rate measurement and lowered just before the end of metering), and fuzzy reasoning is used to determine the current supply flow rate to the target value. The air pressure is controlled by the control valve so that it reaches .

Then, when the output of the weighing machine reaches the target weight, the stop valve is closed.

〔Example〕

The basic concept of the present invention is to adjust the flow rate of fluid by controlling the pressure of pressurized air using a control pulp, to meter and supply one type of liquid from one tank to a metering container, and to close the stop valve at the end of metering. It is something.

However, in reality, it is often implemented as a mixing and measuring device that supplies predetermined amounts of different liquids from a plurality of tanks to a measuring container and mixes and measures the same.

Therefore, an embodiment in which this mixing and measuring is performed will be described below.

In Figure 1, (1,) (1yo)...(IN)
is a tank of liquid, usually in which different types of liquids (including particularly viscous ones) are stored. (21) (2,
)...(2N) is a stop valve provided on the discharge pipe of each tank, which switches between passing and blocking the liquid. (3)
is a measuring container, each stop valve (21) C2
1> Receives liquid supply through (2N). (4
) is a weighing machine that weighs the ff1ffi of the container (3) together with its contents.
Performs ffi detection and outputs it as an electrical signal. (
5) is a primary air regulator that adjusts the pressure of primary air supplied from an air compressor (not shown), and (6) is a primary air regulator that reduces the pressure of the primary air to become secondary air, which is supplied to each tank (1,) (1 Secondary air control regulator that supplies to (IN), (7) is a secondary air gauge that displays the pressure of secondary air, (8,) (8□)...
(8N) is a switching pulp installed in the secondary air supply pipe of each tank to control the supply/stop of secondary air. (9) is a control unit, including a weight measurement unit (10) and a fuzzy inference unit (11).
) and an output control section (12).
is based on the weight data output every moment from the weighing machine (4).
A tare calculation or the like is performed to calculate the current Ti amount of each liquid currently supplied to the container. The fuzzy inference section (11) calculates the flow rate of the liquid being supplied from the change in the current ffl amount output from the weight measurement section (10). Then, the control pulp (6) is controlled by fuzzy reasoning from the response data to the control values accumulated so far so that the target measurement value of the liquid, the time-flow rate function, and the liquid flow rate follow this function. Calculate data. This control data is sent to the control pulp (6) through the output control section (12).

The operation of the metering control device (13) having the above configuration is performed as follows.

Initially, each tank (L) (t□)... (IH) is filled with a predetermined amount of liquid, and each stop valve (2,) (
2,)...(2N) and each switching pulp (8,) (
8□)...(8M) is assumed to be in a closed state. Here, the ffl amount of each liquid to be mixed and measured is set in the control unit (9), and measurement is started.

A tank containing the liquid to be initially metered, for example (1
1) switching valve (81) and stop valve (2,)
is opened and the liquid inside is pumped with pressurized air into the container (
3). The metering and dispensing of one tank is as shown in the flowchart shown in FIG.

When weighing starts, the weight measuring section (1o) reads the weight value output from the weighing machine (4).

The fuzzy inference unit (11) calculates the tare weight of this ff
Compare the 1ffi amount value and the set weight ffi value of the liquid. If the measured 1i amount value does not reach the set weight value,
The flow rate is calculated from the difference with the previous weighed weight value. Then, based on the measured weight, flow rate, and set weight value, fuzzy reasoning is used to create a time-flow rate control function for the liquid (the supply flow rate is increased at the beginning and decreased just before the end to achieve high precision supply in the shortest possible time). The control data of the control regulator (6) is inferred so that the flow rate corresponds to the flow rate (defined for each type of liquid) so that metering can be performed.

The output control section (12) adjusts the control regulator (6) based on this control data. This causes the pressure of the secondary air to change and the flow rate to change. Then, the operation returns to reading the output of the weighing machine (4) again. The loop up to this point is performed in a short time, for example, 0.2 seconds or less, and a response speed sufficient for control can be obtained.

When the output of the weighing machine (4) is read again, the above-mentioned comparison process between the measured weight value and the set weight value is performed, and the total is ff1T.
If the iffi value has not yet reached the set weight value, fuzzy inference starts again from calculating the flow rate, but if the measured weight value has reached the set weight value, the stop valve (2
, ) and the switching valve (8,) are closed to complete the supply metering of the liquid.

If the liquid to be metered and supplied next is, for example, a tank (1,), its switching valve (8t) and stop valve (2,
Open the door and measure and supply the liquid using the same procedure as above.The weight measurement at this time is based on the output of weighing scale a(4).
This is done by taring the weight value immediately before the start of the measurement.

Furthermore, each of the liquids to be mixed and supplied is metered and supplied in order from each tank. As a result, it is possible to mix and measure a plurality of liquids at high speed and with high accuracy at the mixing ratio and mm initially set in the container (3).

〔Effect of the invention〕

Since the present invention adjusts the air pressure in the tank using fuzzy reasoning, highly accurate metering can be performed quickly and reliably.

In particular, when dispensing multiple liquids, flow control
This can be done with a single air control valve and a control unit using fuzzy reasoning, resulting in a significant cost reduction compared to using multiple expensive liquid control valves.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of the configuration of the metering control device of the present invention, and FIG.
This figure is a flowchart showing the procedure of metering control for liquid in one tank in the metering control device shown in FIG. (1,) (1yo)...(IN)...Tank,
(2,) (2□)... (2,) - Stop valve, (3) - Container, (4) - Weighing machine, (
6) - controller, troll regulator, (9) - control unit, (13) - metering control device.

Claims (2)

[Claims] (1) Weigh the total weight of a fluid tank with a stop valve on the discharge pipe, a control regulator that adjusts the air pressure that pressurizes the tank, a container that receives fluid supply through the stop valve, and this container. Based on the current control data of the weighing machine, the output of this weighing machine, and the control regulator, fuzzy reasoning is performed to shorten weighing time and improve weighing accuracy, and then controls the control regulator and opens/closes the stop valve to control the amount of water inside the container. A metering control device comprising: a control unit configured to meter and supply a predetermined amount of fluid. (2) In the metering control device according to claim 1, there are a plurality of fluid tanks equipped with stop valves, a single control regulator and a weighing device, and a control section that selectively opens and closes the stop valve based on fuzzy reasoning. and a control regulator to sequentially meter and supply the fluid in each tank into the container for mixing and metering.