JPH05118899A - Continuous determination system - Google Patents

Abstract

PURPOSE:To enable a particle which is a raw material for industry application to be determined and delivered continuously and highly accurately. CONSTITUTION:This system consists of a controller 1, an inverter 2, a motor 3, a metering feeder 4, a screw 5, a load cell 6, and a current amplifier 7. Especially, an instantaneous delivery weight of a particle is subjected to Fuzzy control by a controller 1 incorporating a Fuzzy operator which automatically adjusts a range from NG(Negative Big) to PB(Positive Big) of a previous membership function for Fuzzy operation according to a delivery speed of the particle, thus achieving a continuous determination and delivery where a range of a delivery speed which can be set is wide more accurately.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is to accurately and continuously quantify a powder, which is an industrial raw material, and discharge it.

[0002]

2. Description of the Related Art Conventionally, quantitative determination of powders such as industrial raw materials has been performed by weight ratio using a measuring instrument. As for the quantitative method, a batch method was mainly used, and for some low-precision, large-volume methods, quantitative measurement and discharge were performed using a belt conveyor scale or the like. Further, as the continuous quantitative system, a screw feeder is used, and PI control (proportional / integral control) of the rotation speed of the screw is performed according to the set discharge speed. However, with this method, it was difficult to perform highly accurate continuous quantification and discharge because the fluctuation of the screw rotation speed was large and the transient characteristics at the system start-up were poor.

[0003]

The problem to be solved is that the rotation speed of the screw attached to the measuring feeder fluctuates sharply due to the fineness and homogenization of the powder for continuous quantification and discharging. The point is that the settling time until the weight reaches the vicinity of the target value is long, and the amount of overshoot at the time of system startup is large. In addition, the settable discharge speed range is narrow.

[0004]

According to the present invention, a deviation between a target value and an actually measured value of discharged weight at the time of sampling and a change in the deviation are input to the controller unit in the antecedent section, and the controller determines the discharge speed according to the set discharge speed. , NB of the antecedent part membership function
(Negative Big) to PB (Positive Big) with a mechanism that can automatically adjust the range, the antecedent conformance Max-
Min operation was performed, and its fitness was projected on the membership function of the consequent part, and a fuzzy arithmetic unit that can calculate the manipulated variable from the area moment of the α-cut membership function was implemented.

[0005]

1 is an embodiment of the device of the present invention, in which 1 is a controller, 2 is an inverter, 3 is a motor, 4 is a metering feeder, 5 is a screw, 6 is a load cell, 7 is a current amplifier, and 8 is a current amplifier. It is a D / A converter. FIG. 2 is a control block diagram of the device of the present invention, in which 1 to 8 are the same as those in FIG. 1, and 9 is a mechanism capable of automatically adjusting the range of the antecedent part membership function according to the set discharge speed. Is a fuzzy arithmetic unit having. In Figure 2, if you set the discharge speed,
As shown in FIG. 3, the fuzzy computing unit 9 automatically expands and contracts the range from NB (Negative Big) to PB (Positive Big) of the antecedent part membership function according to the discharge speed to obtain the target discharge weight. The deviation E and the change D of the deviation are calculated from R and the measured discharge weight Y, and these two values are projected as an antecedent part input value on the consequent part membership function to obtain an operation amount U.
To calculate. The manipulated variable U is output from the D / A converter 8 at a current value (4 to 20 mA), and via the inverter 2,
The motor 3 rotates, and the weighing feeder screw 5 connected thereto rotates to discharge the powder. The weight of the discharged powder is integrated by detecting a change in the current value of the load cell 6 attached to the lower portion of the weighing feeder 4 with the current amplifier 7 and inputting it to the controller.

[0006]

As described above, the continuous quantitative system of the present invention incorporates a fuzzy calculator that automatically adjusts the range of the membership function of the antecedent part according to the discharge weight set in the controller part. In addition, the transient characteristic at the time of system startup is remarkably improved, the time until the discharged weight reaches the target value is reduced to about 1/2 compared with the conventional method (PI control), and the overshoot amount at the time of startup is also 1 It became as small as / 4. Further, the accuracy in the steady state is improved, and the deviation of the discharged weight is reduced to about 1/2 of that of the conventional method (PI control). Further, the range of discharge speeds that can be set is 40 to 150 Kg / h in the conventional method, but is greatly expanded to 20 to 300 Kg / h in the method according to the present invention.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of a continuous quantification system.

FIG. 2 is a control block diagram used in the present invention. Here, the meaning of each symbol is as follows. R Target value of discharge weight E Deviation of discharge weight D Change of deviation in sampling time U Manipulated amount Y Control amount

FIG. 3 is an explanatory diagram showing a change of a membership function of an antecedent part of a fuzzy computing unit according to a discharge speed. The terms used here have the following meanings. NB Negative Big NS Negative Small ZO Zero PS Positive Small PB Positive Big G (E) Conformity to the antecedent input value

FIG. 4 is an explanatory diagram of a membership function for fuzzy arithmetic unit used in the present invention. The meanings of the terms used here are the same as in Figure 3.

[Explanation of symbols]

1 Controller 2 Inverter 3 Motor 4 Metering Feeder 5 Screw 6 Load Cell 7 Current Amplifier 8 D / A Converter 9 Fuzzy Calculator with Mechanism for Adjusting Range of Antecedent Membership Function According to Discharge Speed

Claims (1)

[Claims] 1. An apparatus for continuously quantifying and discharging industrial raw material powder in real time, which is composed of a controller, an inverter, a motor, a weighing feeder, a load cell, and a current amplifier. It is characterized by having a fuzzy calculator that automatically adjusts the range of the fuzzy membership function according to the discharge rate set in the controller, enabling a wide range of discharge rates and highly accurate continuous quantification. It is a continuous quantitative system.