JPH04145329A - Material measuring method - Google Patents

Abstract

PURPOSE:To automatically estimate the proper fall quantity and determine the closing action timing of a measuring gate by performing fuzzy inference based on the measuring speed calculated from the actual measured value and the ratio between the present preset quantity of material is measured with a measuring tank. CONSTITUTION:The measurement value to be measured this time is inputted as a preset measurement value W(kg) from the set input section 9 of a material measurement control device 5. When a measurement start action is performed, the weight of a material is detected by a weight detector 3 in sequence, and the measuring speed V(kg/sec) of the material is calculated from the weight value per unit time. The fall correction quantity W(kg) for the preset measurement value is estimated by a fuzzy controller 6 based on the membership function of the fuzzy set and the inference rule from the inputted data. A standard fall quantity is inputted from the set input section 9 in advance, the standard fall quantity is corrected to calculate the fall quantity for the present measurement, and the proper measurement completion timing is determined by this fall quantity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a material measuring method using an apparatus for dropping and measuring material stored in a storage pin into a measuring tank disposed below.

[Prior Art] Conventionally, for example, in an asphalt plant or a ready-mixed concrete plant, when weighing materials such as gravel or sand stored in storage pins, a predetermined measurement value is set on a weighing operation panel that controls the plant, and a weighing start operation is performed. The weighing gate located below the storage pin located above the weighing tank is opened and the material is discharged into the weighing tank.When a predetermined weight value is detected by the weight detector installed in the weighing tank, the weighing gate is closed. to complete the weighing. At this time, even if the metering gate is closed to stop discharging the material at the same time as the predetermined weight value is detected, the amount of material remaining in the space between the metering gate and the weighing tank (head amount) falls into the measuring tank. , the actual measured value will be increased by the amount of head difference.

Therefore, the head difference is set in advance before weighing, and the weighing gate is closed when the weight detector detects a value obtained by subtracting the head difference from the set weight value during weighing.

[Problems to be Solved by the Invention] However, in order to adjust the amount of head, a head correction value is appropriately set on the weighing operation panel, but this head value is determined by the discharge speed of the material discharged from the storage pin and the storage pin. It is largely determined by the distance from the weighing gate to the material surface in the weighing tank. This discharge rate is fastest when the material level in the storage pin is at full level, and becomes slower as it approaches the empty bell.Also, the distance from the weighing gate to the material surface in the weighing tank is the set weighing value. The larger the distance, the shorter the distance at the end of the measurement, and the smaller the head difference accordingly.In this way, the head difference varies from measurement to measurement, and in the conventional method, a fixed average value is used. Since it is set as the amount of head, measurement errors tend to occur, and if the measurement error becomes large, the operator corrects the set value of the amount of head by referring to the previous measurement error and the material level in the storage pin, and maintains and manages the measurement accuracy. This places a heavy burden on operators.

In view of the above points, the present invention provides a material weighing method that applies fuzzy reasoning that makes use of the experience of a skilled operator, automatically estimates an appropriate amount of head, and determines when to close a weighing gate. The purpose is to

[Means for Solving the Problems] In order to achieve the above object, the present invention operates to open a measuring gate of a storage pin for storing materials, and when a predetermined amount of materials is measured by a measuring tank disposed below. Then, a weight detector attached to the weighing tank detects the amount of change in the weighing value per unit time, calculates the weighing speed, and calculates the ratio of the set weighing value to the preset material weighing speed and the maximum weighing capacity of the weighing tank. is the antecedent of the fuzzy inference rule, and the head correction amount for the set weighing value is the consequent of the inference rule, and based on the weighing speed calculated from the actual weighing value and the ratio of the current set weighing value to the maximum weighing. Perform fuzzy inference, estimate the amount of head correction for the set measurement value, calculate the amount of head for the current measurement,
The measuring gate is closed by determining the point in time when the measuring is completed.

[Function] In the material weighing method according to the present invention, the ratio of the weighing speed of the material in the weighing tank and the set weight value to the maximum weight of the weighing tank is used as an antecedent part of the fuzzy inference rule, and further the fuzzy inference rule is As a consequent part, the head correction amount for the set weighing value is stored in the storage unit, and the weighing speed of the material is calculated from the weighing value of the material falling into the weighing tank during measurement, and the weighing speed and the set weighing value are calculated. Fuzzy inference is performed from the value to estimate the head correction amount for the set measurement value.

Then, the standard head amount is corrected by the head correction amount to calculate the head amount at the current measurement. When the measured value in the measuring tank reaches a value obtained by subtracting the head amount from the set measured value, the measuring is completed, and the measuring gate of the storage pin is closed to complete the measuring.

[Example code] Embodiments of the present invention will be described below based on the drawings.

2 is a storage pin for storing various materials such as gravel, sand, cement, etc., and a weighing gate 2 is provided at the bottom of the storage pin 1 for discharging materials by opening and closing. A weighing device 114 is disposed below the storage pin 1 and is supported by the weight detector 3 and measures the material dispensed from the storage pin 1.

Reference numeral 5 denotes a material weighing control device, which includes a fuzzy control section 6 that performs fuzzy inference using fuzzy set membership functions and fuzzy inference rules, which will be described later. A storage section 8 that stores various data serving as the antecedent part of fuzzy inference rules and data for inference, a setting input section 9 for inputting and setting the data and predetermined set measurement values, etc., and a measurement gate 2 for the storage pin 1 The opening/closing controller 10 is provided to perform opening/closing control. When weighing the material, the weighing gate 2 connected to the opening/closing controller 10 is opened, the material in the storage pin 1 is dispensed into the weighing tank 4, and the weight detector 3 connected to the calculating section 7 detects the material in the weighing tank. Weigh the ingredients in 4 and
Calculate the weighing speed, use fuzzy reasoning to estimate the head correction amount for the set weight value from the weighing speed and the set weight value, correct the standard head amount stored in advance, and complete the proper measurement from the corrected head amount. Determine the point in time. The standard head difference is the head difference when a medium amount is stored in the storage pin 1 and the set weight value W is about half of the maximum weight, and is determined in advance.

Next, a method of fuzzy inferring the amount of head difference with respect to the currently set measured value from the measuring speed of the material in the measuring tank 4 and the currently set measured value will be explained.

The measurement value to be measured this time is inputted as the set measurement value W (Kg) from the setting input section 9 of the material measurement control device 5.

Then, when a measurement start operation is performed, an open signal is issued from the opening/closing controller 10 to the measurement gate 2, and the measurement gate 2 is opened and the material is discharged from the storage pin 1 into the measurement tank 4. In the weighing tank 4, the weight of the material is sequentially detected by the weight detector 3 and sent to the calculation section 7 of the material weighing control device 5. The calculation unit 7 calculates the material weighing speed V from the weight value per unit time.
(Kg/5ec) is calculated. This weighing speed V is input to the fuzzy control section 6 together with the ratio R of the set weighing value W to the maximum weighing amount set previously. The fuzzy control unit 6 estimates the head correction amount ΔW (Kg) for the set measurement value from the input data based on the membership function of the fuzzy set and the inference rule. In addition, a standard head amount is inputted and stored in advance from the setting input section 9, and this standard head amount is converted into the estimated head difference correction amount △W(K
g) to calculate the head difference at the time of the current measurement, and determine the appropriate measurement completion point based on this head difference. Second
The figure shows a membership function for qualitatively evaluating the magnitude of the ratio R of the set weight value to the maximum weight of the weighing tank 4. R(i) (i=1 to 7) in the figure is a constant that defines the form of the membership function and is determined as appropriate. P.B.
PM, PS, ZR, NS, NM, and NB are names given to membership functions in order to qualitatively evaluate the magnitude of the ratio R of the set metric value, and each has the following meaning.

PB:Po5itive Big PM:Po5itive MediumPS:Po
5itive SmallZR: Zer.

NS: Negative Small NM: Neg
ative MediumNB:Negative
Big Also, the vertical axis of the figure is the membership value. Ratio R of the set measurement value set this time using this membership function
Evaluate qualitatively.

FIG. 3 shows membership functions for qualitatively evaluating the magnitude of the material metering speed V. V (i) in the diagram
(i=1 to 7) are constants that define the form of the membership function and are determined as appropriate.

PB, PM, PS, ZR, NS, NM, and NB are names given to the membership functions in order to qualitatively evaluate the magnitude of the material metering speed V, and their meanings are as described above.

FIG. 4 shows an inference rule for qualitatively determining the head correction amount ΔW for the set weight value from a qualitative function of the ratio R of the set weight value and the material metering speed V. For example, the inference rule at the bottom left is IF (Ris NB and V 1sPB
) THEN △W i6 p13. This means, ``If the ratio of the set weight value is very small to the maximum weight of the weighing tank, and the material weighing speed is very high'' (antecedent part), ``If the ratio of the set weight value to the maximum weight of the weighing tank is very high, then the head correction amount for the set weight value is very small. It shows the rule "Make it bigger than that" (consequent part). FIG. 5 shows a membership function for converting the qualitatively determined head correction amount into a quantitative value. ΔW(i) (i=1 to 7) in the figure is a constant that defines the shape of the membership function, and is a head correction amount for the set measurement value, which is determined as appropriate. P.B., P.M.
, PS, ZR, NS, NM, and NB are the names given to the membership functions in order to qualitatively evaluate the magnitude of the head correction amount for the set measurement value, and are the names used in Fig. 4. It corresponds to Moreover, the vertical axis of the figure is the membership value. Then, it is qualitatively determined to which membership function the head correction amount for the set metric value belongs based on the applied inference rule. When the inferred head difference amount for the set measurement value is defined by a plurality of memberships based on a plurality of inference rules, the weighted average value according to each membership value is used as the actual head difference correction amount. Using this fuzzy-inferred head correction amount ΔW (Kg), the standard head amount that has been set and input in advance and stored is corrected, and the head amount at the time of current measurement is calculated. The calculated head amount is set as the head amount for the current measurement, and when the measurement is near completion, the measuring tank 4
When the weight detector 3 detects a value obtained by subtracting the head amount from the currently set measurement value, a measurement completion signal is sent to the opening/closing controller 10, and the opening/closing controller 10 closes the weighing gate 2.

The method of the present invention is not limited to one-step weighing as in this embodiment, but also uses a jog motion in which the weighing gate is fully opened a little before the set weighing value to perform rough weighing, and then the weighing gate is opened and closed intermittently. Of course, it can also be applied to two-stage weighing in which fine weighing is performed. In this case, by applying it to coarse weighing, the measuring accuracy of coarse weighing is further improved, and the jog motion of fine weighing can be reduced as much as possible, leading to a reduction in measuring time.

In addition, although all the membership functions used in this example were triangular, they are not necessarily limited to this shape (various curves may be adopted depending on the characteristics of the weighing device and materials and the knowledge of the operator). This does not change the essence of the present invention (even if the number is arbitrarily set, the essence of the present invention does not change.

[Effects of the Invention] As described above, according to the material control method according to the present invention, the amount of head correction for the set weight value when measuring the material is calculated using a fuzzy method based on the material weighing speed and the ratio of the set weight value to the maximum weighing capacity of the measuring tank. By inference, we calculated the head at the current measurement from this head correction amount, determined the measurement completion point, and closed the weighing gate, so we could control the material with higher precision than conventional weighing control methods. It is capable of metering control.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing the configuration of a material measuring device to which the material control method according to the present invention is applied, Fig. 2 is a diagram showing a membership function for evaluating the ratio of set measured values, and Fig. 3 is a diagram showing the material weighing speed. FIG. 4 is a diagram showing an example of a head correction amount prediction rule, and FIG. 5 is a diagram showing a membership function for evaluating a head difference correction amount. 1... Storage pin 2... Weighing gate 3... Weight detector 4... Weighing tank 5... Material weighing control device 6
...Fuzzy control section

Claims (1)

[Claims] When the measuring gate of the storage pin that stores the material is opened and a predetermined amount of material is measured using the measuring tank located below,
A weight detector attached to the weighing tank detects the amount of change in the weighing value per unit time and calculates the weighing speed, and calculates the preset material weighing speed and the ratio of the set weighing value to the maximum weighing tank of the weighing tank using a fuzzy function. The antecedent part of the inference rule, furthermore, the head correction amount for the set measurement value is the consequent part of the inference rule,
Performs fuzzy inference based on the weighing speed calculated from the actual weighing value and the ratio of the current set weighing value to the maximum weighing value, estimates the head correction amount for the set weighing value, calculates the head for the current weighing, and completes the weighing. A method for measuring materials, characterized in that the measuring gate is closed by determining a time point.