JPS5816447B2 - area alarm device - Google Patents

Description

[Detailed description of the invention] The present invention relates to improvements in area warning devices.

In process control, the analogy is two things, like temperature and pressure.
Combinations of two process variables are often controlled to fall within a predetermined range.

In that case, a region warning device is required that determines and notifies whether or not the combination of process quantities falls within a predetermined region.

Conventional area warning devices only notify whether a combination of process quantities is in or out of the area, but cannot notify to what extent it is in or out of the area.

An object of the present invention is to provide an area warning device that can notify the extent to which a combination of a plurality of input signals falls within a predetermined area and the extent to which it deviates from the predetermined area.

The present invention converts the extent to which a combination of a plurality of input signals is inside or outside a predetermined area into a numerical value on a coordinate axis perpendicular to the area, and reports based on this numerical value.

The present invention will be explained below with reference to the drawings.

FIG. 1 is a conceptual diagram of an embodiment of the present invention.

In FIG. 1, 11, 12, and 13 are arithmetic units, 2 is a low selector, and 3 is an indicator alarm.

Arithmetic units 11 to 13 each perform arithmetic operations, which will be described later, on two input signals X and Y, and provide the results to low selector 2.

Low Selector 2 is powered by three people. The smallest signal is selected and given to the indicator/alarm device 3.

The indicator/alarm device 3 indicates the value of the applied signal, compares it with a set value ZL, and generates an alarm.

By the operations of the arithmetic units 11 to 13 and the row selector 2, the extent to which the combination of input signals X and Y is within or outside a predetermined region is calculated.

The principle of the calculation is as follows.

Area S to which the normal combination of input signals X and Y should belong
is set on the XY field by three points A, B, and C in FIG. 2, then this area S is expressed by the following simultaneous inequalities.

a X + b I Y + c 1≧0a 2 X
10 b 2 Y + c 2≧0 (1) a3X+b3Y+
c3≧0 In formula (1), ai, E)i+ci (1: 1 to 3
) is a constant determined by points A, B, and C.

The Z-axis is taken perpendicular to the XY plane in Figure 2, and in this XYZ space, three half-lines QA, QB starting from point Q
If we consider a cone with edges at , QC, it will look like Figure 3.

In FIG. 3, Zo is the X coordinate of the apex Q of the cone, and ZL is the X coordinate of the same cross section as the area S.

Each surface forming the circumferential surface of this cone P1°P2. P3 is each expressed by the following formula.

Z=d1X+e1y+f 1 (2) Z=
d2X 10e2Y+f2 (3) Z-d3X
+e3Y+f3 (4) Here, Xo and Yo are the XY coordinates of the apex of the pyramid.

Now, any point p (x, y,
z), its X coordinate can be determined from the values of the X and Y coordinates using the following equation.

Z=Min((d1X+e1Y+f1), (d2X+e
2Y+f2), (d3X+03Y+f3)) (7) The reason why equation (7) holds is that, for example, point P is on the circumferential surface of the pyramid P.
1, and if we consider a straight line passing through point P and parallel to the Z axis, each plane P1. X at the intersection of P2P3
The coordinates are obtained using equations (2), (3), and (4), respectively, and among the three values obtained, the value obtained using equation (2) is the smallest value.

That is, the value of the X coordinate of the intersection of the straight line and the plane P1 is the smallest.

This is because the cone is considered to expand downward based on the Z axis, so planes P2 and ■]
This is because the Zffl mark at the intersection of 3 and the straight line is above the X coordinate of point P.

The same thing holds true when point P exists on the cone circumferential surface P2 or P3.

When an arbitrary combination of input signals X and Y is given to equation (7), the obtained value of Z may be larger or smaller than zL.

When Z is thicker than ZL, the intersection is above the cross section S,
When Z is smaller than ZL, the intersection is below the cross section S.

Due to the nature of a cone, if the combination of input signals X and Y is within the region S, the intersection will occur above the cross section S, and if it is outside the region S, the intersection will occur below the cross section S.

By determining whether the value of Z is larger or smaller than ZL, it can be determined whether the combination of input signals X and Y is inside or outside the region S.

Furthermore, the degree to which the object falls within the region S and the extent to which it deviates from the region S can be expressed by the difference between Z and ZL.

The arithmetic units 11, 12, and 13 in FIG.
, (3), and (4), and the row selector 2 performs the calculation of equation (7).

Then, the indicator/alarm device 3 determines the magnitude of Z and ZL, displays an alarm, and also indicates the value of Z (or the value of the difference between Z and ZL).

The above is a case in which the input signal has two dimensions and the setting area has a triangular shape, but the present invention can also be applied to a convex n-gon area in which each external angle is positive.

In general, when the area is given by the inequality a −X+b 1Y+ci≧0(8), Z−Min ((d1X+e1Y+ fl),”
.

( dn

±b iYo+c 1) i=1.2. ..., n Here, Xo, Yo, and Zo are the ZYX coordinates of the apex of the cone, and ZL is a set value.

Furthermore, although the explanation has been given only for the case where the apex of the cone is placed upward, the apex may be placed downward.

In that case, it is necessary to set the selector to the high selector and reverse the inside/outside judgment conditions.

As described above, the present invention provides an area warning device that can notify whether a combination of a plurality of input signals is inside or outside a predetermined area, including the extent thereof.

[Brief explanation of drawings]

FIG. 1 is a conceptual block diagram of an embodiment of the present invention, and FIGS. 2 and 3 are operation explanatory diagrams. 11, 12. 13 mountain calculator, 2...low selector, 3
...Indication alarm.

Claims (1)

[Claims] When the region in which a normal combination of 12 input signals should exist is given by n simultaneous inequalities in two dimensions, each circumference equation of a cone having the same cross section as the region in three dimensions has 2 n arithmetic units that input the values of input signals and perform calculations, a selector that selects the maximum or minimum of the output signals of these arithmetic units, and a selector that indicates the value of the output signal of this selector. An area warning device equipped with an indicator alarm that compares it with a predetermined value and notifies you of the determination result.