JPH0675012B2 - Range setting method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a range setting for determining the measurement range of a measuring device when measuring the temperature of the measuring target by measuring infrared rays emitted from the measuring target, for example. It is about the method.

[Prior Art] It is known that all objects having a temperature of absolute zero or more radiate infrared rays from the surface thereof, and between the radiated infrared ray amount (energy amount) and the surface temperature of the object, There is a certain relationship called Planck's radiation formula. Therefore, the surface temperature of the object can be known by measuring the amount of infrared radiation. This infrared amount is detected by the infrared detector, but one infrared detector can only detect infrared rays coming from a certain direction. However, if a mechanism for bending the light path, that is, a scanning mechanism is provided in front of the infrared detector, infrared radiation coming from various directions can be detected.

FIG. 3 is a diagram showing an example of this method, in which 1 is a rotary mirror which is formed in an annular shape in which the vertical angles of 10 plane mirrors are slightly different, 2 is a silicon window, 3 is a folding mirror, and 4 is a mirror. Is a condenser lens, 5 is a positioning motor, 6 is an infrared detection element arranged in a vertical direction, and 7 are
Is an amplifier provided for each infrared detection element, and is designed to send independent output signals for 10 channels.

In the device thus configured, only infrared rays pass through the silicon window 2 and reach the rotating mirror 1. As described above, since the plane mirrors of the rotary mirror 1 are provided so as to be slightly displaced in the vertical direction, each plane mirror laterally scans a portion of the subject that is slightly displaced in the vertical direction. One rotation of the rotary mirror 1 scans a range of 10 degrees in the vertical direction. On the other hand, ten infrared detectors 6 are arranged in the vertical direction, and the distance between them corresponds to an angle of 1.0 degree in the vertical direction. For this reason, the infrared detector 6 of 10 elements receives the thermal image signal at every 1.0 degree at the same time by the plane mirror of one surface, and the infrared image signal at the position shifted by 1.0 degree from the previous position at the same time at the next plane mirror. . In this way, one rotation of the rotating mirror 1 scans the subject 10 degrees in the vertical direction. Further, in the horizontal direction, the horizontal viewing angle (about 18 degrees) of each plane mirror of the rotating mirror 1 is scanned.

The thermal image signal thus obtained is amplified by each of the ten amplifiers 7 and output. Reference numeral 8 is a temperature table in which data such as that shown in Table 1 whose temperature is corrected by the black body furnace is stored. If a temperature range of, for example, 14 degrees to 23 degrees is required among the temperature ranges shown in Table 1, the temperature range indicated by the symbol a is selected by the switch 9, and the data of the range is written in the conversion table 10.

In this writing, as shown in FIG. 4, the voltage corresponding to the energy of infrared rays, that is, the input voltage value in Table 1 is written on the horizontal axis, and the temperature at that time is written in the vertical direction. Although Table 1 is described with an analog signal, since writing is performed with an 8-bit digital signal, it takes a value of 0 to 255. Therefore, the first
Interpolate the missing parts from the values in the table to create data.

In this case, set the lowest value to zero and the highest value to 255. However, the linearity of the infrared detector 6 is guaranteed only in a certain range. For this reason, when the linearity is out of the linear range, the input signal is attenuated by a filter or the gain of the amplifier 7 is adjusted so that the maximum and minimum values to be measured fall within the linear range of the measuring instrument. I am trying to enter. Further, in order to ensure good linearity and perform accurate measurement, the measurement range is set narrow.

[Problems to be Solved by the Invention] However, when the measurement range is set to be narrow, there is no problem if the measurement target is within the measurement range, but if the measurement target is outside the measurement range, the set measurement range will be parallel. It is necessary to search for the measurement target while moving. However, when the measurement target is very far from the current setting range, it takes time to move the measurement range to that range, and it is very inconvenient when comparing and measuring different measurement targets. ing.

[Means for Solving the Problem] In order to solve such a problem, the first aspect of the present invention is to set the setting ranges sequentially when there is no measurement target in the setting range (step 100 in FIG. 1). When the range is expanded (step 101 in FIG. 1) and it is detected that the maximum and minimum values of the measurement target are included in the set range (step 102 in FIG. 1), the minimum and maximum values of the range The predetermined range is added to the value and then the range expansion is stopped (steps 103 and 104 in FIG. 1).

In the second invention, when there is no object to be measured currently in the set range (step 100 in FIG. 1), the set range is sequentially expanded by the range at that point (step 101 in FIG. 1), and the set range is set. It is detected that the maximum and minimum values of the measurement target are included, or a detection signal is output (step 10 in FIG. 1).
2) When the detection signal is supplied, add the specified amount to the maximum value of the measurement target and set it as the maximum value of the measurement range (step
103), the value obtained by subtracting a predetermined amount from the minimum value of the measurement target is set as the minimum value of the measurement range (step 104 in FIG. 1).

[Operation] In the first aspect of the present invention, the measurement range is gradually doubled, so that the measurement target eventually comes within the measurement range. Therefore, when it is detected that the maximum value and the minimum value of the measurement target are included in the set range, the range expansion is stopped after adding a predetermined amount to the minimum value and the maximum value of the range at that time.

In the second aspect of the invention, the measurement range is gradually doubled, so that the measurement target eventually comes within the measurement range.
Therefore, when it is detected that the maximum and minimum values of the measurement target are included in the set range, the value smaller than the minimum value of the measurement target by a predetermined value is set as the lowest value of the measurement range, and the predetermined value is larger than the maximum value of the measurement target. Confirm the range with the value as the maximum value of the measurement range.

[Embodiment] FIG. 1 is a flow chart showing an embodiment of the present invention. As shown in step 100 in the figure, when there is no measurement target within the measurement range, the current measurement range is doubled as shown in step 101 and the process returns to step 100. If there is no measurement target there, the measurement range is further doubled.

As the process is repeated, the object to be measured comes within the measurement range. Therefore, when it is determined in step 102 that both the minimum value and the maximum value of the measurement target are not within the measurement range, the measurement range is expanded again. When the minimum and maximum values of the measurement target fall within the measurement range, the maximum value max of the measurement target plus 10% of that value is set as the maximum value MAX of the measurement range as shown in step 103. As shown in step 104, the minimum value m
The value obtained by subtracting 10% of that value from in is the minimum value MI of the measurement range.
Set as N. By doing so, the maximum value and the minimum value of the measurement object can be measured with high accuracy.

Although the above description is an example of the second invention,
If the measurement range is slightly widened after step 102, the first invention is obtained.

FIG. 2 illustrates this state, and it is assumed that the temperature measurable range of this device is from t ₁ to t ₁₁ . Now, assume that the measurement range is set from t ₉ to t ₁₀ , the minimum temperature of the measurement target is t ₄ , and the maximum temperature is t ₆ . Since initially measuring object not within the measurement range, the measurement range is expanded to double, it is set to from t ₈ to t _10. Even with this, the measurement target is not within the measurement range, so the measurement range is further doubled and set from t ₅ to t ₁₀ . With this, the maximum value of the measurement target is within the measurement range, but the minimum value is still outside the measurement range. Therefore, the measurement range is further doubled and set from t ₂ to t ₁₀ .

Now that the measurement target is within the measurement range, it is possible to measure the temperature, but the measurement range is too wide and the measurement accuracy is poor. Therefore, the maximum temperature of the measurement target is set to the maximum temperature of the measurement range of the temperature t ₇ which is obtained by adding 10% of the maximum temperature t ₆ . Further, to establish a temperature t3 obtained by subtracting 10% of the value of the temperature from a minimum temperature t ₄ to be measured is the minimum temperature of the measuring range. By doing so, the measurement can be performed in almost the entire measurement range, and the measurement accuracy is improved.

[Effect of the Invention] As described above, according to the present invention, when the measurement range is sequentially set to double until the measurement target falls within the measurement range, and the minimum value and the maximum value of the measurement target fall within the measurement range, Since the measurement range is set by using the minimum value and the maximum value of the measurement target, the measurement can be performed within the full measurement range, and the accuracy is improved.

[Brief description of drawings]

FIG. 1 is a flow chart showing an embodiment of the present invention, FIG. 2 is a diagram for explaining the operation thereof, FIG. 3 is a diagram showing a configuration of an infrared detecting section, and FIG. 4 is a characteristic of a conversion table. It is a graph. 1 ... Rotating mirror, 2 ... Silicon window, 6 ... Infrared detecting element, 7 ... Amplifier, 8 ... Temperature table, 10
...... Conversion table.

Claims (2)

[Claims] 1. In a range setting method for arbitrarily setting a measurement range, if there is no measurement target in the current setting range, the setting range is sequentially expanded by the range at that point, and the maximum value of the measurement target in the setting range is increased. And a minimum value are included, a predetermined amount is added to the minimum value and the maximum value of the range, and then the expansion of the range is stopped. 2. In a range setting method for arbitrarily setting a measurement range, when there is no measurement target within the current setting range, the setting range is sequentially expanded by the range at that point, and the maximum value of the measurement target within the setting range is set. And outputs a detection signal when it is detected that the minimum value is included, and when the detection signal is supplied, the value obtained by subtracting a predetermined value from the minimum value of the measurement target is the minimum value of the measurement range, and the maximum value of the measurement target. A range setting method, wherein a value obtained by adding a predetermined amount to is set as a maximum value of a measurement range.