JP2608629B2 - Temperature compensation device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for correcting the temperature of a measuring instrument or the like whose measurement result is affected by temperature, and in particular, to measuring after the measuring instrument or the like starts operating. The present invention relates to a temperature compensating device when an inertial detector having an accelerometer or the like is used, for which the time required to reach a possible state needs to be as short as possible.

[Conventional technology]

The measuring device is generally susceptible to the influence of temperature, for example, in a measuring instrument having an electronic circuit or the like, a semiconductor,
Since the characteristics of elements such as resistors change due to temperature fluctuations, the temperature greatly affects the measured accuracy. In addition, for example, in an inertial detector, the mechanical parts of various sensors are affected by the temperature more than the electronic circuit, and the measurement accuracy is reduced. Furthermore, measuring instruments generally generate heat themselves,
Usually, measurement is performed in a state where the thermal conditions of the measuring instrument and its environment are stabilized, and various measures have been taken for this purpose. One of them is a method in which a measuring instrument is installed in a constant temperature bath and measurement is performed at a constant temperature without being affected by the surrounding temperature. In this method, since the temperature in the thermostat is always kept constant, the measuring instrument is in thermal equilibrium with the thermostat after a certain period of time has elapsed after the start of operation.
Therefore, the measuring instrument is stable, and a highly accurate measurement result can be obtained. However, the thermostat requires a heater and a cooler, and is complicated and large-scale, so that there are many problems in using it for a moving object such as an aircraft. Moreover, the measurement cannot be performed with sufficient accuracy until the thermal equilibrium state is reached after a certain period of time has elapsed after the operation of the measuring instrument has started.

As another countermeasure, there is a method of detecting the temperature of a measuring instrument and correcting the measurement result with the detected temperature. Of course, the effect of the temperature on the measurement results should be checked in advance. This method is simple and is often used in electronic measuring instruments. However, even with this method, high-precision measurement cannot be performed until a certain period of time has elapsed after the start of operation of the measuring instrument and the surroundings are in thermal equilibrium with the surroundings. Moreover, in this method, since irregular heat is directly transmitted between the measuring instrument and the surroundings, there is a problem that sufficient accuracy cannot be obtained if the surrounding temperature fluctuates.

[Problems to be solved by the invention]

In any case, both of the above methods have a problem that high-precision measurement cannot be performed for a fixed time after the operation of the measuring instrument is started. If this time is short, it is not so much a problem, but for example, in an inertial detector, this time is several hours, which is a big problem in use.

When using a thermostat as a countermeasure for this, how the measurement result of the measuring instrument changes after the operation starts,
Measurement is performed in advance, and the measurement result is corrected based on the measured characteristics. However, since it takes a long time for the temperature of the thermostat itself to reach a constant temperature, it is difficult to shorten the preparation period for measurement by this method.

Also, in the method of measuring the temperature of the measuring instrument and making a correction based on this temperature, a change in the measurement result of the measuring instrument after the start of operation is measured in advance, and the measurement result is calculated based on the measured characteristics. Correction is conceivable. However, in this case, since the heat is directly transmitted between the surface of the measuring instrument and the surroundings, the fluctuation of the temperature distribution is complicated. The measuring instrument itself, especially an inertial detector, has a complicated configuration and is therefore particularly complicated when there is uneven temperature distribution in the device. For this reason, various change states are considered depending on the surrounding conditions, and it is difficult to uniquely determine a change in the measurement result from the measured temperature. Further, in this method, the ambient temperature is not always constant, but may naturally change. In particular, when used in places where the external environment changes drastically, such as in an inertial detector, such as an aircraft or a ship, the measuring instrument is also greatly affected, and the output characteristics of the measurement result also change in a complicated manner. Become.

For this reason, the temperature detection point on the measuring instrument is increased,
Correction may be performed more precisely, but as described above, the change is complicated and sufficient accuracy cannot be obtained at present. Further, increasing the number of temperature detection points in this manner not only increases the cost but also increases the time required for detection and the amount of calculation for calculating the correction amount from the detection result.

The present invention has been made in view of the above problems, and allows a simple device to perform measurement with sufficient accuracy even before a measuring instrument or an element is in a thermal equilibrium state. The purpose is to shorten the.

[Means for solving the problem]

In the present invention, in order to solve the above problems, by thermally insulating the measuring instrument or the element from the surroundings, the temperature change from the start of the operation of the measuring instrument or the element, and the change characteristic of the measurement result associated therewith become constant. So that a sufficient correction can be made.

That is, the temperature correction device according to the present invention is a support for supporting a measuring instrument or an element whose measurement result is affected by temperature, a container for accommodating the measuring instrument or the element and the supporting body with thermal insulation from the surroundings, a measuring instrument or Element, support,
Or, a temperature detector for detecting any temperature of the container, and a temperature rise due to heat generation of a measuring instrument or an element from an initial temperature which is a temperature measured at the start of operation detected by the temperature detector in advance. It stores the time change characteristics of the measurement results of the measuring instrument or element after the operation starts, and sets the temperature detected by the temperature detection unit as the initial temperature and starts the operation of the measuring instrument or element based on the time change characteristics after the operation starts. By providing a correction unit that corrects the later measurement result,
This is to solve the above problem.

[Action]

In the present invention, the measuring instrument and the like are housed inside the housing and are thermally insulated from the surroundings. Therefore, there is almost no heat propagation with the surroundings, and only the heat generated by the operation of the measuring instrument needs to be considered. Before starting operation, the instrument is considered to become the same temperature theta _o and surrounding, the instrument starts to operate, the instrument generates heat due to the operation, the temperature rises. Assuming that the heat value is P and the heat capacity of the measuring instrument and the support is C, the temperature θ increases from the initial value _{θo according} to the following equation.

θ = θ _o + (P / C) · t (1) In the equation (1), t represents time.

In practice, it is not possible to completely insulate completely, so the temperature does not rise indefinitely, but eventually saturates. As approaching the state of saturation, the deviation from the equation (1) increases, but it is sufficiently possible to approximate a certain range by the equation (1).

Moreover, since there is no irregular heat conduction on the surface of the measuring instrument, the measuring instrument is always affected by the temperature in a constant manner even if there is a temperature distribution in the measuring instrument. Therefore, a constant relationship always holds between the measurement result of the measuring instrument and the temperature.

As described above, based on the temperature measured at the start of the operation, the measurement result can be accurately corrected immediately after the start of the operation of the measuring instrument. Also, it is clear that even if the ambient temperature fluctuates after the start of operation, the measuring instrument can be measured without being affected.

〔Example〕

 An embodiment of the present invention will be described with reference to the drawings.

 FIG. 1 is a configuration diagram showing one embodiment of the present invention.

1 is a measuring instrument, which is assumed to be an inertial detector,
The present invention is not limited to a specific measuring instrument, and is intended for a measuring instrument that requires a time period from the start of operation to measurement as short as possible.

Reference numeral 2 denotes a support for supporting the measuring instrument 1, and is preferably made of a material such as a metal having good thermal conductivity and high rigidity in order to reduce the temperature distribution.

Numeral 4 denotes a container for housing the measuring instrument 1 and the support 2 inside, and is a member 3 made of a material having high thermal resistance, that is, a material that is difficult to conduct heat and has high rigidity. Holding. The inside 9 of the container 4 is evacuated or depressurized so that heat is not easily transmitted, and the inner surface and the outer surface of the container 4 have high reflectivity of infrared rays. That is, the measuring device 1 and the support 2 are thermally insulated from the surroundings 8 by the above configuration.

Reference numeral 5 denotes a temperature detection unit that detects any one of the temperature of the measuring instrument 1, the support 2, and the container 4. In FIG. 1, the temperature of the measurement point 7 of the support 2 is detected. Of course, the temperature of a plurality of objects may be measured, or a plurality of locations in the same object may be measured.

A correction unit 6 corrects the measurement result based on the temperature measured by the temperature detection unit 5 and the temperature characteristics of the measuring device 1. When the temperature of the measuring device 1 or the support 2 is detected, the correction is performed while always detecting the temperature and confirming that the temperature rise accompanying the operation of the measuring device 1 shows a predetermined value. Container 4
When only temperature detection is performed, the temperature rise characteristic accompanying the operation of the measuring device 1 is measured in advance, and the temperature rise of the measuring device 1 is calculated from the detected temperature and this characteristic to perform correction. This is to minimize the error.

 Next, the operation of this embodiment will be described.

FIG. 2 is a graph showing temperature changes at three points a, b, and c on the actual measuring instrument 1 after the start of operation in this embodiment. −b, 1−c
Expressed by For reference, 2-a, 2-b, and 2-c represent temperature changes at each point when thermal insulation is not performed. Further, changes in the measurement results in each case are indicated by and.

If the thermal insulation is perfect, the temperature should rise without limit based on the equation (1). However, since there is actually a certain amount of heat propagation, when the temperature rises after a certain time, the deviation will increase. Come up. As is clear from FIG. 2, the temperature difference between each point is much smaller when heat insulation is performed than when heat insulation is not performed.
When the thermal insulation is not performed, the difference between the temperatures at the respective points is large, and it is difficult to determine how the temperatures are related to the measurement results. In contrast, when thermal insulation is performed, each point shows a relatively similar temperature change, and the change characteristics of the measurement result also match this temperature change. This is presumably because there is no irregular heat propagation due to convection of air on the surface of the measuring instrument 1.

The temperature is further increased if the operation is continued as it is because the thermal insulation is performed. However, since the measuring instrument also has an upper limit of the operating temperature, the usable temperature is up to the upper limit temperature. Therefore, it is necessary to stop the operation of the measuring device 1 immediately after the measurement. In some cases, the heat capacity of the support 2 is adjusted in order to adjust the slope of the temperature rise.

Next, FIG. 3 shows a case where the temperature of the surroundings 8 suddenly changes after the start of operation and a change in the measurement result. This is an example in which the temperature suddenly drops. For simplicity, only one point on the measuring instrument 1 is shown, and the temperature in the case of thermal insulation as shown in FIG. The temperature when thermal insulation is not performed is indicated by 4-d, and the measurement result is indicated by 4-d. The temperature when the ambient temperature does not change on the way without performing thermal insulation and the measurement result are respectively 5-d,
Expressed by In the case of thermal insulation, the temperature is not affected by the temperature change of the surroundings 8, so that there is no difference between the case where the surrounding temperature changes and the case where the surrounding temperature does not change.

As is clear from FIG. 3, when the thermal insulation is not performed, when the ambient temperature changes, both the temperature and the measurement result show complicated changes, and it is difficult to correct.

As described above, by performing the thermal insulation, the temperature of the measuring instrument and the measurement result show constant changes after the start of the operation, and it is understood that the measurement is not affected by the surrounding conditions. For this reason, if only the initial temperature is detected, it is possible to predict a temperature change and a change in the measurement result due to the operation, and to perform a highly accurate correction.
Moreover, the calculation for that is also easy. In this embodiment, by measuring the temperature of the measuring instrument 1 obtains the initial value theta _o temperature, correction is performed by seeking changes in temperature and measurement results accompanying the operation accordingly. Further, the temperature is constantly measured, and it is confirmed that the temperature coincides with the calculated temperature change.

When the temperature of the container 4 is measured, the temperature of the measuring device 1 is not directly measured. However, since the temperature of the container 4 is the same as that of the surroundings 8 for a long time before the operation starts, the measuring device 1 1
It is considered that both the container 4 and the container 4 have the same temperature. Therefore, if the temperature of the container 4 is measured, the initial value _θo is obtained. However, considering the fluctuation of the ambient temperature, the measuring device 1 or the support 2
It is desirable to detect the temperature of

In the above description, the measuring instrument 1 has been described as being completely thermally insulated from the surroundings 8; There is almost no unevenness in temperature distribution, and heat conduction is performed between the support 2 and the container 4 through the member 3. Therefore, a relatively constant change is exhibited with the temperature difference between the surroundings 8, that is, the container 4 and the support 2 as a parameter. Therefore, even if the thermal insulation of the member 3 is incomplete, it is possible to perform more accurate correction than before.

Note that, in this embodiment, an actual example of a measuring instrument is shown. However, the same effect can be obtained not only in the actual measuring instrument but also in, for example, a temperature-dependent element used in the measuring instrument and the like. Is clear.

〔The invention's effect〕

According to the present invention, by accommodating a measuring instrument or the like affected by temperature in a simple device and correcting it, it becomes possible to perform measurement immediately after the start of operation, thereby shortening the preparation period of the measuring instrument. Has an effect.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of the present invention. FIG. 2 is a correlation diagram showing a comparison between a temperature change at a point on a measuring instrument and a measurement result when thermal insulation is performed and when thermal insulation is not performed. FIG. 3 is a correlation diagram showing a change in the temperature of a point on the measuring instrument and a change in the measurement result when a temperature change occurs halfway after the operation of the measuring instrument starts. In the drawing, 1... Measuring instrument, 2... Support member, 3... Member, 4... Container, 5... Temperature detecting section, 6. , 9 ... inside the container (vacuum or reduced pressure).

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshiaki Hayakawa 345 Kamimachiya, Kamakura City, Kanagawa Prefecture Inside Mitsubishi Precision Co., Ltd. (JP, U)

Claims (1)

(57) [Claims] 1. A support (2) for supporting a measuring instrument or element (1) whose measurement result is affected by temperature, and the measuring instrument or element (1) and the supporting body (2) are separated from the surroundings (8). A temperature detector (5) for detecting the temperature of any one of the container (4), the measuring instrument or the element (1), the support (2), and the container (4) which is housed in a thermally insulated state; And the measuring instrument or the element (1) accompanying the temperature rise due to the heat generation of the measuring instrument or the element (1) from the initial temperature, which is the temperature at the start of operation detected by the temperature detecting section (5), measured in advance. The time change characteristic after the start of the operation of the measurement result of 1) is stored, and the temperature at the start of the operation detected by the temperature detecting section (5) is set as the initial temperature, and based on the time change characteristic after the start of the operation. , The measuring instrument or element (1)
A temperature compensating device comprising: a compensating unit (6) for compensating a measurement result after the start of the operation of (1).