JPS59120810A - Apparatus for detecting oblique angle - Google Patents

Abstract

PURPOSE:To make it possible to remove a detection error based on a temp. characteristic, by mounting a power mechanism for rotating a magnetic resistance element 180 deg. on a level base. CONSTITUTION:An oblique angle detecting apparatus shown by drawing is equipped with a motor 50, a speed reducing gear group 60, a shield case 70, stopping switches 80a, 80b and stopping switches operating pieces 90a, 90b cooperated with the stopping switches 80a, 80b. At first, an oblique angle is measured and, subsequently, the motor 50 is driven to transmit the rotation thereof to a sensor 20 through the speed reducing group 60 and this sensor 20 is rotated 180 deg. to again measure the oblique angle. Thus measured value is further operated by the operation circuit provicded on a printed circuit board 30 and the resulting obtained value is subjected to digital display due to an oblique angle display device 40.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inclination angle detection device using a magnetoresistive element.

A typical example of an inclination angle detection device is a bubble level, but this bubble level requires direct supervision by a human when reading, and as a result, there is a risk of reading errors. There were disadvantages such as unavoidable labor saving (for example, automatic printing).

To compensate for the drawbacks of the bubble level, tilt angle detection devices that can be read digitally have been proposed.As an example, a tilt angle detection device that uses a magnetoresistive element has been proposed. ing.

FIG. 1 is a diagram showing an example of a conventional tilt angle detection device using a magnetoresistive element. In the figure, lO is a level base, and the level base 10-1. 1 is equipped with a magnetoresistive element sensor 20, and this analog output is converted into a digital signal by a printed circuit board 30 and displayed on an inclination angle indicator 4.
It is now displayed as 0. The structure of the sensor 20 is as follows: 1. Typically, a material (for example, InSb, I
nAs, GaAs, etc. magnetoresistive element f) 22 is deposited by -
In addition, a permanent magnet 23 is provided in the vicinity thereof, and either one of the ceramic substrate or the permanent magnet (permanent magnet in the illustrated example) is always perpendicular to the direction of gravity. Figure 2 shows the above-mentioned inclination angle detection device on the water IP surface 1-
Figure 3 is a diagram when it is placed on an inclined surface 1- with an inclination angle of 0. As shown in Figure 2, when it is placed on a horizontal surface, there is no permanent magnetism. I23 is a magnetoresistive element E22
Therefore, the output of the sensor 20 is O, but when placed on an inclined surface as shown in FIG. Therefore, the deviation is detected by the sensor 20 as a change in the resistance of the magnetoresistive element, and is displayed on the inclination display 30 as a digital table 17 indicating the inclination angle of the inclined surface.

The fB4 diagram is a diagram showing the relationship between the temperature and the resistance value of a magnetoresistive element, and in the diagram, curve A l;1: under a magnetic field, curve B shows the characteristics in the absence of a magnetic field, as shown in the diagram.

Magnetoresistive element rld Even with a constant magnetic field, the resistance value changes when the external temperature changes, resulting in poor temperature characteristics and a detection error due to the external part.

1--1 The present invention aims to eliminate detection errors based on temperature characteristics in a magnetoresistive element sensor as described above.

The structure of the present invention will now be described based on one embodiment.

5 and 6 are schematic diagrams for explaining the problems of the present invention, or in other words, the problems of the conventional device.
is a magnetoresistive element sensor, lOO is an inclined surface of the object to be measured, and if we assume that the relationship is tan θ] - t, a n θ2, in other words, the direction of inclination of the M1 constant object to be measured is completely opposite. , the absolute values of the outputs (-displayed values) from the sensor 20 must be the same. However, if the temperature of the M1 constant object or the ambient temperature is different between the measurement in FIG. 5 and the measurement in FIG. 6, then due to the temperature-output characteristics of the sensor shown in FIG. Absolute values are not equal. Also, this problem
Even if measurements are made using only the conditions shown in Figure 6 or Figure 6, if the temperature at the time of measurement is different, the same output (display) will not be obtained for the same reason as above.

Both of these problems are due to the temperature-output characteristics of the sensor, and there are two ways to solve them:
In other words, (1) provide a temperature-output characteristic compensation 1F tan circuit, (2) rotate the sensor 180' to adjust the temperature of the sensor.
One possibility is to cancel the output characteristics.

However, the method of providing a correction circuit requires a thorough understanding of the characteristics of the sensor, and when mass-producing it, the characteristics of each sensor must be uniform, but during the process of manufacturing the sensor, Since there are problems that are difficult to control, such as the uniformity and properties of the material and the uniformity of the vapor deposition conditions, it is very difficult to make the properties of the laser uniform, and therefore method (1) is difficult to implement. Therefore, in the present invention, 1
- The method according to (2) is adopted, and the sensor is rotated 180 degrees to cancel the temperature-output characteristics of the sensor.

FIG. 7 is a schematic configuration diagram for explaining the operating principle of the present invention.
This figure shows the sensor 20 placed in the direction shown in (a).
The feature is that the measurement is performed in the direction shown in (b), which is changed by 0°. Since the sensor 20 is located on the tilted plane l- in both cases (a) and (b), the only difference is the tilt direction when viewed from the sensor, and therefore the absolute value of the detection output is the same. However, in reality, they are not equal for the reasons mentioned above. The present invention was made in order to solve such problems, and the measurement is carried out according to the following procedure.

1) First, find the output in state (a), and...■2)
First, find the output in state (b), and...<C)3)
1 Next, find ■+■/2, and...
・■4), Finally, find (■ or ■) - ■... [
4) lu 1. The processing is originally +, i) + t'@ =
What should be the relationship of Q, the above-mentioned sensor
temperature - output characteristics? 1, +1', > + (2+
Since x O, the median value is found using the formula (2) above, the midpoint is set to 11, and this midpoint is used to find the inclination angle from the above +4). By measuring with I7 in this way, it goes without saying that it doesn't matter what the temperature of the sensor is - the power characteristic, and since the same measurement object is measured twice, the measurement accuracy is You can also get the side effect of being doubled.

FIG. 8 is a configuration diagram showing an embodiment of the inclination angle detection device according to the present invention, in which 50 is a motor, 60 is a reduction gear,
70 wall case, 80a.

80b is a stop switch, and 90a and 90b are stop I switches that cooperate with the stop I switches 80a and 80b, respectively.
The Itsuji f1 moving piece is shown, and other parts that have the same function as those in Figure 1 have the same reference numbers as in Figure 1.
It is 2. Therefore, in the present invention, in accordance with the above-mentioned measurement principle, first, the inclination angle is measured in the state shown in FIG. Drives the motor 50, transmits its rotation to the sensor 20 via the deceleration southeast group 60, and rotates the sensor 20 by 180 degrees.
2) Measure the inclination angle again in the state shown in FIG. The arithmetic circuit provided performs the above-described calculations (chain equation and (4)), and the resulting value is digitally displayed on the tilt angle display 40.

FIG. 9 is a configuration diagram of main parts showing another embodiment of the present invention. This embodiment includes a reduction gear mechanism 60 (made up of a group of reduction teeth 60f, a belt, and a pulley shown in FIG. 8). 0, and the other operations are the same as the embodiment 17 shown in FIG.

Figure 10 shows the temperature (curve A) and slope value (curve B) measured by the conventional measurement method, and Figure 11 shows the temperature measured according to the measurement principle of the present invention. 1. Is the diagram showing the temperature (curve A) and the slope value (curve B) when Can measure lA1 angle

[Brief explanation of drawings]

Fig. 1 shows an example of a conventional inclination angle detection device; 3 is a diagram of 111 placed on an inclined surface, FIG. 4 is a diagram showing the relationship between temperature and resistance value of the magnetoresistive element, and FIGS. 5 and 6 are for detailed explanation of the present invention. FIG. 7 is a schematic diagram for explaining the operating principle of the present invention, FIG. 8 is a configuration diagram for explaining one embodiment of the present invention, and FIG. FIG. 10 is a diagram showing the main part configuration of the embodiment, FIG. 10 is a diagram showing the results of the conventional measurement method, and FIG. 11 is a diagram showing the measurement results according to the W11 constant principle according to the present invention. 10... Level base, 20... Magnetoresistive element,
30... Printed circuit board, 40... Tilt angle indicator. 50...Motor 7 motor, 60.60■...Deceleration mechanism, 7
0...Shield case, 80a, 80b...Stop +1
Nisuitsuji, 90a, 90b-=stop 1 switch activated J1.100...DELTA11 regular holiday. Figure 1 Figure 4 Mushido-1

Claims (1)

[Claims] A suspended magnetic resistance element (or permanent magnet) and a permanent magnet (
or a magnetoresistive element), and a spirit level base on which the magnetoresistive element sensor is mounted, and the spirit level base is mounted based on the relative positional relationship between the magnetoresistive element f and the permanent magnet. - an inclination angle detection device designed to detect an inclination angle of a surrounding enclosure, characterized in that the level base has a power mechanism for rotating the magnetic resistance element 1000 times; Tilt angle detection device.