JPH04158223A - Detecting device of fault of sensor - Google Patents

Abstract

PURPOSE:To detect an error of a detecting sensor correctly by a method wherein output data are taken in and the detection of the sensor in a faulty state is reckoned as faulty by a reckoning means when the output data are within a certain range. CONSTITUTION:A water level in a bathtub is detected by a sensor element 1. Next, a detected value is delivered as a sensor output voltage to a microcomputer 2. When the sensor output voltage comes in either one of error ranges a1 and b1, the microcomputer 2 reckons it as an error immediately on the basis of data held therein. In this way, the voltage is reckoned as the error substantially outside the range of detection of the sensor, a sphere wherein the operation is indefinite is eliminated and the error of the sensor is detected correctly.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a sensor failure detection device, and particularly to a sensor failure detection device that considers detection of a defective state of a sensor that detects water level in a bathtub as a failure. be.

[Traditional technique #]

Conventionally, when detecting the water level in a bathtub, etc. using a sensor, there is a possibility that the power supply voltage level or ground level applied to the sensor may be defective (
error).

FIG. 5 is a diagram showing a conventional sensor detection area. In FIG. 5, the horizontal axis shows the sensor level, and the vertical axis shows the output voltage from the sensor. Also, Y is the output data from the sensor (
↓ marks a and b indicate blank areas, and C indicates the sensor detection range that can be detected by the sensor.

As shown in FIG. 5, in this conventional example, there is a sensor detection range Y which is the sensor output voltage range, and there are blank areas a and b between this range and the error detection level.

[Problem to be solved by the invention]

As described above, in the conventional example, when detecting water level etc., there is a sensor output voltage range, and a blank area exists between that range and the error detection level, and if the detected value is in this blank area, The problem was that although it was a malfunction, it did not constitute an error (defect).

This invention was made in order to solve the above-mentioned problems, and it is assumed that there is almost no error outside the sensor detection range, so it eliminates the parts where the operation is unclear, eliminates the blank area, and improves the sensor's performance. The purpose is to detect errors correctly.

[Means to solve the problem]

For this reason, the present invention includes a detection sensor that detects water level, etc., and a data processing means that takes in output data from the detection sensor and processes the data, and outputs detection when the detection sensor is in a defective state. The above objective is achieved by a sensor failure detection device that is equipped with a means for determining that a sensor is defective if the data is within a certain range.

[Effect]

The sensor defect detection device according to the present invention uses a detection sensor to detect water level, etc., uses a data processing means to capture output data from the detection sensor and processes the data, and uses a determination means to detect a defective state of the detection sensor. If the output data is within a certain range, it is considered defective.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

This embodiment relates to an error detection device for a water level sensor in a bathtub in an automatic hot water supply system using an electric water heater (hereinafter referred to as electric water heater).

FIG. 1 is a configuration diagram showing the configuration of an embodiment of the present invention, and FIG.
The figure is a diagram showing a data graph held by the microcomputer in Figure 1, Figure 3 is a diagram showing water level detection by the water level sensor of this embodiment, and Figure 4 is a circuit diagram of the control board in Figure 3. .

In FIG. 1, A is a detection sensor, which is composed of a sensor section 1 and is a means for detecting water level and the like. Reference numeral B denotes data processing means, which is composed of a microcomputer (hereinafter referred to as microcomputer) 2, and is means for taking in output data from the detection sensor A and processing the data. Reference numeral C denotes a recognition means (described later), which is constituted by the microcomputer 2 and is a means (to be described later) which regards the detection of a defective state of the detection sensor as being defective if the output data is within a certain range.

In FIG. 3, 3 is a bathtub, and 4 is an 1IJil board, which incorporates the electric circuit shown in FIG.

Next, the operation of this embodiment will be explained using FIGS. 1 to 4.

In FIG. 1, a water level sensor (FIG. 3), which is a sensor unit 1, detects the water level in the bathtub. The detected value is sent to the microcomputer 2 as a sensor output voltage via the electric circuit of the control board 4 (FIG. 4).

As mentioned above, the microcomputer 2 has the data shown in the graph of FIG. 2, so the sensor output voltage is '! If the error falls within either of the error ranges a, , b shown in the shaded area of Figure J2, it is immediately regarded as an error. Note that due to variations in sensors, the resulting error may become a blank area with respect to the standard value (average value) and may be regarded as an error. In this example, the microcomputer input terminal has a power supply of 5V, whereas the error range a (Fig. 2) is 4.8V or more,
The error range is 0.4v or less.

As described above, in this embodiment, a defective state (short circuit, open circuit) of the water level sensor (pressure sensor) is detected when the output voltage from the sensor is within a certain range (in this case, the error range a1 or s). Therefore, it can be regarded as a defect (error).

〔Effect of the invention〕

As explained above, according to the present invention, there is provided a defect detection device that correctly detects sensor errors by regarding almost all errors outside the sensor detection range, eliminating unclear areas of operation, and eliminating blank areas. Obtainable.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing the configuration of an embodiment of the present invention, and FIG.
The figure shows the data graph held by the microcontroller in Figure 1J1,'! Figure J3 is a diagram showing water level detection by the water level sensor of this embodiment, Figure 4 is a circuit diagram of the control board of Figure 3,'!
Figure J5 is a diagram showing the sensor detection area of the conventional example. A...-Detection sensor B--Data processing means C--At first glance means 1--Sensor section 2 =--Microcomputer 3--One bath 4--Control board A I+ b+ =” ”-error range a, b
--------Blank area Note that the same reference numerals in the drawings indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] A detection sensor that detects water level, etc.; and data processing means that takes in output data from the detection sensor and processes the data; What is claimed is: 1. A sensor failure detection device comprising: a means for determining that a sensor is defective if it is within a certain range;