JPH10340122A - Self-diagnosing device for system controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid the operation stopping of a system when a failure does not occur and to surely perform failure management of a system by accumulating observation signals in time sequences and deciding whether failure decision is due to the malfunction of a sensor or not through a sensor malfunction deciding means based on that. SOLUTION: A self-diagnosing device 2 is formed by combing a signal accumulating means 3 and a sensor malfunction deciding means. First, the means 3 of the device 2 that is installed on a number control panel 5 accumulates observation signals which are inputted from a system controller 1. In this state, when accumulated observation signals exceed a set value and a failure signal is sent to the panel 5, a sensor malfunction deciding means 4 decides whether failure decision that is made by the device 1 is due to a sensor malfunction or not based on past observation signals accumulated in the means 3, the shift of an observation signal that is sent after failure decision and the set value which decides a failure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-diagnosis device for a system control device, and for example, when a failure occurs in a compressor system or the like, determines whether the failure is caused by a malfunction of a sensor provided in the system. The present invention relates to a self-diagnosis device of a system control device that can make a determination.

[0002]

2. Description of the Related Art FIG. 3 shows an example of a schematic configuration of a compressor system for generating compressed air essential for a production line. As shown in FIG. 3, the compressor system compresses the air introduced from the suction port into two stages by the compressor, and the air is compressed by the first and second stage compressors 31 and 32. The compressed air is discharged from the discharge port. An intercooler 33 for cooling the compressed air compressed by the first stage compressor 31 is provided between the first stage compressor 31 and the second stage compressor 32.
However, downstream of the second stage compressor 32, the second stage compressor 3
An aftercooler 34 for cooling the compressed air further compressed by the second cooler 2 is provided. The first-stage compressor 31 and the second-stage compressor 32 are driven by an electric motor 35 to lubricate a lubricating oil of a gear at a connection portion thereof, and the oil and the cooling water are supplied to the oil pump 36. An oil cooler 37 for exchanging heat is also provided. Here, in the above-described compression system, for example, the first-stage discharge temperature of the compressed air discharged from the first-stage compressor 31, the second-stage discharge temperature discharged from the second-stage compressor 32, and the oil pump 36 The oil supply temperature and oil supply pressure of the oil supplied from the engine are monitored. For example, a sensor for monitoring the one-stage discharge temperature
Usually, a thermocouple or the like is used. By the way, since a thermocouple uses a thin wire, a connecting portion or the like may be damaged during an attaching operation, and may be disconnected during an actual operation of a system.
If such a sensor failure or a failure of equipment such as a compressor in the system occurs, proper system operation cannot be performed. Therefore, a system control device that controls the system requires a sensor failure or equipment failure. A function for determining a failure is often provided. Here, the failure determination is performed, for example, on condition that the value of the observation signal from the sensor exceeds a set value. The failure diagnosis function described above is, of course, required not only for the compressor system but also for systems provided in various plants such as nuclear power, thermal power, chemicals, and pumps. It is disclosed in JP-A-2-2404. In the plant failure diagnosis device disclosed in the above document, the cause of the failure is specified based on observation data from sensors and data input by an operator.
In particular, with this device, even if a contradiction occurs in the algorithm for investigating the cause due to a sensor failure or the like and the cause cannot be identified as one, it is possible to resolve the contradiction by assuming a sensor failure or input error, Can be presented to the operator.

[0003]

Incidentally, in the plant failure diagnosis apparatus described above, equipment failures and sensor failures are included, but malfunctions of the sensors are not considered. Here, a sensor failure refers to a state in which an abnormal state continues steadily, whereas a sensor malfunction refers to an instantaneous abnormal state due to an external factor, and returns to a normal state when the external factor disappears. Shall be. That is, in a system in which many devices operate, for example, electrical noise or the like is emitted constantly or irregularly, and the sensor may malfunction or noise may be superimposed during transmission of observation signals. There is a possibility that the input from the sensor changes to a value at which the failure determination is performed, and the failure determination is erroneously performed. This noise is removed to some extent by a filter or the like, but it is difficult to eliminate all of the noise. In particular, the compressor system is an indispensable facility in production, so it must be considered that it will be used in all environments. Therefore, it is necessary to avoid as much as possible a situation in which it is determined that a malfunction has occurred due to a malfunction of the sensor even though no malfunction has actually occurred and the operation of the compressor is stopped. In order to solve the problems in the conventional technology, the present invention is to improve a self-diagnosis device of a system control device, and to determine whether a failure determination made by the system control device is caused by a malfunction of a sensor. It is an object of the present invention to provide a self-diagnosis device capable of performing the following.

[0004]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a system control device which determines a system failure based on an observation signal from a sensor provided in the system and performs predetermined control. In a self-diagnosis device of a system control device for performing self-diagnosis of a judgment, a signal accumulating means for accumulating the observation signals in time series, and the failure judgment based on the malfunction of the sensor based on the observation signals accumulated by the signal accumulation means. A self-diagnosis device of a system control device characterized by comprising a sensor malfunction determination means for determining whether or not the self-diagnosis is performed. In the self-diagnosis device of the above system control device, it is determined whether or not the failure determination performed by the system control device is caused by a malfunction of the sensor. Performing predetermined control such as stopping the operation of the system is avoided as much as possible. Therefore, system failure management can be performed more reliably than before. For example, if the system control device determines that a fault has occurred in the system when the observed signal exceeds or falls below a predetermined value, the sensor malfunction determination means determines the difference between the set value and the observed signal by a predetermined value. If the value integrated during the period is greater than the determination value, and if the number of times the observation signal exceeds or falls below the set value within the predetermined period is less than the number of determinations, the failure determination is performed by the sensor. It is determined that this is due to a malfunction. The self-diagnosis device of the system control device is used, for example, in a compressor system. The compressor system is an indispensable system for performing production, and is particularly useful because a situation in which operation is stopped due to a malfunction of a sensor can be prevented as much as possible.

[0005]

An embodiment of the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention. It should be noted that the following embodiments are examples embodying the present invention, and do not limit the technical scope of the present invention. Here, FIG. 1 is a diagram showing a schematic configuration of a self-diagnosis device of a system control device according to an embodiment of the present invention, and FIG. 2 illustrates how a malfunction of a sensor is determined by the self-diagnosis device of the system control device. FIG. As shown in FIG. 1, the self-diagnosis device of the system control device according to the present embodiment determines a system failure based on an observation signal from a sensor provided in, for example, a compressor system (see FIG. 3) and determines a predetermined value. A self-diagnosis device 2 of the system control device for self-diagnosing the failure determination of the system control device 1 for controlling the system, wherein the signal storage means 3 accumulates the observation signals in time series;
And a sensor malfunction judging means for judging whether or not the failure judgment is caused by a malfunction of the sensor based on the observation signal accumulated by the above. The self-diagnosis device 2 of the system control device is provided, for example, in a number control panel 5 that supervises a plurality of compressor controllers. Here, the compressor controller corresponds to the system control device 1, monitors an observation signal from a sensor provided in the compressor system, and determines a failure of a device or the like when the observation signal exceeds a set value. It issues an alarm and sends out a failure signal indicating that a failure has occurred in the unit control panel. Further, when the failure determination is determined, control such as stopping the compressor is performed. Further, in addition to the above-described failure signal, the observation signal, the sequence input / output for control, and the set value for failure determination are sent from the system controller 1, that is, the compressor controller, to the number control panel 5. Further, a control command is sent from the number control panel 5 to the system control device 1. In the self-diagnosis device 2 of the system control device provided in the number control panel 5 and the like, observation signals input from the system control device 1 such as a compressor controller are accumulated in time series by the signal accumulation means 3. In this state, when the observation signal exceeds the set value and a failure signal is sent to the number control panel 5, the self-diagnosis device 2 of the system control device stores the past observation signal stored in the signal storage means 3, Based on the transition of the observation signal sent after the failure determination and the set value for determining the failure, it is determined whether or not the failure determination performed by the system control device 1 is due to a sensor malfunction.

Hereinafter, the determination of the sensor malfunction performed by the sensor malfunction determination means 4 will be described more specifically with reference to FIG. As shown in FIG. 2, when a failure is determined beyond the failure set value, the sensor malfunction determination means 4
First, ΔP = set value−observed signal is calculated every time the observation signal is sampled in the range of time t around the time when the set value is exceeded, and the value P is obtained by integrating this value in the range of time t. Then, it is determined whether or not this value P is larger than the determination value h. That is, P> h. Under this condition, it is confirmed whether or not the observation signal is sufficiently separated from the set value before and after the signal at the time when it is determined that a failure has occurred. Next, it is determined whether the number of times C exceeding the set value within the range of the time t is equal to or less than a predetermined number of times of determination n. Note that the number of sampling points of the observation signal is one. Based on this condition, it is determined whether the signal exceeding the set value is instantaneously generated due to an external factor or constantly generated due to a sensor failure. In the sensor malfunction determining means 4,
When P> h and C <n are satisfied under the above two conditions, it is determined that the failure determination is due to a malfunction of the sensor, and a control command including a determination of the sensor malfunction is transmitted to the system control device 1. , Such as canceling the failure determination. If the above two conditions are not satisfied, it is determined that the failure determination is not due to a malfunction of the sensor, and the failure determination is determined and predetermined control such as stopping the compressor is performed on the system control device 1. Let As described above, in the self-diagnosis device of the system control device according to the present embodiment, it is determined whether or not the failure determination performed by the system control device is due to a malfunction of the sensor. A situation in which the operation of the system is stopped due to a malfunction of the sensor despite the absence of the sensor can be avoided as much as possible.

[0007]

In the above embodiment, the self-diagnosis device of the system control device is provided on a number control panel different from the compressor controller corresponding to the system control device. This is for managing the entire compressor system. However, a self-diagnosis device of the system control device may be provided for each system controller, that is, each compressor controller. Further, in the above embodiment, it is determined that a failure has occurred when the value exceeds the set value. However, even when it is determined that a failure occurs when the value falls below the set value, the system according to the present invention can be used. The self-diagnosis device of the control device is applicable. Even in this case,
The sensor malfunction determination means 4 determines the sensor malfunction when P> h and C <n. Further, in the above embodiment, the failure determination is performed for the compressor system, but the present invention can be applied to other systems. Such a self-diagnosis device of the system control device is also an example of the self-diagnosis device of the system control device in the present invention.

[0008]

As described above, according to the present invention, a system control device that determines a failure of a system based on an observation signal from a sensor provided in the system and performs a predetermined control and performs a self-diagnosis of the failure determination is provided. In the self-diagnosis device of the device, a signal accumulating means for accumulating the observation signals in time series, and whether or not the failure determination is based on a malfunction of the sensor based on the observation signals accumulated by the signal accumulating means. The self-diagnosis device of the system control device is provided with a sensor malfunction judging means for judging. In the self-diagnosis device of the above system control device, it is determined whether or not the failure determination performed by the system control device is caused by a malfunction of the sensor. Performing predetermined control such as stopping the operation of the system is avoided as much as possible. Therefore, system failure management can be performed more reliably than before. For example, if the system control device determines that a fault has occurred in the system when the observed signal exceeds or falls below a predetermined value, the sensor malfunction determination means determines the difference between the set value and the observed signal by a predetermined value. If the value integrated during the period is greater than the determination value, and if the number of times the observation signal exceeds or falls below the set value within the predetermined period is less than the number of determinations, the failure determination is performed by the sensor. It is determined that this is due to a malfunction. The self-diagnosis device of the system control device is used, for example, in a compressor system. The compressor system is an indispensable system for performing production, and is particularly useful because a situation in which operation is stopped due to a malfunction of a sensor can be prevented as much as possible.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a self-diagnosis device of a system control device according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining a malfunction determination of a sensor.

FIG. 3 is a diagram for explaining a compressor system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... System control apparatus 2 ... Self-diagnosis apparatus of system control apparatus 3 ... Signal accumulation means 4 ... Sensor malfunction judgment means

Claims (3)

[Claims] 1. A self-diagnosis device of a system control device for self-diagnosing a failure judgment of a system control device that determines a system failure based on an observation signal from a sensor provided in the system and performs predetermined control. Signal accumulating means for accumulating observation signals in time series; and sensor malfunction judging means for judging whether or not the failure judgment is caused by a malfunction of the sensor based on the observation signals accumulated by the signal accumulating means. A self-diagnosis device for a system control device, comprising: 2. The system control device according to claim 1, wherein when the observation signal exceeds or falls below a predetermined value, the system control device determines that a failure has occurred in the system. When the value obtained by integrating the difference from the observation signal within a predetermined period is larger than a judgment value, and when the number of times the observation signal exceeds or falls below the set value within the predetermined period is equal to or less than the judgment number. 2. The self-diagnosis device for a system control device according to claim 1, wherein the failure determination is determined to be due to a malfunction of the sensor. 3. The self-diagnosis device for a system control device according to claim 1, wherein the system is a compressor system.