State estimation apparatus, method, and program

1. A state estimation apparatus comprising:

a processor;

a memory storing a program executable by the processor; and

a receiver configured to receive a time series of a first signal relating to an operation of a facility of a monitoring target and a second signal, from a sensor that acquires the first signal and the second signal acquired in conjunction with the first signal,

wherein the processor is configured to:

extract a time interval to be analyzed from the time series of the first signal using the second signal acquired in conjunction with the first signal;

estimate a change in a state of the facility using waveform data of the time interval of the first signal;

using a current and a voltage of the facility as the first and second signals, respectively, extract a time interval of the current of the facility operating at the voltage of a specified value or in a specified range;

calculate time-series data of a risk of failure of the facility, using time-series data of current information in the time interval;

apply a filtering process corresponding to a time constant of a temporal change of the state to be estimated, on the time-series data of the risk of failure corresponding to the time interval;

estimate a temporal change in the state of the facility; and

set a maintenance interval for preventing a failure of the facility based on the estimated temporal change.

2. The state estimation apparatus according to claim 1 , wherein the processor is configured to exclude, from an analysis target, a time interval in the time series of the first signal, the time interval corresponding to an operating mode which is unaffected by a change in a state of the facility.

3. A state estimation method that estimates a state of a facility by a computer, the method comprising:

acquiring, by a sensor, a first signal relating to an operation of a facility of a monitoring target and a second signal of the facility in conjunction with the first signal;

obtaining a time series of the first signal and the second signal from the sensor;

extracting a time interval to be analyzed from the time series of the first signal using the second signal acquired in conjunction with the first signal;

estimating a change in a state of the facility using waveform data of the time interval of the first signal;

using a current and a voltage of the facility as the first and second signals, respectively, to extract a time interval of the current of the facility operating at the voltage of a specified value or in a specified range;

calculating time-series data of a risk of failure of the facility, using time-series data of current information in the time interval;

applying a filtering process corresponding to a time constant of a temporal change of the state to be estimated on the time-series data of the risk of failure corresponding to the time interval to estimate a temporal change in the state of the facility; and

setting a maintenance interval for preventing a failure of the facility based on the estimated temporal change.

4. The state estimation method according to claim 3 , comprising:

excluding, from an analysis target, a time interval in the time series of the first signal, the time interval corresponding to an operating mode which is unaffected by a change in a state of the facility.

5. A non-transitory computer-readable recording medium storing a program, which if executed, causes a computer to execute processing comprising:

obtaining a time series of a first signal relating to an operation of a facility of a monitoring target and a second signal, from a sensor that acquires the first signal and acquires the second signal in conjunction with the first signal;

extracting a time interval to be analyzed from the time series of the first signal using a second signal acquired in conjunction with the first signal;

estimating a change in a state of the facility using waveform data of the time interval of the first signal;

using a current and a voltage of the facility as the first and second signals, respectively, to extract a time interval of the current of the facility operating at the voltage of a specified value or in a specified range;

calculating time-series data of a risk of failure of the facility, using time-series data of current information in the time interval;

applying a filtering process corresponding to a time constant of a temporal change of the state to be estimated on the time-series data of the risk of failure corresponding to the time interval to estimate a temporal change in the state of the facility; and

setting a maintenance interval for preventing a failure of the facility based on the estimated temporal change.

6. The non-transitory computer-readable medium according to claim 5 , the processing comprising:

excluding, from an analysis target, a time interval in the time series of the first signal, the time interval corresponding to an operating mode which is unaffected by a change in a state of the facility.

7. A state estimation apparatus comprising:

a processor;

a memory storing a program executable by the processor; and

a receiver configured to receive, from a sensor, a time series of a power supply voltage applied to a facility and a current flowing through the facility,

wherein the processor is configured to:

extract, from the time series of the current, a time interval in which the power supply voltage is at a predetermined value, in a predetermined range, or in a predetermined state;

estimate a state of the facility from current information in the time interval extracted, using a relationship between the current information of the facility and a deterioration degree of the facility including a risk of failure of the facility or a change over time of the facility;

apply a filtering process to the state of the facility estimated from the current information in the time interval to separate and extract a state change of the facility, the filtering process corresponding to a time constant of a temporal change of the state to be estimated; and

set a maintenance interval for preventing a failure of the facility based on the estimated temporal change.