Unit space generating device, plant diagnosing system, unit space generating method, plant diagnosing method, and program

A unit space generating method of generating a unit space used in a case of diagnosing an operation state of a plant on the basis of a Mahalanobis distance, the method comprising:

• a sampling data acquisition step of acquiring a sampling data group of a state quantity of the plant, which is measured for each fixed cycle;
• an adoption determination step of determining whether or not to adopt the sampling data group as a unit space generation data group, which is based on the unit space, on the basis of an adoption probability calculated each time the sampling data group is acquired;
• a unit space generation step of generating the unit space on the basis of a plurality of the adopted unit space generation data groups;
• and
• a step of acquiring an output value of the plant corresponding to the sampling data group,
• wherein in the adoption determination step,
• the adoption probability is calculated such that the sampling data group at a point where an absolute value of at least one of a change rate and a change amount of the acquired output value is large is likely to be adopted, and
• the adoption probability is raised as the absolute value of at least one of the change rate and the change amount of the acquired output value increases.

A program that causes a computer of a unit space generating device, which generates a unit space used in a case of diagnosing an operation state of a plant on the basis of a Mahalanobis distance, to function, the program causing the computer to execute:

• a sampling data acquisition step of acquiring a sampling data group of a state quantity of the plant, which is measured for each fixed cycle;
• an adoption determination step of determining whether to adopt the sampling data group as a unit space generation data group, which is based on the unit space, on the basis of an adoption probability calculated each time the sampling data group is acquired;
• a unit space generation step of generating the unit space on the basis of a plurality of the adopted unit space generation data groups;
• and
• a step of acquiring an output value of the plant corresponding to the sampling data group,
• wherein in the adoption determination step,
• the adoption probability is calculated such that the sampling data group at a point where an absolute value of at least one of a change rate and a change amount of the acquired output value is large is likely to be adopted, and
• the adoption probability is raised as the absolute value of at least one of the change rate and the change amount of the acquired output value increases.