1. An apparatus comprising: a processor; and one or more computer readable mediums collectively including instructions that, when executed by the processor, cause the processor to: obtain a plurality of healthy sensor data, each of the healthy sensor data includes a plurality of sensed values of a corresponding sensor among a plurality of sensors in normal operation; generate a healthy data distribution of at least two sensors among the plurality of sensors based on the plurality of healthy sensor data; and generate a function of a status probability distribution of the plurality of sensors with respect to time under a condition of sensor data with respect to time based on the healthy data distribution.