Patent Document ID: 8326790
Application ID: 12488315
Patent Flag: 1

Claim One:
1. A method for fault reasoning comprising: obtaining sensor readings of a building control system; transforming sensor readings into a vector of fuzzy observable states; matching each of the fuzzy observable states against states in a table listing observable states that admit particular faults and observable states that exclude particular faults; and performing reasoning on outputs of the matching including determining a number of admitting successive time steps needed to increase a fault rate from a first percent to a second percent; wherein transforming measurements to a vector of fuzzy observable states is expressed as a vector S with values from an interval of zero to one indicating how a combination of measurements belongs to particular observable states; a mapping of table has rows which are multiplied by corresponding values from the vector S to result in a table indicating how faults are admitted and excluded by observable states relative to vector S; for each fault, admitting and excluding rates are calculated as maximal positive and minimal negative values, respectively; and a difference Fa between the admitting and excluding rates is calculated for each fault.