Fault tolerant automatic control system utilizing analytic redundancy

An aircraft flight control computer for fault tolerant automatic control of an aircraft, comprising:

• a data processing apparatus, said data processing apparatus transforming a mathematical model of the aircraft into a plurality of linear equations,
• said data processing apparatus further comparing a signal from a sensor with an expected value resulting from the plurality of linear equations to determine whether the sensor is functioning properly.

A method for fault tolerant automatic control of a time-varying device, comprising the steps of:

• transforming a mathematical model of the time-varying device into a plurality of linear equations;
• and
• comparing a signal from a sensor with an expected value resulting from the plurality of linear equations to determine whether the sensor is functioning properly.

A computer readable storage medium for storing code which causes one or more computers to control a dynamic device having a sensor which senses a time-varying parameter, the code causing the one or more computers to:

• transform a mathematical model of the dynamic device into a plurality of linear equations;
• and
• compare a signal from the sensor with an expected value resulting from the plurality of linear equations to determine whether the sensor is functioning properly.

A system for detecting the failure of a time-varying sensor, comprising:

• a computer capable of (i) transforming a status signal from a sensor and a corresponding reference signal into a non-time-varrying coordinate system, (ii) generating a sensor estimate in the non-time-varying coordinate system based on the transformed sensor status signal and the transformed reference signal, (iii) transforming the sensor estimate into a physical coordinate system, and (iv) detecting an error in the sensor based on a comparison of the transformed sensor estimate and the sensor status signal.