Inertial reference unit and system with enhanced integrity and associated integrity-checking methods

An inertial reference unit (URI) for providing and monitoring flight parameters of an aircraft, comprising:

• a first measurement channel (V1) comprising:
• a first high-performance inertial measurement unit (UMI1) comprising first measurement means for measuring specific forces and first measurement means for measuring angular velocities, and
• a first computing unit (CPU1) coupled to the first inertial measurement unit (UMI1) and comprising a first inertial processing function (IP1) able to compute pure inertial data based on the measurements of said first measurement unit;
• a second measurement channel (V2) comprising:
• a second inertial measurement unit (UMI2) of performance lower than the first inertial measurement unit (UMI1) and comprising second measurement means for measuring specific forces and second measurement means for measuring angular velocities, and
• a second computing unit (CPU2) coupled to the second inertial measurement unit (UMI2) and comprising a second inertial processing module (IP2) able to compute pure inertial data based on the measurements of said second measurement unit;
• an integrity check function (CTR) able to implement a method for checking the integrity of the data of the first measurement channel (V1) based on the data provided by the second measurement channel (V2);
• and
• a synchronization means for synchronizing the measurements of the first and second inertial measurement units;
• the first and second inertial measurement units being mechanically mounted fixedly with one another in the inertial reference unit (URI).