  Micro Aerial Vehicles (MAVs) rely on onboard attitude and position sensors
for autonomous flight. Due to their size, weight, and power (SWaP) constraints,
most modern MAVs use miniaturized inertial measurement units (IMUs) to provide
attitude feedback, which is critical for flight stabilization and control.
However, recent adversarial attack studies have demonstrated that many commonly
used IMUs are vulnerable to attacks exploiting their physical characteristics.
Conventional redundancy-based approaches are not effective against such attacks
because redundant IMUs have the same or similar physical vulnerabilities. In
this paper, we present a novel fault-tolerant solution for IMU compromised
scenarios, using separate position and heading information to restore the
failed attitude states. Rather than adding more IMU alternatives for recovery,
the proposed method is intended to minimize any modifications to the existing
system and control program. Thus, it is particularly useful for vehicles that
have tight SWaP constraints while requiring simultaneous high performance and
safety demands. To execute the recovery logic properly, a robust estimator was
designed for fine-grained detection and isolation of the faulty sensors. The
effectiveness of the proposed approach was validated on a quadcopter MAV
through both simulation and experimental flight tests.
