We address the problem of estimating the state of a differentially flat
system from measurements that may be corrupted by an adversarial attack. In
cyber-physical systems, malicious attacks can directly compromise the system's
sensors or manipulate the communication between sensors and controllers. We
consider attacks that only corrupt a subset of sensor measurements. We show
that the possibility of reconstructing the state under such attacks is
characterized by a suitable generalization of the notion of s-sparse
observability, previously introduced by some of the authors in the linear case.
We also extend our previous work on the use of Satisfiability Modulo Theory
solvers to estimate the state under sensor attacks to the context of
differentially flat systems. The effectiveness of our approach is illustrated
on the problem of controlling a quadrotor under sensor attacks.Comment: arXiv admin note: text overlap with arXiv:1412.432
