False Data Injection Attack for Switched Systems

This letter studies the secure state estimation problem for switched systems. The single/joint false data injection attacks are designed with the aim at altering the sensor signal and/or switching signal. Firstly, it is shown that the attack will steer system state to infinity but could be detectable by
$\chi ^{2}$
detector when only the switching signal is attacked. In addition, the attack acting on sensor signal is designed, which can be recognized by the summation (SUM) detector but fails by
$\chi ^{2}$
detector. Then a joint attack strategy is devised and a sufficient condition is given to guarantee that the joint attack is strictly stealthy. The joint attack performs well since it can launch a strictly stealthy attack compared with the sensor signal attack. Finally, a numerical example is given to verify the theoretical results.