This paper describes how to design and implement a mechanism that helps to mitigate sensor attacks on industrial control systems. The proposed architecture is based on concepts from fault-tolerant control techniques. This short note explains how a Kalman filter can be used simultaneously with optimal disturbance decoupling observers to improve the performance of the mitigation mechanism for sensor attacks in cyber-physical control systems. Our proposal mitigates attacks by generating a signal that compensates the change provoked by the attacker, while at the same time reducing the number of false alarms. We demonstrate the effectiveness of our proposal using a three tanks control simulation
