Corrective control of input/output asynchronous sequential machines with adversarial inputs

In this note, we examine the control of asynchronous sequential machines with adversarial inputs. The considered asynchronous machine is of input/output type, where access to the state of the machine is not available. The adversarial input represents an unknown disturbance that can provoke unauthorized state transitions. The problem is to develop output feedback controllers that counteract the effects of the adversarial input, while controlling the machine so that the closed-loop system can match a prescribed model. The existence of appropriate corrective controllers depends on certain reachability and detectability properties of the machine and the model.