Effects of electromagnetic interference on controller-computer upsets and system stability

Electromagnetic interference (EMI) causes controller upsets manifested as errors in control-law computation on a controller computer, or as disturbances in data transmission between sensors/actuators and the controller computer, which may be critical to system stability. We compute the probability of these EMI-induced upsets in terms of the parameters governing EMI behaviors and the conditional probabilities of upsets in the presence of EMI, which is useful for the design and verification of the integrity of reliable controllers. The results are used to modify a system dynamic equation to examine asymptotic stability with probability one for the random sequences of the system states evolving according to the resultant dynamic equation, which are validated via a simple EMI experiment in a reverberation chamber.