fuzzy differential equation; second order control system; fuzzy solution; likelihood
In this paper, the observability of fuzzy logic second order control system is studied from the aspect of fuzzy differential equations. The fuzzy observability in the weak sense is created using the concept of “likelihood” to indicate on which level and along which solution the state is most likely observable. One of the initial state range has been derived with the given input and output. The result generalizes the previous results.
 Balasubramaniam P., Park J. Y.: Controllability for the nonlinear fuzzy neutral Volterra integrodifferential equations. Preprint
 Cesari L.: Optimization – Theory and Application
. Springer, Berlin 1983 MR 0688142
 Ding Z., Ma, M., Kandel A.: On the observability of fuzzy dynamical system (I). Fuzzy Sets and Systems 88 (1990), 155–174