We consider the problem of constructing the optimal closed loop control in the time minimal control problem, with terminal constraint belonging to a manifold of codimension one, for systems of the form $v̇=X+uY$, $\left|u\right|\le 1$ and $v\in R^2$ or $R^3$, under generic assumptions. The analysis is localized near the terminal manifold and is developed to control a class of chemical systems.

Equivalence of several feedback and/or feedforward compensation schemes in linear systems is investigated. The classes of compensators that are realizable using static or dynamic, state or output feedback are characterized. Stability of the compensated system is studied. Applications to model matching are included.