On controlled invariance for fully nonlinear systems

We give a necessary and sufficient condition for local controlled invariance that applies to fully nonlinear control systems. This generalizes an earlier result of Nijmeijer and van der Schaft by eliminating some of the constant-rank assumptions for the distributions that occur in the statement of their result. Our work is related to the recent work of Cheng and Tarn, who showed that such constant-rank assumptions can be weakened when discussing the local controlled invariance of nonlinear systems that are affine in the control.