Sensitivity analysis in optimal control

We consider a general optimal control problem in which the constraints depend on a parameter ??, and the resulting optimal-value function V(??). A formula for the generalized gradient of V is given, and then used to obtain results concerning the problem´s stability and controllability. These results apply, in particular, to the time-optimal control problem, for which their consequences include a new criterion ensuring local null-controllability of the system and continuity of the minimal time function at the origin.