The main result of this paper contains a representation of the minimum cost of a free time control problem in terms of the upper envelope of generalized semisolutions of the Hamilton-Jacobi equation. A corollary generalizes a similar result due to Vinter using smooth subsolutions.
Citation:
Nour, C. (2004). Smooth and Nonsmooth Duality for Free Time Problems. In Optimal Control, Stabilization and Nonsmooth Analysis (pp. 323-331). Springer, Berlin, Heidelberg.