Abstract
A time optimal control problem is replaced by an equivalent one with a performance index in the form of integral form. Constraints on controls are assumed. To obtain the optimality conditions for the Neumann problem, the generalization of the Dubovitskii-Milyutin theorem given byWalczak (1984, Acta Universitatis Lodziensis Folia Mathematica, 187-196; 1984, J. Optim. Theor. Appl., 42, 561-582) was applied.