Agrachě, A. A.; Gamkrelidze, R. V. Variation of “time change” in optimal control. (English. Russian original) Zbl 0723.49023 Sov. Math., Dokl. 41, No. 2, 227-231 (1990); translation from Dokl. Akad. Nauk SSSR 311, No. 2, 265-270 (1990). Summary: We consider a time-optimal problem for smooth systems. We derive necessary conditions for optimality, particularly for bang-bang controls which satisfy Pontryagin’s maximum principle. As an application, we consider a rigid body which is allowed to rotate at a given speed about two fixed axes. MSC: 49K30 Optimality conditions for solutions belonging to restricted classes (Lipschitz controls, bang-bang controls, etc.) Keywords:time-optimal problem; smooth systems; necessary conditions for optimality; bang-bang controls PDFBibTeX XMLCite \textit{A. A. Agrachě} and \textit{R. V. Gamkrelidze}, Sov. Math., Dokl. 41, No. 2, 227--231 (1990; Zbl 0723.49023); translation from Dokl. Akad. Nauk SSSR 311, No. 2, 265--270 (1990)