Felix Leonidovich Chernous'ko, a leading scientist in the field of mechanics and control theory, celebrated his sixtieth birthday.
The wide range of his research interests and achievements covers the dynamics of rigid bodies containing cavities with a liquid or movable internal masses, the theory of optimal control, the theory of differential games, vibration theory, the theory of the estimation of the state of dynamical systems, computational methods of variational calculus and optimal control, and robotics. The important results he obtained in these areas have been recognized both in Russia and abroad.
During the 1960s, he carried out a large series of researches on the dynamics of a rigid body with cavities containing a liquid. Using the classical methods of separation of motions, he studied the angular motion of the body depending on the shape of the cavity, the extent to which it was filled, and the viscosity of the liquid. These investigations were quickly recognized, earning him the reputation of a talented scientist in mechanics. His results were of great value in the design of spacecraft, which were being intensively developed at that time.
Felix Leonidovich Chernous'ko has made a considerable contribution to the theory of optimal control. His efforts were focused mainly on optimal control algorithms intended for use in control engineering. He suggested that the small-parameter methods of non-linear mechanics could be used to solve optimal control problems and developed a small-parameter technique for weakly controllable systems, which enabled closed-for m analytical approximations to optimal controls to be constructed. This method was used to optimize the control of spacecraft. He suggested the method of successive approximations for solving optimal control problems and the method of local variations, which enabled a wide class of variational problems in mechanics and control to be solved. The method of successive approximations was the first computational algorithm based on Pontryagin's maximum principle.