On the Input Estimation Problem for PDE: the Regularized Solutions and Evolutionary Numerical Algorithms I. Sivergina Institute of Mathematics and Mechanics S.Kowalewski Str. 16, 620219 Ekaterinburg, Russia siv@oou.imm.intec.ru The present paper is devoted to the input estimation problem for dynamical system described by the partial differential equation of parabolic type. The so called $H_\infty$- approach to the deterministic treatment of uncertainties in the system is taken. Two issues are treated here. The first of these is the evolutionary procedure of estimating the input of the system. The second is the regularization problem for the informational state of the system - the last one is the value function in a optimization problem related to an estimation problem under consideration.