The subject of the article is a two-level optimization system of thermal processing of pellets mode within an automated control system of technological process of a horizontal-grate machine. At the top level the problem of the static optimization of the mode is solved periodically  based on a  mathematical models of a technological zones. At the bottom level, the pellets layer's immeasurable parameters are estimated with a help of a state observer and the optimal thermal processing mode is being stabilized.

Keywords: horizontal-grate machine, mode optimization, mathematical model, state observer