Method of controlling photographic emulsion manufacturing process by non-linear approximation

Claim 1

1 . A method of controlling a photographic emulsion manufacturing process by non-linear approximation, said method comprising: defining the set U (k) of a plurality of process inputs, such as the flow rate of silver nitrate, as follows: defining the set X (k) of a plurality of states, such as the silver halide concentration, as follows: defining the set Y (k) of a plurality of process outputs, such as the potential of silver and the pH value, as follows: non-linearly approximating the system by an equation of state which is given by the following formula: defining an evaluation function J (k) expressed by the following formula: where obtaining a feedback matrix F b (k) and a feed-forward control matrix F f (k) which minimize said evaluation function J (k); and calculating manipulated variables which are to be applied to a plant (2) from the obtained feedback matrix F b (k) and feed-forward matrix F f (k), where G is a function for correcting an input limitation applied on the plant (2) and ΔU C (k) is U C (k) - U C (k-l).