Search for the Optimal Control over Current Regimes in Electroplating Processes with Multi Anodes at a Diversified Assortment of Treated Articles

Abstract

Methods of controlling electroplating processes are considered, and the shortcomings in the use of basic engineering and structural configurations for this purpose are revealed. An original approach consisting of controlling current regimes in a multianode bath is proposed. In implementing this approach, the problem of the optimal control over electroplating processes in compliance with the criteria of the coating’s nonuniformity and process duration is formulated. The electroplating process in a bath with multi anodes is considered as an object of control, for which the input and output vectors of the process are specified, together with the external disturbances and the control vector. The control vector is related with the optimality criterion by composing a mathematical model with the distributed coordinates based on an elliptic partial differential equation with different ways of correcting the corresponding current in every anodic section. A series of experiments with a complicatedly shaped article are performed to prove the adequacy of this mathematical model and the efficiency of the proposed approach and demonstrate a “ravine” character of the target criterion function. A three-level architecture is selected for the control system to implement the optimal control. The procedure of the preliminary search for the optimal control with the formation of a corresponding matrix is proposed due to the very time-consuming character of the solution of the formulated problem. The actions to be performed in the cases when the control matrix contains or does not contain the found solution for an incoming lot of articles are considered.