Automated Control System for the Process of Electroplating in a Bath with a Non-Conductive of Electric Current Screen

Abstract

The article has developed an automated control system for the electroplating process, which has a two-level architecture. At the lower level, the technological parameters of each bath are controlled: temperature stabilization and electrolyte level in the bath; stabilization or software control of electric current. At the upper level, the problem of calculating the optimal configuration of a non-conductive of electric current perforated screen is solved, providing a minimum value of the unevenness of the coating. For this, a nonlinear mathematical model of the galvanic process in a bath with a perforated screen is developed which differs from the known ones by adding boundary conditions on a non-conductive screen. It is noted that the nonlinearities contain the equations of the model describing the boundary conditions near the anode and cathode of the galvanic bath. Therefore, a numerical method for solving the model equations is developed, which is distinguished by the implementation of Newton’s method in Maxima (the mathematical package) through input/output redirection. The article describes an algorithm for working with a mathematical package, a feature of which is the preparation of package commands in a text format and parsing the results of calculations also from a text file. The applied numerical method for solving the system of model equations has a quadratic convergence rate which indicates its effectiveness on a large grid, for example, of 900 nodes. Numerous computational experiments is shown a tenfold gain in time compared to the traditional iterative method described in well-known articles.For the first time, the problem of discrete optimization was posed and solved for the developed automated control system for the electroplating process. A feature of the formulation of this problem are restrictions that allow only a complete enumeration of possible values of the varied parameters, the volume of which is not large. Therefore, a sequential algorithm for solving the optimization problem is used. The combinations of possible values of the varied parameters and criterion values are given, and the time for solving the optimization problem is analyzed.