The production of nitrogen from air using membrane gas separation processes is widely used in many industries. The problem of controlling the gas separation process is associated with multi-loop control using control of several variables. To build a model of a gas separator, a detailed analysis of the gas separation process was carried out in this work. This article proposes a fuzzy logic controller used to match pressure fluctuations and air flow of a gas separator. The performance of the proposed controller was evaluated in comparison with traditional controllers. The proposed fuzzy logic controller makes it possible to increase the accuracy of the gas separation control system and reduce the duration of transient processes.
Keywords: fuzzy logic, controller, gas separation, membrane technology, nitrogen, control system
A new approach to increasing the efficiency of extreme control systems by improving the method of searching for the extremum of the objective function is presented. In its multidimensional nonlinear optimization, instead of a traditional linear search along a once selected direction, an exploratory search is used, the direction of which at each step is adapted to the topology of the objective function. This makes it possible to localize an extremum as quickly as possible and significantly reduce the time of its determination. An algorithm for interpolation search for an extremum in the found interval is proposed. The objective function is modeled by a cubic spline segment based on information about its gradient vector at the boundary points of the interval, as a result of which the number of interpolation search steps is significantly reduced. The possibility of simplified nonsmooth interpolation using first-order splines in the extremum region is considered. The results of a numerical experiment confirm the high efficiency of the new method in solving various problems.
Keywords: extremal control systems, nonlinear optimization, acceleration of extremum search, quasi-Newton method, polynomial interpolation, non-smooth interpolation