Робастное управление запасами в сетях поставок в условиях неопределенности спроса и транспортных запаздываний

Abstract

The dissertation for the degree of doctor of technical sciences, specialty 05.13.07 – automation of control processes. – The National Technical University "Kharkiv Polytechnic Institute", Kharkiv, 2016. The dissertation is devoted to the development of a concept and synthesis methods of automated systems of robust inventory control in supply networks with uncertainty of demand and time-delays on the basis of extension of the invariant ellipsoids method using the descriptor system approach and parameter-dependent Lyapunov function. A discrete mathematical model in state space of supply network is developed, which has parametric uncertainty of affine type. The control law is based on the periodic inspection of resources stock levels and constructed in the form of a linear dynamic feedback with respect to deviation between cash and safety stock levels of resources. In order to suppress the influence of the changes in external demand while ensuring robust stability of a closed system the invariant ellipsoids method is used, which reduces the synthesis of optimal controller to a problem of the search for the smallest invariant ellipsoid of the closed system. Using linear matrix inequalities the controller synthesis problem is reduced to a sequence of semidefinite programming problems, that are solved numerically in real time. A descriptor system approach with parameter-dependent Lyapunov function is used to reduce the degree of conservatism of control results. A necessary and sufficient conditions of the control existence for a constrained robust guaranteeing inventory control synthesis problem in supply networks are formulated. A problem of estimating the allowable region in the space of control actions is formulated in terms of solvability of bilinear matrix inequalities system, for solution of which an iterative algorithm is proposed. A mathematical model of the water distribution system as an automatic control object in the form of a set of linear subsystems with nonlinear relationships under condition of the existence of a quadratic constraints on their values is developed. A problem of pumping stations modes control automation in the centralized water supply system is solved.