No 4 (2023)

This paper considers subsonic turbojet aircraft fuel consumption minimization problem during cruise phase, assuming fixed time of arrival. The problem takes into account real atmosphere data. We utilize tailwind/headwind component values at various flight levels, as well as air temperatures and atmospheric pressures at various altitudes. The solution to the altitude and speed flight profile optimization problem is through constrained coordinate descent method. The paper considers optimizing the fuel consumption of a medium-haul aircraft during the cruise phase using sample data set on temperature, pressure, and wind speed. The proposed approach achieves a decrease in fuel consumption of 1.2% when optimizing with regard to real atmosphere.

The dynamic properties of the response of a one-dimensional elastic mechanical system to an external mechanical action are examined. Transfer functions are calculated in two channels: from the force action at one of the system boundaries to the displacement of the medium sections and to the temperature. The asymptotic behavior of the transfer function is analyzed for each channel in the neighborhood of the origin on the complex plane. The case of no heat exchange between the system and the environment is considered separately.

We propose a new approach to filtering under arbitrary bounded exogenous disturbances based on reducing this problem to an optimization problem. The approach has a low computational complexity since only Lyapunov equations are solved at each iteration. At the same time, it possesses advantages essential from an engineering-practical point of view, namely, the possibilities to limit the filter matrix and to construct optimal filter matrices separately for each coordinate of the system’s state vector. A gradient method for finding the filter matrix is presented. According to the examples, the proposed recurrence procedure is rather effective and yields quite satisfactory results. This paper continues the series of research works devoted to feedback control design from an optimization perspective.

The paper proposes a predictive approach to assessing special classes of dangerous states in the development of technological processes in order to make proactive decisions. The developed approach is based on a hybrid model based on the combination of an evidence-based classifier, fuzzy logic, and a Dempster–Shafer probabilistic scheme for evidence combination. The article presents a formal description of the predictor of critical states of the technological process. The resulting approach is universal and applicable in the automation of any complex technical systems. As an example, this article considers the application of the developed approach to solve the problem for assessing the safety of the technological process of shunting trains on a hump yard. The presented example shows the high efficiency and practical usefulness of the developed approach.

A new mathematical model of transportation along the transport network represented by an undirected multigraph is formulated. A new criterion for the optimality of cargo carriages schedule is proposed. The criterion in addition to the time characteristics of transportation includes their cost, the number of undelivered cargoes. The problem to find the optimal schedule is formulated as a problem of mixed integer linear programming. Various variants of the algorithm for searching for an approximate solution to the problem are proposed. Informative examples are considered.