Reliability and Quality of Complex Systems

Background. The problem of increasing noise immunity, secrecy, reliability, throughput and range of ground and airborne electronic systems (RES), as well as determining the values of the residual resource, is relevant in the modern world. The technical condition of radio engineering systems depends on many factors, the main ones of which will be taken into account. Knowing the standard values of the diagnostic parameters of units and assemblies, it is possible to predict the residual resource of the system, i.e. its operation from the moment of technical diagnostics of the parameter until the moment it receives the limit value. Materials and methods. The paper considers the application of the Sugeno-Kan fuzzy-logical inference algorithm for assessing the residual resource for aviation radio engineering equipment. Results. The paper presents a theoretical representation of fuzzy logic, residual resource and the application of fuzzy-logical inference algorithms for solving the problems of extending and predicting the residual resource of aviation radio engineering devices. Conclusions. Technical recommendations for practical applications of extending and predicting the residual resource of technical products are obtained.

Background. Unmanned aerial vehicles (UAV) are widely used in present-day reality. When developing UAV new models, solution of both design-and- appearance and program-algorithm problems such as, for example, control and navigation algorithms has to be found. Materials and methods. In development of the UAV a mathematical simulation is commonly used. Mathematical simulation enables studying of the UAV’s operability both in routine mode and in emergency without producing UAV physical model. Results and conclusions. The article proposes a mathematical model of multirotor UAV using a quadcopter as an example, basic aspects of the multirotor UAV aerodynamics are set forth, equations of centroidal motion and motion around mass-center of a quadcopter are handled.

Background. The piercing mechanism (piercer) developed is a device of blast initiation for removing ice obstruction in rivers during spring freshet with chaotic piles of formless blocks of ice, when impact accelerations at barriers contact are equiprobable in the line at a solid angle Ω = 2π steradians, i.e. in a hemisphere. Materials and methods. Major feature of developed design of the piercing mechanism to differ it from similar devices is use of magnetic system, increasing the speed of striker acceleration at the end of its travel thanks to additional acceleration of the striker by the magnet system. Kinetic energy of the striker spent for cylinder spring compression is compensated by the magnetic system, enabling reliable initiation of a blasting cap. Such additional attraction depends neither on rate of the contact of the body with obstacle, consequently nor on the value of initiated acceleration, and so the piercing mechanism will snap into action both at high and low rates of the contact with the obstacle. Ball-form of the inertial body as well as its location between flat face of the striker and conic surface of the package provide transfer of the ball inertia to axial striker both at its axial and lateral travel ( at presence of appropriate impact accelerations). Use of rolling contact bearing in the form of ball racer eliminates sliding friction of the inertial body (sphere) and guarantee reliable initiation of the piercing mechanism at a contact of the device with an obstacle with low rate at different angle (with impact accelerations at any of side directions). Results and conclusions. Submitted work demonstrates possibility ofdesigning of reliable and technologically effective piercing mechanism for the contact with an obstacle of complex form at different angles, and at low rate.

Background. The inertia switches are traditionally used in mobile vehicles for commutating the electric circuits of the engineering systems. Triggering of such devices takes place mainly when having taken integral along linear acceleration while the vehicle’s space motion. To integrate the linear acceleration, both magnetic induction and hydraulic dampers are customary used. In a number of cases the hydraulic dampers, simplifying design of inertia switchers, are preferred. Given work presents the results of development of the inertia switch design, its mathematical model: differential equations, describing motion of mobile design elements, and the initial motion conditions, as well. For differential equating as follows assumptions are taken: the liquid is incompressible; no account to inertia switch components variation in dimension due to environmental variation in temperature; no account to dumping liquid viscosity variation due to environmental temperature variation. Materials and methods. The major feature of inertiaswitch designed to distinguish it from similar inertia devices is its feasible actuation at acceleration along either of the two axial directions. The contact system switches from the initial state at releasing and following turning of the jumper strap. Design of the inertia switch enables reliable retention of the initial state of a contact system at any operation conditions of the mobile vehicles as well as fail-safe switching while vehicle motion during specified period of time (speedup, braking) with acceleration of no less than certain (specified) value. Presented results demonstrate possibility of development of the reliable and technologically effective inertia switch, designed for engineering systems of the independent mobile vehicles.

Background. The paper presents a diagnostic system for optimizing the operating modes of the diesel locomotive cooling system, the components of which are: a diagnostic algorithm and hardware selection for import substitution, a structural and functional diagram (model). Materials and methods. The system is adapted to changes in outside air temperature by using methods for identifying thermal parameters in the cooling-warming modes of diesel locomotive power plants; it is implemented on the basis of the ldm-sam7x128 controller-designer. The software is written in C++ with partial use of the assembler language. Results and conclusions. The proposed algorithm and diagnostic methods make it possible to increase the reliability of power equipment in the substation of the Russian Railways highspeed transport system. A diagnostic system equipped with an intelligent sensor automates this process by reading its parameters via a digital channel from the EPD chip. The TEDS specification allows for automatic configuration of the sensor and simplifies its alignment with other electronic equipment. All information about the sensor is stored in theTEDS memory of the integrated circuit, eliminating the need to create a separate database for storing calibration information.

Background. The study is aimed at developing approaches and methods for information support of multi-criteria decision-making in management problem-solving of natural-industrial system entities in the Arctic region of Russia in order to ensure their environmental safety and resilient operation under the influence of negative natural and man-made factors. Regional peculiarities and specific character of economic development condition on the vulnerability of entities localized in the territory of a given region in terms of the emergence of adverse triggering events of various genesis, necessitating the development of effective measures and policy decisions that enhance the reliability and safety of existing regional infrastructure entities. To make informed decisions and a reasonable choice of measures to counteract current threats when managing safety and resilience of ecosystems, the evaluation and analysis of alternative decisions based on multiple criteria should be carried out. Materials and methods. The unified methodological framework of our study includes the fundamentals of safety sciences, risk management methodology, and the stateof- the-art resilience concept of complex systems, as currently developing research area. The proposed approach to a multilevel integral estimation of environmental safety of territories is based on the combined use of index-based methods for quantitative and qualitative analysis of heterogeneous indicators of ecosystem resilience and hierarchical aggregation of the assessments. Results and conclusions. A modified index-based method, expanding the capabilities of existing methodologies for calculating the integral index of environmental conditions by incorporating qualitative indicators and situational factors, taking into account their unequal significance and antagonism, as well as maintaining the balance of indicators, has been developed. The method is based on the automatic transformation of estimates into membership functions and fuzzy convolution of the normalized indicators across levels of the organizational hierarchy. Proposed method allows for a quantitative assessment of the exposure degree of natural-industrial system entities on the state of ecosystem resilience under incompleteness and uncertainty of the raw data, and can be used to prepare and implement a set of preventive and reactive measures to improve the environmental safety of the territory when providing control and impact monitoring of these entities.