System Design Techniques Research Articles

Method for splitting the feasible region to increase the variability of continuous optimization test problems

The solution of optimization problems is essential for the design and control of technical systems. The optimization problem arising in practice has a high dimension, nonlinear criteria, and constraints. There are a lot of continuous optimization tasks for testing and research of optimization algorithms performance. These tasks have a convex range of acceptable values limited to a specified range for each parameter. The problem of generating test multidimensional continuous optimization tasks with nonlinear constraints and splitting the feasible region is considered. A method was proposed for splitting the feasible region by separate domains using the multidimensional grid of forbidden solutions. As a result, the problem acquires properties closer to optimizing technical systems with complex constraints. The method allows creating an unlimited number of test optimization problems, which can be used to research and develop optimization algorithms. The method is simple to implement, and the impact on the computational complexity of tasks is insignificant. Research has been carried out on four widely used continuous single-objective optimization test functions, with the Genetic algorithm and the Particle Swarm Optimization algorithm. It is shown that the proposed method has an influence on the process of solving multidimensional continuous optimization problems by population algorithms and on the dependence of the accuracy of the algorithm on its heuristic coefficients.

Adaptive state estimation of state-affine systems with unknown time-varying parameters

In this paper we provide two significant extensions to the recently developed parameter estimation-based observer design technique for state-affine systems. First, we consider the case when the full state of the system is reconstructed in spite of the presence of unknown, time-varying parameters entering into the system dynamics. Second, we address the problem of reduced order observers with finite convergence time. For the first problem, we propose a simple gradient-based adaptive observer that converges asymptotically under the assumption of generalised persistent excitation. For the reduced order observer we invoke the advanced dynamic regressor extension and mixing parameter estimator technique to show that we can achieve finite convergence time under the weak interval excitation assumption. Simulation results that illustrate the performance of the proposed adaptive observers are given. This include, an unobservable system, an example reported in the literature and the widely popular, and difficult to control, single-ended primary inductor converter.

Generalized parameter estimation-based observers: Application to power systems and chemical–biological reactors

In this paper we propose a new state observer design technique for nonlinear systems. It consists of an extension of the recently introduced parameter estimation-based observer, which is applicable for systems verifying a particular algebraic constraint. In contrast to the previous observer, the new one avoids the need of implementing an open loop integration that may stymie its practical application. We give two versions of this observer, one that ensures asymptotic convergence and the second one that achieves convergence in finite time. In both cases, the required excitation conditions are strictly weaker than the classical persistent of excitation assumption. It is shown that the proposed technique is applicable to the practically important examples of multimachine power systems and chemical–biological reactors.

Fault Simulations in a Multiterminal High Voltage DC Network with Modular Multilevel Converters Using Full-Bridge Submodules

The concept of high-voltage DC transmission using a multiterminal configuration is presently a central topic of research and investment due to rekindled interest in renewable energy resource integration. Moreover, great attention is given to fault analysis, which leads to the necessity of developing proper tools that enable proficient dynamic simulations. This paper leverages models and control system design techniques and demonstrates their appropriateness for scenarios in which faults are applied. Furthermore, this paper relies on full-bridge submodule topologies in order to underline the increase in resilience that such a configuration brings to the multiterminal DC network, after an unexpected disturbance. Therefore, strong focus is given to fault response, considering that converters use a full-bridge topology and that overhead power lines connect the terminals.

Stabilization and $\mathcal {H}_{2}$ Static Output-Feedback Control of Discrete-Time Positive Linear Systems

This article investigates the problem of designing <inline-formula><tex-math notation="LaTeX">$\mathcal {H}_{2}$</tex-math></inline-formula> robust (or gain-scheduled) static output-feedback (or state-feedback) controllers for discrete-time positive linear systems affected by time-invariant (or time-varying) parameters belonging to a polytope. For this purpose, an iterative procedure based on robust (parameter-dependent) linear matrix inequalities (LMI) is proposed. Unlike most approaches, where the controller is obtained by means of a change of variables, the synthesis conditions deal with the control gain directly as an optimization variable, which is specially appealing to cope with closed-loop positivity or structural constraints. The existence of feasible initial conditions for the iterative procedure and some relaxation strategies adopted to reduce the conservativeness of the method are also discussed. Numerical examples borrowed from the literature and statistical comparisons show that the proposed technique is in general less conservative than other approaches, providing solutions and handling cases where traditional design techniques for positive systems cannot be applied.

An Overview of Information-Theoretic Security and Privacy: Metrics, Limits and Applications

This tutorial reviews fundamental contributions to information security. An integrative viewpoint is taken that explains the security metrics, including secrecy, privacy, and others, the methodology of information-theoretic approaches, along with the arising system design principles, as well as techniques that enable the information-theoretic designs to be applied in real communication and computing systems. The tutorial, while summarizing these contributions, argues for the simultaneous pivotal role of fundamental limits and coding techniques for secure communication system design.

Optimal control and learning for cyber‐physical systems

Optimal control and learning for <scp>cyber‐physical</scp> systems

Formal Specification Approach for Smart Space Development

Being an important application of the Internet of Things, smart spaces are increasingly developed throughout the world for different purposes ranging from home automation to smart grids. Despite the considerable focus given to the practical development of smart spaces, there are few attempts of utilizing formal methods in this domain. Especially, the requirements of developing a smart space have not yet been formally specified, to the best of the authors’ knowledge. To fill this gap, a formal specification approach is presented in this paper for smart space development. The proposed approach first identifies the key components of a smart space, then it uses a state-based formal specification language – Z, to formally specify the requirements of these components. The requirements of developing a hypothetical smart space are considered for formal specification in this paper. This work does not only demonstrate how the components of complex systems, such as smart spaces, can elegantly be modeled using a Software Engineering formalism. But it can also be used as a step towards defining a holistic smart space development framework, along with requirement engineering and system design techniques.

Area exclosure effects on soil properties and woody species diversity in Amelake sub-watershed, Southern Ethiopia

ABSTRACT Land degradation in the form of soil and vegetation decline has been an ecological and agricultural problem in Ethiopian highlands. To overcome this issue, the government and local community has been practised area exclosure across the country including Amelake sub-watershed, southern Ethiopia. This study aimed to evaluate area exclosure effects on soil basic properties and woody species diversity in Amaleke sub-watershed. Composite soil samples and Woody plant species were collected with the transects by systematic sampling plot design technique from area exclosure for 10 years and adjacent degraded land with similar landscape position. The collected soil samples from area exclosure and degraded land were analysed through ANOVA whereas woody plant species determined by Shannon diversity. The result revealed that area exclosure had significantly (P < 0.05) different values for all basic soil properties except for soil bulk density, sand, EC and pH. Whereas 16 woody species representing 12 families were recorded in the study site. Out of the 12 families, all were recorded in the exclosure while 5 were recorded in the degraded site. Diversity index result revealed that the woody plant species diversity in exclosure and adjacent degraded land were 1.41 and 1.1, respectively. Similarly, species evenness in exclosure and degraded site were 2.41 and 1.84, respectively, whereas species richness in area exclosure and degraded land was 15 and 6, respectively. In general, exclosure has a great contribution to maintain health soil environment and woody plant species in the study area. Therefore, to improve the soil basic properties and woody species diversity area exclosure practices will be expanded to other degraded watersheds.

Tension modeling and precise tension control of roll-to-roll system for flexible electronics

This study proposes the design of a roll-to-roll system for flexible electronics that enables accurate and precise tension control. It analyzes the factors for change in the tension of a roll-to-roll system and develops a tension model for each section to successfully predict the tension that is applied to such a system, the sagging of film according to tension, and deformation due to residual stress. This series of modeling processes allow engineers to design a roll-to-roll system for flexible electronics. Both a velocity control method for the tension between in-feeder and out-feeder—where there is no change of roller radius—and torque control method for the tension in modules like the rewinder, where the roll radius changes, are proposed. A roll-to-roll system according to the proposed design procedure and tension control methods was manufactured and experimented on under various test conditions. The accuracy and precision of velocity control between the in-feeder and the out-feeder were 100.01% and 1.15%, respectively, whereas those of torque control between the out-feeder and the rewinder were 99.9% and 1.35%, respectively, both at one sigma. The experiments confirmed that the two proposed types of tension control methods were accurate and precise. The experimental result with a monitoring sensor showed that the modeling was valid and that an accurate roll-to-roll system minimizing tension reduction was built. This study successfully demonstrated roll-to-roll system design and control techniques that are applicable to various pieces of roll-to-roll process equipment.

DECODING TECHNIQUE FOR LOW POWER DESIGN IN XILINX

This research paper is a survey of the current status of research and practice in various disciplines of low power VLSI developments. The paper briefly discusses the rationale of the contemporary, and concentrates on low power design, it presents the metrics and techniques that are used to access the merits of the assorted proposed for the improved energy efficiency. Power dissipation [1], [5] has become an important consideration in terms of performance and scope for VLSI chip design. The research paper describes the decoding strategies, methodology, and techniques for low power system design. Here also we have proposed the decoding technique and compared with silent coding to scale back the transition state and conserved the power which is additionally described during this research. KEYWORDS—Power minimization, decoding technique, silent coding.

Technology of spacecraft on-board equipment design support

The Technology is shown that combines knowledge bases, information and graphic resources into a set of automated software tools. Technology includes the methods of intellectual models’ building and the tools of scenario creation for measurement, data transmission, test results’ control and visualization. It is implemented in the software-mathematical model of the on-board equipment control system and the software of the testing equipment. Software is integrated into a technological platform for the design and testing of technical systems. Application of Technology reduces the time of the on-board equipment design and production, reduces import dependency of Russian space development and increases its competitiveness in the space systems’ market.

METHOD FOR SPLITTING THE FEASIBLE REGION TO INCREASE THE VARIABILITY OF CONTINUOUS OPTIMIZATION TEST PROBLEMS

The solution of optimization problems is essential for the design and control of technical systems. The optimization problem arising in practice has a high dimension, nonlinear criteria, and constraints. There are a lot of continuous optimization tasks for testing and research of optimization algorithms performance. These tasks have a convex range of acceptable values limited to a specified range for each parameter. The problem of generating test multidimensional continuous optimization tasks with nonlinear constraints and splitting the feasible region is considered. A method was proposed for splitting the feasible region by separate domains using the multidimensional grid of forbidden solutions. As a result, the problem acquires properties closer to optimizing technical systems with complex constraints. The method allows creating an unlimited number of test optimization problems, which can be used to research and develop optimization algorithms. The method is simple to implement, and the impact on the computational complexity of tasks is insignificant. Research has been carried out on four widely used continuous single-objective optimization test functions, with the Genetic algorithm and the Particle Swarm Optimization algorithm. It is shown that the proposed method has an influence on the process of solving multidimensional continuous optimization problems by population algorithms and on the dependence of the accuracy of the algorithm on its heuristic coefficients.

Investigation of errors in the representation of 3D models in determining the parameters of parts of devices BY the example of a two-mass rotating system with elastic coupling

Objective. The objective of the study is to consider the application field of modern device development and design methods using the means of 3D modeling and simulation of physical processes. The validity of the application and criteria for the reliability of the results obtained in the sequential design of the mechanical part of the electric drive and the control system are investigated.Methods. Methods of model representation of 3D objects in computer-aided design systems are considered, as well as methods for solving problems of determining strain under the applied load. Using the example of an elementary joint, the obtained results of the dynamic characteristic of an elastic shaft in a computer-aided design system are compared with those calculated analytically.Results. The article defines the basic principles and relations applicable to describing the shape of 3D models. Methods are shown by which it is possible to obtain information about the mass-centering model characteristics. The relations that form the basis of numerical methods for solving problems of determining elastic deformations of bodies are also given. The error that can occur when using insufficiently small elementary volumes in solving the problem of determining elastic deformation is shown.Conclusion. The use of 3D modeling in the design of complex technical systems is justified and speeds up production processes. However, numerical methods cannot always give an accurate result leading to the need to either increase the complexity of calculations or additionally adjust some designed device parameters.

Discrete-Time Pole-Region Robust Controller for Magnetic Levitation Plant

Robust pole-placement based on convex DR-regions belongs to the efficient control design techniques for real systems, providing computationally tractable pole-placement design algorithms. The problem arises in the discrete-time domain when the relative damping is prescribed since the corresponding discrete-time domain is non-convex, having a “cardioid” shape. In this paper, we further develop our recent results on the inner convex approximations of the cardioid, present systematical analysis of its design parameters and their influence on the corresponding closed loop performance (measured by standard integral of absolute error (IAE) and Total Variance criteria). The application of a robust controller designed with the proposed convex approximation of the discrete-time pole region is illustrated and evaluated on a real laboratory magnetic levitation plant.

Prospects for the implementation of autonomous power supply systems of agro-industrial production

Annotation Purpose. Improving the efficiency of agricultural production by creating a reliable autonomous power supply system based on natural and own renewable energy sources. Methods. Methods of system analysis and design of technical systems. Results. Principles of building an effective system for the use of natural and own renewable energy sources in agriculture. The general structure and parameters of the energy supply system of agricultural production. Conclusions 1. According to the energy strategy, Ukraine by 2030 should increase the share of renewable energy in its overall energy balance by almost 3 times – from 8 to 25%. 2. One of the real ways to increase the reliability and efficiency of electricity supply of agricultural facilities is the transition to autonomous energy supply systems based on the use of their own renewable energy sources with a relative production cost within 0.43–0.98 of the cost of centralized electricity production. 3. The structure of a specific power supply system of the agro-industrial sector should be formed on the basis of the characteristics of production and household needs, assessment of the potential and characteristics of renewable energy sources and conditions of safe, cost-effective operation. Keywords: agricultural production, renewable energy, ecology, efficiency.

Principles of choosing natural renewable energy sources for farm conditions

Annotation Purpose. Improving the efficiency of agricultural production and reducing its negative impact on the environment through the use of natural renewable energy sources. Methods. Methods of system analysis and design of technical systems. Results. Principles of building an autonomous system of electricity supply of farms on the basis of natural renewable energy sources. The general structure of the system of autonomous energy supply of agricultural production. Conclusions 1. Over the next 30 years, Ukraine should completely switch to renewable energy, increasing its production by more than 10 times. 2. Under the conditions of Ukraine, the basic natural source of energy when creating autonomous systems of electrical supply of agricultural facilities should take solar energy. 3. In the structure of autonomous power supply systems of farms, it is necessary to provide energy storage facilities and equipment for the use of excess energy at certain periods of the year. Keywords: agricultural production, renewable energy, reliability, efficiency.

The engineering design of fermentation unit for microbial plant protection products small-scale manufacturing

Annotation Purpose. Fermentation unit development based of thin-walled bioreactors for microbial plant protection products manufacturing. Methods. System design technique, cost-effectiveness analysis, experimental proof and tests. Results. The fermentation unit was designed. It consists of upgraded industrial sterilizer for nutrient medium making and it further sterilization, two thin-walled fermenters, which could be run in two agitation modes: air bubbling and external loop circulation by pump. Equipment sterilization was substituted by disinfect cleaning and steaming. Air and water flows were sterilized by filtration and UV-radiation. Conclusions 1. The engineering design of modern fermentation unit FU-500 with 500 dm3 per cycle capacity was developed, intended for further design documents development and also for using in investment projects. 2. The design of cleaning and sterilization procedures support was worked out, specifically easy-removal piping system was employed; fermentation vessels were fitted with minimum amount of connecting sockets and had no prominent parts inside. 3. In comparison with the fermentation complex CFM-420 the present engineering design permits technical and economical parameters significant improvement, in particular capacity increasing at 19 %, equipment weight decrease at 47 %, rated output power reduction at 69 % and 60 % operating aria save. Keywords: design, thin-walled fermenter, simplified sterilization, plant protection.

Интегративные основы создания и развития Белорусской космической системы дистанционного зондирования

Using the example of the creation of the Belarusian space system for Earth remote sensing, the possibility of the practical implementation of the method of program-target design of complex organizational and technical systems in conditions of system constraints (determined by the complex of the existing characteristic features of the external and internal states of the government) is considered. The results of analyzing the existing dilemma made it possible to develop a methodological framework and justify a set of scientific and organizational procedures within the program-target method that provided an effective solution to ERS tasks in the interests of the Republic of Belarus and the Union State. The results also allowed the formation of a new scientific direction for the development of the created BSRSS and formation of a multi-level system comprising space, aviation and ground segments of ERS.

Методика комплексной оценки эффективности функционирования организационно-технических систем при организации метрологического обеспечения

a method for complex assessment is proposed, efficiencies production characteristics the system metrological support, which in contrast to the existing ones-allows you to evaluate^ the sufficiency of both forces and funds- metrological support, identify problematic issues organization- (planning) of metrological support, identify problematic issues organization (planning) of metrological-support at the design of organizational and technical systems.