scholarly journals MODEL FOR ASSESSING SITUATIONAL AWARENESS OF SPACE SYSTEM

2019 ◽  
pp. 83-91
Author(s):  
V. I. Erokhin ◽  
A. P. Kadochnikov ◽  
S. V. Sotnikov ◽  
A. A. Vaganov ◽  
D. A. Valeryanov
Keyword(s):  
Mathematical Model ◽  
Numerical Experiment ◽  
Control Region ◽  
Situational Awareness ◽  
Elliptical Orbit ◽  
Geostationary Orbit ◽  
Space System ◽  
Numerical Example

The paper presents a mathematical model for assessing the situational awareness of the space system. The model includes a set of algorithms, the main ones being the algorithm for simulating the motion of a spacecraft in a highly elliptical orbit, the algorithm for determining the observability of a given controlled area by a given spacecraft in a highly elliptical orbit at a given time, and the algorithm for determining the observability of a given controlled area by a spacecraft in a geostationary orbit. The model allows the assessment of the information capabilities of a space system of various ballistic structures and compositions. A model numerical example is considered, which makes it possible to compare observability indices of a given control region with two possible variants of a ballistic construction of a spacecraft constellation. The results of the numerical experiment showed the correctness of the proposed mathematical model.

Advanced space system for geostationary orbit surveillance

2016 ◽  
Vol 50 (7) ◽  
pp. 575-580
Author(s):  
N. N. Klimenko ◽  
A. E. Nazarov
Keyword(s):  
Geostationary Orbit ◽  
Space System

scholarly journals Modelling time efficiency of cobot-supported kit preparation

2019 ◽  
Vol 106 (5-6) ◽  
pp. 2227-2241 ◽  
Author(s):  
Patrik Fager ◽  
Martina Calzavara ◽  
Fabio Sgarbossa
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Cycle Time ◽  
Laboratory Experiments ◽  
Spare Parts ◽  
Batch Preparation ◽  
Assembly Quality ◽  
Numerical Example ◽  
Business To Business ◽  
Support Time

AbstractKitting – meaning to supply assembly with components in presorted kits – is widely seen as beneficial for assembly quality and efficiency when there is a multitude of component variants. However, the process by which kits are prepared – the kit preparation – is labour-intensive, and kit errors are problematic at assembly processes. The use of robotics to support kit preparation has received some attention by researchers, but literature is lacking with respect to how collaborative robots – cobots – can support kit preparation activities. The purpose of this paper is to identify the potential of a cobot to support time-efficient batch preparation of kits. To address the purpose, the paper presents a mathematical model for estimation of the cycle time associated with cobot-supported kit preparation. The model is applied in a numerical example with experimental data from laboratory experiments, and cobot-supported kit preparation is compared with manual kit preparation. The findings suggest that cobot-supported kit preparation is beneficial with diverse kits and smaller components quantities per SKU (Stock Keeping Unit) and provides less variability of the outcome, when compared to manual kit preparation. The paper reveals several insights about cobot-supported kit preparation that can be valuable for both academics and practitioners. The model developed can be used by practitioners to assess the potential of cobots to support kit-batch preparation in association with assembly, spare parts, repair and maintenance, or business to business industry.

scholarly journals The Analytical Study of the Value of Adhesion of Cement Gel between Reinforcement and Concrete

2020 ◽  
Vol 26 (3) ◽  
pp. 483-495
Author(s):  
A. N. Nikolyukin ◽  
◽  
V. P. Yartsev ◽  
S. A. Mamontov ◽  
I. I. Kolomnikova ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Numerical Modeling ◽  
Numerical Experiment ◽  
Bearing Capacity ◽  
Analytical Study ◽  
Bonding Process ◽  
Periodic Profile

Disruption of the adhesion of reinforcement to concrete causes significant deformation of the structure, which can subsequently lead to the loss of its bearing capacity. There is a need to study the bonding process between concrete and reinforcement under various influences. The results of a numerical experiment on pulling out reinforcement of periodic profile from concrete are presented. A mathematical model to study the processes taking place in the field of embedding reinforcement in concrete has been built. The results of numerical modeling are described.

scholarly journals Learning the basics of a battery pack control system

2020 ◽  
Vol 164 ◽  
pp. 13006 ◽  
Author(s):  
Kirill Kobzev ◽  
Sergey Vyalov ◽  
Alexander Rybak
Keyword(s):  
Mathematical Model ◽  
Control System ◽  
Numerical Experiment ◽  
Structural Parameters ◽  
Operation Mode ◽  
Power Source ◽  
Design Parameters ◽  
Hydraulic Systems ◽  
Original Design ◽  
Functional Features

The article discusses the control system of a hydraulic power source of constant pressure, which is a pump-storage power source, equipped with the original design of the automatic unloading of the hydraulic pump, which provides relay switching of its operation mode. A mathematical model is proposed, obtained using a modeling technique based on the application of the theory of volumetric rigidity of hydraulic systems and their elements. The results of a numerical experiment carried out by numerically solving the equations that make up the mathematical model of a power source are also presented. As a result of a numerical experiment, the main technical capabilities of the considered power source and the influence of its main structural parameters and functional features of the system on operational properties are revealed. The results showed that due to changes in various design parameters of the unloading machine, you can not only change the upper (maximum) and lower (minimum) values of the battery charging pressure, but also adjust their difference depending on the requirements for the power source. The main property of a power source with an automatic unloading device of the proposed design, confirmed as a result of a numerical experiment, is that the automatic unloading device provides a clear relay switching of the pump operation mode from unloading to operating mode and vice versa. The revealed properties make it very promising to use a pump-accumulator power source in the hydraulic systems of mobile machines and technological equipment.

Analysis of a two-dimensional stair-case warranty policy with preventive maintenance

2020 ◽  
Vol 32 (1) ◽  
pp. 51-67
Author(s):  
Jinting Wang ◽  
Sheng Zhu ◽  
Simiao Du
Keyword(s):  
Mathematical Model ◽  
Preventive Maintenance ◽  
Optimal Strategy ◽  
Optimal Solution ◽  
Two Dimensional ◽  
Rectangular Region ◽  
Numerical Example ◽  
Warranty Cost

Abstract We develop a mathematical model to study optimal preventive maintenance (PM) strategy under a two-dimensional stair-case warranty policy considering both age and usage of a product. During the warranty term, sellers implement preventive maintenance within the stair-case region of the warranty policy and upon failure a product is repaired minimally and immediately. Our objective is to find the optimal PM strategy that minimizes the seller’s cost of warranty while jointly considering the age and usage intervals of the PM policy and the level of PM executed. We also discuss how our results compare to those in a two-dimensional warranty policy with a rectangular region, and we find that the stair-case policy is preferable for sellers. An algorithm is provided to find the optimal solution and a numerical example is presented to illustrate how to find an optimal strategy with our proposed method. We show numerically that the expected total warranty cost is convex both in the age and the usage of the product under certain conditions.

scholarly journals Economic and theoretical study of the power supply from a pump-battery based on a discharge machine

2020 ◽  
Vol 175 ◽  
pp. 05042
Author(s):  
Kirill Kobzev ◽  
Sergey Vyalov ◽  
Alexander Rybak
Keyword(s):  
Mathematical Model ◽  
Numerical Experiment ◽  
Structural Parameters ◽  
Operation Mode ◽  
Power Source ◽  
Design Parameters ◽  
Hydraulic Systems ◽  
Original Design ◽  
Functional Features ◽  
Pump Storage Power

The article discusses the control system of a hydraulic power source of constant pressure, which is a pump-storage power source, equipped with the original design of the automatic unloading of the hydraulic pump, which provides relay switching of its operation mode. A mathematical model is proposed, obtained using a modeling technique based on the application of the theory of volumetric rigidity of hydraulic systems and their elements. The results of a numerical experiment carried out by numerically solving the equations that make up the mathematical model of a power source are also presented. As a result of a numerical experiment, the main technical capabilities of the considered power source and the influence of its main structural parameters and functional features of the system on operational properties are revealed. The results showed that due to changes in various design parameters of the unloading machine, you can not only change the upper (maximum) and lower (minimum) values of the battery charging pressure, but also adjust their difference depending on the requirements for the power source.

The Position Analysis of Spherical Seven-Bar Mechanism

2011 ◽  
Vol 101-102 ◽  
pp. 193-196
Author(s):  
Zhao Feng Zhang ◽  
Zhi Huan Zhang
Keyword(s):  
Mathematical Model ◽  
Analytical Solutions ◽  
Polynomial Equation ◽  
Constraint Equations ◽  
Position Analysis ◽  
Numerical Example ◽  
Location Parameters ◽  
Sylvester Resultant ◽  
Univariate Polynomial

In this paper, we turn plane seven-bar mechanism into spherical seven-bar mechanism, using quaternion to construct mathematical model for spherical seven-bar mechanism. Three constraint equations are obtained according to the angles constraint. Using Sylvester resultant elimination by two steps, a 32 degree univariate polynomial equation can be obtained. A numerical example confirms that analytical solutions of spherical seven-bar mechanism are 32 and with the help of Mathematic software to solve the location parameters.

STABILITY OF A MATHEMATICAL MODEL DESCRIBING THE COVID-19 PANDEMIC IN TERMS OF THE ENVIRONMENT, SOCIAL DISTANCING AND REINFECTION

2021 ◽  
Vol 66 (3) ◽  
pp. 8-19
Author(s):  
Nhu Luong Ngoc ◽  
Huyen Lai Thi Ngoc ◽  
Giang Vu Thi Huong ◽  
Hang Pham Thi
Keyword(s):  
Mathematical Model ◽  
Social Distancing ◽  
Numerical Example ◽  
The Stability

In this paper, we propose and study the stability of a mathematical model for the Covid-19 pandemic incorporating the environment, social distancing and reinfection. A numerical example is carried out to consider the obtained results.

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