scholarly journals Low passive filters applications in naval engineering

2021 ◽  
Vol XXIV (1) ◽  
pp. 130-138
Author(s):  
BORDIANU Adelina

In this paper one analyses different low passive filters that are used successfully in naval engineering applications. Filters are successfully used in marine control systems, supply systems on board or for reduction of harmonic distortion. The advantages and disadvantages of the filters were also presented. Using Matlab and Simulink the filters electrical circuits (3 rd and 5 th order passive filters Chebyshev and Elliptical are considered in this paper) were analysed.

Author(s):  
Ilya Fedotov ◽  
Vyacheslav Tikhonov

The article deals with investigation of electromechanical and energetic characteristics of traction electric drive with vector systems of direct torque control. As a controlled object the traction asynchronous motor ДТА-1У1, which is used to drive the trolley-bus is considered. At the present time the usage of traction asynchronous electric drives for town transport is relevant. Due to development of power electronic devices and microprocessor-based control systems it became possible to replace DC electric drives with electric drives with asynchronous motors. The article contains brief description of two different types of control systems: field-oriented control (FOC) and direct torque control (DTC). Principles of work for both systems are considered and the main advantages and disadvantages associated with the use of these systems are pointed out. The models of both systems for traction asynchronous electric drive, built in modeling environment MATLAB/Simulink, are given in this article for further comparative analysis. As the main quality factor of control total harmonic distortion (THD) is used.


1965 ◽  
Vol 180 (1) ◽  
pp. 246-259
Author(s):  
R. Ruggles

The author discusses some of the problems of failure-survival automatic flight control systems and suggests some basic ground rules as design criteria. The advantages and disadvantages of some of the main types of system are discussed: duplex, triplex, triple component, duplicate-monitored and quadruplex systems being covered. In particular, a quadruplex actuator is described which has been designed and developed mainly for automatic flight control system applications where a very high degrees of failure-survival capability is required. A detailed failure analysis of the various systems is carried out and the importance of the electrical and hydraulic supply system configurations and failure rates is brought out.


Author(s):  
A J Kinloch

When considering methods for joining materials, there are many advantages that engineering adhesives can offer, compared to the more traditional methods of joining such as bolting, brazing, welding, mechanical fasteners, etc. The advantages and disadvantages of using engineering adhesives are discussed and it is shown that it is possible to identify three distinct stages in the formation of an adhesive joint. Firstly, the adhesive initially has to be in a ‘liquid’ form so that it can readily spread over and make intimate molecular contact with the substrates. Secondly, in order for the joint to bear the loads that will be applied to it during its service life, the ‘liquid’ adhesive must now harden. In the case of adhesives used in engineering applications, the adhesive is often initially in the form of a ‘liquid’ monomer which polymerizes to give a high molecular weight polymeric adhesive. Thirdly, it must be appreciated that the load-carrying ability of the joint, and how long it will actually last, are affected by: (a) the design of the joint, (b) the manner in which loads are applied to it and (c) the environment that the joint encounters during its service life. Thus, to understand the science involved and to succeed in further developing the technology, the skills and knowledge from many different disciplines are required. Indeed, the input from surface chemists, polymer chemists and physicists, materials engineers and mechanical engineers are needed. Hence, the science and technology of adhesion and adhesives is a truly multidisciplined subject. These different disciplines have been brought together by developing a fracture mechanics approach to the failure of adhesive joints. The advances that have been made in applying the concepts of fracture mechanics to adhesive joints have enabled a better understanding of the fundamental aspects of adhesion and the more rapid extension of adhesives technology into advanced engineering applications.


Author(s):  
Alden Yellowhorse ◽  
Larry L. Howell

Ensuring that deployable mechanisms are sufficiently rigid is a major challenge due to their large size relative to their mass. This paper examines three basic types of stiffener that can be applied to light, origami-inspired structures to manage their stiffness. These stiffeners are modeled analytically to enable prediction and optimization of their behavior. The results obtained from this analysis are compared to results from a finite-element analysis and experimental data. After verifying these models, the advantages and disadvantages of each stiffener type are considered. This comparison will facilitate stiffener selection for future engineering applications.


Author(s):  
Trong-Thang Nguyen

<p>In this study, the author analyzes the advantages and disadvantages of multi-level inverter compared to the traditional two-level inverter and then chose the suitable inverter. Specifically, the author analyzes and designs the three-level inverter, including the power circuit design and control circuit design. All designs are verified through the numerical simulation on Matlab. The results show that even though the three-level inverter has a low number of switches (only 12 switches), but the quality is very good: the total harmonic distortion is small; the output voltage always follows the reference voltage.</p>


Author(s):  
E. I. Gracheva ◽  
A. N. Gorlov ◽  
Z. M. Shakurova

The article examines the main features of the layout of electrical equipment for shop networks of internal power supply with the definition of indicators for a group of shop customers connected to a single power center, affecting the choice of the structure of schemes for shop network sites. The parameters characterizing the circuit topology are revealed. A study is presented of the influence of the load factor of workshop transformers on their reactive power factor, it is proved by calculation by technical and economic criteria the feasibility of replacing a workshop transformer with two with a lower total power. The calculation of energy savings in the in-plant power supply systems. The type of dependences tgφ of transformers ТМ and ТСЗ with various rated powers in the function of loading transformers is established. The most significant factors of the growth of idle power losses during operation are presented. With determination of losses of active and reactive power and electricity in transformers and losses of active power in a high voltage distribution network A feasibility study was carried out on the options for internal power supply schemes with two transformers of lower power installed instead of one, and the feasibility of such a replacement to increase the efficiency of the equipment was proved and the estimated payback period for the investment capital was determined. A comparative analysis of the studied power supply schemes of industrial enterprises with the identification of their advantages and disadvantages.


Author(s):  
Yu. A. Protasevich ◽  
O. A. Zmeev ◽  
D. A. Sokolov

The article describes an approach to organizing the teacher-students interaction in programming courses using the Git version control system. In order to select the most suitable and affordable system for educational needs a comparative analysis of different Git repository management systems was carried out. Based on the experience of various educational institutions that use version control systems in their courses, the advantages and disadvantages of using these systems in teaching were identified. Taking into account the existing problems, a software solution was developed based on the GitLab system. As part of this solution, a method is proposed for organizing the work of a teacher and students in disciplines that use version control systems. This approach implies using both GitLab and additional system, which serves as a manager for Git repositories and is designed to facilitate the work of the teacher and administrator by automating the tasks they perform. The main purpose of the article is a detailed description of this approach: limiting permissions to both teachers and students, GitLab organization and functionality, a list of use cases for each user. The article also presents common workflows of the additional system, its main entities and their relationships and an overview of the features that the system provides.


2020 ◽  
Vol 25 (3) ◽  
pp. 7-12
Author(s):  
Rud V.V. ◽  

This paper considers the problems of the integration of independent manipulator control systems. Areas of control of the manipulator are: recognition of objects and obstacles, identification of objects to be grasped, determination of reliable positions by the grasping device, planning of movement of the manipulator to certain positions with avoidance of obstacles, and recognition of slipping or determination of reliable grasping. This issue is a current problem primarily in industry, general-purpose robots, and experimental robots. This paper considers current publications that address these issues. Existing algorithms and approaches have been found in the management of both parts of the robot manipulator and solutions that combine several areas, or the integration of several existing approaches. There is a brief review of current literature and publications on the above algorithms and approaches. The advantages and disadvantages of the considered methods and approaches are determined. There are solutions that cover either some areas or only one of them, which does not meet the requirements of the problem. Using existing approaches, integration points of existing implementations are identified to get the best results. In the process, a system was developed that analyzes the environment, finds obstacles, objects for interaction, poses for grasping, plans the movement of the manipulator to a specific position, and ensures reliable grasping of the object. The next step was to test the system, test the performance, and adjust the parameters for the best results. The resulting system was developed by the research team of RT-Lions, Technik University, Reutlingen. The hardware research robot includes an Intel Realsense camera, a Sawyer Arm manipulator from Rethink Robotics, and an internally grabbing device.


2013 ◽  
Vol 210 ◽  
pp. 26-31 ◽  
Author(s):  
Łukasz Konieczny ◽  
Rafał Burdzik

The paper presents the comparison of the characteristics of spring and damping components used in conventional and non-conventional automotive suspensions. The conventional suspension is based on steel coil springs and hydraulic dampers with fixed characteristics. As an example, the adaptive non-conventional suspension shows the characteristics of hydropneumatic suspension components (suspension are constantly being developed and is now based on mechatronic control systems of damping characteristics). The paper summarizes the advantages and disadvantages of these solutions.


Author(s):  
Hamdy Mohamed Soliman

With development of power electronics and control Theories, the AC motor control becomes easier. So the AC motors are used instead of the DC motor in the drive applications. With this development, a several methods of control are invented. The field oriented control and direct torque control are from the best methods to control the drive systems. This paper is compared between the field oriented control and direct torque control to show the advantages and disadvantages of these methods of controls. This study discussed the effects of these methods of control on the total harmonic distortion of the current and torque ripples. This occurs through study the performance characteristics of the AC motor. The motor used in this study is an induction motor. This study is simulated through the MATLAB program.


Sign in / Sign up

Export Citation Format

Share Document