scholarly journals THE USE OF MOBILE CONTROL METHODS FOR STABILIZATION OF A SPACECRAFT WITH AEROMAGNETIC DEORBITING SYSTEM

2019 ◽  
Vol 6 (125) ◽  
pp. 41-54
Author(s):  
Anatolii Alpatov ◽  
Erik Lapkhanov
Keyword(s):  
Executive Control ◽  
Permanent Magnets ◽  
Control Method ◽  
Electrical Energy ◽  
Angular Motion ◽  
Control Law ◽  
Control Methods ◽  
Advantages And Disadvantages ◽  
Electromagnetic Control ◽  
Control Devices

The search for optimal control algorithms for spacecrafts is one of the key areas in rocket and space technology. Taking into account certain restrictions and requirements in a specific space mission, the selection of certain executive devices of the spacecraft is carried out and the corresponding control law is synthesized. One of such space missions is the providing of angular motion stabilization of a utilized spacecraft with aeromagnetic deorbiting system. The stabilization of spacecraft angular motion is needed for the orientation of aerodynamic element perpendicular to the vector of atmosphere dynamic flux with the aim of increasing of aerodynamic braking force. In this mission, the main optimization criterion is the minimization of the on-board electrical energy consumption which is needed for the control of angular motion. The original construction of the aeromagnetic deorbiting system consists of aerodynamic flat sails element and executive control devices with permanent magnets. However, not all spacecraft can be equipped with additional executive control devices with permanent magnets. That’s why with the aim of expansion of aeromagnetic deorbiting system application, using extra source of electromagnetic control executive devices is proposed in this research.The purpose of the article is the search of the control law which provides minimal consumption of electrical on-board energy by electromagnetic control executive devices during long-term deorbiting mission. For satisfying this criterion of optimization using of mobile control methods to orientate the spacecraft with aeromagnetic deorbiting system are proposed in this investigation. Computer modeling of orbital motion of spacecraft with aeromagnetic deorbiting system show the efficiency of using proposed mobile methods for angular motion control which realized by electromagnetic devices – magnetorquers. It has been showed that because of using mobile control method consumption of on-board electrical energy significantly less than with classical approach. The advantages and disadvantages have been determined.

scholarly journals Birth Control: A Review of Pharmacological and Non-pharmacological Modalities, Associated Pros and Cons, and Their Effectiveness

2021 ◽  
pp. 225-232
Author(s):  
Maryam Fairag ◽  
Malak ALGhamdi ◽  
Abdulaziz Baghlaf ◽  
Bader Alallah ◽  
Turki Alharbi ◽  
...  
Keyword(s):  
Family Planning ◽  
Birth Control ◽  
Control Method ◽  
Hormonal Contraception ◽  
Multiple Birth ◽  
Control Methods ◽  
Contraceptive Methods ◽  
Advantages And Disadvantages ◽  
Pros And Cons ◽  
Combined Hormonal Contraception

Introduction: Family planning importance is increasing progressively and is regarded as an essential part in every couple’s life. Family planning has a lot of benefits for the whole family as it provides a better control over the period between each pregnancy leading to a better balance over the personal, financial, and societal life. There are multiple birth control methods, from which couples can choose from with the assistance of their physicians since each method has its own advantages and disadvantages. Furthermore, some contraceptive methods may be more suited for a certain couple or situation than another one. This review of current methods aims to shed the lights on the various contraception options along with their advantages and disadvantages to aid providers in taking care of their patients. Methodology: A thorough search was carried out on PubMed using the most suitable keywords representing the aim of the present study. A total of 120 were found and based on whether they are suited to achieve the aim of the study, 28 were selected. Discussion: There is a great variety of birth control methods, and each has its associated advantages and disadvantages. Barrier contraceptive methods, most common of which are male condoms, are extremely popular in Western countries. Combined hormonal contraception methods which are available in the form of pills, patches, and rings. Progestin only contraception either in the form of a pill, injection or an implant is the most commonly used type among breastfeeding women. Furthermore, intrauterine devices are another effective contraceptive method which may be copper-based or hormonal-based. Conclusion: Contraception is an integral part of family planning, which can be achieved through a variety of methods. Each birth control method has its own pros and cons that should be explained to the couple clearly, so they can choose the method that is most suited for them.

scholarly journals COMPARE THE EFFICIENCY OF CONTROLLED STIFFNESS DAMPER WITH VARIABLE FRICTION DAMPER FOR SEISMIC PROTECTION OF BUILDING

2009 ◽  
Vol 12 (8) ◽  
pp. 81-89
Author(s):  
Phuc Quang Bao Nguyen ◽  
Hoa Nhan Pham ◽  
Thang Quoc Chu
Keyword(s):  
Control Method ◽  
Seismic Protection ◽  
Control Law ◽  
Modal Control ◽  
Clamping Force ◽  
Friction Damper ◽  
Vibration Mitigation ◽  
Friction Dampers ◽  
Advantages And Disadvantages ◽  
Variable Friction

The implementation of variable friction dampers (VFD) for vibration mitigation of seismic structures generally requires an efficient semi-active control law. In this paper, a semi-active modal control method is proposed to determine the controllable clamping force of a variable friction damper. A comparative study was performed on a multiple DOF structure controlled by passive friction dampers, variable friction dampers in subsection numerical examples. Finally, this paper also provides preliminary conclusions about the advantages and disadvantages for friction dissipators.

scholarly journals A Novel INDI based Guidance Law for Fixed Wing Aircrafts: Derivation and Application

2022 ◽  
Author(s):  
Mengtang Li ◽  
Beichen Ding
Keyword(s):  
Control Method ◽  
Control Law ◽  
Control Methods ◽  
Guidance Control ◽  
Transformation Matrices ◽  
Guidance Law ◽  
Univariate Function ◽  
Mathematical Operations ◽  
Guidance Laws ◽  
Derivation Process

In this paper, we comprehensively present and derive two INDI principle based guidance laws for fixed wing aircrafts. More specifically, two control methods are mathematically derived in detail, where the first decouples the lateral and the longitudinal channels while the second takes the interactions into account. The cumbersome mathematical operations involved in the derivation process aim at reaching a more concise control method and also at providing the community with clearer physical concepts behind this formula. The reason for manipulating transformation matrices is to find a univariate function and to isolate the variable as a virtual input. Efficient and modular guidance control law is then permitted. Lastly, the proposed guidance methods are applied to a 6 dof nonlinear platform under various flight modes to demonstrate the feasibility and advantages.

scholarly journals A Novel INDI based Guidance Law for Fixed Wing Aircrafts: Derivation and Application

2022 ◽  
Author(s):  
Mengtang Li ◽  
Beichen Ding
Keyword(s):  
Control Method ◽  
Control Law ◽  
Control Methods ◽  
Guidance Control ◽  
Transformation Matrices ◽  
Guidance Law ◽  
Univariate Function ◽  
Mathematical Operations ◽  
Guidance Laws ◽  
Derivation Process

In this paper, we comprehensively present and derive two INDI principle based guidance laws for fixed wing aircrafts. More specifically, two control methods are mathematically derived in detail, where the first decouples the lateral and the longitudinal channels while the second takes the interactions into account. The cumbersome mathematical operations involved in the derivation process aim at reaching a more concise control method and also at providing the community with clearer physical concepts behind this formula. The reason for manipulating transformation matrices is to find a univariate function and to isolate the variable as a virtual input. Efficient and modular guidance control law is then permitted. Lastly, the proposed guidance methods are applied to a 6 dof nonlinear platform under various flight modes to demonstrate the feasibility and advantages.

Control Methods of Active Power Filter

2011 ◽  
Vol 317-319 ◽  
pp. 2342-2345
Author(s):  
You Jie Ma ◽  
Jian Zhao ◽  
Xue Song Zhou
Keyword(s):  
Control Method ◽  
Great Influence ◽  
Active Power Filter ◽  
Active Power ◽  
System Control ◽  
Control Methods ◽  
Single Cycle ◽  
Power System Control ◽  
Advantages And Disadvantages ◽  
Power Filter

Active power filter (APF) is an important device to compensate harmonic and reactive current in power system control method adopted has a great influence on its performance. The paper introduces several control methods used by APF, including the deadbeat control, single-cycle control, space vector control and so on. After comparing and analyzing their individual advantages and disadvantages, some improvements for APF performance are proposed.

scholarly journals Improving the Comfort of the Vehicle Based on Using the Active Suspension System Controlled by the Double-Integrated Controller

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Tuan Anh Nguyen
Keyword(s):  
Control Method ◽  
Integrated Control ◽  
Active Suspension ◽  
Suspension System ◽  
Control Methods ◽  
Passive Suspension ◽  
Positive Effects ◽  
Advantages And Disadvantages ◽  
Passive Suspension System ◽  
Integrated Controller

When the vehicle moves on the road, many external factors affect the vehicle. These effects can cause oscillation and instability for the vehicle. The oscillation of the vehicle directly affects the safety and comfort of passengers. The suspension system is used to control and extinguish these oscillations. However, the conventional passive suspension system is unable to fully meet the vehicle’s requirements for stability and comfort. To improve these problems, these are much modern suspension system models that have been used in the vehicle to replace the passive suspension system. The modern suspension systems are used as the air suspension system, semiactive suspension system, and active suspension system. These systems which are controlled automatically by the controller were established based on the control methods. There are a lot of control methods which are used to control the operation of the active suspension system. These methods have their advantages and disadvantages. Almost, conventional control methods such as PID, LQR, or SMC are commonly used. However, they do not provide optimal efficiency in improving a vehicle’s oscillation. Therefore, it is necessary to establish a novel solution for the active suspension system control to improve the vehicle’s oscillation. In this paper, the method of using the double-integrated controller is proposed to solve the above problem. The double-integrated controller consists of two hydraulic actuators which are controlled completely separately. This is a completely novel and original method that can provide positive effects. This research focuses on establishing, simulating, and evaluating the novel control method (the double-integrated control) for the active suspension system. The results of the research have shown that when the vehicle is equipped with the active suspension system which is controlled by the double-integrated controller, the maximum values of displacement and acceleration of the sprung mass are significantly reduced. They reach only 6.25% and 9.10% (case 1) and 6.00% and 6.12% (case 2) compared to the conventional passive suspension system. Besides, its average values which are calculated by RMS are only about 3.91% and 4.67% (case 1) and 4.48% and 4.77% (case 2) compared to the above case. Therefore, the comfort and stability of the vehicle have been improved. This paper provides new concepts and knowledge about the double-integrated control method which will become the trend to be used in the next time for the systems of the vehicle. In the future, experimental procedures also need to be conducted to be able to more accurately evaluate the results of this research.

scholarly journals Advanced control and design methods of the auxiliary resonant commutated pole inverter

2015 ◽  
Vol 63 (2) ◽  
pp. 489-494 ◽  
Author(s):  
S. Karyś
Keyword(s):  
Power Loss ◽  
Control Method ◽  
Design Methods ◽  
Control Methods ◽  
Power Transistors ◽  
Advantages And Disadvantages ◽  
Advanced Control ◽  
And Control

Abstract This paper presents several methods that enable the reduction of power loss in the auxiliary resonant commutated pole inverter - ARCP. Presented methods can be divided into static and dynamic ones. The static methods are related to an appropriate design of the inverter, whereas dynamic ones to advanced control of the power transistors. A variety of design and control methods are presented together with their advantages and disadvantages. The new control method of the current in the resonant branch is described. The main benefits of the proposed extended control method and their constrains are shown

Nonlinear Feedback Control of the Inductrack System Based on a Transient Model

2021 ◽  
Author(s):  
Ruiyang Wang ◽  
Bingen (Ben) Yang ◽  
Hao Gao
Keyword(s):  
Feedback Control ◽  
Permanent Magnets ◽  
Control Method ◽  
Control Law ◽  
Operating Speed ◽  
Nonlinear Feedback ◽  
Transient Model ◽  
Mechanical Coupling ◽  
Wide Range ◽  
Halbach Arrays

Abstract As a new strategy for magnetic levitation envisioned in the 1990s, the Inductrack system with Halbach arrays of permanent magnets has been intensively researched. The previous investigations discovered that an uncontrolled Inductrack system may be unstable even if the vehicle travels well below its operating speed and that instability can be persistent near and beyond the operating speed. It is therefore necessary to stabilize the system for safety and reliability. With strong nonlinearities and complicated electro-magneto-mechanical coupling, however, the transient response of such a dynamic system is difficult to predict with fidelity. Because of this, model-based feedback control of Inductrack systems has not been well addressed. In this paper, by taking advantage of a recently available 2-DOF transient model, a new feedback control method for Inductrack systems is proposed. In the control system development, active Halbach arrays are used as an actuator, and a feedback control law, which combines a properly tuned PID controller and a nonlinear force-current mapping function, is created. The proposed control law is validated in numerical examples, where the transient motion of an Inductrack vehicle traveling at constant speed is considered. As shown in the simulation, the control law efficiently stabilizes the Inductrack system in a wide range of the operating speed, and in the meantime, it renders a smooth system output (real-time levitation gap) with fast convergence to any prescribed reference input (desired levitation gap).

A Novel Switching Control Method for Hypersonic Flying Vehicle

2014 ◽  
Vol 668-669 ◽  
pp. 419-422 ◽  
Author(s):  
Juan Wang ◽  
Ji Long Liu ◽  
Min Wang ◽  
Yu Zhe Wang
Keyword(s):  
Attitude Control ◽  
Control Method ◽  
Rapid Development ◽  
Switching Control ◽  
Control Law ◽  
Control Methods ◽  
Control Performance ◽  
Precise Control ◽  
Simulation Results

With the rapid development of aeronautics technology, hypersonic flying vehicle is playing an increasingly important role, yet control methods on such vehicle were stilled confined with classical PID (proportional, integration and differentiation) or its variations. In order to have better control performance, a switching control method was used to design the attitude control law for hypersonic missile, which guaranteed higher angle precise control than PID. Simulation results showed the effectiveness and the superiority of the proposed switching methods over the classical PID and other typical switching methods.

Recent Advances in Reinforcement Learning for Traffic Signal Control

2021 ◽  
Vol 22 (2) ◽  
pp. 12-18 ◽  
Author(s):  
Hua Wei ◽  
Guanjie Zheng ◽  
Vikash Gayah ◽  
Zhenhui Li
Keyword(s):  
Reinforcement Learning ◽  
Real World ◽  
Intelligent Transportation Systems ◽  
Transportation Systems ◽  
Traffic Signal ◽  
Signal Control ◽  
Traffic Signal Control ◽  
Control Methods ◽  
Advantages And Disadvantages ◽  
Recent Advances

Traffic signal control is an important and challenging real-world problem that has recently received a large amount of interest from both transportation and computer science communities. In this survey, we focus on investigating the recent advances in using reinforcement learning (RL) techniques to solve the traffic signal control problem. We classify the known approaches based on the RL techniques they use and provide a review of existing models with analysis on their advantages and disadvantages. Moreover, we give an overview of the simulation environments and experimental settings that have been developed to evaluate the traffic signal control methods. Finally, we explore future directions in the area of RLbased traffic signal control methods. We hope this survey could provide insights to researchers dealing with real-world applications in intelligent transportation systems

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