Arbitrary Attitude Research Articles

Improved contactless attitude control law of uncooperative spacecraft by laser ablation

Laser ablation technology enables contactless debris removal, providing the advantages of safety and cost efficiency. To deorbit space debris using laser ablation, the attitude motion of the debris must be controlled in advance. Although a previous study derived an attitude control procedure, it empirically determines control gains and is easily affected by assumed preconditions. To solve this problem, this paper proposes an improved attitude control law using laser ablation. Previous methods use feedback control based on the angular velocity error and error quaternions to obtain a reference torque. By analogy with a magnetic attitude control law, this study designs a reference torque based on the angular momentum errors and presents theoretical condition for designing the control gains. Numerical examples using the proposed control law are conducted to control the target attitude from a random initial rotation of 1 rpm to an arbitrary attitude, which verify the effectiveness of the proposed method. Furthermore, the position, direction, and magnitude uncertainties of laser irradiation are introduced to numerically examine their effects on the control accuracy under environmental disturbances.

Muckrakıng Through the Novel: Upton Sınclaır’s the Jungle and the Early Hıstory of Human Resources Management

Abstract Background and Purpose This study is based on the assumption that the novel, which is a modern narrative form, reflects the canon of the period in which it was written. In this context, the study tries to show how human resources management practices were carried out in large-scale industrial units in a period when the human resources management function was not specialized, with The Jungle novel by Upton Sinclair. Design/Methodology/Approach: The study is based on a typology that Bruce E. Kaufman used while describing the early history of US HRM. Kaufman lists fourteen factors that characterize early HRM. One of them is the revealing activities of the Progressive movement. Therefore, the novel is considered here as a means of disclosure. Designed on this basis, the study analyses The Jungle novel around the following themes: the foreman’s empire, child labour, occupational health and safety, wages, job insecurity, career, and the blue-collar/white-collar divide. Results The novel shows that although the scale of manufacturing units grew in the early 1900s, human management practices were not yet institutionalized and specialized. Therefore, HRM routines are carried out with the arbitrary attitude of foremen, wages are below the natural wage level, child labour is widely used, and there is a working life full of risks in terms of occupational health and safety. Conclusion When the narrative of the novel about human management is read in parallel with the academic studies describing the period, the parallelism between the two narratives shows why the novels can be used as material for academic studies.

The Image of Java and Its People in Emilie’s Eyes Under the Perspective of New Historicism

Emilie Java 1904 by Catherine Van Moppès is a French novel that portrays Indonesia's portrait in Java in 1904, a century of Dutch colonialism in Indonesia. This novel describes Indonesian colonialism through the third lens, a narration from a French person's point of view. This research aims to identify the historiography of Java in 1904, where the Dutch carried out deep colonialism using a new historicism perspective. The qualitative descriptive method was used. The data involved words, phrases, and sentences containing Javanese historiography in the novel. This study found that 1) the Javanese people are friendly, embrace Islam, and have solid ancient beliefs. The nature of Javanese men who still despise women is also reviewed; 2) From the European perspective, Java's conditions are described as exotic and beautiful but chaotic and dangerous; 3) Colonialism is also seen from a neutral side by writing that shows the negative side of priyayi and the arbitrary attitude of the Dutch toward the natives. This novel implies that the Javanese were civilized before the Dutch came, which contradicts the primary purpose of Westerners coming to the East. Otherwise, she also showed the negative and positive side of Java and its people toward the Dutch.

Public Relations and Local Wisdom Mining Company Strategy Through a Harmonious Approach

The issue of environmental damage is the hottest every time a mining company is present in the community. Starting from the issue of environmental damage to the company's arbitrary attitude toward the surrounding community. PT Nusa Alam Lestari has a way that is different from other companies, namely using a harmonious approach to local wisdom around the environment of PT Nusa Alam Lestari. In the existence of this phenomenon, researchers in this case aim to find out public relations practices and local wisdom of mining companies with a harmonious approach. The research method uses a qualitative method with a critical approach with an analysis of social construction theory. Research informants include company management, public relations practices and community leaders and local communities around the company's operational areas. PT Nusa Alam Lestari's public relations strategy uses a local wisdom approach that is instilled in the company's values ​​which have a correlation with the local community, society or traditional groups. The results of this study indicate that the analysis of social construction in PT Nusa Alam Lestari's public relations strategy includes; (1) Externalization, namely through the process of inculcating the values ​​adopted by the company that have a correlation with the community, or local customary groups. (2) The process of objectification in this case is formed from the business of PT. Nusa Alam Lestari in understanding the local community around it with the approach of local community wisdom. (3) Internalization can be implemented in the process of building a positive image for community leaders as in public relations management by frequently listening to the wishes, needs of communities, communities and traditional groups around the mine.

HEGEMONY OF LANGUAGE AS REFLECTED IN BURNETT’S A LITTLE PRINCESS

This research is intended to find out the form of the hegemony of language that is conducted by the ruling class over the subaltern people in the Novel A Little Princess. This research also explains the causal factor and its effects on the characters of Burnett’s novel in the Victorian Era. The researcher uses Gramsci’s concept of hegemony. Hegemony is the predominance obtained by consent rather than the force of one class over other classes. This research applies to library research because the corpus is a novel entitled A Little Princess. Besides that, this research is a concept analysis. The researcher explains the object and relates it to concepts, theories, or other relevant sources. It can be concluded that the ruling class conducts the hegemony of language because there is a diamond mine. The hegemony of language in this novel brings many impacts. They are: French becomes a nobility language in the Select Seminary environment, the classification of society as two classes (aristocratic and pariah class), a snobbish attitude, unfair and arbitrary attitude towards pariahs, and the emergence of resistance.

Study of Gust Calculation and Gust Alleviation: Simulations and Wind Tunnel Tests

Feedforward gust alleviation control using gusts as input signals has received increasing attention in recent years. One of the most important issues in such a control scheme is how to obtain the high-quality gust information during an aircraft’s flight. In this study, a calculation method for obtaining gust information when an aircraft is flying with an arbitrary attitude is derived, based on which a simplified calculation method is established. A wind tunnel test was carried out to verify the gust calculation method. Numerical simulations were employed to investigate the influence of sensor characteristics on the gust calculation accuracy and gust alleviation performance. The results show that the time delay of the sensor has a very important influence and leads to decreases in the gust calculation accuracy and the alleviation effect. A five-hole probe was mounted on an aircraft model for gust sensing, and a gust alleviation wind tunnel test was conducted by combining the gust calculation with the feedforward gust alleviation system. The accurate calculation of the gust signal enables the feedforward gust alleviation system to achieve a 39.12% reduction of wing root bending moment and a 65.47% reduction of wingtip acceleration on average.

Design and Implementation of a MHz Frequency Transformer with a Ferromagnetic Fluid Core

Design and optimization of a magnetic fluid cored transformer are studied for high frequency applications. An easy and cheap fluid core is designed and used to decrease the eddy current and loses, thereby low conducting and paramagnetic features are added. The core exhibits both fluid and solid characteristics exerting high frequency modes in the fluid and low current due to the iron powder inside. The finite element analysis simulations are performed via COMSOL Multi-physics package for different mass fractions of iron powder. The maximum peak-to-peak voltage and power are found as 526 mV and 188.8 mW at 12 MHz from the simulations. 3D patterns prove that the magnetic flux and magnetization exhibit turbulence in the core, thereby localized magnetic values indicate an arbitrary attitude for various frequencies. Optimum mass fraction is found as 0.7, which is parallel with experimental results. The transformer operates between 11 MHz and 13.5 MHz optimally.

Interlaced Attitude Estimation for Spacecraft Using Vector Observations

This paper proposes an interlaced attitude estimation method for spacecraft using vector observations, which can simultaneously estimate the constant attitude at the very start and the attitude of the body frame relative to its initial state. The arbitrary initial attitude, described by constant attitude at the very start, is determined using quaternion estimator which requires no prior information. The multiplicative extended Kalman filter (EKF) is competent for estimating the attitude of the body frame relative to its initial state since the initial value of this attitude is exactly known. The simulation results show that the proposed algorithms could achieve better performance compared with the state-of-the-art algorithms even with extreme large initial errors. Meanwhile, the computational burden is also much less than that of the advanced nonlinear attitude estimators.

Perspektif Keadilan Dalam Rumah Tangga

Marriage has the goal of benefiting and prospering in life. Marriage is not only crucial to achieving the happiness of human life on earth. In terms of its kinds, marriage has much diversity. However, unions recognized in the Marriage Law and the Islamic Law Compilation are monogamous and polygamous marriages in Indonesia. Polygamy is discussed in Islam, but the government regulates it with stringent regulations regarding practising polygamy. Law Number 1 of 1974 concerning marriage as a positive response to regulating a husband who wants to marry more than one person. Republic of Indonesia Government Regulation No. 9 of 1975 concerning the Implementation of Law No.1 of 1974 concerning Marriage and in the Compilation of Islamic Law, which regulates polygamy and the requirements for polygamy for Muslims. Ideally, the two regulations of Law no. 1/1974 and KHI aim to provide terms and conditions for husbands who want to remarry (polygamy). These provisions aim to minimize the arbitrary attitude of husbands (men) towards wives (women). This provision is also for the creation of a sakinah, mawaddah and warrahmah. Polygamy that occurs around us still ignores the rules of polygamy as above. Most of them practice polygamy only because of the fulfilment of lust, so they often forget and even violate the main principles in Islamic law, namely the realization of justice and benefit.

The Study on the Structural Optimization of Non-Planar Multi-rotor Helicopters Using the Force capacity

In recent years, multi-rotor helicopter has been used in various fields. However, it has the disadvantages. A general multi-rotor helicopter needs to change its attitude when moving horizontally. Therefore, fluctuations in the attitude of the aircraft to counter disturbances pose a risk of contact with structures when approaching a structure in infrastructure inspection. Furthermore, in contact work, it is required to independently control translational motion and rotational motion, such as maintaining the position of the aircraft while maintaining an arbitrary attitude. Based on the above background, the study is being conducted on a non-planar multi-rotor helicopter in which translational motion and rotational motion can be controlled independently. In this study, in order to establish the optimum design of the airframe specialized in the arbitrary axial direction, an evaluation index called ”Force capacity” is applied to the non-planar multi-rotor helicopter, and the attitude of each rotor is optimized.

Lagrangian Derivation of Variable-Mass Equations of Motion using an Arbitrary Attitude Parameterization

Lagrange’s equation is a popular method of deriving equations of motion due to the ability to choose a variety of generalized coordinates and implement constraints. When using a Lagrangian formulation, part of the generalized coordinates may describe the attitude. This paper presents a means of deriving the dynamics of variable-mass systems using Lagrange’s equation while using an arbitrary constrained attitude parameterization. The equivalence to well-known forms of the equations of motion is shown.

TINJAUAN DEKONSTRUKTIF ATAS KONSEP OTORITAS KHALED M. ABOU EL-FADL

This article discusses a deconstructive review of the concept of authority of Khaled M. Abou el-Fadl. The phenomenon of authoritarianism is now the most troubling phenomenon for the development of contemporary Islamic thought. This phenomenon not only describes a rigid and undeveloped tradition of Islamic thought, but also has an impact on immoderate socio-religious behavior. Khaled M. Abou el-Fadl described this phenomenon as a consequence of human representation of Islamic authority. In terms of representation by authoritative humans, humans are often treated authoritatively and out of the substance of Islamic authority itself. This authoritarian attitude in treating the authoritative foundation of Islam is what Khaled calls authoritarianism. It can reside in humans and manipulate meanings into interpretations which often only serve the interests of some people. Through the deconstruction method, authoritarianism does not only appear as an arbitrary attitude towards authority, but also shows a conceptual network that indirectly shifts the construction of authority itself. Khaled, besides showing an attitude of "overcoming" authority, also shows the loss of the element of morality from the authority structure itself. So that the phenomenon of authoritarianism is not only a problem of intellectuality, but also morality, between humans and authorities in discourse space.

TINJAUAN DEKONSTRUKTIF ATAS KONSEP OTORITAS KHALED M. ABOU EL-FADL

This article discusses a deconstructive review of the concept of authority of Khaled M. Abou el-Fadl. The phenomenon of authoritarianism is now the most troubling phenomenon for the development of contemporary Islamic thought. This phenomenon not only describes a rigid and undeveloped tradition of Islamic thought, but also has an impact on immoderate socio-religious behavior. Khaled M. Abou el-Fadl described this phenomenon as a consequence of human representation of Islamic authority. In terms of representation by authoritative humans, humans are often treated authoritatively and out of the substance of Islamic authority itself. This authoritarian attitude in treating the authoritative foundation of Islam is what Khaled calls authoritarianism. It can reside in humans and manipulate meanings into interpretations which often only serve the interests of some people. Through the deconstruction method, authoritarianism does not only appear as an arbitrary attitude towards authority, but also shows a conceptual network that indirectly shifts the construction of authority itself. Khaled, besides showing an attitude of "overcoming" authority, also shows the loss of the element of morality from the authority structure itself. So that the phenomenon of authoritarianism is not only a problem of intellectuality, but also morality, between humans and authorities in discourse space.

Separation Algorithm of the Soyuz MS Spacecraft from Nonstabilized International Space Station

We propose an easy-to-implement algorithm providing the safe (collision-free) separation of the Soyuz MS crew transfer vehicle from the ports of the Rassvet (MRM-1) and Poisk (MRM-2) mini-research modules of the International Space Station at an arbitrary station attitude at the time of separation and angular velocities exceeding the maximum permissible for the current undocking algorithm. A criterion of collision-free separation process is described and a comprehensive mathematical model used for calculation is presented.

Globally Stable Attitude Control of a Fixed-Wing Rudderless UAV Using Subspace Projection

This letter extends recent work on globally asymptotically stable nonlinear attitude control of fully actuated vehicles to underactuated vehicles, specifically, a rudderless fixed-wing airplane. Previous work uses a quaternion attitude representation and Lyapunov theory to establish global asymptotic stability for attitude tracking in a fully actuated fixed-wing airplane, beginning from arbitrary initial conditions. Many small unmanned aerial vehicles are, however, heavily constrained with respect to sensor and actuator resources. A common situation is a flying wing configuration with a pair of elevons that serve the purpose of both the elevator as well as the ailerons. While it is not possible to track an arbitrary attitude in the three-dimensional (3-D) attitude space, we show that it is still possible to track a 2-D subspace of the unit quaternion space. Projecting a desired attitude onto a 2-D subspace is achieved by solving an optimization problem in the quaternion attitude formulation. The resulting controller is verified using simulations that demonstrate satisfactory performance.

Self-calibration of gyro asymmetry for single-axis forward–reverse rotating inertial navigation system under arbitrary attitude

In recent years, the applications of rotating inertial navigation systems (INSs) have been developed rapidly. By controlling the rotation of the inertial measurement unit, the drift error of an inertial device can be modulated and the divergence of INS errors can be suppressed. However, attitude errors and velocity errors accumulate as the result of the scale factor asymmetry of gyros based on a forward–reverse rotating system, which offers better performance than single-axis rotational navigation systems. In this paper, the error mechanism of scale factor asymmetry in forward–reverse rotating systems is discussed in detail. Based on a system-level fitting method, error deduction of the scale factor asymmetry of a gyro under different conditions, including the level and tilt environments, are introduced, respectively. Thus, a self-calibration and compensation method based on scale factor asymmetry is proposed. The simulation and experiment results show that the iterative calibration and compensation method has a positive effect on eliminating scale factor asymmetry, and the precision of initial alignment and navigation can be improved after compensation.

Attitude Control of Underactuated and Momentum-Biased Satellite Using State-Dependent Riccati Equation Method

This paper deals with the attitude control problem of an underactuated satellite controlled by two reaction wheels. The angular momentum of the satellite is assumed to be non-zero or biased. Under these conditions, rotation to arbitrary attitude (roll, pitch, and yaw) is not possible, but direction or limited attitude control (roll and pitch) is possible. For such control, a nonlinear controller is proposed to utilize the angular momentum as gyroscopic torque. The controller is designed using the State-Dependent Riccati Equation (SDRE) method. This SDRE method provides a systematic way to design nonlinear controllers for diverse combinations of two reaction wheels. The proposed method has been verified by numerical simulations and the designed control system works satisfactorily.

Effect of arbitrary yaw/pitch angle in bird strike numerical simulation using SPH method

The influences of arbitrary attitude angles on bird strike on a fixed rigid flat plate and a rotary jet-engine fan are studied. A verified realistic bird model and a hemispherical-ended cylinder substitute bird model are modeled by using the smoothed particle hydrodynamics (SPH) method. Since birds can strike aircraft engine from any orientations, simulations of bird models striking a rigid flat plate at random attitude angles are first done as a validation test. Results show that different attitude angles of bird model have distinct effect on the response of bird strike. As the attitude angle increases, the peak impact force becomes larger and the bird model loses more energy. By considering the rotation of the jet-engine fan ignored before, the impact behavior of realistic bird models striking on rotating engine blades from arbitrary attitude angles is investigated. Effects of the attitude angle on the most concerned impact force, kinetic energy and von Mises stress of blade roots are discussed. It is concluded that considering attitude angles of real bird and rotation of the jet-engine fan in bird strike simulation has practical significance on structural tolerant design.

High-fidelity geometry models for improving the consistency of CHAMP, GRACE, GOCE and Swarm thermospheric density data sets

During the last two decades, accelerometers on board of the CHAMP, GRACE, GOCE and Swarm satellites have provided high-resolution thermosphere density data to improve our knowledge on atmospheric dynamics and coupling processes in the thermosphere-ionosphere region. Most users of the data have focused on relative density variations. Scale differences between datasets and models have been largely neglected or removed using ad hoc scale factors. The origin of these scale differences arises from errors in the aerodynamic modelling, specifically in the modelling of the satellite outer surface geometry and of the gas-surface interactions. Therefore, the first step to remove the scale differences is to enhance the geometry modelling. This work forms the foundation for the future improvement of characterization of satellite aerodynamics and gas-surface interactions models at TU Delft, as well as for extending the use of sideways and angular accelerations in the aerodynamic analysis of accelerations and derivation of thermosphere datasets. Although work to improve geometry and aerodynamic force models by other authors has focused on CHAMP and GRACE, this paper includes the GOCE and Swarm satellites as well. In addition, it uses a density determination algorithm that is valid for arbitrary attitude orientations, enabling a validation making use of attitude manoeuvres. The results show an improvement in the consistency of density data between these four missions, and of data obtained before, during and after attitude manoeuvres of CHAMP and Swarm. The new models result in larger densities, compared to the previously used panel method. The largest average rescaling of density, by switching to the new geometry models is reached for Swarm at 32%, the smallest for GRACE at 5%. For CHAMP and GOCE, mean differences of 11% and 9% are obtained respectively. In this paper, an overview of the improvements and comparisons of data sets is provided together with an introduction to the next research phase on the gas-surface interactions.

Social Movement as an Organic Intellectual in Fighting for Environment Justice in East Borneo

Samarinda is one of areas established by Energy, Resource, and Mineral Ministry to belong to mining business region. For that reason, Samarinda City Government issues coal mining management policy according to the authority it has. This research aimed to explain organic intellectual social movement from “Gerakan Samarinda Menggugat” (GSM) (English: Movement of Samarinda Sue”). This study was an evaluative qualitative research, referring to Antonio Gramsci’s organic intellectual theory. Techniques of collecting data used were observation, in-depth interview, and documentation. Data validation was conducted using Triangulation, and data analysis using an interactive model. The result of research showed that the effect of coal mining license sale overlapping between population-dense areas, among others, resulted in ex-mining holes leaving poisonous water and heavy metal that has taken child life toll in Samarinda City. Departing from the situation encountered by people due to injustice and arbitrary attitude to people, Gerakan Samarinda Menggugat (GSM) was born. The sue was filed by 19 Samarinda City citizens affiliated with Gerakan Samarinda Menggugat (GSM) fighting for environment justice using Citizen Law Suit.