scholarly journals FDIR for the IMU Component of AOCS Systems

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Maurício N. Pontuschka ◽  
Ijar M. da Fonseca
Keyword(s):  
Automatic Detection ◽  
Fault Identification ◽  
Space Applications ◽  
Tetrahedral Configuration ◽  
Orbit Control ◽  
Definition Of ◽  
And Control ◽  
Control Division ◽  
Good Agreement

The main objective of this paper is the study of a FDIR for an IMU aiming at space applications with focus on the gyro signal analysis and the tests of the filtering algorithms. The algorithms have been tested by using lab data provided by the DMC LABSIM (Physical’s Simulation Laboratory of the Space Mechanics and Control Division of INPE). The results have demonstrated good agreement with the concepts applied in this study. Automatic detection procedures are very important in the characterization of occurrence, definition of criteria, and device types in the scenario of AOCS FDIR. An IMU comprised of four gyros in a tetrahedral configuration is one of the assumed components for the AOCS (attitude and orbit control subsystem) considered in this work. The types of failures considered in this paper are the step abrupt change, ramp/drift/slow, stuck, cyclic, erratic, spike, and finally the stuck for variance alteration noise. An appropriate algorithm for the automatic detection of each type of fault is developed. The approach includes the mapping capability of fault event indicators to the IMU. This mapping is very important in the characterization of the occurrence, definition of criteria, and device types as well as associated fault identification for an AOCS.

Heat Transfer Enhancement Due to Coolant Extraction on the Cold Side of Effusion Cooling Plates

2015 ◽  
Vol 137 (12) ◽  
Author(s):  
Riccardo Da Soghe ◽  
Antonio Andreini ◽  
Bruno Facchini ◽  
Lorenzo Mazzei
Keyword(s):  
Heat Transfer ◽  
Pressure Ratio ◽  
Operating Conditions ◽  
Transfer Enhancement ◽  
Cold Side ◽  
Convective Cooling ◽  
Definition Of ◽  
And Control ◽  
Innovative Techniques

Effusion cooling represents one of the most innovative techniques to limit and control the metal temperature of combustors liner, and recently, attention has been paid by the scientific community on the characterization and the definition of design practices of such devices. Most of these studies were focused on the heat transfer on the hot side of effusion cooling plates, while just few contributions deal with the effusion plates cold side convective cooling. This paper reports a numerical survey aimed at the characterization of the convective cooling at the effusion plates cold side. Several effusion holes spacing is accounted for in conjunction with representative operating conditions. The study led to the development of an empirical correlation for the prediction of the cold side heat transfer coefficient enhancement factor, EF: it expresses the EF related to each extraction hole as a function of the pressure ratio β and the effusion plate porosity factor σ.

Heat Transfer Enhancement due to Coolant Extraction on the Cold Side of Effusion Cooling Plates

2014 ◽  
Author(s):  
R. Da Soghe ◽  
A. Andreini ◽  
B. Facchini ◽  
L. Mazzei
Keyword(s):  
Heat Transfer ◽  
Pressure Ratio ◽  
Operating Conditions ◽  
Transfer Enhancement ◽  
Cold Side ◽  
Convective Cooling ◽  
Aero Engine ◽  
Definition Of ◽  
And Control

Effusion cooling represents one the most innovative technique to limit and control the metal temperature of aero-engine combustors liner and, recently, attention has been paid by the scientific community on the characterization and the definition of design practices of such devices. Most of these studies were focused on the heat transfer on the hot side of effusion cooling plates while just few contributions deal with the effusion plates cold side convective cooling. This paper reports a numerical survey aimed at the characterization of the convective cooling at the effusion plates cold side. Several effusion holes spacing are accounted for in conjunction with representative operating conditions. The study led to the development of an empirical correlation for the prediction of the cold side heat transfer coefficient enhancement factor EF: it expresses the EF related to each extraction hole as a function of the pressure ratio β and the effusion plate porosity factor.

scholarly journals Characterization of Sustainable Robotic Materials and Finite Element Analysis of Soft Actuators Under Biodegradation

2021 ◽  
Vol 8 ◽  
Author(s):  
Toshiaki Nagai ◽  
Ashitaka Kurita ◽  
Jun Shintake
Keyword(s):  
Mechanical Properties ◽  
Biodegradable Materials ◽  
Biodegradable Material ◽  
Element Analysis ◽  
Soft Actuator ◽  
Degradation Rates ◽  
Soft Actuators ◽  
And Control ◽  
Good Agreement

Biodegradability is an important property for soft robots that makes them environmentally friendly. Many biodegradable materials have natural origins, and creating robots using these materials ensures sustainability. Hence, researchers have fabricated biodegradable soft actuators of various materials. During microbial degradation, the mechanical properties of biodegradable materials change; these cause changes in the behaviors of the actuators depending on the progression of degradation, where the outputs do not always remain the same against identical inputs. Therefore, to achieve appropriate operation with biodegradable soft actuators and robots, it is necessary to reflect the changes in the material properties in their design and control. However, there is a lack of insight on how biodegradable actuators change their actuation characteristics and how to identify them. In this study, we build and validate a framework that clarifies changes in the mechanical properties of biodegradable materials; further, it allows prediction of the actuation characteristics of degraded soft actuators through simulations incorporating the properties of the materials as functions of the degradation rates. As a biodegradable material, we use a mixture of gelatin and glycerol, which is fabricated in the form of a pneumatic soft actuator. The experimental results show that the actuation performance of the physical actuator reduces with the progression of biodegradation. The experimental data and simulations are in good agreement (R2 value up to 0.997), thus illustrating the applicability of our framework for designing and controlling biodegradable soft actuators and robots.

scholarly journals Organizations and economics

2010 ◽  
Vol 6 (1) ◽  
pp. 39-45
Author(s):  
RICHARD ADELSTEIN
Keyword(s):  
Central Planning ◽  
Alternative Conceptions ◽  
Principal Agent ◽  
Organizational Economics ◽  
Explicit Characterization ◽  
Principal Agent Problem ◽  
Definition Of ◽  
And Control

Abstract:Judge Posner (2010) identifies organizational economics with the principal-agent problem and offers no definition of the crucial term organization, which leads him to force the principal-agent template on social formations that are not organizations and to neglect aspects of their operation that might be illuminated by alternative conceptions of organizational economics. This response offers an explicit characterization of organizations as central planning agencies, considers Posner's examples in light of the problems of purpose, information, and control faced by all central planners, and draws upon an emerging capabilities theory of organizations to extend the scope of Posner's analysis and suggest insights beyond those that flow from the principal-agent approach.

scholarly journals Application of Emission and Absorption Spectroscopy for Characterization of a Copper Converting Process

1988 ◽  
Vol 42 (1) ◽  
pp. 128-133 ◽  
Author(s):  
Wilhelm Wendt ◽  
Marcus Aldén ◽  
Willy Persson
Keyword(s):  
Band Structure ◽  
Absorption Edge ◽  
Emission Spectra ◽  
Emission And Absorption Spectra ◽  
Discrete Structures ◽  
Copper Converting ◽  
And Control ◽  
Absorption Measurements ◽  
Good Agreement

The emission and absorption spectra of a copper converter flame have been investigated. It was found that the emission spectra consisted of Planck radiation and superimposed discrete structures. The band structure was dominated by PbS in the slag-making stage and by PbO in the copper-making stage. Towards the end of the slag-making stage the ratio of the PbO and PbS band intensities (PbO/PbS) changed, in good agreement with thermodynamical calculations. Absorption measurements were performed during the copper-making stage, where the absorption edge of SO2 at about 380 nm was the dominating feature. The implications of these measurements for process steering and control are discussed.

administrasi ketatausahaan sekolah

2020 ◽  
Author(s):  
Isra Revenia
Keyword(s):  
Information Needs ◽  
Control Functions ◽  
Definition Of ◽  
The Right ◽  
And Control

This article is made to know the destinantion and the administrasi functions of the school in order to assist the leader of an organazation in making decisions and doing the right thing, recording of such statements in addition to the information needs also pertains to the function of accountabilitty and control functions. Administrative administration is the activity of recording for everything that happens in the organization to be used as information for leaders. While the definition of administration is all processing activities that start from collecting (receiving), recording, processing, duplicating, minimizing and storing all the information of correspondence needed by the organization. Administration is as an activity to determine everything that happens in the organization, to be used as material for information by the leadership, which includes all activities ranging from manufacturing, managing, structuring to all the preparation of information needed by the organization.

A STRATEGY FOR MONITORING THE IMPACTS OF COMBINED SEWER OVERFLOWS ON THE OHIO RIVER

1994 ◽  
Vol 30 (1) ◽  
pp. 167-175
Author(s):  
Alan H. Vicory ◽  
Peter A. Tennant
Keyword(s):  
National Policy ◽  
The United States ◽  
Ohio River ◽  
Combined Sewer Overflows ◽  
Treatment Technology ◽  
Design Storm ◽  
Combined Sewer ◽  
Sewer Overflows ◽  
Definition Of ◽  
And Control

With the attainment of secondary treatment by virtually all municipal discharges in the United States, control of water pollution from combined sewer overflows (CSOs) has assumed a high priority. Accordingly, a national strategy was issued in 1989 which, in 1993, was expanded into a national policy on CSO control. The national policy establishes as an objective the attainment of receiving water quality standards, rather than a design storm/treatment technology based approach. A significant percentage of the CSOs in the U.S. are located along the Ohio River. The states along the Ohio have decided to coordinate their CSO control efforts through the Ohio River Valley Water Sanitation Commission (ORSANCO). With the Commission assigned the responsibility of developing a monitoring approach which would allow the definition of CSO impacts on the Ohio, research by the Commission found that very little information existed on the monitoring and assessment of large rivers for the determination of CSO impacts. It was therefore necessary to develop a strategy for coordinated efforts by the states, the CSO dischargers, and ORSANCO to identify and apply appropriate monitoring approaches. A workshop was held in June 1993 to receive input from a variety of experts. Taking into account this input, a strategy has been developed which sets forth certain approaches and concepts to be considered in assessing CSO impacts. In addition, the strategy calls for frequent sharing of findings in order that the data collection efforts by the several agencies can be mutually supportive and lead to technically sound answers regarding CSO impacts and control needs.

Introduction

2018 ◽  
Author(s):  
Elizabeth S. Radcliffe
Keyword(s):  
Early Modern ◽  
Historical Background ◽  
Consistent Picture ◽  
And Control ◽  
Good And Evil

The Introduction offers, first, a brief historical background to Hume’s theory of the passions, which is further elaborated in the APPENDIX. Foremost among the theses of the early modern rationalists—like Reynolds, Senault, Descartes, Cudworth, and Clarke—to which Hume is responding are: that many passions left unregulated lead to the pursuit of unsuitable objects, that reason can overcome the pernicious influence of the passions and control our actions, and that the passions are states that represent good and evil. Second, the Introduction presents a sketch of Hume’s characterization of reason and passion and his account of their relationship. Third, it explains the method of interpretation used in this book and previews its chapters. The approach is coherentist: to present an intelligible and consistent picture of Hume’s theory of passion and action, accounting for as many of the relevant texts as possible.

scholarly journals Design, Construction, and Control for an Underwater Vehicle Type Sepiida

Robotica ◽  
2020 ◽  
pp. 1-18
Author(s):  
M. Garcia ◽  
P. Castillo ◽  
E. Campos ◽  
R. Lozano
Keyword(s):  
Embedded System ◽  
Closed Loop ◽  
Underwater Vehicle ◽  
Mathematical Representation ◽  
Closed Loop System ◽  
Vehicle Type ◽  
Mathematical Equations ◽  
And Control ◽  
Design Construction

SUMMARY A novel underwater vehicle configuration with an operating principle as the Sepiida animal is presented and developed in this paper. The mathematical equations describing the movements of the vehicle are obtained using the Newton–Euler approach. An analysis of the dynamic model is done for control purposes. A prototype and its embedded system are developed for validating analytically and experimentally the proposed mathematical representation. A real-time characterization of one mass is done to relate the pitch angle with the radio of displacement of the mass. In addition, first validation of the closed-loop system is done using a linear controller.

An LQ Approach to Active Control of Vibrations in Helicopters

1996 ◽  
Vol 118 (3) ◽  
pp. 482-488 ◽  
Author(s):  
Sergio Bittanti ◽  
Fabrizio Lorito ◽  
Silvia Strada
Keyword(s):  
Optimal Control ◽  
Active Control ◽  
Linear Quadratic ◽  
Control Effort ◽  
Vibration Effect ◽  
Suitable Definition ◽  
Lq Optimal Control ◽  
The One ◽  
Definition Of ◽  
And Control

In this paper, Linear Quadratic (LQ) optimal control concepts are applied for the active control of vibrations in helicopters. The study is based on an identified dynamic model of the rotor. The vibration effect is captured by suitably augmenting the state vector of the rotor model. Then, Kalman filtering concepts can be used to obtain a real-time estimate of the vibration, which is then fed back to form a suitable compensation signal. This design rationale is derived here starting from a rigorous problem position in an optimal control context. Among other things, this calls for a suitable definition of the performance index, of nonstandard type. The application of these ideas to a test helicopter, by means of computer simulations, shows good performances both in terms of disturbance rejection effectiveness and control effort limitation. The performance of the obtained controller is compared with the one achievable by the so called Higher Harmonic Control (HHC) approach, well known within the helicopter community.

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