Linearized J2 and Atmospheric Drag Model for Control of Inner-Formation Satellite System in Elliptical Orbits

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Lu Cao ◽  
Hengnian Li
Keyword(s):  
Formation Control ◽  
Sliding Mode ◽  
Satellite System ◽  
Atmospheric Drag ◽  
Error Feedback ◽  
Real Time Control ◽  
Special Configuration ◽  
Drag Model ◽  
Time Control

A new set of linearized differential equations governing relative motion of inner-formation satellite system (IFSS) is derived with the effects of J2 as well as atmospheric drag. The IFSS consists of the “inner satellite” and the “outer satellite,” this special configuration formation endows its some advantages to map the gravity field of earth. For long-term IFSS in elliptical orbit, the high-fidelity set of linearized equations is more convenient than the nonlinear equations for designing formation control system or navigation algorithms. In addition, to avoid the collision between the inner satellite and the outer satellite, the minimum sliding mode error feedback control (MSMEFC) is adopted to perform a real-time control on the outer satellite in the presence of uncertain perturbations from the system and space. The robustness and steady-state error of MSMEFC are also discussed to show its theoretical advantages than traditional sliding mode control (SMC). Finally, numerical simulations are performed to check the fidelity of the proposed equations. Moreover, the efficacy of the MSMEFC is performed to control the IFSS with high precision.

scholarly journals Estimation of Wave Characteristics Based on Global Navigation Satellite System Data Installed on Board Sailboats

Sensors ◽  
2019 ◽  
Vol 19 (10) ◽  
pp. 2295
Author(s):  
Paolo De Girolamo ◽  
Mattia Crespi ◽  
Alessandro Romano ◽  
Augusto Mazzoni ◽  
Marcello Di Risio ◽  
...  
Keyword(s):  
Satellite System ◽  
Western Mediterranean ◽  
Real Time Control ◽  
Western Mediterranean Sea ◽  
Time Control ◽  
Self Sufficiency ◽  
Local Wave ◽  
System Data ◽  
Global Navigation Satellite ◽  
Wave Properties

This paper illustrates a methodology to get a reliable estimation of the local wave properties, based on the reconstruction of the motion of a moving sailboat by means of GNSS receivers installed on board and an original kinematic positioning approach. The wave parameters reconstruction may be used for many useful practical purposes, e.g., to improve of autopilots, for real-time control systems of ships, to analyze and improve the performance of race sailboats, and to estimate the local properties of the waves. A Class 40 oceanic vessel (ECO40) left from the port of “Riva di Traiano” located close to Rome (Italy) on 19 October 2014 to perform a non-stop sailing alone around the world in energy and food self-sufficiency. The proposed system was installed on ECO40 and the proposed method was applied to estimate the wave properties during a storm in the Western Mediterranean Sea. The results compared against two sets of hindcast data and wave buoy records demonstrated the reliability of the method.

Flow control with active dimples

2007 ◽  
Vol 111 (1125) ◽  
pp. 705-714 ◽  
Author(s):  
S. Dearing ◽  
S. Lambert ◽  
J. Morrison
Keyword(s):  
Pressure Sensors ◽  
Fast Response ◽  
Vortex Generators ◽  
Control Surface ◽  
Real Time Control ◽  
Capacitance Change ◽  
Time Control ◽  
Design And Manufacture ◽  
Smart Skin

Abstract The long-term goal is to design and manufacture optimal ‘on-demand’ vortex generators, ‘dimples’ that can produce vortices of prescribed strength and duration for the real-time control of aerodynamic flows that are either undergoing transition or are fully turbulent, attached or separating. Electro-active polymers (EAP) are ideal for a dimple control surface, offering high strain rate, fast response, and high electromechanical efficiency. EAP can also be used as the basis of a resistanc – or capacitance – change pressure sensor, development of which has just begun. In terms of manufacture, inkjet printing of EAP also offers a paradigm shift such that a monolithic control surface is a very real possibility. Important features for integration into a control system are robustness and a predictable, repeatable motion. With these objectives in mind, the suitability of EAP-based actuators is assessed both mechanically and aerodynamically. The ultimate goal is to integrate these devices, along with shear-stress and pressure sensors and distributed control, also under development, into a flexible ‘smart skin’ which could be incorporated into an airframe structure. The response of a laminar boundary layer to forcing is investiagted using mechanical dimples.

scholarly journals Sliding Mode Real-Time Control of Photovoltaic Systems Using Neural Estimators

2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
J. A. Ramos-Hernanz ◽  
O. Barambones ◽  
J. M. Lopez-Guede ◽  
I. Zamora ◽  
P. Eguia ◽  
...  
Keyword(s):  
Sliding Mode ◽  
Weather Conditions ◽  
Maximum Power ◽  
Photovoltaic Module ◽  
Real Time Control ◽  
Maximum Power Point ◽  
Point Tracking ◽  
Time Control ◽  
Power Point ◽  
Artificial Neuronal Network

The maximum power point tracking (MPPT) problem has attracted the attention of many researchers, because it is convenient to obtain the maximum power of a photovoltaic module regardless of the weather conditions and the load. In this paper, a novel control for a boost DC/DC converter has been introduced. It is based on a sliding mode controller (SMC) that takes a current signal as reference instead of a voltage, which is generated by a neuronal reference current generator. That reference current indicates the current (IMPP) at the maximum power point (MPP) for given weather conditions. In order to test the designed control system, a photovoltaic module model based on a second artificial neuronal network (ANN) has been obtained from experimental data gathered during 18 months in the Faculty of Engineering Vitoria-Gasteiz (Spain). We have analyzed the performance of such model and we found that it is very accurate (MSE = 0.062 A andR= 0.991 with test dataset). We also have tested the performance of the overall SMC design with both simulated and real tests, concluding that it guarantees that the power in the output of the converter is very close to the power of the photovoltaic module output.

scholarly journals Simulation and assessment of long-term stormwater basin performance under real-time control retrofits

2020 ◽  
Vol 17 (5) ◽  
pp. 467-480
Author(s):  
Zoë K. Schmitt ◽  
Clayton C. Hodges ◽  
Randel L. Dymond
Keyword(s):  
Real Time ◽  
Real Time Control ◽  
Time Control

Real time control via a high order sliding mode controller of a multi-cellular converter

2009 ◽  
Vol 42 (17) ◽  
pp. 346-351
Author(s):  
M. DJEMAI ◽  
K. BUSAWON ◽  
K. BENMANSOUR ◽  
A. MAROUF
Keyword(s):  
Real Time ◽  
Sliding Mode ◽  
High Order ◽  
Sliding Mode Controller ◽  
Real Time Control ◽  
Time Control
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