scholarly journals Wave-Based Attitude Control of Spacecraft with Fuel Sloshing Dynamics

2016 ◽  
Vol 63 (2) ◽  
pp. 263-275 ◽  
Author(s):  
Joseph William Thompson ◽  
William O’Connor
Keyword(s):  
Mathematical Model ◽  
Attitude Control ◽  
Experimental Validation ◽  
Uniform Structure ◽  
Structural Flexibility ◽  
Control Laws ◽  
Single Plane ◽  
Pendulum Model ◽  
Sloshing Dynamics ◽  
Upper Stage

Abstract Wave-Based Control has been previously applied successfully to simple under-actuated flexible mechanical systems. Spacecraft and rockets with structural flexibility and sloshing are examples of such systems but have added difficulties due to non-uniform structure, external disturbing forces and non-ideal actuators and sensors. The aim of this paper is to extend the application of WBC to spacecraft systems, to compare the performance of WBC to other popular controllers and to carry out experimental validation of the designed control laws. A mathematical model is developed for an upper stage accelerating rocket moving in a single plane. Fuel sloshing is represented by an equivalent mechanical pendulum model. A wave-based controller is designed for the upper stage AVUM of the European launcher Vega. In numerical simulations the controller successfully suppresses the sloshing motion. A major advantage of the strategy is that no measurement of the pendulum states (sloshing motion) is required.

scholarly journals Neighboring Optimal Guidance and Constrained Attitude Control for Accurate Orbit Injection

2021 ◽  
Author(s):  
Mauro Pontani ◽  
Fabio Celani
Keyword(s):  
Attitude Control ◽  
Initial Position ◽  
Low Earth Orbit ◽  
Guidance And Control ◽  
Optimal Guidance ◽  
Combined Use ◽  
Upper Stage ◽  
Neighboring Optimal Guidance ◽  
And Control ◽  
Guidance Technique

AbstractAccurate orbit injection represents a crucial issue in several mission scenarios, e.g., for spacecraft orbiting the Earth or for payload release from the upper stage of an ascent vehicle. This work considers a new guidance and control architecture based on the combined use of (i) the variable-time-domain neighboring optimal guidance technique (VTD-NOG), and (ii) the constrained proportional-derivative (CPD) algorithm for attitude control. More specifically, VTD-NOG & CPD is applied to two distinct injection maneuvers: (a) Hohmann-like finite-thrust transfer from a low Earth orbit to a geostationary orbit, and (b) orbit injection of the upper stage of a launch vehicle. Nonnominal flight conditions are modeled by assuming errors on the initial position, velocity, attitude, and attitude rate, as well as actuation deviations. Extensive Monte Carlo campaigns prove effectiveness and accuracy of the guidance and control methodology at hand, in the presence of realistic deviations from nominal flight conditions.

Automatic Flight Control of Unmanned Helicopter Based on Nonlinear Model

2012 ◽  
Vol 472-475 ◽  
pp. 1492-1499
Author(s):  
Run Xia Guo
Keyword(s):  
Nonlinear Model ◽  
Flight Control ◽  
Attitude Control ◽  
Lyapunov Stability Theory ◽  
Test Results ◽  
Unmanned Helicopter ◽  
Control Laws ◽  
Control Approach ◽  
State Dependent ◽  
Compensation Technique

The Unmanned helicopter (UMH) movement was divided into two parts, namely, attitude and trajectory motion. And then a two-timescale nonlinear model was established. The paper improved and expanded state dependent riccati equation (SDRE) control approach, deriving analytical conditions for achieving global asymptotic stability with lyapunov stability theory. Proof was given. By combining improved SDRE control with nonlinear feed-forward compensation technique, the full envelop flight attitude control laws could be designed. On the basis of attitude control, trajectory controller was developed. Actual flight tests were carried out. Test results show that the control strategy is highly effective.

A Study on Exhaust Muffler Using Counter-Phase Counteract

2014 ◽  
Vol 986-987 ◽  
pp. 810-813
Author(s):  
Ying Li Shao
Keyword(s):  
Mathematical Model ◽  
Experimental Validation ◽  
Noise Source ◽  
Low Frequency ◽  
Frequency Noise ◽  
Expansion Chamber ◽  
Band Noise ◽  
Exhaust Noise ◽  
Perforated Pipe ◽  
The Mathematical Model

The exhaust noise, which falls into low-frequency noise, is the dominant noise source of a diesel engines and tractors. The traditional exhaust silencers, which are normally constructed by combination of expansion chamber, and perforated pipe or perforated board, are with high exhaust resistance, but poor noise reduction especially for the low-frequency band noise. For this reason, a new theory of exhaust muffler of diesel engine based on counter-phase counteracts has been proposed. The mathematical model and the corresponding experimental validation for the new exhaust muffler based on this theory were performed.

Stabilizing Feedback Controls for Nonlinear Hamiltonian Systems and Nonconservative Bilinear Systems in Elasticity

1982 ◽  
Vol 104 (1) ◽  
pp. 27-32 ◽  
Author(s):  
S. N. Singh
Keyword(s):  
Asymptotic Stability ◽  
Hamiltonian Systems ◽  
Attitude Control ◽  
Sufficient Conditions ◽  
Bilinear Systems ◽  
Feedback Controls ◽  
Control Laws ◽  
Nonlinear Maps ◽  
The Stability ◽  
Necessary And Sufficient

Using the invariance principle of LaSalle [1], sufficient conditions for the existence of linear and nonlinear control laws for local and global asymptotic stability of nonlinear Hamiltonian systems are derived. An instability theorem is also presented which identifies the control laws from the given class which cannot achieve asymptotic stability. Some of the stability results are based on certain results for the univalence of nonlinear maps. A similar approach for the stabilization of bilinear systems which include nonconservative systems in elasticity is used and a necessary and sufficient condition for stabilization is obtained. An application to attitude control of a gyrostat Satellite is presented.

scholarly journals Design And Development Of Power And Attitude Control Subsystems For RYESAT

2021 ◽  
Author(s):  
Michael William Richard. Alger
Keyword(s):  
Attitude Control ◽  
Sliding Mode ◽  
Attitude Motion ◽  
Critical Systems ◽  
Magnetic Torque ◽  
Design And Development ◽  
Control Laws ◽  
Spacecraft Control ◽  
Standard Interface ◽  
Data Bus

This thesis describes the design and development of Ryerson University's first CubeSat (RyeSat) with a focus on power and attitude control subsystems. This satellite is intended to become the initial of a series of CubeSats built by Ryerson University to perform research in spacecraft control algorithms and actuators. RyeSat is built around a standard interface, which specifies both a data-bus and a switchable power supply system for non critical systems. To facilitate the development of this satellite a prototype power subsystem was created, programmed and tested. In addition to developing the system's architecture and power subsystem; analysis was preformed to size both reaction wheels and magnetic torquers. This analysis showed that a commercially available motor could be adapted to fulfill the attitude control requirements of a CubeSat and also showed that miniature magnetic torque rods would be more efficient that magnetic torque coils typically used on CubeSats. Finally, control laws for these actuators were designed and an adaptive nonlinear sliding mode controller for reaction wheels was applied to control the 3-axis attitude motion of RyeSat.

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