scholarly journals A Numerical Comparison of Inertia-Free Attitude Control Laws for a Spacecraft with a Discrete Flexible Mode

2013 ◽  
Author(s):  
Marc Camblor ◽  
Antai Xie ◽  
Gerardo Cruz ◽  
Sergio Esteban ◽  
Taeyoung Lee ◽  
...  
Keyword(s):  
Attitude Control ◽  
Numerical Comparison ◽  
Control Laws ◽  
Flexible Mode

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.

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.

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.

The Satellite Attitude Control Law Design Based on Machine Learning

2014 ◽  
Vol 519-520 ◽  
pp. 741-746 ◽  
Author(s):  
Guo Jiang Sun ◽  
Jin Hui Li ◽  
Shi Ming Chen ◽  
Yun Feng Dong
Keyword(s):  
Machine Learning ◽  
Attitude Control ◽  
Fitness Function ◽  
Control Law ◽  
Sensors And Actuators ◽  
Control Laws ◽  
Satellite Attitude ◽  
Control Precision ◽  
Attitude Error ◽  
Satellite Attitude Control

Traditional optimization algorithms can only optimize parameters in control laws. Machine learning method can optimize parameters and evolve satellite attitude control law automatically under certain criterion. Single axis satellite attitude simulation system with noise was built up, which included satellite attitude dynamic model, sensors and actuators model. The control laws inputs were attitude error, attitude errors integral and angular velocity error, and outputs were actuators control instructions. Control laws fitness function was an attitude errors statistical function. With suitable function set selected for genetic programming (GP) and parse tree used to represent a control law expression, GP was used to evolve control law expression automatically. Simulation result shows that this method can evolve control law with uncertainties noise better. The evolved control law response and control precision are better than PID, and it can be used in satellite attitude control.

Nonlinear Attitude Control Laws for the Bell 412 Helicopter

2008 ◽  
Vol 31 (1) ◽  
pp. 44-52 ◽  
Author(s):  
Daniel J. Walker ◽  
Mark Voskuijl ◽  
Binoy J. Manimala ◽  
Arthur W. Gubbels
Keyword(s):  
Attitude Control ◽  
Control Laws

On-earth testbed for implementation of attitude control laws

2011 ◽  
Author(s):  
Hossein Karimpour ◽  
Mojtaba Mahzoon ◽  
Mehdi Keshmiri
Keyword(s):  
Attitude Control ◽  
Control Laws

Guidance and control algorithms for mini UAV autopilots

2017 ◽  
Vol 89 (1) ◽  
pp. 133-144 ◽  
Author(s):  
Elisa Capello ◽  
Giorgio Guglieri ◽  
Gianluca Ristorto
Keyword(s):  
Attitude Control ◽  
Path Following ◽  
Adaptive Controller ◽  
Computationally Efficient ◽  
Control Laws ◽  
Content Type ◽  
Guidance And Control ◽  
Aerial Vehicle ◽  
Set Up ◽  
And Control

Purpose The aim of this paper is the implementation and validation of control and guidance algorithms for unmanned aerial vehicle (UAV) autopilots. Design/methodology/approach The path-following control of the UAV can be separated into different layers: inner loop for pitch and roll attitude control, outer loop on heading, altitude and airspeed control for the waypoints tracking and waypoint navigation. Two control laws are defined: one based on proportional integrative derivative (PID) controllers both for inner and outer loops and one based on the combination of PIDs and an adaptive controller. Findings Good results can be obtained in terms of trajectory tracking (based on waypoints) and of parameter variations. The adaptive control law guarantees smoothing responses and less oscillations and glitches on the control deflections. Practical implications The proposed controllers are easily implementable on-board and are computationally efficient. Originality/value The algorithm validation via hardware in the loop simulations can be used to reduce the platform set-up time and the risk of losing the prototype during the flight tests.

Shaped Time-Optimal Feedback Controllers for Flexible Structures

2004 ◽  
Vol 126 (1) ◽  
pp. 173-186 ◽  
Author(s):  
Lucy Y. Pao ◽  
Chanat La-orpacharapan
Keyword(s):  
Phase Plane ◽  
Closed Loop ◽  
Flexible Structures ◽  
Input Shaping ◽  
Feedback Controllers ◽  
Control Laws ◽  
Loop Control ◽  
Flexible Mode ◽  
Time Optimal ◽  
Acceleration And Deceleration

This paper describes the design of closed-loop control laws for servomechanisms with one dominant flexible mode. An input shaping technique is employed to alter the rigid body phase-plane trajectory that is used in time-optimal servomechanisms. The resulting controllers lead to near time-optimal performance without unwanted residual vibrations. After the basic technique is outlined for a system with one undamped flexible mode, extensions are given considering different acceleration and deceleration capabilities, damping, and slew rate limits.

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