Active Control Comparison of Vibration in Flexible Spacecraft Using Different Active Friction Joints

2013 ◽  
Vol 446-447 ◽  
pp. 1160-1164
Author(s):  
Sahar Bakhtiari Mojaz ◽  
Hamed Kashani
Keyword(s):  
Energy Dissipation ◽  
Attitude Control ◽  
Vibration Suppression ◽  
Excitation Amplitude ◽  
Step Function ◽  
Flexible Spacecraft ◽  
Control Effort ◽  
Stick Slip ◽  
Control Comparison ◽  
Frictional Joints

Vibration properties of most assembled mechanical systems depend on frictional damping in joints. The nonlinear transfer behavior of the frictional interfaces often provides the dominant damping mechanism in structure and plays an important role in the vibratory response of it. For improving the performance of systems, many studies have been carried out to predict measure and enhance the energy dissipation of friction. This paper presents a new approach to vibration reduction of flexible spacecraft with enhancing the energy dissipation of frictional dampers. Spacecraft is modeled as a 3 degree of freedom mass-spring system which is controlled by a lead compensator and System responses to step function evaluated. Coulomb and Jenkins element has been used as vibration suppression mechanisms in joints and sensitivity of their performance to variations of spacecraft excitation amplitude and damper properties is analyzed. The relation between frictional force and displacement derived and used in optimization of control performance. Responses of system and control effort needed for the vibration control are compared for these two frictional joints. It is shown that attitude control effort reduces, significantly with coulomb dampers and response of system improves. On the other hand, due to stick-slip phenomena in Jenkins element, we couldn’t expect the same performance from Jenkins damper.

Nonlinear Attitude Control of Flexible Spacecraft With Scissored Pairs of Control Moment Gyros

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Jixiang Fan ◽  
Di Zhou
Keyword(s):  
Attitude Control ◽  
Vibration Suppression ◽  
Large Angle ◽  
Singularity Analysis ◽  
Flexible Spacecraft ◽  
Attitude Motion ◽  
Nonlinear Feedback ◽  
Nonlinear Controller ◽  
Control Moment ◽  
Steering Law

Dynamic equations describing the attitude motion of flexible spacecraft with scissored pairs of control moment gyroscopes are established. A nonlinear controller is designed to drive the flexible spacecraft to implement three-axis large-angle attitude maneuvers with the vibration suppression. Singularity analysis for three orthogonally mounted scissored pairs of control moment gyros shows that there exists no internal singularity in this configuration. A new pseudo-inverse steering law is designed based on the synchronization of gimbal angles of the twin gyros in each pair. To improve the synchronization performance, an adaptive nonlinear feedback controller is designed for each pairs of control moment gyros by using the stability theory of Lyapunov. Simulation results are provided to show the validity of the controllers and the steering law.

Vibration suppression-based attitude control for flexible spacecraft

2017 ◽  
Vol 70 ◽  
pp. 487-496 ◽  
Author(s):  
Zhaohui Wang ◽  
Ming Xu ◽  
Yinghong Jia ◽  
Shijie Xu ◽  
Liang Tang
Keyword(s):  
Attitude Control ◽  
Vibration Suppression ◽  
Flexible Spacecraft

Robust adaptive sliding mode attitude control and vibration damping of flexible spacecraft subject to unknown disturbance and uncertainty

2011 ◽  
Vol 34 (4) ◽  
pp. 436-447 ◽  
Author(s):  
Qinglei Hu
Keyword(s):  
Feedback Control ◽  
Sliding Mode Control ◽  
Attitude Control ◽  
Vibration Suppression ◽  
Sliding Mode ◽  
Flexible Spacecraft ◽  
Adaptive Sliding Mode Control ◽  
Adaptive Sliding Mode ◽  
Mode Control ◽  
Control Command

This paper is concerned with the development of a control system for rotational manoeuvre and vibration suppression of a flexible spacecraft. The design approach presented here treats the problem of spacecraft attitude control separately from the elastic vibration suppression problem. As a stepping stone, a state feedback sliding mode control command is designed to achieve the reference trajectory tracking control of attitude angle. This is followed by the design of an adaptive sliding mode control law using only output for robust stabilization of spacecraft in the presence of parametric uncertainty and external disturbances. Even if this controller has the ability to reject the disturbance and deal with uncertainty, it excites the elastic modes of flexible appendages. The undesirable vibration is then actively suppressed by applying feedback control voltages to the piezoceramic actuators, in which the modal velocity feedback control method is adopted here for determining the control voltages. The effectiveness of the control schemes in handling external disturbance and uncertainty in the system parameters is also studied. Both analytical and numerical results are presented to show the theoretical and practical merit of this hybrid approach.

A View to the Energy Dissipation Mechanism of a Gas Foil Bearing’s Structure due to Dry Friction

2012 ◽  
Author(s):  
José A. Matute ◽  
Rafael O. Ruiz ◽  
Sergio E. Diaz
Keyword(s):  
Energy Dissipation ◽  
Dry Friction ◽  
Nonlinear Behavior ◽  
Excitation Amplitude ◽  
Equivalent Model ◽  
Stick Slip ◽  
Friction Forces ◽  
Energy Dissipation Mechanism ◽  
Variable Function ◽  
Dissipation Mechanism

The purpose of the present work consists on improving the understanding of the energy dissipation mechanism in the structure of a gas foil bearing. The analysis is based on an analytical model capable of predicting bumps deformation due to a load on the top coupled with dry friction forces at the top and bump ends. Models of mass-individual bump and mass-bump foil subject to a harmonic force are predicted numerically. The nonlinear behavior due to dry friction results in the possibility of stick-slip conditions over the surfaces in contact. The Variation of parameters such as excitation amplitude, mass magnitude, coefficient of friction, and bump geometry were considered. Equivalent dynamic coefficients of stiffness and damping are estimated through a least squares curve fitting, which constitutes a linearization of the system with dry friction. A computer program was developed in order to consider the effect of stick-slip. As a final product of this research the nonlinear model of the structure support was used to obtain a linear and simplified equivalent model. In most studied cases it is possible to represent the system with a linearized model of constant stiffness and viscous damping which is a variable function of the studied parameters and the frequency.

scholarly journals Active Fractional-Order Sliding Mode Control of Flexible Spacecraft Under Actuators Saturation

2021 ◽  
Author(s):  
milad alipour ◽  
Maryam Malekzadeh ◽  
alireza ariaei
Keyword(s):  
Fractional Order ◽  
Attitude Control ◽  
Vibration Suppression ◽  
Sliding Mode ◽  
Fixed Time ◽  
Flexible Spacecraft ◽  
Terminal Sliding Mode ◽  
Damping Matrix ◽  
Active Vibration Suppression ◽  
Active Vibration

Abstract In this article, a novel multi-purpose modified fractional-order nonsingular terminal sliding mode (MFONTSM) controller is designed for the flexible spacecraft attitude control and appendages passive vibration suppression, assuming the control torque saturation in the system dynamics. Furthermore, an active FONTSM controller is proposed separately to perform active vibration suppression of the flexible appendages using piezoelectric actuators. The fixed-time stability of the closed-loop system for both the passive and active controllers is analyzed and proved using the Lyapunov theorem. Finally, the performance of the proposed controllers has been tested in the presence of uncertainties, external disturbances, and the absence of the damping matrix in order to study the effectiveness of the proposed method.

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