Attitude Stabilization Of Flexible Spacecraft Research Articles

Semi-globally input-to-state stable controller design for flexible spacecraft attitude stabilization under bounded disturbances

Semi-globally input-to-state stable (ISS) control law is derived for flexible spacecraft attitude maneuvers in the presence of parameter uncertainties and external disturbances. The modified rodrigues parameters (MRP) are used as the kinematic variables since they are nonsingular for all possible rotations. This novel simple control is a proportional-plus-derivative (PD) type controller plus a sign function through a special Lyapunov function construction involving the sum of quadratic terms in the angular velocities, kinematic parameters, modal variables and the cross state weighting. A sufficient condition under which this nonlinear PD-type control law can render the system semi-globally input-to-state stable is provided such that the closed-loop system is robust with respect to any disturbance within a quantifiable restriction on the amplitude, as well as the set of initial conditions, if the control gains are designed appropriately. In addition to detailed derivations of the new controllers design and a rigorous sketch of all the associated stability and attitude convergence proofs, extensive simulation studies have been conducted to validate the design and the results are presented to highlight the ensuring closed-loop performance benefits when compared with the conventional control schemes.

Networked flexible spacecraft attitude maneuver based on adaptive fuzzy sliding mode control

For the attitude stabilization of networked flexible spacecraft during large angle slew maneuver, a novel type of adaptive fuzzy sliding mode control (AFSMC) method for solving the dynamic model with network-induced delay, nonlinear and uncertain parameters is proposed in this paper. A novel and systematic sliding mode control (SMC) scheme, which integrates a time-advanced nonlinear predictor, is proposed to compensate for the network-induced delay and to overcome the negative effect of uncertainties. Then, an adaptive fuzzy system is used to approximate the strong coupling nonlinear dynamics between rigid hub and flexible appendages. Following that, the designed adaptive algorithms are developed in the sense of the Lyapunov stability theorem, so that system-tracking stability can be guaranteed. Finally, simulation results show that, with the application of the proposed method, not only high-precision attitude stabilization of flexible spacecraft is achieved, but also the elastic vibration of flexible spacecraft during maneuver is suppressed effectively, and the system is robust against system uncertainties, network-induced delays and any outer disturbances.

The attitude stability of a spacecraft with two flexible solar arrays in the gravitational field

The attitude stability of flexible spacecraft is discussed in this paper. The Euler’s equations of spacecraft and the equations of forced vibration of two flexible solar arrays are derived. The governing equation is discretized via the Galerkin method, and the stability of relative equilibrium of spacecraft in the orbit frame is determined based on the Kelvin–Tait–Chetayev theorem. The sufficient condition of stability in the analytical form for the n-term truncated modal is established based on the governing equation.

Attitude stabilization of flexible spacecraft during stationkeeping maneuvers

This paper present s t h e a n a l y s i s and design o f r e a c t i o n j e t a t t i t u d e c o n t r o l system f o r a spacecraf t having l a r g e f l e x i b l e s a l a r a r rays . During t r a n s l a t i o n a l t h r u s t i n g maneuvers, t h e s o l a r a r r a y f l e x i b i l i t y s t r o n g l y i n t e r a c t s w i t h the Pulse-Width and Pulse-Frequency (PdPF) modulator. A simple t r a n s f e r f u n c t i o n model o f f l e x i b l e spacecra f t i s used f o r t h e p r e l im inary c o n t r o l design. The s t a t i c and dynamic charact e r i s t i c s o f the PWPF modulator a re discussed i n d e t a i l . Nonl inear s t a b i l i t y ana lys is i s performed us ing t h e descr ib ing f u n c t i o n o f the modulator. R e l a t i v e s t a b i l i t y margin w i t h respec t t o the l i m i t c y c l e c o n d i t i o n o f a s t r u c t u r a l mode i s used as a measure o f t h e non l inear c o n t r o l system robustness. The performance and s t a b i l i t y margin p r e d i c t e d by c l a s s i c a l s i n g l e a x i s design, a r e v e r i f i e d from t h e 3-ax is non l inear d i g i t a l s imulat i o n s .