Adaptive output feedback tracking control of spacecraft formation

Abstract

SUMMARYIn this paper, an adaptive, output feedback control design methodology is presented for a spacecraft formation flying (SFF) system. A Lagrangian derivation of the SFF model is considered to produce position dynamics for follower spacecraft #n relative to follower spacecraft #ðn À 1Þ, where n is an arbitrary positive integer, assuming that the leader spacecraft in the formation follows a no-thrust, natural, elliptical orbit. Next, a control law is designed to provide a filtered velocity measurement and a desired adaptive compensation with semi-global, asymptotic, relative position tracking. To show the efficacy of the control algorithm, all desired trajectories are generated online by numerically solving the unperturbed nonlinear SFF dynamics with initial conditions satisfying a no-thrust, natural orbit constraint equation. The proposed control law is simulated for the case of two and three spacecraft and is shown to yield semiglobal, asymptotic tracking of the relative position in addition to the convergence of disturbance parameter estimates.

Adaptive Output Feedback Spacecraft Formation Flying Via Observer Based Feedback Linearization

“…The satellite system parameters are taken from [22] for computation. These are µ = 3.986004 × 10 14 (m 3 /s 2 ) and m f = 100 (kg), the semi-major axis a c = 7200 (km), eccentricity e = 0.001, and θ(0) = 0 (rad).…”

“…Also the adaptive laws presented in [21,23,24] require relative velocity feedback. Authors have presented an output feedback formation controller [22], in which filtered velocity measurements are used for synthesis. Recently an output feedback formation control system using the tuning functions method has been designed [30].…”

“…For uncertain satellite formation systems (SFS) adaptive control laws have been derived [21][22]. For deep-space formation flying an adaptive neural controller has been designed in [23].…”

Output feedback control of Lorentz-augmented spacecraft rendezvous

“…Present closed-loop controllers for Lorentz-augmented spacecraft relative motion are almost all full-state feedback controllers [8,6], which are thus inapplicable to cases without relative velocity measurements. Since eliminating velocity sensors could reduce the cost and mass for control system [18], to handle the relative motion control without velocity measurements, an output feedback controller is designed in this paper.…”

Adaptive control for satellite formation flying under thrust misalignment

“…Majority of nonlinear control approaches for SFF missions are based on full state feedback controllers which assume that both position and velocity sensors are available. On the other hand, Wong [5] designed an adaptive output feedback tracking control in the absence of velocity measurement.…”