This paper investigates the appointed-time attitude stabilization problem of a rigid spacecraft under disturbance and parametric uncertainty. A continuous sliding mode observer is presented to observe synthetical term. To circumvent singularity in terminal control, new nonsingular surface designed by employing concept switching control. Based on observation information deriving from proposed ob...

This paper is concerned with the development of a control system for rotational maneuver and vibration suppression of a flexible spacecraft. It is assumed that the system parameters are unknown. 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...

This paper presents a Takagi-Sugeno fuzzy model-based controller which stabilizes the attitude of spacecraft with a partially-filled fuel tank. First, the nonlinear equations of motion of spacecraft containing a liquid fuel store is presented briefly. Then, the fuzzy modeling and the parallel distributed compensation control technique are applied. The proposed fuzzy controller is a nonlinear co...

This is the second in a series of papers that exploit the physical coupling of tethered spacecraft to derive a propellant-free spin-up and attitude control strategy. We take a nonlinear control approach to underactuated tethered formation flying spacecraft, whose lack of full state feedback linearizability, along with their complex nonholonomic behavior, characterizes the difficult nonlinear co...

An efficient and accurate computational approach is proposed for optimal attitude control of a rigid body. The problem is formulated directly as a discrete time optimization problem using a Lie group variational integrator. Discrete necessary conditions for optimality are derived, and an efficient computational approach is proposed to solve the resulting two point boundary value problem. The us...

An output feedback structured model reference adaptive control law has been developed for spacecraft rendezvous and docking problem. The effect of bounded output errors on controller performance is studied in detail. Output errors can represent an aggregation of sensor calibration errors, systematic bias or some stochastic disturbances present in any real sensor measurements or state estimates....

Electromagnetic actuators are a particularly effective and reliable technology for attitude control of small satellites. As is well known, the main difficulty in the design of attitude control laws based on such actuators is related to the fact that magnetic torques are instantaneously constrained to lie in the plane orthogonal to the local direction of the geomagnetic field vector. Controllabi...

This paper presents preliminary results for the application of DMOC to multibody systems. DMOC is a technique that produces optimal control histories for boundary value problems directly from a discretized Lagrange-D'Alembert principle, and therefore does not require the equations of motion to be explicitly known. This work will be used to develop a methodology for rapidly predicting the perfor...

In this paper a result on attitude tracking control of a micro satellite by integrator backstepping based on quaternion feedback is presented, and the controller is shown to render the system equilibrium point UGAS by application of the LaSalle-Yoshizawa theorem. This is a part of a study of possible control methods for the spacecraft ESEO, a spacecraft included in the SSETI project initiated b...

Abstrucr-The NASA Scatterometer (NSCAT) is a spaceborne scatterometer which flew aboard the National Space Development Agency of Japan's ADvanced Earth Observing Satellite (ADEOS). The NSCAT instrument has proven to be remarkably sensitive and accurate, achieving a calibration of within a few tenths of a dB. The key source of calibration error for NSCAT 0' measurements is the spacecraft attitud...