in this paper, an adaptive attitude control algorithm is developed based on neural network for a satellite using four reaction wheels in a tetrahedron configuration. then, an attitude control based on feedback linearization control has been designed and uncertainties in the moment of inertia matrix and disturbances torque have been considered. in order to eliminate the effect of these uncertain...

As the level of human interaction with robotic systems increases, robot mobility becomes more important. Two wheeled robots offer higher levels of mobility and manoeuvrability when compared to their four wheeled counterparts with the ability to turn on the spot and easily negotiate tight corners. Whilst the stabilisation of two wheeled platforms has been well studied, there is no published rese...

Accurate disturbance models are necessary to predict the e!ects of vibrations on the performance of precision space-based telescopes, such as the Space Interferometry Mission (SIM). There are many possible disturbance sources on such spacecraft, but mechanical jitter from the reaction wheel assembly (RWA) is anticipated to be the largest. A method has been developed and implemented in the form ...

This paper presents the approach adopted by Surrey Satellite Technology Ltd (SSTL) for development of reaction wheels incorporating commercial components and the accelerated life test / qualification philosophy. The paper focuses on the mechanical development and re-qualification of reaction wheel which has flown successfully on many missions having conducted years of in orbit operation. The sc...

A [Cu(II)16] wheel was isolated serendipitously from the reaction of acetylacetone dioxime with copper(ii) chloride and lanthanide ions in a reaction initially designed to produce heterometallic 3d-4f cages. The ligand has been transformed in situ to three different forms, all found within the [Cu16] wheel, with the original ligand completely absent.

Microvibration management onboard spacecraft with high stability requirements has drawn increasing interest from engineers and scientists, and this paper discusses a reaction wheel design that allows a significant reduction of midto high-frequency microvibrations and that has been practically implemented in industry. Disturbances typically induced by mechanical systems onboard a spacecraft (esp...

A control system is proposed for a low Earth orbit gravity gradient stabilised microsatellite using Z wheel. The microsatellite is 3-axis stabilized using a yaw reaction wheel, with dual redundant 3-axis magnetorquers. Two vector magnetometers and four dual sun sensors are carried in order to determine the full attitude. The attitude was estimated using an Euler angles (small libration version)...

A control system is proposed for a low Earth orbit gravity gradient stabilised microsatellite using Z wheel. The microsatellite is 3-axis stabilized using a yaw reaction wheel, with dual redundant 3-axis magnetorquers. Two vector magnetometers and four dual sun sensors are carried in order to determine the full attitude. The attitude was estimated using an Euler angles (small libration version)...