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)...

The present paper considers the problem of autonomous synchronization of attitudes in a swarm of spacecraft. Building upon our recent results on consensus on manifolds, we model the spacecraft as particles on SO(3) and drive these particles to a common point in SO(3). Unlike the Euler angle or quaternion descriptions, this model suffers no singularities nor double-points. Our approach is fully ...

This paper addresses the attitude determination and control problem for the University at Buffalo’s GLADOS mission. The main objective of the mission is to collect multi-band photometric data of resident space objects to improve space situational awareness. The team plans to use two optical payloads, a wide-field camera and a spectrometer, to achieve this goal. The attitude control system uses ...

Fractional Order Control methods were applied to a three-axis reaction wheels satellite attitude control system. To show the advantages of this method, a comparative study between a Linear Quadratic Regulator and a Fractional Order Control was established through two principal fractional control laws. The aim is to establish an efJicient control law which satisJies a given speczjication and mai...

The subject of this research is to study the use of internal moving masses as the primary means of attitude control for a small satellite platform. The goal of this research is to validate the dynamic model formulated in [1] which describes the under-actuated rotational dynamics of a 3U cubesat with two internal orthogonal linearly translating masses. Models have been developed to simulate angu...

For parameter estimations, we have developed a extended kalman filter(EKF) and unscented kalman filter(UKF) for linear as well as non-linear spacecraft systems. We have described the differences of two approaches mathematical equation for modeling of the system value of mean square error, error covariance and For state estimation of satellite, two different type of filters has been described i....

Magnetic torquing is attractive for generation of control torques on small satellites. The concept is that interaction between the Earth's magnetic eld and a magnetic eld generated by a set of coils in the satellite is used for actuation. This principle is inherently nonlinear, and diicult to use because control torques can only be generated perpendicular to the geomagnetic eld vector. So far, ...

Magnetic torquing is attractive as a control principle on small satellites. The actuation principle is to use the interaction between the earth's magnetic eld and magnetic eld generated by a coil set in the satellite. This control principle is inherently nonlinear, and diicult to use because control torques can only be generated perpendicular to the geomagnetic eld vector. This has been a serio...

This paper describes a path toward the development of theory for using a low noise high frame rate camera as a star tracker for spacecraft attitude estimation. The benefit of using a low noise high frame rate camera is that star data can be sampled at a faster rate while allowing one to measure very dim stars, increasing the number of stars available for attitude estimation. The development of ...

The attitude control of a satellite is often characterized by a limit cycle, caused by measurement inaccuracies and noise in the sensor output. In order to reduce the limit cycle, a nonlinear fuzzy controller was applied. The controller was tuned by means of reinforcement learning without using any model of the sensors or the satellite. The reinforcement signal is computed as a fuzzy performanc...