Attitude Determination and Control System for AAUSAT-II (2 groups)

This project proposal is recommended as a two group cooperation, dividing the estimation and control tasks between the groups, and sharing the common responsebilities.

Background

The AAU CubeSat project started in September 2001 and has had the goal to let students build and launch a nano-satellite with the purpose to provide for "hands-on" education and gain experience with nano-satellite technology. The satellite was launched on the 30th of June 2003 from Plesetsk in Russia on top of the Rockot Launcher.

Following the AAU CubeSat the new CubeSat AAUSAT-II has been under development for the past 18 months. The satellite design is coming to an end, and the prototype subsystems have been built. The satellite will soon go into the integration and testing phase, with expected launch in December, 2005.

The status of the project is:

  • SW design of the Attitude Determination and Control System (ADCS) has not been designed.
  • HW integration and test of the satellite subsystems.
  • SW integration and test of the subsystem software, which is to run on the On-board Computer (OBC).

Purpose

The Attitude Determination and Control System (ADCS) is mandatory for almost all satellites since there is a pointing requirement at some level of accuracy. In order to obtain high pointing accuracy, the satellite’s ADCS has to be able to manipulate incoming sensor information an appropriate manner and generate correct and optimal control signals. The ADCS on AAUSAT-II is considered a scientific experiment payload, because of its advanced HW functionality compared to the satellite size, i.e. it is equipped with magnetorquers and momentum wheels.

The sensor system of AAUSAT-II consists of a magnetometer and Sun sensors. These sensors are used to acquire two vectors in the satellite body frame. Using ephemeris modeling, the same two vectors can be estimated in an inertial frame. Using these two vector pairs, an estimate of the satellite attitude is calculated.

The actuator system consists of magnetic coils, which are used to generate a magnetic field on the satellite. The generated magnetic field interacts with the Earth magnetic field, and is used to generate torques on the satellite, and thereby allowing control of the satellite attitude and angular velocity. In addition, AAUSAT-II will carry one or more miniature momentum wheels.

The goal of the project is to design and implement an algorithm, for estimating and controlling the attitude of AAUSAT-II using the HW platform which has been developed by E04 9th semester students. In addition the groups will be responsible for the HW and SW integration and test.

Scope

  • Estimation algorithms
  • Control algorithms
  • Modeling of satellite dynamics and kinematics
  • Modeling of space environment and ephemeris
  • System simulation
  • Testing and validation
  • HW and SW integration and testing of AAUSAT-II
This is the full scope of the joint work of the two groups.

Proposal by AAUSAT-II Management.

Supervisor: Dan Bhanderi - Spam protected. Please type in manually..