Session

Technical Session XI: Mission Enabling Technologies 2

SSC10-XI-6.pdf (3947 kB)
Presentation Slides

Abstract

Large angle attitude manoeuvres are often subjected to dynamic and celestial path constraints such as maintaining ground link communication, GPS lock, or Sun avoidance while tracking various primary targets in real time. Considered in this paper is an onboard approach to maximizing the signal lock with GPS satellites with a restricted antenna field of view while tracking primary attitude targets. The proposed time optimal attitude controller does not require a priori knowledge of the target(s) and avoids the time and computational requirements of typical avoidance and random search techniques. Included in this paper are the attitude requirements to maintain GPS lock as derived from ground based and on orbit experiments as well as the proposed controller and the results of numerical simulations. This controller has been developed for the Canadian Advanced Nanosatellite eXperiment (CanX) 4 and 5 satellites currently under development at the University of Toronto’s Space Flight Laboratory. CanX-4 and CanX- 5 are identical satellites that will be launched together and will make use of differential GPS measurements and a cold gas propulsion system to demonstrate autonomous sub-meter control formation flying based on differential GPS Measurements.

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Aug 12th, 9:14 AM

Attitude Manoeuvring Under Dynamic Path and Time Constraints for Formation Flying Nanosatellites

Large angle attitude manoeuvres are often subjected to dynamic and celestial path constraints such as maintaining ground link communication, GPS lock, or Sun avoidance while tracking various primary targets in real time. Considered in this paper is an onboard approach to maximizing the signal lock with GPS satellites with a restricted antenna field of view while tracking primary attitude targets. The proposed time optimal attitude controller does not require a priori knowledge of the target(s) and avoids the time and computational requirements of typical avoidance and random search techniques. Included in this paper are the attitude requirements to maintain GPS lock as derived from ground based and on orbit experiments as well as the proposed controller and the results of numerical simulations. This controller has been developed for the Canadian Advanced Nanosatellite eXperiment (CanX) 4 and 5 satellites currently under development at the University of Toronto’s Space Flight Laboratory. CanX-4 and CanX- 5 are identical satellites that will be launched together and will make use of differential GPS measurements and a cold gas propulsion system to demonstrate autonomous sub-meter control formation flying based on differential GPS Measurements.