H. Bolandi; M. Abedi; M. Haghparast
Volume 6, Issue 1 , April 2013, , Pages 31-46
Abstract
This paper presents robust fault detection based on adaptive thresholds for a three axis satellite. For this purpose, first we described the attitude control system (ACS) as a quasi linear parameter model. Next, an interval observer has been designed that based on, effect of the satellite parameter uncertainties ...
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This paper presents robust fault detection based on adaptive thresholds for a three axis satellite. For this purpose, first we described the attitude control system (ACS) as a quasi linear parameter model. Next, an interval observer has been designed that based on, effect of the satellite parameter uncertainties has been propagated into the alarm limits and so the adaptive thresholds are generated. In this paper, it is shown that the developed method minimizes the missing alarm rates; also this approach detects small or incipient faults more effectively than the classical fault detection algorithms with constant thresholds. In the next part of paper, we propose an isolation algorithm using the fault tree approach. Also, an accommodation system has been designed based on reconfiguration of available actuators. Accordingly, after isolation of faulty reaction wheels, the accommodation system turns them off and replaces the suitable magnetic tourqers instead of the faulty reaction wheels and so the attitude control error is maintained limited.
Mohammad Saberi-Tavakoli; Fariborz Saghafi
Volume 5, Issue 4 , January 2013, , Pages 47-60
Abstract
This paper has tried to control for multiple satellite formation flight under a method called Virtual structure. First the algorithm was implemented in the reference coordinate system has no gradient and then we have developed the same algorithm for a circular orbit around the earth within a set of satellites ...
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This paper has tried to control for multiple satellite formation flight under a method called Virtual structure. First the algorithm was implemented in the reference coordinate system has no gradient and then we have developed the same algorithm for a circular orbit around the earth within a set of satellites that are in circulation. Then for each of the satellites we have added collision avoidance controller to the system. And then the control system on the satellites such as SPHERES taking into account the constraints operators has control over their implementation.
