TY  - JOUR
A1  - Kempf, Florian
A1  - Scharnagl, Julian
A1  - Heil, Stefan
A1  - Schilling, Klaus
T1  - Self-organizing control-loop recovery for predictive networked formation control of fractionated spacecraft
JF  - Aerospace
N2  - Going beyond the current trend of cooperating multiple small satellites we arrive at fractionated satellite architectures. Here the subsystems of all satellites directly self-organize and cooperate among themselves to achieve a common mission goal. Although this leads to a further increase of the advantages of the initial trend it also introduces new challenges, one of which is how to perform closed-loop control of a satellite over a network of subsystems. We present a two-fold approach to deal with the two main disturbances, data losses in the network and failure of the controller, in a networked predictive formation control scenario. To deal with data loss an event based networked model predictive control approach is extended to enable it to adapt to changing network conditions. The controller failure detection and compensation approach is tailored for a possibly large network of heterogeneous cooperating actuator- and controller nodes. The self-organized control task redistribution uses an auction-based methodology. It scales well with the number of nodes and allows to optimize for continuing good control performance despite the controller switch. The stability and smooth control behavior of our approach during a self-organized controller failure compensation while also being subject to data losses was demonstrated on a hardware testbed using as mission a formation control scenario.
KW  - networked predictive control
KW  - fractionated spacecraft
KW  - controller failure recovery
KW  - self-organization
KW  - formation control
KW  - auction based task assignment
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-288041
SN  - 2226-4310
VL  - 9
IS  - 10
ER  - 
TY  - JOUR
A1  - Scharnagl, Julian
A1  - Kempf, Florian
A1  - Schilling, Klaus
T1  - Combining Distributed Consensus with Robust H-infinity-Control for Satellite Formation Flying
JF  - Electronics
N2  - Control methods that guarantee stability in the presence of uncertainties are mandatory in space applications. Further, distributed control approaches are beneficial in terms of scalability and to achieve common goals, especially in multi-agent setups like formation control. This paper presents a combination of robust H-infinity control and distributed control using the consensus approach by deriving a distributed consensus-based generalized plant description that can be used in H-infinity synthesis. Special focus was set towards space applications, namely satellite formation flying. The presented results show the applicability of the developed distributed robust control method to a simple, though realistic space scenario, namely a spaceborne distributed telescope. By using this approach, an arbitrary number of satellites/agents can be controlled towards an arbitrary formation geometry. Because of the combination with robust H-infinity control, the presented method satisfies the high stability and robustness demands as found e.g., in space applications.
KW  - distributed control
KW  - robust control
KW  - consensus
KW  - H-infinity
KW  - satellite formation flying
KW  - formation control
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-228431
VL  - 8
IS  - 319
ER  -