@article {157,
	title = {Internal force analysis and load distribution for cooperative multi-robot manipulation},
	journal = {IEEE Transactions on Robotics (T-RO)},
	volume = {31},
	year = {2015},
	pages = {1238 - 1243},
	doi = {10.1109/TRO.2015.2459412},
	author = {S. Erhart and S. Hirche}
}
@conference {163,
	title = {An impedance-based control architecture for multi-robot cooperative dual-arm mobile manipulation},
	booktitle = {IEEE/RSJ International Conference on Intelligent Robots and Systems},
	year = {2013},
	address = {Tokyo},
	doi = {10.1109/IROS.2013.6696370},
	url = {;},
	author = {S. Erhart and D. Sieber and S. Hirche}
}
@conference {161,
	title = {Iterative optimal feedback control design under relaxed rigidity constraints for multi-robot cooperative manipulation},
	booktitle = {Proceedings of the 52nd IEEE Conference on Decision and Control (CDC)},
	year = {2013},
	address = {Florenz, Italien},
	abstract = {Cooperative manipulation of multiple robots presents an interesting control application scenario of coupled dynamical systems with a common goal. Here, we treat the problem of moving a formation of physically interconnected robots to a desired goal while maintaining the formation. This control problen is for example relevant in cooperative transport of an object from an initial to a final configuration by mobile robotic manipulators. To achieve the control goal we formulate an LQR-like optimal control problem that, in addition to goal regulation and minimization of input energy, includes the formation rigidity constraint in a relaxed form expressed as a biquadratic penalty term. The control problem is solved by two different iterative algorithms, a gradient descent using adjoint states and a quasi-Newton method, that determine a static linear state-feedback matrix. The proposed control design and the iterative algorithms are validated and compared in numerical simulations showing the efficacy of both approaches.},
	url = {;},
	author = {D. Sieber and F. Deroo and S. Hirche}
}
