@article{eprints4027, pages = {86--93}, volume = {45}, year = {2012}, booktitle = {IFAC Conference on Nonlinear Model Predictive Control}, title = {Nonlinear MPC and MHE for Mechanical Multi-Body Systems with Application to Fast Tethered Airplanes}, author = {S{\'e}bastien Gros and Mario Zanon and Milan Vukov and Moritz Diehl}, publisher = {Elsevier}, journal = {IFAC Proceedings Volumes}, note = {4th IFAC Nonlinear Model Predictive Control Conference International Federation of Automatic Control Noordwijkerhout, NL. August 23-27, 2012}, number = {17}, url = {http://eprints.imtlucca.it/4027/}, keywords = {real-time NMPC \& MHE; multi-body mechanical systemshigh-index DAE; code generation}, abstract = {Mechanical applications often require a high control frequency to cope with fast dynamics. The control frequency of a nonlinear model predictive controller depends strongly on the symbolic complexity of the equations modeling the system. The symbolic complexity of the model equations for multi-body mechanical systems can often be dramatically reduced by using representations based on non-minimal coordinates, which result in index-3 differential-algebraic equations (DAEs). This paper proposes a general procedure to efficiently treat multi-body mechanical systems in the context of MHE \& NMPC using non-minimal coordinate representations, and provides the resulting computational times that can be achieved on a tethered airplane system using code generation.} }