Research Area: VEHICLE DYNAMICS AND OTHER ENGINEERING APPLICATIONS
Nonlinear science has a broad range of applications in vehicle dynamics and
other fields of engineering ranging from the damping of vibrating machines and
the stabilization of lasers and chemical reactors to the maneuvering of
aircrafts in the post stall regime where conventional controls become
inefficient because of detaching airflows. Other problems of aircraft dynamics
relate to the sensitivity of spin entry and spin recovery maneuvers to an
offset of the lateral center of mass of the aircraft and to the gyroscopic
torque from the rotors of the engines.
On the background of a recent prediction of 70% growth in the total transport
volume in the EU before year 2010, revitalization of the railways as a
preferred mode of transportation represents a promising alternative. However,
the quality of railway transport must be improved, and the speed must be
increased. This involves the development of new types of suspense systems that
can provide a smoother ride while at the same time reducing noise and wear of
the tracks.
Other applications relate to the prevention of catastrophies at sea. Situations
may actually arise that a boat capsizes even though the design and stability
conform with all required standards. The problem is that the ship may be
linearly stable, but globally unstable in the sense that it capsizes under
large amplitude rolling or swaying motions. Moreover, the basin of attraction
for the linearly stable state may completely erode. Many technical control
systems operate with on-off regulation and hence have no stable equilibrium
points.
For households installations this is the case, for instance, for refrigerators
and freezers as well as for air conditioners and oil and gas burners. In the
construction of industrial plants, engineers similarly exploit the simplicity
and robustness of on-off regulation for a variety of different functions.
Interaction between two such systems can lead to a broad range of complex
nonlinear dynamic phenomena, including mode-locking, period-doubling
bifurcations, chaos, and coexisting solutions with fractal basin boundaries.
Research is presently concentrated on
Main collaborators are the Danish National Railway Agency, The Danish State
Railway, and the Dept. of Aeronautics, University of Budapest.