For Safe Bicycle-Riding

Typically, we learn how to ride a bicycle as a child. We learn the inherent characteristics of two-wheeled vehicles by practice, and have then the not immediately obvious dynamics in mind, usually without being aware of them: to steer into the fall when balancing our bicycle to keep upright, to countersteer when initiating a cornering manoeuvre, to steer the bicycle by steering torques rather than by angles. Getting older, we may lose quick reflexes, and it becomes more difficult to balance our bicycle and keep it safely on the desired trajectory. As a consequence, and unfortunately, an increasing number of accidents and injuries are reported from elderly bicycle riders, especially as the support from an electric motor makes cycling attractive right up until old age. To counteract this trend, a rider support system, motivated by advanced driver assistance systems (ADAS) for cars, is developed and studied. In particular, a steer-by-wire-system is designed and realisation and implementation on a demonstrator e-bike is ongoing.

Project Goals

The aims of the project are

• Research on a steer-by-wire system that allows a better understanding of the interaction between bicycle and rider, with focus on the required steering feel/feedback, realisation of countersteer, critical delay times, etc.
• Research on different control strategies to stabilize the upright motion at low speeds and to support the rider at evasive manoeuvres
• Research on controllability measures and measures on bicycle handling quality
• Design and comparison of different control strategies and state estimators
• Research on steering assistance systems to increase road safety, in particular for vehicles with dynamics inherent to two-wheeled vehicles

So far, bicycle models, tyre-road contact models, and human rider models of different complexity have been developed, parameterised at test runs, and are available in simulation. Control strategies have been worked out, and the control design has been tested in simulation. The design of the steer-by-wire system is finished, and realisation is ongoing. The exciting roll-out and first test manoeuvres are expected to come true soon.

Figure 1: Design-drawing of the steer-by-wire system

References

Edelmann, Johannes, Manfred Plöchl, and Peter Lugner. "A steer-by-wire control strategy for a tilting three-wheeled vehicle., opens an external URL in a new window" In Proc. of the 21st International Symposium on Dynamics of Vehicles on Roads and Tracks, p. 11. 2009.

Edelmann, Johannes, Manfred Plöchl, and Peter Lugner. "Modelling and analysis of the dynamics of a tilting three-wheeled vehicle., opens an external URL in a new window" Multibody System Dynamics 26, (2011): 469-487.

Edelmann, Johannes, and Manfred Plöchl. "Electronic stability control of a narrow tilting vehicle., opens an external URL in a new window" SAE International Journal of Materials and Manufacturing 4, no. 1 (2011): 1006-1013.

Edelmann, Johannes, Martin Haudum, and Manfred Plöchl. "Bicycle rider control modelling for path tracking., opens an external URL in a new window" Ifac-Papersonline 48, no. 1 (2015): 55-60.

Klinger, Florian, Julia Nusime, Johannes Edelmann, and Manfred Plöchl. "Wobble of a racing bicycle with a rider hands on and hands off the handlebar., opens an external URL in a new window" Vehicle System Dynamics 52, no. sup1 (2014): 51-68.

Researchers

• Michael Ruttmann
• Luca Valenzano (Politecnico di Torino)
• Elias Bauer and Sebastian Fleischmann (HTL Hollabrunn)
• Johannes Edelmann

Project Funding

Internal