The doctoral dissertations of the former Helsinki University of Technology (TKK) and Aalto University Schools of Technology (CHEM, ELEC, ENG, SCI) published in electronic format are available in the electronic publications archive of Aalto University - Aaltodoc.

Optical Position Detection to Measure Tyre Carcass Deflections and Implementation for Vehicle State Estimation

Ari Tuononen

Dissertation for the degree of Doctor of Science in Technology to be presented with due permission of the Faculty of Engineering and Architecture for public examination and debate in Auditorium AS1 at Helsinki University of Technology (Espoo, Finland) on the 7th of December, 2009, at 12 noon.

Overview in PDF format (ISBN 978-952-248-250-1)   [2225 KB]
Dissertation is also available in print (ISBN 978-952-248-249-5)


Future active safety systems for vehicles will need accurate information about the state of the vehicle. Tyre sensors certainly offer an interesting option to evaluate the operating state of an individual tyre. On the other hand, tyre behaviour in some driving conditions is not completely understood and tyre sensor measurements can contribute to the fundamentals of tyre research as well.

This thesis discusses a method to measure the carcass deflection of a rolling tyre. Tyre force estimation algorithms are proposed and tested in real time with a low-cost micro-controller unit. The tyre force information is then exploited to estimate the lateral state of a car. In addition, the tyre sensor signals in aquaplaning are carefully studied and the hydrodynamic and viscous aquaplaning zones were separated from the data in post-processing. Another method was developed to estimate partial and full aquaplaning in real time.

The results obtained support the development of more production-friendly tyre sensor concepts. The relations between carcass deflections and tyre forces that were obtained can be useful for completely different types of sensors. In addition, tyre behaviour in complex conditions can be measured and the results can validate tyre models.

This thesis consists of an overview and of the following 5 publications:

  1. A. J. Tuononen. 2008. Optical position detection to measure tyre carcass deflections. Vehicle System Dynamics, volume 46, number 6, pages 471-481. © 2008 Taylor & Francis. By permission.
  2. Ari J. Tuononen and Lassi Hartikainen. 2008. Optical position detection sensor to measure tyre carcass deflections in aquaplaning. International Journal of Vehicle Systems Modelling and Testing, volume 3, number 3, pages 189-197. © 2008 by authors and © 2008 Inderscience Enterprises. By permission.
  3. Ari J. Tuononen. 2009. On-board estimation of dynamic tyre forces from optically measured tyre carcass deflections. International Journal of Heavy Vehicle Systems, volume 16, number 3, pages 362-378. © 2009 by author and © 2009 Inderscience Enterprises. By permission.
  4. A. J. Tuononen and M. J. Matilainen. 2009. Real-time estimation of aquaplaning with an optical tyre sensor. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, volume 223, number D10, pages 1263-1272. © 2009 Professional Engineering Publishing. By permission.
  5. Ari J. Tuononen. 2009. Vehicle lateral state estimation based on measured tyre forces. Sensors, volume 9, number 11, pages 8761-8775. © 2009 by author.

Keywords: tyre sensor, optical position detection, active safety systems, vehicle state estimation

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© 2009 Helsinki University of Technology

Last update 2011-05-26