Arun Kumar Kantheti's thesis defense (automatic control department)

Recent studies show that underground metro systems have high concentrations of particulate emissions, mainly generated by braking systems, posing a significant risk to public health. This thesis, carried out as part of the BREAQ project, aims to reduce these emissions by optimizing train driving profiles.

The research work focuses on the development of optimal train control strategies using indirect methods to minimize braking-related emissions.

First, to efficiently handle constraints in optimal control problems, a numerical continuation procedure is implemented, enabling iterative integration of constraints. Two initialization techniques are proposed to solve the well-known problem of initializing solvers for Boundary Value Problems. The effectiveness of these tools is demonstrated using numerical examples before being applied to the main problems of this thesis.

Building on these methodological developments, the thesis first tackles the classical eco-driving problem by integrating a non-linear energy efficiency model. Results indicate that this approach outperforms those obtained with affine models. In addition, analysis of the trade-offs between journey time and energy consumption highlights the potential of this approach for rail operators.

Then, a multi-objective optimal control problem, simultaneously taking into account an energy criterion and brake wear, is formulated to minimize braking emissions. The results show that, for a given journey time, there is a trade-off between emissions and increased energy consumption. This method provides rail operators with a practical tool for adapting driving profiles according to operational priorities, balancing energy efficiency and wear reduction. Such an approach could be particularly beneficial for reducing braking emissions in subway metro networks.

Finally, a preliminary experimental study is being carried out on a scaled-down braking test rig to better understand the dynamics of braking temperature and particulate emissions. Preliminary models of brake temperature and particulate emissions are proposed. These results provide a basis for the development of more accurate models in future research.

Rapporteurs:

• Mrs Lydie NOUVELIÈRE , Maître de Conférence HDR, Université Evry Paris-Saclay, France
• Mr. Antonio SCIARRETTA , Dr. HDR, ASN, IFP Energies Nouvelles, France

Examiners:

• Mr Michel BASSET, Professeur des Universités, Université Haute-Alsace, France
• Mr Guillaume COLIN, Professeur des Universités, PRISME/ECM-Polytech Orléans, France

Director of research:

• Mr. Sébastien DELPRAT, Professeur des Universités, Université Polytechnique Hauts-de-France, France

Co-supervisor:

• Mr. Denis BERDJAG, Senior Lecturer, Université Polytechnique Hauts-de-France, France

Guest members:

• Mme. Karine PAJOT, Air Quality Manager, Alstom Transport SA, France
• Mr. Aamir KAMRAN, Brakes and Air Supply System Engineer, Alstom Transport SA, France