Ma recherche en théorie pure d'automatique porte sur la commande adaptative des systèmes non−linéaires et non−linéairement paramétrés. Peu de résultats sont disponibles dans la littérature dans ce domaine, dont une partie aborde le problème via certaines pro-priétés liées à la convexité de fonctions. J'ai construit, pendant ces années, de résultats permettant la commande adaptative d'une classe de systèmes contenant une paramétrisa-tion multilinéaire, de laquelle plusieurs systèmes physiques font partie (donnant lieu aux publications jointes entre le MIT et moi (publications [L1], [C33] et [C18]).
Troisième partie
Scienti c contributions
Chapitre 8
Transportation challenges : an overview
This Part of the manuscript is dedicated to introducing and discussing the scienti c results whose details will be available in the annexes as a selection of papers. It is organized in the following way. Chapter 8.1 contains an overview of the transportation context and a structuring of the driving assistance systems design problem. The goal is to come from `Macro' to `Micro', that is to rst have an overview on a set of challenges linked to Transportation including on how to structure the problem of increasing road safety by embedding systems in the vehicle, to only after this, talking on how to design (by using control theory) these systems or on how to evaluate them.This part is organized as follows : After the transportation context is discussed is Chapter 8.1 , Chapter 9 contains my scienti c contributions. These include my research results, my contributions in students advising, in the coordination of research groups, and the collaborative works. It is structured in 3 sections : Section 9.1 introduces what will be the greed for a part of the main contributions, that are described in Sections 9.2 and 9.3. Section 9.1 is also dedicated to showing to the reader how theory and abstractions can be very important for solving real problems. Chapter 9.4 describes some results from collaborative works.
A discussion from a multidisciplinary view is provided in Chapter 9.5 through a survey paper of myself.
Since the results here are in the intersection of the control theory and the transpor-tation communities, Part VI provides some fundamental notions on control theory - by adopting a qualitative description - to help the non control readers to understand the contributions.
8.1 The transportation context
This section aims in giving an overview of dierent contextual elements in transpor-tation. The citizens quality of life, the sustainable development, and the road safety are for example discussed below.
We will also show that the Europeans directives point out to a global approach in transportation and in the development of Intelligent Transport Systems. Indeed, given the complexity and the importance of the transportation systems to the citizens, a global
54 CHAPITRE 8. TRANSPORTATION CHALLENGES : AN OVERVIEW approach is the only way to achieve improvements with respect to a large set of dierent objectives (safety, reduction of green house gases, minimum travel times, better mobility, etc) [10].
In this sense, ITS must be of an integrated nature. This is de ned in [1] as :
ITS integrate telecommunications, electronics and information technologies with trans-port engineering in order to plan, design, operate, maintain and manage transtrans-port systems. The application of information and communication technologies to the road transport sec-tor and its interfaces with other modes of transport will make a signi cant contribution to improving environmental performance, e ciency, including energy e ciency, safety and security of road transport, including the transport of dangerous goods, public security and passenger and freight mobility, whilst at the same time ensuring the functioning of the internal market as well as increased levels of competitiveness and employment.
Let us see also the directives of the European Parliament on the priority areas for Intelligent Transport Systems (ITS) [1]. First, it is de ned that the need for ITS comes from : The increase in the volume of road transport in the Union associated with the growth of the European economy and mobility requirements of citizens is the primary cause of increasing congestion of road infrastructure and rising energy consumption, as well as a source of environmental and social problems.
The priority areas for the development and use of speci cations and standards are identi ed in [1] below :
Optimal use of road, tra c and travel data
Continuity of tra c and freight management ITS services ITS road safety and security applications
Linking the vehicle with the transport infrastructure
We will see in the following a functional analysis to list some of the very broad and wide range of elements involved, that can give then an idea of the challenges.
The citizens quality of life. The following points are for example involved : The noise pollution : noise increases the stress.
The time travels and the quality of the day to day travels. Without tra c jam it is much better... no stress.
The transport must be accessible to all and then well adapted to disabled and elder people.
The safety must be integrated and improved being in all cases a necessary condition. The sustainable development. Some key points are :
Greenhouse gases reduction. There are dierent ways to reduce the GHG. One of them is to improve the combustion engine technology, and to search for alternative fuels. With this goal, following an agreement between the European Commission and industry [3], CO2 emissions from new passenger cars sold in the EU have de-creased by 12.4% between 1995 and 2004. Following this agreement, research and technological development co-funded by the EU has had a strong focus on clean and energy e cient vehicle technologies and alternative fuels, such as biofuels, hydrogen and fuel cells [4]. The deployment of electric vehicles is another way of reducing GHG emissions.
8.1. THE TRANSPORTATION CONTEXT 55 Consumption reduction : this involves research on how to help the driver to drive
reducing consumption.
The eco-vehicle : electric and hybrid vehicles, regenerative braking.
Systems to optimize the vehicle energy taking into account the road tra c. Integration of the electric vehicles in the smart grids and the involved challenges. The environment around the town and the associated ecosystem : a road that goes
through a national park ; a road that goes through urban environment ; a road in an agricultural region.
Road safety. Many dierent elements and research topics are involved, such as :
To work on the driving schools to make the youth people conscious of dierent and very important information : for example on the eects of the speed increase on the accident[9] ; Also, it is recommended that the driver and the passengers stop the car each 2 hours to a restroom. This can save a life in the case an accident occurs. However, unfortunately few people know that.
The driver can be helped by a driving assistance system but, except for the automa-ted driving context, it is very important that he keeps the responsibility of driving. and does not rely too much on the system in order to avoid negative eects like the complacency eect [5].
Questions of reliability of the electric vehicles.
The road automation concepts and the road safety : automation can bring com-fort and bring better health for example to people that need to take the highways everyday to go to work. One of the expected bene ts in automation is the mobi-lity improvement - uidity of the tra c - , but the reliabimobi-lity questions, including the human-machine cooperation issues are fundamental and many challenges exist before constructing a reliable and operational system [6].
The dierent existing and under research systems for road safety : embedded in the vehicle, installed in the infrastructure, or both ; of warning or of intervening type ; systems to avoid the accident or systems to reduce the severity or the consequences of the collision (collision mitigation systems or passive safety). Also, driving assistance systems are not dissociated from the type of the road network [7].
Dierent needs exist for driving assistance systems : to protect the passengers from collisions with xed objects on the road side as trees for rural roads or other objects in the urban environment. To protect the vulnerable road users (VRUs : this is very important in the urban context .
... but dierent solutions can be necessary depending on the road network type : Some common needs to all types of road networks. The points below are concerned for all the network types.
The greenhouse gases emissions reduction.
The improvement of the tra c uidity (reduction of the tra c jams). The augmentation of the road safety.
Human-machine cooperation studies : for all discussed systems the HMC studies must be present.
Dierent priorities can exist depending on the road network. Let us consider the two dierent cases below :
56 CHAPITRE 8. TRANSPORTATION CHALLENGES : AN OVERVIEW 1. In terms of safety :
in highways, the avoidance of secondary accidents is of major importance given the high speed of the vehicles. Warning systems based on telecommunications to inform the coming vehicles of accidents on the road allow the coming vehicles to reduce their speeds with enough anticipation.
Many secondary roads are of double direction and the relative speeds can increase up to 180km/h or more. [8] underlines that the speed is an important risk factor since it is almost always present as an occurance and/or gravity factor. As a matter of fact, independently on the origin of the accident, the reaction margin of the drivers to avoid the collision is determined by their speeds. In addition, the gravity of the accident depends on the collision energy and then on the speeds before and in the moment of the collision. The speed (inadapted or excessive) would play a major role in more than 40% of the mortal accidents. Lane departure prevention systems is probably more important then in secondary roads then in highways where the number of accidents is much smaller (the number of deaths in highways in 2012 represents 7% of the total while in the secondary roads it represents 66% of the total number [9])
In urban areas, one of the fundamental features is the high number of VRUs : pedestrians, cyclists, rollers, children, mothers with pushchairs, elder people, etc. It is fundamental then to protect them. Systems for VRUs protection is certainly much more important in urban areas than in highways.
In terms of the advanced driving assistance systems (ADAS) : certainly the public buses in urban areas ask for dierent ADAS than the buses for inte-city travels via highways. The reason is that the problem de nition changes since as discussed the safety challenges are not the same (for example, the maximum allowed speeds are very dierent in urban areas from the maximum allowed speeds in highways). Also, the urban areas contain vehicles that other areas do not, as for example the autolibs.
2. In terms of the quality of life :
The reduction of the noise pollution is certainly more critical in urban areas. In terms of sustainable development : there are also further questions like the
(short and long) term eects of the noise pollution in the roads in the middle of the forests.
Having in mind the complexity of the transportation context, we can now look at the speci c problem of improving road safety by the design of driving assistance systems. This problem, although it is a subset of the transportation global problem, it is itself a very complex problem as well, since it involves a diversity of road scenarios and human cooperation studies since the human being is in direct contact with the assistance system. The following section gives a structure from the European PReVENT Project, that helps to formulate a speci c problem for ADAS synthesis.