Electric, Energy Efficient and Autonomous Vehicle – V3EA

The transition to electric vehicles (EV) is already well underway. The technologies for EV modules, such as electric motors, power electronics, batteries, and regenerative braking systems, are rapidly improving. However, some of the main obstacles include weak autonomy, long charging time, lack of charging infrastructure and high purchase costs. Thus, several research works have been oriented towards enhancing EV autonomy. In particular, high energy density single-source (mainly battery) and hybrid multi-sources EV that combine several sources with complementary characteristics (battery, supercapacitor, fuel cell) are under development. The challenge today is to design a reliable, stable and ecological powertrain with a hybrid energy storage system associated with an intelligent real-time energy management strategy.
On the other hand, the autonomous vehicle (AV) in under intensive development to improve road safety and to release the driver. Several studies are proposed to deal with decision-making and trajectory planning for AV. However, these studies are often treated independently of energy aspects, while autonomous and connected vehicles have a significant potential for reducing energy consumption. The decision step is coupled with the control of the vehicle dynamics in order to follow the selected trajectory while guaranteeing stability and comfort. The control of the vehicle could be divided into high-level and low-level, and depends on the actuators structure of the EV.
EV can be driven by one centralized motor or by distributed motors in the wheels. With distributed in-wheel motors, vehicle stability and handling is enhanced because of the rapid and precise independent control of the driving and steering torques on each wheel. In addition, the redundant actuators can be used to achieve multiple control targets.
This project considers full electric vehicles with four distributed in-wheel motors. To improve EV autonomy and efficiency, the power supply system is composed of three different kinds of power sources: battery, fuel cell, and ultracapacitors.
The energy efficiency of a vehicle is a determinant of its operational cost and environmental impact.
In this context, this research work proposes to study energy saving at three levels of the autonomous in-wheels EV, ranging from the decision-making level of the AV to the level of hybridization while considering the control for a safe, stable, comfortable, and economical driving. These levels are often treated independently in the literature while strong interactions actually link them. The objectives at different levels can be summarized by the following:
Objectives of level 1 on decision making and trajectory planning:
? Detect the driving zone; and plan a local path and a speed profile,
? Respect the driving code, the dynamic constraints of the vehicle (comfort, stability) and avoid fixed / mobile obstacles,
? Take into account uncertainties (perception, intention of others, occlusions, etc.),
? Consider the criterion of energy consumption.
Objectives of level 2 on vehicle dynamics high-level control:
? Develop Global Chassis Control (GCC) to improve stability, maneuverability and comfort,
? Follow a trajectory and a reference speed,
? Control the actuators: the steering and the 4 independent in-wheel motors,
? Reduce energy consumption by applying a suitable distribution of the forces at the wheels level.
Objectives of level 3 on electric vehicle low-level multi-sources control:
? Development of real-time EMS to meet power demands,
? Taking into account the dynamics, SOC and SOH of sources,
? Improvement of the lifespan of sources,
? Robust converter control, and minimization of electrical losses in the traction chain.
Moreover, the different developments and the global architecture composed of the three combined levels will be validated on the experimental platforms of the partners, in order to evaluate the global energy efficiency of the proposed approaches.