Coordination of automated vehicles at intersections: decision, efficiency and control

International audienceThis papers studies the kind of control that is needed to efficiently coordinate multiple automated vehicles. An intersection is chosen in order to present the main concept but consequences of this work also hold for other areas of cooperation, such as lane changes or maneuvers in parking lots. We chose the classical framework for multi-robots systems: the coordination space i.e. we assume the future paths are known and fixed. The problem is to coordinate the speeds of the vehicles. We first prove a theorem stating that a smooth feedback control cannot always avoid gridlocks: for more than 2 vehicles, there are always starting states ending into gridlocks. The paper then proposes some ways to avoid this drawback, leading to a better conceptual way to take decision in such a cooperative system, in order to have provable efficient decision and control

Large deviation principale for Markov chains in continuous time

Related research report available at http://hal.inria.fr/docs/00/07/27/76/PDF/RR-3877.pdfInternational audienceLet Y t be a homogeneous nonexplosive Markov process with generator R defined on a denumerable state space E (not necessarily ergodic). We introduce the empirical generator G t of Y t and prove the Ruelle-Lanford property, which implies the weak LDP. In a fairly broad setting, we show how to perform almost all classical operations (e.g., contraction) on the weak LDP under suitable assumptions, whence Sanov's theorem follows

Priority-based intersection management with kinodynamic constraints

We consider the problem of coordinating a collection of robots at an intersection area taking into account dynamical constraints due to actuator limitations. We adopt the coordination space approach, which is standard in multiple robot motion planning. Assuming the priorities between robots are assigned in advance and the existence of a collision-free trajectory respecting those priorities, we propose a provably safe trajectory planner satisfying kinodynamic constraints. The algorithm is shown to run in real time and to return safe (collision-free) trajectories. Simulation results on synthetic data illustrate the benefits of the approach.Comment: to be presented at ECC2014; 6 page

Time-optimal Coordination of Mobile Robots along Specified Paths

In this paper, we address the problem of time-optimal coordination of mobile robots under kinodynamic constraints along specified paths. We propose a novel approach based on time discretization that leads to a mixed-integer linear programming (MILP) formulation. This problem can be solved using general-purpose MILP solvers in a reasonable time, resulting in a resolution-optimal solution. Moreover, unlike previous work found in the literature, our formulation allows an exact linear modeling (up to the discretization resolution) of second-order dynamic constraints. Extensive simulations are performed to demonstrate the effectiveness of our approach.Comment: Published in 2016 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS

Discrete events model for dual mode transport system simulation and evaluation

Full text also available at http://www.mech.kuleuven.be/MT-ITS2011/downloads/Abstracts/042,%20A.%20de%20La%20Fortelle%20et%20al.,%20Discrete%20Events%20Model%20for%20Dual%20Mode%20Transport%20System%20Simulation%20and%20Evaluation.pdfInternational audienceThe European project CATS --- City Alternative Transport System --- is developing and evaluating a new vehicle system using a single type of vehicle for two different usages: individual use or collective transport. Real experiments will necessarily take place with a limited number of vehicles and stations. Hence there is a need for evaluation using simulations. INRIA is developing a discrete events simulator for that purpose, based on a previous work done for collective taxis. We present in this paper the model we use for the CATS project. This model rely on an adapted events/decision graph that extends previous graphs. The new feature of this model is the way we deal with two modes that can be extended to many other modes. This work therefore shows on a concrete example a method to efficiently merge multiple modes into one model

Cybercars : Past, Present and Future of the Technology

Automobile has become the dominant transport mode in the world in the last century. In order to meet a continuously growing demand for transport, one solution is to change the control approach for vehicle to full driving automation, which removes the driver from the control loop to improve efficiency and reduce accidents. Recent work shows that there are several realistic paths towards this deployment : driving assistance on passenger cars, automated commercial vehicles on dedicated infrastructures, and new forms of urban transport (car-sharing and cybercars). Cybercars have already been put into operation in Europe, and it seems that this approach could lead the way towards full automation on most urban, and later interurban infrastructures. The European project CyberCars has brought many improvements in the technology needed to operate cybercars over the last three years. A new, larger European project is now being prepared to carry this work further in order to meet more ambitious objectives in terms of safety and efficiency. This paper will present past and present technologies and will focus on the future developments

Autonomous driving at intersections: combining theoretical analysis with practical considerations

International audienceThe move towards automated driving is gaining impetus recently. This paper follows the approach of combining theoretical analysis with practical issues. It gives an insight of some practical problems that are encountered when running automated vehicles in real environments, using intersection crossing as a major example. The aim is not to try to be exhaustive but to show some criteria (safety, efficiency, reactivity, resilience, scalability…) for decision making in automated driving that have to be balanced before any mass deployment. In a second part we introduce mathematical tools that can help define algorithms and systems that improve current state of the art. We will also show some perspective for accommodating the hypotheses of these mathematical tools with real life constraints