Olivier Lebeltel

SpaceEx: scalable verification of hybrid systems

We present a scalable reachability algorithm for hybrid systems with piecewise affine, non-deterministic dynamics. It combines polyhedra and support function representations of continuous sets to compute an over-approximation of the reachable states. The algorithm improves over previous work by using variable time steps to guarantee a given local error bound. In addition, we propose an improved approximation model, which drastically improves the accuracy of the algorithm. The algorithm is implemented as part of SpaceEx, a new verification platform for hybrid systems, available at spaceex.imag.fr. Experimental results of full fixed-point computations with hybrid systems with more than 100 variables illustrate the scalability of the approach.

Programmation bayésienne des robots

Cet article propose une mthode originale de programmation des robots fonde sur linfrence et lapprentissage baysien. Cette mthode traite formellement des problmes dincertitude et dincompltude inhrents au domaine considr. La principale difficult de la programmation des robots vient de linvitable incompltude des modles utiliss. Nous exposons le formalisme de description dune tche robotique ainsi que les mthodes de rsolution. Nous lillustrons en utilisant ce systme pour programmer une application de surveillance pour un robot mobile : le Khepera. Pour cela, nous utilisons des ressources gnriques de programmation appeles descriptions . Nous montrons comment dfinir et utiliser de manire incrmentale ces ressources (comportements ractifs, fusion capteur, reconnaissance de situations et squences de comportements) dans un cadre systmatique et unifi

Basic Concepts of Bayesian Programming

The purpose of this chapter is to introduce gently the basic concepts of Bayesian programming.

A Bayesian framework for robotic programming

We propose an original method for programming robots based on bayesian inference and learning. This method formally deals with problems of uncertainty and incomplete information that are inherent to the field. Indeed, the principal difficulties of robot programming comes from the unavoidable incompleteness of the models used. We present the formalism for describing a robotic task as well as the resolution methods. This formalism is inspired by the theory of probability, suggested by the physicist E. T. Jaynes: “Probability as Logic” [1]. Learning and maximum entropy principle translate incompleteness into uncertainty. Bayesian inference offers a formal framework for reasoning with this uncertainty. The main contribution of this paper is the definition of a generic system of robotic programming and its experimental application. We illustrate it by programming a surveillance task with a mobile robot: the Khepera. In order to do this, we use generic programming resources called “descriptions”. We show how to...

Formal and Informal Methods for Multi-Core Design Space Exploration.

We propose a tool-supported methodology for design-space exploration for embedded systems. It provides means to define high-level models of applications and multi-processor architectures and evaluate the performance of different deployment (mapping, scheduling) strategies while taking uncertainty into account. We argue that this extension of the scope of formal verification is important for the viability of the domain.

Wings Were Not Designed to Let Animals Fly

“Functional change in structural continuity,” i.e., the opportunistic evolution of functions together with structures, is a major feature of biological evolution. However it has seldom struck a roboticians mind as very relevant for building robots, i.e., for design. This paper proposes starting points for investigating this unusual issue.