Rapid response to the M_w 4.9 earthquake of November 11, 2019 in Le Teil, Lower Rhône Valley, France

On November 11, 2019, a Mw 4.9 earthquake hit the region close to Montelimar (lower Rhône Valley, France), on the eastern margin of the Massif Central close to the external part of the Alps. Occuring in a moderate seismicity area, this earthquake is remarkable for its very shallow focal depth (between 1 and 3 km), its magnitude, and the moderate to large damages it produced in several villages. InSAR interferograms indicated a shallow rupture about 4 km long reaching the surface and the reactivation of the ancient NE-SW La Rouviere normal fault in reverse faulting in agreement with the present-day E-W compressional tectonics. The peculiarity of this earthquake together with a poor coverage of the epicentral region by permanent seismological and geodetic stations triggered the mobilisation of the French post-seismic unit and the broad French scientific community from various institutions, with the deployment of geophysical instruments (seismological and geodesic stations), geological field surveys, and field evaluation of the intensity of the earthquake. Within 7 days after the mainshock, 47 seismological stations were deployed in the epicentral area to improve the Le Teil aftershocks locations relative to the French permanent seismological network (RESIF), monitor the temporal and spatial evolution of microearthquakes close to the fault plane and temporal evolution of the seismic response of 3 damaged historical buildings, and to study suspected site effects and their influence in the distribution of seismic damage. This seismological dataset, completed by data owned by different institutions, was integrated in a homogeneous archive and distributed through FDSN web services by the RESIF data center. This dataset, together with observations of surface rupture evidences, geologic, geodetic and satellite data, will help to unravel the causes and rupture mechanism of this earthquake, and contribute to account in seismic hazard assessment for earthquakes along the major regional Cévenne fault system in a context of present-day compressional tectonics

Design of a new measurable approach for the qualification of the behaviour of an autonomous vehicle

International audienceThe safety assessment of autonomous driving system is a major challenge in the automotive industry and the role of simulation in development and testing of autonomous vehicles has become predominant to significantly reduce the hundreds of millions of miles required to demonstrate the safety performance of such systems. In this paper, a novel methodology is presented to assess automated vehicles safety performance based on a multifactorial analysis of severity indicators in the vicinity of the under test self-driving car. The set of severity indicators includes commonly used time intervals (Inter Vehicular Time, Time to Collision, Time to Steer, ...), distance-based indicators, traffic congestion indicators and a newly developed indicator relying on overlapping geometrical regions. Unsupervised clustering techniques are then used to investigate the correlations, dependence among the whole set of indicators. To address the problem of combining these heterogeneous quantities to derive a global measure of dangerousness for a given scenario, appropriate scaling is performed and various aggregation methods are tested against cut-in, cutout and cut-through scenarios

Benchmarking the HRP-2 humanoid robot during locomotion

International audienceIn this paper we report results from a campaign of measurement in a laboratory allowing to put a humanoid robot HRP-2 in a controlled environment. We have investigated the effect of temperature variations on the robot capabilities to walk. In order to benchmark various motions modalities and algorithms we computed a set of performance indicators for bipedal locomotion. The scope of the algorithms for motion generation evaluated here is rather large as it spans analytical solutions to numerical optimization approaches able to realize real-time walking or multi-contacts