Preserving stability of huge agriculture machines with internal mobilities: Application to a grape harvester

International audienceThis paper proposes an algorithm for estimating on-line the rollover risk of huge machine moving on natural ground. The approach is based on the reconstruction of lateral load transfer thanks to an observer, able to take into account terrain specificities (grip conditions and geometry). Capabilities are tested through experiments on a grape harvester

Low cost active devices to estimate and prevent off-road vehicle from rollover

International audienceThis paper proposes to investigate the use of active devices, able to anticipate for hazardous situations, by using low cost sensors. In this approach, the risk of rollover is considered thanks to the Lateral Load Transfer (LLT) metric, able to characterize gradually the dynamic mass repartition on the vehicle, without using expensive cell forces. In order to account for variable conditions, an observer algorithm is used in order to adapt on-line the grip conditions thanks to a dynamical yaw model. Once adapted, this model supply the dynamic variable influencing the evolution of LLT. This metric can then be estimated thank to a second partial dynamic model considering the roll plane. Thanks to the vehicle parameters (mass, elevation of centre of gravity), the risk of rollover may be accurately computed

Prévention des risques de renversement par action sur la vitesse : application aux quads

International audienceThis paper proposes an algorithm dedicated to estimate on-line the risk of rollover of an All-Terrain Vehicle (ATV), together with the maximal admissible speed preserving its stability. This work considers the case of off-road motion, subjected to low and varying grip conditions. As a result, an observer using several layers is developed to account for sliding. This permits to feed a dynamical model of the ATV, which is on-line adapted and consequently relevant. This model is exploited in two ways. First, it permits to estimate on-line the Lateral Load Transfer (LLT), representative of the level of stability. Secondly, the model is used in order to derive the velocity leading to a risk of rollover. Vehicle actual velocity is then limited to this value, considered as the maximal admissible speed, so that stability can be ensured anytime

Procédé de réduction du risque de basculement d'un véhicule automoteur équipé d'un système de suspension pilotable

Ce procédé comporte : - une première étape de calcul, à partir d'une pluralité de signaux délivrés par des capteurs (28, 29) du système de suspension pilotable, d'une grandeur mesurée (TCm) en tant que valeur courante (TC) d'un transfert de charge - une seconde étape de calcul d'une grandeur estimée (TCe), à partir des signaux délivrés par des capteurs cinématiques (50-58) placés à bord du véhicule et d'un modèle dynamique du véhicule, ladite grandeur estimée étant prise en tant que valeur courante du transfert de charge lorsque la grandeur mesurée n'est pas disponible - une étape d'évaluation du risque de basculement à partir de la valeur courante (TC) du transfert de charge et, en cas de risque de basculement élevé, - une étape d'émission d'un signal de sécurité (S)