Auto-adaptive and string stable strategy for intelligent cruise control

International audienceThis study completes the study of a longitudinal control strategy based on a non-linear acceleration profile model. The model is thoroughly defined by a set of two design parameters that make the control policy auto-adaptive. The control strategy is safe and Stop&Go consistent. The string stability property of the control policy is also analysed. Simulation results show that the control policy has a good string stability property with high string stability margin with respect to Pipes and Chandler's control strategy

Extraction de données visant à caractériser les situations de conduite pour l'amélioration de la sécurité

International audienceAujourd'hui, pour être efficace les systèmes de régulation de vitesse doivent pouvoir prendre en compte l'environnement du véhicule. Ils disposent alors d'un capteur de type radar (ou autre) qui permet la détection des véhicules obstacles assurant ainsi au véhicule équipé du régulateur de vitesse de pouvoir réagir face à une situation potentiellement dangereuse. Or les travaux actuels de recherche sur ce domaine font souvent l'hypothèse d'une route droite et plane. Malheureusement, dans la pratique, les profils de route s'avèrent plus complexes. Dans cet article, nous montrons comment à l'aide d'un système de détection à balayage, il est facilement possible d'identifier la situation courante dans laquelle le véhicule se trouve aussi bien sur route droite que sur route courbe. La notion de scénario est introduite afin d'évaluer la dangerosité de la situation. De plus il est montré que le balayage permet d'accroitre la sécurité et le confort en offrant une distance de détection beaucoup plus grande sur route courbe que les systèmes fixes

Extraction de données visant à caractériser les situations de conduite pour l'amélioration de la sécurité

International audienceAujourd'hui, pour être efficace les systèmes de régulation de vitesse doivent pouvoir prendre en compte l'environnement du véhicule. Ils disposent alors d'un capteur de type radar (ou autre) qui permet la détection des véhicules obstacles assurant ainsi au véhicule équipé du régulateur de vitesse de pouvoir réagir face à une situation potentiellement dangereuse. Or les travaux actuels de recherche sur ce domaine font souvent l'hypothèse d'une route droite et plane. Malheureusement, dans la pratique, les profils de route s'avèrent plus complexes. Dans cet article, nous montrons comment à l'aide d'un système de détection à balayage, il est facilement possible d'identifier la situation courante dans laquelle le véhicule se trouve aussi bien sur route droite que sur route courbe. La notion de scénario est introduite afin d'évaluer la dangerosité de la situation. De plus il est montré que le balayage permet d'accroitre la sécurité et le confort en offrant une distance de détection beaucoup plus grande sur route courbe que les systèmes fixes

Traffic Data Extraction for Road Safety Improvement

8 pagesInternational audienceThis paper demonstrates the benefit of scanning perception systems especially scanning radars on vehicle detection in ITS applications. Theoretical results prove that the distance of detection can be drastically improved and traffic scenarios be recognized with the use of scanning systems. Higher detection distance enables suitable anticipative actions in the vehicles control for avoiding car accidents

Excellent String Stability Property for a Safe Longitudinal Control

International audienceIn this paper we evaluate the string stability property of a longitudinal control strategy designed to be safe, comfortable and robust. The human driving model is assumed to follow the pipes model. Results show that the control model is structurally string stable so that no servoloop controller is needed. As human driving model is string unstable, we show that only 5% penetration rate of the ACC model should guarantee traffic stability for some scenario in mixed environment. Such satisfactory result relies on a string stability margin (SSM) that is much higher than the SSM of some ACC control strategy for the given scenario. Because the control strategy is nonlinear, absolute stability and SSM value cannot be given. Yet the strategy seems sable for different scenarios

Artificial pancreas for type 1 diabetes: Closed-loop algorithm based on Error Dynamics Shaping

Editeur commercial ElsevierInternational audienceThe present study evaluates Error Dynamics Shaping (EDS) as an alternative closed-loop strategy for subcutaneous insulin delivery in type 1 diabetes. EDS uses the energy-based principle of damping to ensure a robust stability of closed-loop systems despite strong unknown disturbances. It benefits from intuitive tuning criteria and provides explicit state feedback control laws requiring few computational resources. Using FDA approved UVa T1DM simulator, the robustness of an EDS controller against meal profile variability was tested in one scenario over a day and three scenarios over a week with meal variability. No hypoglycaemia was recorded and hyperglycaemias kept limited. In silico, EDS controller proved effective in achieving normoglycaemia and robust to meal disturbances

Error Dynamics Shaping: a new robust control for nonlinear systems

International audienceThis paper introduces to Error Dynamics Shaping (EDS), an original nonlinear control methodology inspired from energy-based principles, which allows a robust stabilisation of closed-loop systems despite parametric uncertainties and disturbances. This methodology provides explicit state feedback control laws with intuitive tuning parameters. Based on the early idea to try and generate dissipative closed-loops with an adjustable damping degree when controlling physical systems, EDS defines a control procedure devoted to nonlinear systems that needs no energy formulation. It only requires the knowledge of a state space model of the system to be controlled. This approach is first described in a formal way, and then illustrated through an example

Stabilizing control with commuttation frequency limitations for a step up converter

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Intelligent Transportation Systems: A Safe, Robust, and Comfortable Strategy for Longitudinal Monitoring

ISSN 1751-956XInternational audienceAn original non cooperative longitudinal control strategy, based on a new, nonlinear, and second order reference model is studied. The control strategy yields analytical dynamic solutions and pays extreme care to safety constraints. It lowers the safe inter-vehicular distance and is also robust towards errors of sensors when measuring the speed of obstacles. This robustness, valid for slow moving obstacles as well as fast moving ones is a decisive benefit of this strategy. The strategy consists in two main phases depending on vehicles relative interdistance. Considering acceleration and jerk (time derivative of acceleration) as comfort metrics, it is also shown that the control strategy proves comfortable. Simulation results validate the control strategy

A new safe and robust strategy for automotive cruise control.

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