Design of The CRONE Automatic Headlight Leveling System

Automotive headlights system represents a safety key system when it comes to drive by night. It aims to increase the comfort of the driver by providing a clear visibility in order to anticipate obstacles and follow the right path. One of the main challenges that the lighting system is facing today is its automatic leveling adjustment. Variations of load of the vehicle, its dynamics and the environment are the main sources of disturbance to the leveling system. These disturbances causes variations of vehicle pitch angle and as a result the lighting cut-off level that may glare other road users and affect the driver's visibility range. This paper proposes an innovative automatic leveling system based on an ultrasonic motor which is able to dynamically reject such disturbances on the lighting cut-off level using a robust CRONE controller

ℋ<inf>2</inf>-norm of a class of fractional transfer functions suited for modeling diffusive phenomena

International audienceThis paper focuses on the H2-norm of a class of implicit fractional order transfer functions well suited to describe input-output behaviour of diffusive systems. First, analytical expression of the H2-norm of this kind of transfer function is established. This result is then used to evaluate the quality of an integer order approximation of such an implicit fractional transfer function

Detection of Electric Contact Resistance Variations in Automotive Connectors

International audienceCar manufacturers have to size electric and electronic systems to avoid the risk of short circuits while, at the same time, ensuring a viable economic balance. In other words, the copper mass must be sufficient for safety reasons but not excessive for cost reasons. It is, thus, nec- essary to monitor the critical points of the electric archi- tecture in order to make an appropriate decision to main- tain a high level of safety. However, due to physical and economic constraints, direct temperature measurement of these critical points is seldom possible. Moreover, temper- ature monitoring at these points would not allow one to determine whether the rise in temperature was related to degradation of the contact or whether it was due to the generation of thermal power by another component. The objective of this paper is, thus, to propose a new method to monitor critical points of the electric architecture that does not require direct measurements. In order to achieve this objective, an electrothermal model of the architecture was developed, and a diagnosis method was used. The method was applied to detect abnormal variations in the contact resistance inside a connector, which is a critical point com- monly encountered in the electrothermal chain of automo- tive vehicles. The efficiency of the algorithm was evaluated on a dedicated test bench. The proposed approach is able to detect a deviation of about 10% in the contact resistance, thus validating the proposed methodology