International audienceThis paper deals with the problem of active damping of vehicle oscillations. A complete methodology based on an H∞ optimization is presented. Several dedicated analysis tools are used in order to analyze the behavior of the closed-loop system. Two tuning parameters allow the design of a controller managing the compromise between performance (in terms of oscillation attenuation and limit cycles) and robustness. Finally, a feedforward component is designed in order to improve the performance without changing the robustness properties or the controller complexity. Simulation results obtained with an experimentally validated model show the efficiency of the resulting controller

This paper deals with the problem of active damping of driveline oscillations in order to improve driveability and passenger comfort. Precisely, longitudinal vibrations occur during transient changes in driver demand, and they affect the driveability in a negative way. A robust and efficient controller is proposed, driving the engine in order to actively damp the driveline oscillations. The methodology considered is based on the prediction and compensation of the shaft torque at relevant frequencies.The main advantage and originality of the proposed approach consists in the simplicity of the design and the possibility to adjust the controller, directly on the vehicle, without redesign. This is made possible because the controller parameterization has a "physical" meaning. Three post-design tuning parameters are then available to manage the compromise between performance and robustness. The resulting controller is evaluated on a test car with a SI engine.

This article proposes a diesel oxidation catalyst diagnostics strategy based on the exothermic process generated by exhaust gas species oxidation in the catalyst. The diagnostics strategy is designed to be applied on-board and respecting real-time electronic control unit computational limitations. Diagnosis purposes are fulfilled by means of the comparison of the passive model temperature, which represents the outlet temperature of a non-impregnated diesel oxidation catalyst, and the measurement provided by the on-board catalyst-out temperature sensor. Thus, the presented diagnostics strategy uses only two production grade temperature sensors and the measurements of air and fuel mass flows from the electronic control unit. Passive diagnostics is based on the oxidation of engine-raw emissions, whilst active diagnostics is based on the oxidation of requested post injected fuel. Post-injection strategy is also discussed for active diagnosis. Then, the diagnostics strategy is able to discern whether the diesel oxidation catalyst is able to oxidise or not.

International audienceno abstrac