No abstract

This paper presents an integrated linear parameter-varying (LPV) control approach of an autonomous vehicle with an objective to guarantee driving comfort, consisting of cruise and semi-active suspension control. First, the vehicle longitudinal and vertical dynamics (equipped with a semi-active suspension system) are presented and written into LPV state-space representations. The reference speed is calculated online from the estimated road type and the desired comfort level (characterized by the frequency weighted vertical acceleration defined in the ISO 2631 norm) usingprecomputed polynomial functions. Then, concerning cruise control, an LPV H2 controller using a linear matrix inequality (LMI) based polytopic approach combined with the compensation of the estimated disturbance forces is developed to track the comfort-oriented reference speed. To further enhance passengers’ comfort, a decentralized LPV H2 controller for the semi-active suspension system is proposed, minimizing the effect of the road profile variations. The interaction with cruise control is achieved by the vehicle’s actual speed being a scheduling parameter for suspension control. To assess the strategy’s performance, simulations are conducted using a realistic nonlinear vehicle model validated from experimental data. The simulation results demonstrate the proposed approach’s capability to improve driving comfort.

The objective of this work was to evaluate the influence of elevated temperature on the fatigue resistance of an all aluminum conductor. A dispositive was developed to reach temperatures like those undergone by high-voltage electrical conductors during their useful life. This dispositive is based on the classical temperature control of proportional integral derivative. In this work, the dispositive used for heating the conductor/suspension clamp assembly and the methodology used to execute fatigue tests at 75 °C of one "All Aluminum Conductor" (Orchid) were presented in detail. There is a remarkable and sensible difference between S and N curves for tests carried out at room temperature and those accomplished at 75 °C, which may indicate degradation of all aluminum conductors when tested under fatigue conditions at higher temperatures.