Vehicle controllability assessment using detailed multibody vehicle simulations

摘要

ISO 26262, the functional safety standard for automotive electric and electronic (E/E) systems, requires a controllability assessment to be made as part of the hazard and risk classification process. As well as influencing the function’s Automotive Safety Integrity Level (ASIL), the verifiable controllability may also limit the functions intervention options and intensity during normal operation. For electric driven vehicles this limits their accident-avoidance/-mitigation potential. For an in-wheel motor driven electric vehicle it is questioned whether the failure of a motor could lead to a risk. It is obvious that the result of the risk assessment depends on the operating scenarios chosen. As numerous factors define a driving situation, the possible detailing of these factors is unlimited. In a previous paper, the results of a study regarding the controllability of a vehicle driven by in-wheel motors using a simplified linear bicycle model were presented. In this paper we extend the previous work by qualitatively and quantitatively identifying the hazards associated with in-wheel motors and by quantify the vehicle level effects that could be expected using validated detailed multibody vehicle models in both straight line and cornering events.