Electric vehicle corner architecture: driving comfort evaluation using objective metrics

Abstract

The presented paper is dedicated to the driving comfort evaluation in the case of the electric vehicle architecture with four independent wheel corners equipped with in-wheel motors (IWMs). The analysis of recent design trends for electrified road vehicles indicates that a higher degree of integration between powertrain and chassis and the shift towards a corner-based architecture promises improved energy efficiency and safety performances. However, an in-wheel-mounted electric motor noticeable increases unsprung vehicle mass, leading to some undesirable impact on chassis loads and driving comfort. As a countermeasure, a possible solution lies in integrated active corner systems, which are not limited by traditional active suspension, steer-by-wire and brake-by-wire actuators. However, it can also include actuators influencing the wheel positioning through the active camber and toe angle control. Such a corner configuration is discussed in the paper as applied to a sport utility vehicle (SUV). A new chassis design was developed and tested for this reference vehicle using multi-body dynamics simulation. The integrated operation of the active suspension and the wheel positioning control has been analyzed in this study with different driving scenarios and objective metrics for driving comfort evaluation. Additionally, handling and stability tests have also been performed to confirm that new systems do not deteriorate driving safety. The obtained results contribute to a comprehensive assessment of IWM-based architecture, formulated from a driving comfort perspective that is helpful for further designs of electric vehicle corners.