Ride Performance on Wheel Rotation Speed Driven Controlled Damper System

摘要

The trend in vehicle electrification has been increasing. However, the mass of the electric vehicle increases with the battery size. Consequently, the ride and handling performance may be insufficient to meet user expectations. This study aims to provide the value of the dynamic performance of electric vehicles. In a previous study, we proposed a skyhook damping system that is driven by the wheel rotation speed signals. However, there was a problem of the feeling of a stiff ride when applying the skyhook algorithm with a slow signal communication cycle. In this paper, we clarified the causes of an incorrect damping coefficient switching timing, which excites the higher-order mode of the suspension system through a numerical analysis. As a solution, we proposed a minimal control strategy that can achieve both body damping (1-2 Hz) and isolation (3-6 Hz) through its smooth damping switching function under the limitation of a slow communication cycle of 20 ms. The performance of the proposed algorithm showed a significant improvement based on a numerical analysis and vehicle tests. As a limitation of the proposed algorithm, it has a fixed point near the sprung resonance frequency, a recommended treatment for which is discussed herein.