Vehicle Attitude Control via Load Resistance Regulation of a Hydraulic–Electric Energy-Harvesting Suspension

Vehicle dynamics during autonomous driving can cause passenger discomfort as well as motion sickness. This article introduces an energy-efficient vehicle attitude control method through load resistance control in a hydraulic–electric energy-harvesting suspension. A thorough study on how external load resistance affects a vehicle’s pitch, roll, and vertical acceleration has been conducted without requiring additional energy input. To analyze the effects that the variation of load resistance has on vehicle attitude, a 10 DOF vehicle model and a hydraulic–electric energy-harvesting suspension have been developed. The relationship between load resistance and vehicle attitude is defined and experimentally demonstrated in slalom tests under real-world conditions. The results demonstrate that reducing the load resistance from 70 Ω to 30 Ω reduces peak roll angle by 33.9% and peak pitch angle by 30.4%, while the RMS values are reduced by 46.2%, 28.6%, and 28.6% for roll angle, pitch angle, and vertical acceleration, respectively. A frequency-domain analysis shows that these improvements are achieved without shifting vibrational energy into the 4–8 Hz range most perceptible to humans. This systematic approach provides an energy-efficient way to improve vehicle stability and ride comfort, with potential implications for reducing motion sickness in autonomous driving systems. The quantitative relationship between load resistance and vehicle attitude provides a new understanding of the dynamics of a vehicle with energy-harvesting suspension systems.