Parallel Active Link Suspension: Full Car Application With Frequency-Dependent Multiobjective Control Strategies

In this article, a recently proposed at basic level novel suspension for road vehicles, the parallel active link suspension (PALS), is investigated in the realistic scenario of a sport utility vehicle (SUV) full car. The involved rocker-pushrod assembly is generally optimized to maximize the PALS capability in improving the suspension performance. To fully release the PALS functions of dealing with both low- and high-frequency road cases, a PID control scheme is first employed for the chassis attitude stabilization, focusing on the minimization of both the roll and pitch angles; based on a derived linear equivalent model of the PALS-retrofitted full car, an
$H_{\infty }$
control scheme is designed to enhance the ride comfort and road holding; moreover, a frequency-dependent multiobjective control strategy that combines the developed PID and
$H_{\infty }$
control is proposed to enable: 1) chassis attitude stabilization at 0–1 Hz; 2) vehicle vibration attenuation at 1–8 Hz; and 3) control effort penalization (for energy saving) above 10 Hz. With a group of ISO-defined road events tested, numerical simulation results demonstrate that, compared to the conventional passive suspension, the PALS has a promising potential in full-car application, with up to 70% reduction of the chassis vertical acceleration in speed bumps and chassis leveling capability of dealing with up to 4.3-m/s
²
lateral acceleration.