Dynamic modeling and adjustable damping layered control of air suspension hybrid system

ABSTRACT

Due to the coupling of continuous variables and discrete events, the vehicle height adjustment and damping force control system of air suspension can be described as a typical hybrid system, which poses theoretical challenges for researchers in recent years. Therefore, this paper focuses on the modelling and control of the air suspension hybrid system, realising the coordination control between the solenoid valve on-off status and the magneto-rheological damper current. A highly nonlinear hybrid dynamical mechanism model of vehicle height and damping force adjustment is established to describe the continuous dynamic behaviour and the discrete events of air suspension. Based on some assumptions and piecewise linear approximation for nonlinear components of air suspension, the mixed logical dynamical model compiled by the hybrid systems description language is constructed by introducing the auxiliary logical variables and the continuous logical variables. Using this model, a novel layered control strategy is designed and the efficient is verified by test results.The simulation results show that the proposed control method can not only adjust the vehicle height without switching the solenoid valve frequently,but also improve the ride comfort without deteriorating the handling stability, which leads to the closed-loop system with a favourable dynamical property.

KEYWORDS:

• Air suspension
• hybrid system
• mixed logical dynamical
• model predictive control
• layered control
• dynamic modeling

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This paper was supported by the National Natural Science Foundation of China under grant number 51375519 and the Basic Science and Preface Technology Research Project of Chongqing in China under grant number cstc2015jcyjBX0133.

Notes on contributors

Qiguo Hu

Qiguo Hu, Ph.D. (back), professor, master tutor of mechanical design and theory, vehicle engineering, and vehicle application engineering. Mainly engaged in mechanical and automotive system dynamics, system optimization design and reliability design, safety and reliability, performance and strength analysis, modern quality engineering and application, enterprise diagnosis and consulting and other aspects of teaching and research.

Wei Lu

Wei Lu is currently studying for the master’s degree at vehicle engineering from the Chongqing Jiaotong University. His research interests include vehicle dynamics control and vehicle application engineering.

Jingzhen Jiang

Jingzhen Jiang was born in 1995, graduate students in Chongqing Jiaotong University. Her research interests include vehicle dynamics control and mechanical design.