Coordinated control of AFS and DYC for vehicle handling and stability based on optimal guaranteed cost theory

Abstract

Considering the uncertainty of tyre cornering stiffness due to the frequent variation of running conditions, a new coordination scheme is proposed based on optimal guaranteed cost control technique by coordinating active front steering and direct yaw moment control. A general procedure to develop an optimal guaranteed cost coordination controller (OGCC) is presented, and the effect of uncertainty deviation magnitude on the control system is discussed. An optimal coordination (OC) scheme based on LQR is also presented. Many simulations are carried out on an 8-DOF nonlinear vehicle model for a slalom manoeuvre and a lane-change manoeuvre, respectively. The simulation results show that the OGCC scheme has superior stability and tracking performances at different running conditions compared with the OC scheme.

Keywords:

• active front steering
• direct yaw moment
• vehicle stability control
• optimal guaranteed cost control
• coordinated control
• vehicle dynamics