Journal Article

The Control of Handling Stability for Active Inward Tilt Vehicles Based on the Phase-Plane Lateral Stability Region

Zhang, Chen, Yao, Jialing

2026

Overview

For autonomous vehicles, high-speed cornering can easily lead to degraded handling stability and increased risks of sideslip or even rollover. Therefore, vehicle phase-plane stability-region analysis has become an important topic in active safety-control research. However, most existing studies still construct phase-plane stability regions mainly based on simplified vehicle models, without sufficiently considering the influence of vertical load transfer during cornering on tire lateral forces and stability boundaries. To address this issue, this paper proposes a hierarchical control strategy based on phase-plane analysis for active inward tilt vehicles. This method adopts a three-degree-of-freedom vehicle dynamics model and a tire model. By carefully comparing the phase-plane stability regions of active inward tilt and passive roll vehicles and by further analyzing the state-trajectory convergence characteristics of active inward tilt vehicles under different longitudinal speeds, front wheel steering angles, and road adhesion coefficients, the effects of active inward tilt on stability-region expansion and vehicle-state convergence are revealed. Subsequently, a hierarchical control strategy is proposed as an integrated solution to improve vehicle handling stability. The upper-level controller dynamically adjusts the reference values and objective weights according to whether the vehicle state is located in the stable, critical, or dangerous region. The lower-level NMPC controller optimizes the front wheel steering angle and active suspension forces to achieve coordinated trajectory tracking and stability control. Double lane-change simulation results show that active inward tilt can improve the left–right vertical load distribution and expand the lateral stability region. Compared with passive roll and conventional active inward tilt control, the proposed strategy reduces the phase-plane state convergence area by 68% and 75%, respectively, thereby improving vehicle handling stability and active safety under extreme conditions.

• Publisher: MDPI AG
• Subject: active inward tilt / Analysis / Attitude (inclination) / Autonomous vehicles / Control algorithms / Control stability / Controllers / Convergence / Cornering / Driverless cars / Equilibrium / Handling / Lane changing / Lateral forces / Lateral stability / lateral stability region / Load distribution (forces) / Load transfer / nonlinear model predictive control / passive roll / Roads & highways / Sideslip / Steering / Tires / Trajectories / Vehicles / Velocity / Vertical distribution / vertical load transfer / Vertical loads