A Distributed Driving Six-Wheel Steering Commercial Vehicle Chassis Stability Domain Criterion for Coordination of Multiple Subsystems

The coordination of multiple subsystems of the distributed driving six-wheel steering commercial vehicle chassis (DD-6WS CVC) is improved to increase its adaptability to diverse and complex operating conditions. A three-degree-of-freedom (3-DOF) nonlinear model of the DD-6WS CVC, integrating slip ratio and sideslip-coupled tire dynamics, is employed to delineate the three-dimensional (3D) nonlinear stability region across multiple steering modes using Lyapunov exponents. Additionally, the qualitative impact of various driving conditions on the vehicle's stability is examined. Through optimization of Lyapunov exponents based on the state and control variables of each steering mode, optimal steering modes are identified, and an exponential direct yaw moment control (DYC) intervention strategy is devised. Simulations are conducted using a multi-corner race-level path. This methodology enables the identification of chaotic oscillations' instability phenomena in the DD-6WS CVC phase diagram and the formulation of stability region evaluation indices, including convergence performance. Moreover, it facilitates the avoidance of unnecessary direct yaw moment system interference and enables smooth multi-steering mode switching.