Hybrid trigger cooperative control of six-wheeled commercial vehicles with multiple sub-systems based on sub-regional linearization model

In the context of distributed driving six-wheel steering (DD-6WS) commercial vehicles, the integration of auxiliary steering systems and direct yaw moment control (DYC) is critical for improving maneuverability and stability while driving. However, the nonlinear dynamic characteristics of vehicles under high-speed conditions make it difficult to fully exploit the benefits of multi-subsystem functionality. To address this issue, a sub-regional linearization (SRL) theory is proposed that uses nonlinear tire dynamic data to accurately capture the dynamics of commercial vehicle models. Additionally, a nonlinear stability criterion (the Lyapunov exponent) and a Mixed-Logic Dynamic (MLD) approach are used to create an intervention mechanism for multiple subsystems. Furthermore, hysteresis control is incorporated to mitigate frequent subsystem interventions caused by minor fluctuations in state variables. The results of simulations across various speed ranges using the HYSDEL toolbox and MATLAB-Trucksim platform demonstrate that using SRL models significantly improves the lateral control stability of commercial vehicles at high speeds while effectively reducing the frequency of triggers for auxiliary systems through the successful implementation of MLD control at high or low speeds. An orderly and precise triggering logic solves challenges caused by coupling and conflicts in vehicle redundant control.