Combined Tire Slip and Slip Angle Tracking Control for Advanced Vehicle Dynamics Control Systems

This paper describes a combined tire longitudinal slip and lateral slip angle tracking control approach as part of an overall advanced vehicle dynamics control system. Nonlinear sliding mode control is used to manipulate the driving/braking/steering of each wheel to track slip and slip angles specified by a higher-level controller and a control allocation algorithm. Controlling slip and slip angles, which depend on individual wheel and vehicle dynamic states, relies on a tire model to estimate the induced tire longitudinal and lateral forces as well as self-aligning moment. Further, vehicle body states are treated here as exogenous signals independent of the slip/slip angle controller in order to isolate and simplify the control design. The performance of this control approach is evaluated and compared against results for conventional vehicle control systems in a full-vehicle CarSimreg model simulation. Improved performance is observed under an adverse split-mu hard braking scenario