Optimal distribution of braking and steering tire forces subject to stability constraints

This paper presents an integrated vehicle dynamics control which manages to coordinate steering and braking subsystems using Optimal Distribution of tire Forces (ODF). Specically, we introduce an ODF scheme, which treats the standard stability conditions of the phase-plane as inequality constraints in the optimization problem. The established scheme works to fulll the objectives of a higher-level controller, as much as possible, without violating vehicle dynamics stability conditions. A sliding mode enhanced adaptive high-level control assesses the desired total yaw moment and lateral force for vehicle control. The proposed controller only requires online adaptation of control gains without acquiring the knowledge of upper bounds on system uncertainties. An optimization problem incorporating six inequality constraints is solved analytically by Karush-Kuhn- Tucker (KKT) conditions. To coordinate braking and steering subsystems, a phaseplane based adaptation mechanism is suggested to adjust the weighting coecients in the considered cost function. The simulation cases show that vehicle stability can be improved eectively by the suggested scheme