Coordinated control of longitudinal/lateral/vertical tire forces for distributed electric vehicles

In this paper, a novel coordinated control method of longitudinal/lateral/vertical tire forces is proposed which overcomes the shortcomings of current studies on global chassis control for electric vehicles. An objective function combining the tire workload and the dynamic ratio of vertical forces is developed, 15 equality and inequality constraints including desired driving demands, tire friction limitations and actuator characteristics are considered, and a non-convex optimization problem with multiple constraints for coordinated control of longitudinal/lateral/vertical tire forces is formulated. An optimization algorithm combining constrained optimization and feasible region planning is proposed to solve this key problem. Finally, simulations based on Matlab/Simulink and CarSim are conducted, demonstrating that the proposed coordinated control method controls vehicle attitude effectively and improves handling stability simultaneously, while providing better stability and robustness over other methods.