Vehicle Chassis Integrated Control Based on Multimodel and Multilevel Hierarchical Control

Aiming at the differences of vehicle chassis key subsystems influence on vehicle handling stability and effective acting regions, comprehensive considering of the nonlinear characteristic of the tires and the dynamic coupling among suspension, steering, and braking subsystems in vehicle chassis, the 14-DOF full vehicle model is built. Based on the control characteristic local optimum of each subsystem, multilevel hierarchical control theory is adopted and the vehicle stability coordinated control system including organization, coordination, and execution level is established. Using sliding mode control theory and the inverse tire model, the generalized target forces and moments from organization level are translated into the tire sideslip angle and slip ratio. And then, based on the principle of functional allocation, the control functions of each subsystem are coordinated and the function decoupling of vehicle chassis complex system is realized. The Matlab/Simulink platform is used and the full vehicle stability coordinated control system is simulated. The results show that the full vehicle coordinated control system based on multilevel hierarchical control theory can improve the vehicle stability preferably than the subsystem combined control and uncontrolled system.