Passivity Based Hierarchically Decentralized Range Extension Control of In-wheel-motor Vehicles

Range extension control of in-wheel-motor electric vehicles have been studied for years. However, there is still lack of theoretical results for rigorously stabilizing the overall control system which suffers nonlinear tire-force characteristics. In addition, it is required to locally guarantee safe motion of each driven wheel while globally increase the cruising range per charge. To deal with aforementioned issues, this paper utilizes passivity theory to present a hierarchical range extension control system. Each wheel is provided a local disturbance observer based anti-slip controller. By managing the aggregation of local wheel velocities, the global controller gives the total driving command which is optimally allocated to each wheel. The torque of each wheel is, therefore, the sum of the local control signal and the distributed signal from the global controller. Beside proving the stability rigorously, the effectiveness of the proposed control system is evaluated using Carsim-Matlab co-simulator.