| As a new direction of pure electric vehicle(PEV), four wheel independently driven electric vehicle(4WIDEV) brings innovative configuration in powertrain and control mode. And hence triggered a wave of research around the world. In this paper,The 4WIDEV was developed by Southeast University vehicle laboratory for the research.The main contents of this dissertation are summed as follows:1.Dynamic equations of vehicle motion and the relationship between vehicle variables are given in chapter two. Based on the equations, a open-loop simulation framework for vehicle system is built in Matlab/Simulink.Due to the redundancy features of the 4WIA electric vehicles, adaptive adjustment the control distribution matrix to solve the problem of the in-wheel motor without the need to adjust the basic law.In the control systems the control allocation should be taken to get better control performance and capabilities.The control design is divided into two part,the high-level is designed to produce a generalized control instruct to track the designed vehicle motion using the silding-mode control.The low-level si used to distribute the generalized control among the four wheels.the nature fo minimizing the cost function is to find the optimal solution for the function. When the motor had fault,We need not to change the upper controller design, but only need to adjust the control distribution matrix to achieve fault-tolrant control for motor failure.then Simulation using Simulink and Carsim show the effectiveness of the proposed fault-tolerant control approaches.2.High frequency chatter in the actual control system lead to instability of system.To solve the chatter problem of sliding mode control,the high-level controller was used with robust control.Robust control system based on feedback linearization using LMI toolbox.the low-level control used a new method to achieve control distribution.with the tire constraints. Simulation show the effectiveness of the proposed fault-tolerant control approaches. |
