Research On Drive System Failure Control For Distributed Drive Electric Vehicles

In recent years,with the environmental and energy problems become increasingly prominent,new energy vehicles have become an important development direction of the automotive industry,as a representative of new energy vehicles,electric automobiles naturally become a hot research at home and abroad,and distributed drive electric vehicles due to have a unique drive structure,the dynamic control characteristics of the advantages are more obvious.Distributed drive electric vehicle controls each round of torque independently,power unit redundant configuration,making the vehicle in the event of drive system failure still has a certain driving ability,through the reconstruction of the wheel torque to ensure that vehicle continues to drive safely.Therefore,it is very important to study the control method of distributed driving electric vehicle drive system after failure,which is one of the key technologies to develop this kind of vehicle.In this paper,study the distributed drive electric vehicle drive system failure after the control strategy to guarantee the stability and the dynamic performance of the vehicle.The parameters of the drive motor are matched according to the vehicle dynamics performances.The dynamic model of the vehicle is established in CarSim and improving it on the basis of the traditional automobile model with Simulink,the CarSim-Simulink simulation platform of the distributed driving electric vehicle is established to study the failure control strategy of the distributed driving electric vehicle drive system.Realize the active fault detection of the motor based on fuzzy control principle.Analyze the failure of drive system,and put forward the conventional control method of drive system failure to ensure that the left and right sides of the vehicle driving torque are equal.The simulation results show that the running state of the vehicle is improved,but the yaw rate and side slip angle are still large,the vehicle deviates from the target trajectory,so it is necessary to further improve the control strategy to improve the stability under transport condition.Combine with the traditional body stability control technology,and introduce the direct yaw control on the basis of the conventional failure control.The yaw rate is set as the control target,and the yaw rate feedback model is established to calculate the required yaw moment.The simulation results show that the vehicle can keep track of the expected value of the yaw rate,and continue to drive according to the driver's intention after the drive system fails,which verifies the reliability of the top-level controller of the designed direct yaw moment control system.Establish the coordinate optimization allocation strategy for torque.It is difficult to simultaneously meet the longitudinal force demand and yawing moment demand of the vehicle after the failure of the drive system,so the torque and stability are the multi-objective,and the torque is allocated coordinately under the constraint of the boundary condition,then select the utilization factor of the adhesion coefficient as an optimization target to achieve further optimization of the distribution of torque to enhance the vehicle's overall driving performance.The simulation results show that coordinate optimization allocation strategy of torque can balance the power and stability according to the vehicle state,improve the driving performance after the failure of the drive system,and verify the effectiveness of the failure control strategy.