Multi-objective Coordinated Torque Optimization And Allocation Control Method For Distributed Drive Electric Vehicles Based On Multi-agent

Just a century ago,the automobile was born,but the oil resources consumed and the environmental pollution caused have seriously affected the development of human society.Automotive electrification is seen as an important way to address traffic emissions and energy security issues.The advantages of simplified chassis structure,rapid torque response,and precise control execution have led to the distributed electric drive vehicle with the hub motor as the power unit being known as the "ultimate form" of future automotive chassis development.The advantages of the distributed electric drive vehicle in dynamic control are primarily reflected in two aspects: one is that the four wheel torques are independently and continuously controllable,with more controllable degrees of freedom;Secondly,the distributed electric drive vehicle typically uses the hub motor to directly drive the wheels.It has the advantages of rapid response speed and high control accuracy compared to the complex power system of conventional vehicles.In this paper,we take the distributed electric drive vehicle as our research object and fully exploit these advantages,with the goal of improving handling stability,braking safety,and energy savings for distributed electric drive vehicles,and investigates in depth the optimal torque coordination control allocation strategy of distributed electric drive vehicles.Under the support of Jilin Provincial Science and Technology Development Plan,this paper analyzes and studies the torque coordinated distribution control method of distributed drive electric vehicles.The main content of the research is:(1)Aiming at the problem that it is difficult to give consideration to both vehicle stability and vehicle economy under the driving and steering conditions of DDEV,this paper proposes a coordinated torque optimization control method of AFS and direct yaw moment(DYC)of distributed drive electric vehicles based on MAS model.Firstly,through vector transformation,the sideslip angle and yaw rate at the center of mass are decoupled,the vehicle 2 DOF 8 input model is transformed into four 2 DOF 2 input models,and the reduced dimension system is regarded as four agents.According to the hardware connection structure and communication topology of the DDEV,the reduced dimension model of the coordinated optimal control of DYC and AFS of the DDEV is established based on graph theory.Secondly,combining SMC with DMPC,in order to improve the robustness of the system against parameter changes and perturbations,a sliding mode discrete dynamic surface function is proposed for the first agent,in view of the deviation between the vehicle yaw rate and the sideslip angle of the center of mass and ideal values.Considering the economy and stability of the ith agent,an optimal distribution method of driving torque based on SMC and DMPC is proposed for engineering applications.(2)Aiming at the problems of poor braking safety and vehicle stability of vehicles with four channel ABS when braking on low adhesion separated road or split road,this paper proposes a multi-objective optimized torque coordinated optimal control method of AFS and ABS based on multi-agent MPC.First,the single wheel control method is used to establish the single wheel equation based on slip ratio and the yaw stability equation based on AFS.The four wheels and the vehicle’s center of mass are regarded as multi-agent.The mathematical model of distributed drive electric vehicle based on the coordinated control of AFS and ABS in graph theory is established to reduce the dimension of the model.Secondly,based on multi-agent theory,this paper proposes a coordinated optimization torque control method of AFS and ABS based on DMPC in order to achieve the following ideal values of the vehicle slip rate,yaw rate and sideslip angle of the center of mass so as to improve the safety of the vehicle’s braking and stability of handling.(3)A joint simulation platform for torque coordination control of Carsim Matlab/Simulink distributed drive electric vehicle was built,and the control algorithms of the two parts proposed in this paper were verified by experiments under different simulation conditions.