Study On Dynamics Modeling And Energy-efficient Torque Allocation Algorithm For In-wheel Motor Electric Vehicle

It is convenient for people to travel since the automobiles are manufactured.However, the automobiles bring about a series of serious problems. Not only theenvironmental pollution does harm to human health, but also oil resources aregradually dried up which is threatening the sustainable development of mankind.Therefore, development of electric vehicle and its energy-saving technologies is thebest choice to deal with this challenge for the automotive industry.Four-wheel-motor electric vehicle is the future trend of development of electricvehicle because it has many advantages. One of the most important advantages is thatthe front and the rear axle driving torques of four-wheel-motor electric vehicle can beallocated at any rate. So it provides a more flexible research space for the bestdistribution rate of the diving torques and the regenerative torques. Therefore, thestudy of energy-saving regenerative braking torques control algorithm will begradually based on electric vehicle instead of hybrid vehicle. The energy-savingtechnology based on electric vehicle will become an important research field in future.In this thesis, energy-saving torque allocation algorithm for four-wheel-motor electricvehicle is studied by simulation. Electric vehicle dynamics modeling, energy-savingdriving torque allocation algorithm and validation by simulation are included in thisthesis.In this thesis, four-wheel-motor electric vehicle model which has15degrees offreedom is developed. It contains3-degree-of-freedom vehicle body module, four1-degree-of-freedom wheel modules, four2-degree-of-freedom tire modules, brakingsystem module, motor module and battery module. The electric vehicle model isverified by CarSim which is a commercial software.Energy-saving algorithms based on ideal torque allocation rate and based on thebest efficiency are proposed. Energy-saving algorithm based on ideal torqueallocation rate reduces the tire sliding by making full use of road adhesion conditions.So it is suitable for low-adhesion road. Energy-saving torque allocation algorithmbased on the best efficiency distributes diving torques and regenerative brakingtorques reasonably to make the driving motors work in a more efficient state, so that the energy-saving effect is implemented. It is suitable for high-adhesion road.The energy-saving driving torque allocation algorithms are validated bysimulation of urban cycle working conditions based on electric vehicle modeldeveloped in this thesis. Simulation results show that the energy-saving torqueallocation algorithms can save energy.