Optimization Of AMT Shift Schedule Under Multiple Power Sources

There are more and more commercial vehicles equipped with AMT,because AMT can not only shift automatically,but it has high working efficiency and low cost.And the gear shifting strategy is obviously important to vehicles,especially for hybrid electric vehicles.Both combustion and thermodynamics of engine and electromagnetics of motor should be taken into account.This is the difficulties in optimization of gear shifting.In this paper,the simulation model of vehicles is established based on the singleaxle parallel hybrid vehicles.And the energy management strategy of power source and gear shifting strategy are optimized.The main contents of the paper are as follows:Firstly,the simulation model of important parts of vehicles such as engine,motor and battery are established in MATLAB/Simulink according to different torque and speed input of power source and the relationship between current,voltage and SOC.The whole vehicle simulation model is also finished.The precision of simulation model is validated in typical city cycle from China and the validation of energy management and gear shifting strategy can be also finished by the simulation model.Secondly,the energy management strategy is optimized by equivalent consumption minimization strategy(ECMS).As the most important parameter,equivalent factor is selected by Pontryagin Minimum Principle(PMP)and the equivalent factor which is suitable for the vehicle and driving condition is determined.And the influence of different equivalent factor towards fuel consumption is compared.In typical city cycle from China,optimal strategy and real vehicle strategy are compared to validate the superiority of the optimal strategy.At last,the efficiency model of power source is established and the optimal area of gear shifting is obtained by intersection method.The gear shifting line is extracted by Kmeans algorithm.And Dynamic Programing(DP)is compared with the optimal strategy.What is more,in typical city cycle from China,the optimal gear shifting strategy is compared with real vehicles strategy.