Research On Control Strategy Of Hybrid Vehicle Based On Chain Drive Coupler

This dissertation was completed with the combined support and funding of the National Natural Science Foundation of China project "Variation Mechanism of Tooth Chain and Its Key Design Technology(51775222)" and the key research and development project of Jilin Provincial Science and Technology Development Program "Research on Key Technologies of Timing Chain System for Passenger Car Hybrid Engine(20200401136GX)".The research on the control strategy of hybrid vehicles is a significant research field of new energy vehicles,and the power coupling device,as a key component to make sure the accurate implementation of the control strategy,has become one of the essential elements of vehicle design.Based on the configuration of a hybrid vehicle on the market,this article uses the chain drive coupler as the power coupling device of hybrid vehicle on the basis of fully considering the characteristics of the silent chain system.In this,the control strategy of hybrid vehicles based on chain drive coupling is studied,and the specific research content is as follows.First,by comparing and analyzing the different peculiarities of rule-based control strategy,optimization control strategy and intelligent algorithm-based control strategy,combined with the working principle of chain drive coupler,a rule-based motor auxiliary control strategy that can meet the control requirements of "fuel economy as the main and taking into account the whole vehicle dynamics" is formulated,and a control strategy model is built in the Simulink platform system.Second,the automobile simulation software CRUISE is used to build a vehicle simulation model,and by entering the power source calculation results into the simulation module,the co-simulation of strategy and model is carried out by using the interface of the simulation platform.The simulation outcome indicate that the whole vehicle can control the engine to work in the high-efficiency torque range according to the design requirements of the control strategy and smoothly realize the switching of the working mode of the whole vehicle.By setting different initial SOC values of the power battery in the simulation model,it is verified that the engine can start the generator at the appropriate time point and promote the improvement of the power battery state of charge.The simulation outcomes suggest that the fuel economy of the hybrid vehicle with this control strategy system is improved by more than 15%,and it can reach the requirements of the power performance of the whole vehicle,the acceleration time of both hybrid100km/h and 50km/h are reduced on the basis of the original configuration,and the maximum vehicle speed is increased by more than 35% on the foundation of the design,which further verifies the effectiveness of the design of the control policies.Thirdly,the multibody dynamics simulation model of the chain drive coupler is established,and the dynamic characteristics of the chain drive coupler are studied by taking several sets of rotational speeds of the power coupling part under typical automobile cycle conditions as the driving load of the chain drive system.The calculation results show that under this control strategy,the silent chain system has good motion stability,great dynamic characteristics,meshing contact force and interlink tension are within the safe range,the instantaneous transmission ratio error is small,and its maximum value does not more than 1%.In summary,the control strategy of hybrid vehicles based on chain drive couplers proposed in this dissertation is feasible,which can not only meet the dynamic characteristics of chain drive couplers,but also attain the requirements of vehicle economy and power to the greatest extent.