Study And Simulation On Energy Control Strategy Of Parallel Hydraulic Hybrid Vehicle

Developing of clean and environmentally-friendly inter-city vehicles is an importantmethod of solving energy shortage and environmental pollution problems which is encounteredin the process of the social development. Hydraulic hybrid vehicle has the characteristic of highpower density. On one hand it maximizes absorption of the braking energy. On the other hand,the characteristics of the four-quadrant operation of the pump/motor can make the engine workin the optimal workspace in order to maximize vehicle fuel economy, reduce vehicle fuelconsumption and emissions, and ease the pressure of the urban environment.This paper originates from the Jilin S&T Bureau Fund project-‘The application research onthe secondary regulation technology in hydraulic energy saving vehicle’ and theschool-enterprise cooperation project-‘The development of concrete mixing truck based on thehydraulic energy saving technology’. The hybrid electric vehicle energy control strategy has aextensive research in China, but the hydraulic hybrid vehicle energy control strategy has juststarted. The energy control strategy developed in this paper based on the logic threshold inreference to a lot of hybrid electric vehicle control strategy, according to the parallel hydraulichybrid vehicle configuration features. The correctness of control strategies and energy savingeffect of the hybrid program are verified on AMESim software platform.In this paper, the study of biaxial parallel hydraulic hybrid vehicle control strategy is in thefollow aspects.(1) The hydraulic hybrid system compared with the hybrid electric vehicles, has morepower density, higher security and more reliability. Through the comparative analysis of thedifferent structural forms of hydraulic hybrid systems, this paper determines the double-axisparallel hydraulic hybrid system and draws its structure diagram.(2) Theoretical analysis of the working conditions of start, acceleration, constant speed,deceleration, and braking are gived in this paper. And it establishes mathematical models of keycomponents and the whole vehicle dynamics models. This paper makes a theoretical study ofthe vehicle braking process. Hybrid vehicles brake control strategy is developed after analyzingthe principle of vehicle braking and the ABS antilock braking principle.(3) By determining determine the hybrid vehicle engine optimal work area and analysingthe current control strategy research, It develops the control strategies based on the logic threshold.(4) In order to verify the correctness of the model, this paper gives the simulation ofstandard conditions of starting and accelerating. And in the loop condition, the parallelhydraulic hybrid vehicle component parameters and the key parameters of control strategies areoptimized. The models are simulated with optimized parameters. It is proved that parallelhydraulic hybrid system can effectively improve vehicle fuel economy.