Coordinate Control Of Mode Switch For Dual Planetary Hydraulic Hybrid Vehicle

Be different with the traditional vehicle, The hybrid vehicle have at least two powersources.The work patterns of the hybrid vehicle are built by the different work forms of thepower sources. The existing researches on the hybrid vehicles mainly focuses on the energydistribution strategy on the steady-state. The fuel economy of the hybrid vehicle is greatlyimproved through the reasonable distribution and optimizing the power source, However,Because of the power sources’dynamic response characteristics, especially the response time ofthe engine is too long, The actual total output torque may can’t be consistent with the requiredtotal torque of the vehicle when the work pattern is changing, so that the vehicle may appear thephenomenon such as underpowered and impacted and so on. Have a good dynamic performanceis an important symbol of the maturity of the hybrid technology.This paper do some research on the coordinated control way of the dual planetary hydraulichybrid vehicle when the work pattern is changing. The engine’s torque and rotational speed canbe decoupled with the vehicle’s required torque and its speed through the dual planetarystructure. The vehicle economy is greatly improved as a result of liberating the engine. However,The dual planetary hydraulic system is difficult, because it has three different power sources.According to this configuration, The research is as follows:First, Analyzed the influence factors of the engine dynamic character and the way toacquire the engine dynamic torque. As to the planetary configuration, The actual dynamic torqueon the front tooth circle can get through the hydraulic pump/motor A, Researched the dynamiccharacter of the pump/motor and build its dynamic model.Second, Analyzed the work patterns of the dual planetary hydraulic hybrid vehicle and theconditions to change the work patterns. Established its dynamic model and pointed out that thepower performance and the jerk of the vehicle on the dynamic state depend on the torque on theravigneaux planet carrier and its rate of change. Analyzed the reason of underpowered andimpacted when the work patterns are changing between the modes that the engine works and notwork. Expounded the methods to avoid this phenomenon. As to the ravigneaux configuration,Established its dynamic model,analyzed the conditions to change the two ratios and the way tocontrol the two disc brakes. Third, Established the co-simulated model of the dual planetary hydraulic hybrid vehicleusing the software AMESim, Matlab/simulink and Matlab/stateflow. The result proved thecorrectness of the analysis and the feasibility of the control method above. With the dynamiccontrol, the underpowered phenomenon was avoided, also the jerk can meet the demand.