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Yu H.-S.,Shanghai JiaoTong University | Yu H.-S.,Shanghai Maple Automobile Co. | Zhang J.-W.,Shanghai Maple Automobile Co. | Zhang T.,Shanghai Maple Automobile Co.
Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering

A new electromechanical power-splitting full-hybrid transmission with two shifting elements, namely a four-shaft planetary gear and an electronic continuously variable transmission, is introduced in this paper. This transmission was developed with the aim of combining all the advantages of an internal combustion engine and two electric motors in an optimal way so as to improve the power performance and the fuel economy. The architecture and analogy of the four-shaft planetary gear are analysed, a control strategy is designed, and the engine management system and hybrid control system are calibrated. To evaluate the performance, the control strategy and the calibrated results, nine tests were performed as per the New European Driving Cycle under various initial conditions, different maps and different thresholds. The test results indicate that a four-shaft planetary gear, electronic continuously variable transmission hybrid electric vehicle can realize good fuel economy and good emissions performance except for nitrogen oxide emissions. The best fuel consumption obtained was 5.4 l/100 km. The amount of nitrogen oxide emissions needs to be decreased by optimizing the control strategy of the hybrid control system and calibration of the engine management system in future research. © 2012 IMechE. Source

Zhou J.-H.,Jiangsu University | Yuan Y.-N.,Nantong University | Liu X.-Q.,Jiangsu University | Chen D.-H.,Jiangsu University | Wang C.-L.,Shanghai Maple Automobile Co.
Neiranji Gongcheng/Chinese Internal Combustion Engine Engineering

The comparative analysis of prototype engine between conventional starting motor start and high-speed cranking start with ISG (integrate starter/generator) was carried out to examine the variation regulation of engine transient speed, cylinder pressure, fuel compensation factor, intake air pressure, ignition timing, HC conversion efficiency, exhaust temperature and transient HC emission. The results show that, with cranking speed increasing, the intake pressure drops, causing the intake air quantity reduces, and fuel-film evaporation time shortens, the mixture atomization gets insufficient. The misfire occurs and the transient HC emission peak arises. All these phenomena have close relationship with ECT (engine coolant temperature). Fuel compensation in the first few working cycles of starting process can correct original lean mixture so as to decrease HC emission. Retarding ignition can raise the exhaust gas temperature. The conversion efficiency of three-way catalytic converter (TWC) in cold and warmed-up conditions is quite different. When engine is warmed up and the ignition timing is -10 °CA, the TWC lights off within 40 s and its HC conversion efficiency reaches about 90 % within 60 s. Source

Wang C.-L.,Shanghai JiaoTong University | Yin C.-L.,Shanghai JiaoTong University | Luo G.,Shanghai Maple Automobile Co. | Wang L.,Shanghai JiaoTong University
Neiranji Xuebao/Transactions of CSICE (Chinese Society for Internal Combustion Engines)

The idle-stopping function of hybrid electric vehicle(HEV) not only increases the starts, but also postpones three-way catalyst(TWC) activation, bringing unfavorable influence on engine emission. So start process of hybrid is worth of studying. To satisfy the drivability and acceleration performance, extra fuel is required for engine at conventional vehicle acceleration. Transient fuel will deteriorate emissions dramatically, and it is hard to control the transient emissions. Hybrid start and acceleration strategies were developed based on the ISG characteristic. The air-fuel ratio(AFR) at cold start and hot start is under control. The concept of ISG "fast" and "slow" torque to overcome the conventional engine transient fuel is proposed. Reasonable ECU and VCU parameters are determined. Tests at NEDC driving cycle were conducted both on conventional and hybrid modes. Result shows that the conventional start fuel reduces with aid of ISG motoring. The transient fuel at acceleration is replaced by the ISG torque. The HEV can simultaneously realize reduction in fuel consumption and emissions. Source

Huang Z.,Shanghai JiaoTong University | Zhang J.,Shanghai JiaoTong University | Lu T.,Shanghai JiaoTong University | Xiang Y.,Shanghai Maple Automobile Co. | Liu J.,Xiangtan University
Zhongguo Jixie Gongcheng/China Mechanical Engineering

The mainly influence factors of the clutch engagement during starting process had been analyzed thoroughly; a Map control strategy was applied to reduce the starting jerk and the friction work by considering throttle angle, engine speed, idle object speed and input shaft speed. Due to the influence of nonlinear dynamic characteristics with time-delays of clutch electrohydraulic position control system, a DMC-PID cascade control algorithm was proposed for clutch position control, which took the advantages of the strong robustness and predictability of DMC, the strong anti-jamming ability of PID. Road tests were implemented using the proposed Map control strategy with Shanghai Maple model AMT, which proves that the method is effective. Source

Tang X.,Shanghai JiaoTong University | Zhang J.,Shanghai JiaoTong University | Yu H.,Shanghai JiaoTong University | Yu H.,Shanghai Maple Automobile Co. | Liang Z.,Shanghai JiaoTong University
International Journal of Electric and Hybrid Vehicles

A torsional vibration dynamic model is built to predict the torsional vibration characteristics of a power-split hybrid system. On the basis of this dynamic model, the system dynamic equations of hybrid driveline are set, from which the natural frequencies and relevant mode shapes under different driving modes are solved using the corresponding eigenvalue problem. The calculated results show that the low frequencies occur mainly in the torsional vibration of wheels and vehicle, the intermediate frequencies are relevant to the torsional vibration of the sun gears, the differential and the reducer, in general, and the high frequencies are related to the torsional vibration of planets. Copyright © 2013 Inderscience Enterprises Ltd. Source

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