Research For Economy Control Strategy Of Full Hybrid Electric Vehicle With AMT

ISG (Integrated Starter/Generator) type full hybrid electric vehicle (HEV)equipped with planetary gear mechanism belongs to parallel hybrid structure, comparedwith the common medium HEV, the ratio of motor power is higher. The vehicle isdriven independently by motor when the wet multi-disc clutch’s engagement, whichincreases the utilization of motor, therefore the fuel consumption and emission could bereduced. At the same time, this structure can realize multiple kinds of operating mode,such as the power coupling ways of torque couple and rotating speed synthesis. Thespeed of engine and motor are the same in the way of torque couple, this method issuitable for high-power motor drive system, and it is convenient to select the optimaltorque allocation plan in a wide range of torque for engine and motor, furthermore,change the engine working point, which can improve the vehicle performance andoperational efficiency; In rotating speed synthesis way, engine and motor are interactingeach other, but the engine revolving speed can be changed by adjusting the rotatingvelocity of motor, in order to realizing stepless speed regulation in a certain scope,which optimizes the whole vehicle transmission efficiency. According to the above twopoints, selecting the different power coupling ways will improve the economic potentialof HEV system.The merits of Automatic Manual Transmission (AMT) include high transmissionefficiency, compacted structure, great succession and low cost of production. Automaticshifting is carried out with AMT, and it has no low efficient hydraulic torque converter.The HEV is for the characteristics of energy saving and emission reduction, and thereasonable shift schedules is helpful to get a higher fuel economy for HEV.In order to improve the vehicle fuel economy, some research about the HEV whichis equipped planetary gear and AMT are performed, main works as follows:①The work modes which can be realized in the full HEV are analyzed, such aspure electric mode, driving charging mode, engine drive alone mode, motor assist modea and b; the parts state of motion under each mode of hybrid system are analyzed too.②The models of related parts in full hybrid system are built, such as driver modelbased on fuzzy controller, driver torque recognition model which is used to find therelationship between accelerating/braking pedal opening degree and needed torque, thetheory and value combined model for engine, motor and battery, the driving dynamic model of hybrid system. The full HEV performance simulation model based on forwardalgorithm is established using these models.③A method of dividing engine working region is proposed, which is targeted tomaximizing the conversion efficiency between fuel energy and electric energy in battery.The transformational relation between battery SOC variation and motor equivalent fuelconsumption is got by using the conversion between engine fuel consumption andelectric energy charging in battery, which supply the base for the calculation ofIntegrated Specific Fuel Consumption (ISFC) under different operating modes of fullHEV.④Taking the minimum of instantaneous ISFC as objective, the optimizationabout operating region is completed under pure electric mode, engine drive alone mode,driving charging mode, motor assist mode, and the energy management strategy undereach mode is got. Based on it, taking the minimum of ISFC as objective, the fueleconomy shift schedules under different operating modes is built, which is used for fullHEV equipped AMT.⑤The performance simulation is performed in Matlab/Simulink. The test benchof full HEV is established and the test is completed, moreover, the effectiveness ofproposed strategy has been verified by full HEV test bench.