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Jianxing Zhang,Chunhua Zheng,차석원,Shanxu Duan 한국정밀공학회 2016 International Journal of Precision Engineering and Vol.17 No.9
In order to achieve the best fuel economy for hybrid vehicles, energy management strategies should optimize the power allocation between power sources. Recently, Pontryagin’s Minimum Principle (PMP) has been attracting attention for the energy management of hybrid vehicles owing to the solution optimality and the calculation instantaneity. In the PMP, there is an important control parameter, which is defined as the co-state variable and difficult to be determined. This research mainly deals with the co-state variable, where the PMP is applied to a fuel cell hybrid vehicle (FCHV) and a hybrid electric vehicle (HEV) respectively, and the effect of the co-state variable on the optimal solution is discussed for each case. The determination of the co-state variable for the cases of certain driving cycles and uncertain driving cycles is discussed, and an online co-state variable updating method is proposed for the uncertain driving cycle cases and its effectiveness is proved.
Study on transmission error and torsional stiffness of RV reducer under wear
Ronghua Zhang,Jianxing Zhou,Zheng Wei 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.8
In order to discuss the influence of wear dynamic evolution on the degradation of core transmission performance, transmission error and meshing torsional stiffness of RV reducer, taking BX-40E reducer as the research object, based on Langkali-Nikraves contact force model and Archard wear theory, the wear coefficients with different position conditions were obtained through equivalent wear experiments. The RV transmission dynamic model considering wear, meshing stiffness, meshing force, meshing tooth pairs and transmission error linkage was established by using centralized parameter method and dynamic subsystem method. Compared with the traditional tooth profile wear simulation, which distribution and size of the wear depth curves were more and more different with wear dynamic evolution, theoretically concluded that the dynamic update of wear coefficient is necessary and correct for the accurate simulation of tooth surface wear. The transmission error shows a "double hump" distribution mapped to the wear depth of the tooth profile, and deteriorates with the wear accumulation. The equivalent torsional stiffness of cycloid pin teeth decreases piecewise approximately linearly due to wear. In the previous stage, the reduction rate is small because the tooth detachment first occurs at the tooth top and root, and the single tooth torsional stiffness near the tooth top and root is smaller. The research results provide a new idea and theoretical basis for improving the transmission accuracy, stability holding ability, wear reduction and life extension of RV reducer.
Jingqi Zhang,Jianxing Zhou,Shengnan Wang,Haiwei Wang,Feng-xia Lu 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.9
In order to solve the problem of radiation noise of helicopter reducer with symmetrical structure, a simulation method is proposed to predict the noise of gearbox of a helicopter reducer from steady dynamic response to the acoustic radiation calculation. Primarily, taking the influence of time-varying stiffness into consideration, the lumped mass model of gear-rotorbearing system is established. The dynamic load of transmission system is solved by NewMark-β method, which is regarded as excitation of the gearbox. Then finite element model of housing is established, the radiated noise of the housing is predict by finite element and boundary element method, the influence of multi-source excitation on the radiated noise of the gearbox is analyzed. Finally, the radiated noise of the reducer under different working conditions is explored. All conclusions of this research could provide theoretical reference for vibration and noise reduction of helicopter reducer.