Shifting Process Control for Two-Speed Automated Mechanical Transmission of Pure Electric Vehicles

Datong Qin,Mingyao Yao,Shu-Jiang Chen,류성기 한국정밀공학회 2016 International Journal of Precision Engineering and Vol.17 No.5

Shifting processes are analyzed for a pure electric vehicle equipped with a two-speed automated mechanical transmission without a clutch in order to study the relationship between shifting jerk, shifting time, and synchronizer tooth grinding. Results show that shifting time has a negative correlation with shifting jerk, which is related to the torque variation rates of the driving and shifting motors. Tooth grinding of the synchronizer is related to the relative speed between the synchronizer sleeve and lock ring during shifting processes. Based on the analysis, a shifting control strategy for pure electric vehicles is proposed in order to decrease shifting jerk, avoid tooth grinding of the synchronizer, and shorten shifting time. Experimental results obtained show that the proposed control strategy can achieve smooth, reliable, and quick shifts for an electric vehicle.

Study on Dynamic Characteristics and Load Sharing of a Herringbone Planetary Gear with Manufacturing Errors

Fei Ren,Datong Qin,Teik Chin Lim,류성기 한국정밀공학회 2014 International Journal of Precision Engineering and Vol. No.

In this paper, a new and generalized dynamic model for a herringbone planetary gear train (HPGT) is proposed to investigate thefree and forced vibration characteristics, as well as load sharing characteristics by employing the lumped-parameter approach. Theproposed model takes into account manufacturing eccentric errors of the components and tooth profile errors of all gears. The modelcan be used for the vibration performance and dynamic load sharing analysis of the HPGT with different types of manufacturingerrors and arbitrary number of planets. The free and forced vibration, as well as the load sharing of an HPGT with three planetsare numerically computed with the model presented, and these are analyzed respectively in time domain and frequency domain. Theeffects of the manufacturing eccentric error and tooth profile error as well as component float on load sharing are discussedrespectively. Results indicate that manufacturing errors have an impact on dynamic characteristics and load sharing. The float cansignificantly reduce the load sharing coefficient of the system.

Influence of random road excitation on DCT vehicle dynamic characteristics during starting and shifting

Zheng Guo,Datong Qin,Antai Li,Jihao Feng,Yonggang Liu 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.9

Road excitation is the basic input of vehicle vibration, which greatly impacts on vehicle ride comfort. In addition, it can cause vertical vibration of the vehicle, leading to deformation of the powertrain mount. Similarly, the longitudinal movement of the powertrain can also cause deformation of the powertrain mount. Due to the effect of the powertrain mount, there is a mutual coupling between the vehicle in the longitudinal and vertical directions, which has a great influence on the smoothness and comfort of the vehicle. In order to reveal the impact of random road excitation on the vehicle dynamic characteristics of a dual clutch transmission (DCT) vehicle under starting and shifting conditions, a longitudinal-vertical coupled dynamic model of the DCT vehicle considering the powertrain mount was established. This model includes dynamic torque model of the engine, powertrain mount model, transmission system model, tire model and road excitation model. The influence of random road excitation on the vehicle’s dynamic characteristics is analyzed under starting, shifting, and different starting and shifting intentions. The simulation results of the longitudinal-vertical coupling dynamic DCT vehicle model considering road excitation are compared with vehicle test results, the model is found to accurately reflect the influence of road excitation on the dynamic performance of DCT vehicles under starting and shifting conditions, thus verifying the correctness of the model.

Study of Synchronization Characteristics of a Multi- Source Driving Transmission System Under an Impact Load

Jing Wei,Ruizhi Shu,Datong Qin,Teik C. Lim,Aiqiang Zhang,Fanming Meng 한국정밀공학회 2016 International Journal of Precision Engineering and Vol.17 No.9

Multi-source driving transmission systems, in which the gear assembly is driven by multiple induction motors, are extensively used in new energy, aerospace, marine engineering, and in other fields. The multi-source driving system faces an even-load distribution problem, i.e., torque or speed synchronization issues. In this study, the synchronization characteristics of a multi-source driving transmission system under an impact load at different load change rates are studied. An accurate electromechanical coupling dynamic model of the system considering the flexible shafts, support bearing and meshing gear pair is established by applying virtual equivalent shaft elements. By considering the time-varying meshing and the coupling effects of the dynamic electric motor and the speed, torque and stator current synchronization characteristics are investigated using this model. Computational results show that the influence of the load change rate on the speed synchronization characteristics of the system is minor, but has a significant influence on the torque and stator current synchronization characteristics. The stator current root mean square value (RMS) can be chosen as a feedback signal to monitor the synchronization characteristics of the system. The proposed research provides the theoretical basis for the formulation of the synchronization control strategy for multi-source driving transmission systems.

Graphene Quantum Dots Enhanced Photocatalytic Activity of Sb2WO6 Under Ultraviolet- and Visible-Light Irradiation

Shan Li,Zhongping Chen,Datong Wu,Yong Qin,Yong Kong 대한화학회 2020 Bulletin of the Korean Chemical Society Vol.41 No.5

A novel composite of graphene quantum dots functionalized Sb2WO6 (GQDs/Sb2WO6) was prepared by an electrostatic self-assembly method and used as a photocatalyst for the degradation of an organic pollutant. The resulting GQDs/Sb2WO6 was characterized by electron microscopy and optical measurements. The photocatalytic activity of GQDs/Sb2WO6 was investigated by degrading methyl orange (MO) under UV-light and visible-light irradiation. Compared with pure Sb2WO6, enhancement of the photocatalytic performance of GQDs/Sb2WO6 was achieved, and the degradation efficiency for MO was almost 100% within 3 h under UV-light irradiation and 71.4% within 3 h under visible-light irradiation. The photocatalytic degradation mechanism of GQDs/Sb2WO6 was illustrated by free radical and hole scavenging experiments, and the main active species were confirmed to be holes (h+) and superoxide anion radicals (O2·?). Moreover, the GQDs/Sb2WO6 composites exhibited high recyclability and stability and had potential application for decomposing other organic contaminants in water.

Construction of Near-infrared Irradiation-controlled Drug Delivery System Based on Silica@polypyrrole@mesoporous Silica and PEG-PCL-PEG

Yang Yao,Chengqiang Ding,Jun Gao,Datong Wu,Xiaolin Liu,Yong Qin,Yong Kong 대한화학회 2019 Bulletin of the Korean Chemical Society Vol.40 No.9

Morphologies of different samples.

MODELING AND CONTROL OF ENGINE STARTING FOR A FULL HYBRID ELECTRIC VEHICLE BASED ON SYSTEM DYNAMIC CHARACTERISTICS

Yonggang Liu,Daqi Chen,Zhenzhen Lei,Datong Qin,Yi Zhang,Rui Wu,Yong Luo 한국자동차공학회 2017 International journal of automotive technology Vol.18 No.5

This paper focuses on the dynamic modeling and control of engine starting for a Full Hybrid Electric Vehicle (FHEV) consisting of an Integrated Starter Generator (ISG) and Dual Clutch Transmissions (DCTs). The dynamic characteristics of the engine, the ISG motor and the main clutch are analyzed respectively. The dynamic models of the main components of the powertrain system are also established taking the system dynamic characteristics into consideration. The FHEV dynamic model of engine starting during electric driving mode has been investigated in detail. The coordinated control strategy of engine starting has been proposed based on the powertrain system dynamic characteristics. The simulation for the engine starting control during electric driving mode has been performed based on the Matlab/Simulink platform. The simulation results show that the proposed control strategy satisfies the requirements of response and smoothness during engine starting process. Furthermore, a bench test has been carried out to analyze the system characteristics during engine starting process. The test data is highly agreeable to the simulation data and the effectiveness of engine starting control strategy is validated by the comparison between simulation results and the test data.

Configuration Design and Optimization of a Novel Two-Mode Compound Power-Split Hybrid System

Hu Minghui,Zeng Li,Fu Guangshun,Zhou Anjian,Li Zhonghua,Qin Datong 한국자동차공학회 2021 International journal of automotive technology Vol.22 No.4

Through the analysis of a CHS (Chinese hybrid system) compound power-split configuration, it is found that enhancing the system's speed decoupling ability can reduce the electric power loss, optimize the engine operating point distribution, and enhance the vehicle dynamics. This paper proposes a novel compound power-split configuration with a twospeed AMT (Automated manual transmission), which includes an electric-vehicle mode, a low-speed power-split mode, and a high-speed power-split mode. First, the electric power characteristics and rotational speed/torque characteristics of the CHS compound power-split configuration are analyzed using the lever method, theoretically demonstrating the rationality of the two-speed AMT+ compound power-split configuration. Then, the genetic algorithm is employed to optimize the multiparameters and multi-objectives in terms of the vehicle dynamics and economy. Finally, a comparative simulation and analysis of the vehicle’s economic and dynamic properties is performed for the new two-speed AMT+ compound power-split configuration and the original CHS compound power-split configuration. The results show that the vehicle economy is increased by 6.9 % for the new configuration, the acceleration time per 100 kilometers is decreased by 27.5 %, and the maximum speed is increased by 13.2 %.