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.

Finite Element Analysis of the Axial Mechanical Properties of Piezoelectric Actuator with Tubular Interdigitated Electrodes

Liu Yonggang,Wu Zhou,Wang Hongbin,Zhang Ting 한국물리학회 2020 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.77 No.10

We theoretically investigate a new type of piezoelectric actuator with tubular interdigitated electrodes. A partial model is adopted due to the axial symmetry of the actuator, which is divided into non-overlapping opposing electrode pairs on the center plane of the branch electrode. We present a finite element model of actuator and analyze its static-dynamic properties by using the commercially available finite element software ABAQUS. The length-to-diameter ratio of the tubular actuator can be as larger as necessary, so we are more concerned with the axial mechanical properties of the actuator. Thus we studied the influence of the electrode's shape and structure size on the clamping stress and free strain of the partial models. We also analyzed an ordinary piezoelectric model of the same size. We demonstrated that the partial model displayed significantly improved axial performance over the ordinary one. The axial stress of the partial model can reach 2.75 times that of the ordinary one, and the axial free strain can reach 1.55 times that of the ordinary one. According to the results of the static analysis, appropriate electrodes and structural parameters were selected to establish a tubular actuator model, with which modal and harmonic response analysis were performed. A modal analysis was used to obtain the frequencies and the shapes of the axial vibration. Each pair of electrodes is shunted to a sinusoidal varying voltage. Using the results of the harmonic response analysis, we obtained the actuator's axial resonance curve.

Alternatively Polarized Macrophages Regulate the Growth and Differentiation of Ependymal Stem Cells through the SIRT2 Pathway

Yonggang Ma,Ming Deng,Xiao-qi Zhao,Min Liu 한국뇌신경과학회 2020 Experimental Neurobiology Vol.29 No.2

Ependymal stem cells (EpSCs) are dormant stem cells in the adult spinal cord that proliferate rapidly and migrate to the site of injury after spinal cord injury (SCI). Although they can differentiate into neurons under appropriate conditions in vitro, EpSCs mainly differentiate into astrocytes in vivo. Our previous study confirmed that alternatively polarized macrophages (M2) facilitate the differentiation of EpSCs towards neurons, but the detailed mechanism remains elusive. In the present study, we found that M2 conditioned medium could upregulate the expression of Sirtuin 2 (SIRT2) in EpSCs in vitro through the BDNF/TrkB-MEK/ERK signaling pathway. As an important deacetylase, SIRT2 deacetylated stable Ac-α- tubulin (Acetyl alpha Tubulin) in microtubules and thus promoted EpSC differentiation into neurons. The present study provides a theoretical basis and a new way to improve neural recovery, such as regulating the growth and differentiation of EpSCs by increasing the proportion of M2 cells in the local microenvironment or upregulating the expression of SIRT2 in EpSCs.

A Study on the Ethnic Identity Machanisms of Scattered and Mixed Ethnic Groups

Mingxin Liu,Yonggang Li 인하대학교 다문화융합연구소 2020 다문화와 교육 Vol.5 No.1

Beicheng community of Qingzhou city is the only Manchu ghetto of Shandong province. On the basis of describing community’s historical change, this paper will analysis factors of the ethnic identity mechanism of Manchu in this scattered area, and show its difference from others.

Robot Search Path Planning Method Based on Prioritized Deep Reinforcement Learning

Yanglong Liu,Zuguo Chen,Ming Lu,Chaoyang Chen,Xuzhuo Zhang,Yonggang Li 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.8

The path planning process of the robot relies too much on environmental information, which makes it difficult to obtain the optimal search path when the search and rescue tasks are carried out in a complex postdisaster environment. Thus, a path planning method based on prioritized deep reinforcement learning is proposed in the paper. The core idea of the method is that the robot first builds an environment mathematical model based on the obtained information through the sensors. Then, to make the robot can obtain the optimal search policy in an extremely complex environment, the prioritized replay mechanism is used to improve deep reinforcement learning. Finally, the simulation results show that the search path planning method based on prioritized deep reinforcement learning proposed can not only improve the convergence speed of the model but also is endowed good robustness in this paper.

STRONG CONVERGENCE OF STRICT PSEUDO-CONTRACTIONS IN Q-UNIFORMLY SMOOTH BANACH SPACES

Pei, Yonggang,Liu, Fujun,Gao, Qinghui The Korean Society for Computational and Applied M 2015 Journal of applied mathematics & informatics Vol.33 No.1

In this paper, we introduce a general iterative algorithm for finding a common element of the common fixed point set of an infinite family of ${\lambda}_i$-strict pseudo-contractions and the solution set of a general system of variational inclusions for two inverse strongly accretive operators in q-uniformly smooth Banach spaces. Then, we analyze the strong convergence of the iterative sequence generated by the proposed iterative algorithm under mild conditions.

Enhancing the penetration stability of plasma jet in liquid by improving the chamber structure

Yi Liu,Yonggang Yu,Shanshan Mang 한국물리학회 2019 Current Applied Physics Vol.19 No.9

Two kinds of chamber structures were designed to improve the penetration stability of plasma jet in the working fluid. They are the cone-truncated chamber with an inclined wall structure and the stepped-wall chamber with an abrupt expanding structure. Based on the experiment, the penetration characteristics of plasma jet in liquid were investigated by the numerical calculation, especially the multiphase flow field structure and the jet penetration stability. In the cone-truncated chamber, the arc-like pressure wave does not evolve into the plane wave like the wave evolution rule in the traditional cylindrical chamber, and an alternating structure of arc-like wave and the plane wave is formed in the stepped-wall chamber. The stability control of stepped wall is more significant than that of inclined wall because the low-pressure vortex formed at the corner of step enhances the radial induction effect. Besides, the stepped-wall structure can restrain the moving randomness of the big vortex's core. The axial expansion speed of plasma jet in the ambient fluid is decreased exponentially and the speed estimation formula was obtained in this work.

A Coordinative Control Strategy for Power Electronic Transformer Based Battery Energy Storage Systems

Sun, Yuwei,Liu, Jiaomin,Li, Yonggang,Fu, Chao,Wang, Yi The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.6

A power electronic transformer (PET) based on the cascaded H-bridge (CHB) and the isolated bidirectional DC/DC converter (IBDC) is capable of accommodating a large scale battery energy storage system (BESS) in the medium-voltage grid, and is referred to as a power electronic transformer based battery energy storage system (PET-BESS). This paper investigates the PET-BESS and proposes a coordinative control strategy for it. In the proposed method, the CHB controls the power flow and the battery state-of-charge (SOC) balancing, while the IBDC maintains the dc-link voltages with feedforward implementation of the power reference and the switch status of the CHB. State-feedback and linear quadratic Riccati (LQR) methods have been adopted in the CHB to control the grid current, active power and reactive power. A hybrid PWM modulating method is utilized to achieve SOC balancing, where battery SOC sorting is involved. The feedforward path of the power reference and the CHB switch status substantially reduces the dc-link voltage fluctuations under dynamic power variations. The effectiveness of the proposed control has been verified both by simulation and experimental results. The performance of the PET-BESS under bidirectional power flow has been improved, and the battery SOC values have been adjusted to converge.

Study on Magnetic Force Calculation of Spherical Permanent Magnets

Yuyang Zhang,Yonggang Leng,Dan Tan,Jinjun Liu Korean Magnetics Society 2018 Journal of Magnetics Vol.23 No.4

This paper presents three approaches to calculate the interacting magnetic force about spherical permanent magnet, respectively based on magnetic dipole-dipole model, equivalent magnetic charge model and equivalent magnetizing current model. We use all of three models to fully calculate and study the behaviors of lateral and axial forces with respect to the related positions between a pair of spherical magnets. The accuracies of the calculation results are compared with the experimental data. In conclusion, the magnetic dipole-dipole model has the most advantageous accuracy and efficiency for the magnetic force calculation about spherical permanent magnets on account of the particularity of sphere. Our study provides an important criterion for choosing a proper method to calculate magnetic force about spherical permanent magnet.

Research on intelligent launching control of dual clutch transmissions based on adaptive neural fuzzy inference system

Guodong Zhao,Yonggang Liu,Kening Zhai,Fengyang Jiang,Qi Huang,Zheng Chen 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.7

Vehicle launching has an important influence on driving performance of the vehicle. For vehicles with dual clutch transmissions (DCT), the clutch torque control is the key to the launching control. Therefore, a data-driven control method for DCT launching process based on adaptive neural fuzzy inference system (ANFIS) is proposed. Firstly, the vehicle test data during launching process is collected and the optimal clutch torque is obtained based on multi-objective particle swarm optimization (MOPSO). Afterward, to learn the launching control rules from optimization results, the combination of neural network and fuzzy logic algorithm, referred to as an ANFIS, is established. The dataset of the optimized launching clutch torque is utilized to train the ANFIS controller. Finally, the simulation and test results show that the datadriven control can accurately learn the launching control rules from the optimality, thereby achieving the optimal control for different launching intentions.