LPV/H ∞ CONTROLLER DESIGN FOR PATH TRACKING OF AUTONOMOUS GROUND VEHICLES THROUGH FOUR-WHEEL STEERING AND DIRECT YAW-MOMENT CONTROL

Peng Hang,Xinbo Chen,Fengmei Luo 한국자동차공학회 2019 International journal of automotive technology Vol.20 No.4

This paper focuses on the path-tracking controller design for autonomous ground vehicles (AGVs) using fourwheel steering (4WS) and direct yaw-moment control (DYC) systems. In order to deal with the parametric uncertainties, a linear parameter-varying (LPV) H∞ controller is designed as the high-level controller to generate the front and rear wheel steering angles and external yaw moment based on linear matrix inequality (LMI) approach. The lower-level controller is designed for torque allocation between the left and right side wheels to yield the desired total longitudinal force and external yaw moment utilizing weighted least square (WLS) allocation algorithm. To test the performance of the proposed pathtracking controller, numerical simulations are carried out based on a high-fidelity and full-vehicle model constructed in CarSim. Simulation results show that the LPV/H∞ controller has better path-tracking performance than the fixed gain H∞ controller. To show the superiority of 4WS+DYC control system, the contrast simulation is performed based on LPV/H∞ controller. Simulation results indicate that 4WS+DYC control system has better path-tracking performance and handling stability than active front steering (AFS), AFS+DYC and 4WS control systems.

Plasma-catalytic decomposition of ethyl acetate over LaMO3 (M = Mn, Fe, and Co) perovskite catalysts

Yuxiang Cai,Xinbo Zhu,Wenshuo Hu,Chenghang Zheng,Yangyang Hu,Menghan Chen,Xiang Gao 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.70 No.-

Plasma-catalytic decomposition of low concentration ethyl acetate with LaMO3 (M = Co, Mn and Fe)perovskite catalyst was investigated in a coaxial dielectric barrier discharge (DBD) reactor. Thecombination of perovskite catalyst and plasma enhanced ethyl acetate decomposition, and the activitysequence was LaCoO3> LaMnO3> LaFeO3. Characterizations results indicated that the activation ofsurface oxygen species and amount of oxygen vacancies contributed to ethyl acetate decompositionremarkably. FT-IR analysis demonstrated that the employment of LaCoO3 catalyst also reduced theamount of unwanted by-products. Based on these results, reaction mechanism of ethyl acetate plasmacatalyticdecomposition process was proposed.

ROBUST CONTROL FOR FOUR-WHEEL-INDEPENDENT-STEERING ELECTRIC VEHICLE WITH STEER-BY-WIRE SYSTEM

Peng Hang,Xinbo Chen,Shude Fang,Fengmei Luo 한국자동차공학회 2017 International journal of automotive technology Vol.18 No.5

A four-wheel-independent-steering (4WIS) electric vehicle (EV) with steer-by-wire (SBW) system is proposed in this paper. The fast terminal sliding mode controller (FTSMC) is designed for the SBW system to suppress external disturbances. Taking unstructured and structured uncertainties into consideration, a robust controller is designed for the 4WIS EV utilizing μ synthesis approach and the controller order reduction is implemented based on Hankel-Norm approximation. Since sideslip angle is the feedback signal of robust controller and it is hard to measure, the extended Kalman filter (EKF) is employed to estimate sideslip angle. To evaluate the vehicle performance with the designed control system, step and sinusoidal steering maneuvers are simulated and analyzed. Simulation results show that the designed control system have good tracking ability, strong robust stability and good robust performance to improve vehicle stability and handing performance.

Study on Wheel-Side Drive System with a Single Trailing Arm

Wang Bin,Chen Xinbo,Lyu Hongming,Niu Xinwei 한국자동차공학회 2021 International journal of automotive technology Vol.22 No.5

In order to reduce unsprung mass and ensure driving comfortability, a novel electrical vehicle (EV) drive system, which integrated the wheel-side reducer and a single trailing arm, was studied in this paper. Firstly, the general structure of the drive system was studied, in which the reducer not only worked as a wheel-side reducer but also as the single trailing arm. Then, the transmission power losses were modeled by integrating different load-independent and load-independent models of power losses. Next, the experiment of the power losses test for the wheel-side drive system was conducted, which declared the patterns of power losses of electric motor and the whole drive system. Finally, the power losses of wheel-side reducer based on NEDC are studied, which illustrates oil churning and gear sliding power losses are the main types of transmission power losses. At low rotational velocities, gear friction power losses are larger than oil churning power losses. While at high rotational velocities, oil churning power losses are dominant. The transmission efficiency of the reducer based on NEDC varies among the range of 78 ~ 95 %, which depends on the torque and rotational velocity transmitted from the driving motor to EV’s wheel.

The anti-tumor efficacy of 20(S)-protopanaxadiol, an active metabolite of ginseng, according to fasting on hepatocellular carcinoma

Wenzhen Li,YifanWang,Xinbo Zhou,Xiaohong Pan,Junhong Lu,Hongliu Sun,Zeping Xie,Shayan Chen,Xue Gao 고려인삼학회 2022 Journal of Ginseng Research Vol.46 No.1

Background: 20(S)-protopanaxadiol (20(S)-PPD), one of the main active metabolites of ginseng, performs a broad spectrum of anti-tumor effects. Our aims are to search out new strategies to enhance anti-tumor effects of natural products, including 20(S)-PPD. In recent years, fasting has been shown to be multifunctional on tumor progression. Here, the effects of fasting combined with 20(S)-PPD on hepatocellular carcinoma growth, apoptosis, migration, invasion and cell cycle were explored. Methods: CCK-8 assay, trypan blue dye exclusion test, imagings photographed by HoloMonitorTM M4, transwell assay and flow cytometry assay were performed for functional analyses on cell proliferation, morphology, migration, invasion, apoptosis, necrosis and cell cycle. The expressions of genes on protein levels were tested by western blot. Tumor-bearing mice were used to evaluate the effects of intermittent fasting combined with 20(S)-PPD. Results: We firstly confirmed that fasting-mimicking increased the anti-proliferation effect of 20(S)-PPD in human HepG2 cells in vitro. In fasting-mimicking culturing medium, the apoptosis and necrosis induced by 20(S)-PPD increased and more cells were arrested at G0-G1 phase. Meanwhile, invasion and migration of cells were decreased by down-regulating the expressions of matrix metalloproteinase (MMP)-2 and MMP-9 in fasting-mimicking medium. Furthermore, the in vivo study confirmed that intermittent fasting enhanced the tumor growth inhibition of 20(S)-PPD in H22 tumor-bearing mice without obvious side effects. Conclusion: Fasting significantly sensitized HCC cells to 20(S)-PPD in vivo and in vitro. These data indicated that dietary restriction can be one of the potential strategies of chinese medicine or its active metabolites against hepatocellular carcinoma.

UKF Estimation Method of Centroid Slip Angle for Vehicle Stability Control

Pan Wang,Xiaobin Fan,Xinbo Chen,Juean Yi,Shuwen He 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.7

Vehicle center of sideslip angle is an essential parameter in vehicle stability control system. In view of the current problems is taken as the research object including low estimation accuracy and poor real-time performance of the current centroid sideslip angle, the four-wheel motor driven electric vehicle. The estimation problem of the sideslip angle is studied in-depth when the vehicle is in a nonlinear state. In addition, an Unscented Kalman Filter (UKF) estimation method is proposed to reduce observation error and improve the practicability of the estimation system. First of all, the research starts with building a 7-degree-of-freedom vehicle model which is based on the Dugoff tire model. Then, after measuring the state parameters, the UKF algorithm is used to estimate the sideslip angle. By comparing with the Extended Kalman Filter (EKF) algorithm, it is confirmed that the estimation method can not only better estimate the center of sideslip angle in real time, but also greater improve the handling stability of the vehicle in the driving state. Besides, the effectiveness of the algorithm is further verified by the real vehicle road test.