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State observation of nonlinear off-road vehicle system under complex maneuver condition
Zepeng Gao,Sizhong Chen,Hongbin Ren,Zheng Liu 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.10
The information of vehicle attitude and tire force under complex environment and maneuver condition is of great significance for system risk prediction and active control system intervention. In order to collect the accurate system states, the coupling vehicle dynamics model and moving horizon estimation method are employed to solve the online optimization problem based on the premise of rolling optimization. Furthermore, the accurate observation and acquisition of the vehicle system state are realized. On this basis, the simulation process of the vehicle state observation using moving horizon estimation method and unscented Kalman filter algorithm are implemented, respectively. The corresponding observation results under complex maneuvering conditions are further validated by using the hardware-in-the-loop experimental platform. Finally, the comparison of the observation results obtained by the unscented Kalman filter and moving horizon estimation algorithms demonstrate that the moving horizon estimation method can effectively improve the observation accuracy of vehicle system state in complex environment, including vehicle roll angle and tire dynamic force. The results obtained through moving horizon estimation method are conducive to the further signal early warning, risk prediction and assessment, as well as systematic intervention and active rollover control.
Zepeng Zhang,Guanzheng Zhuang,Maguy Jaber,Jiahua Gao,Shanmao Peng 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.56 No.-
This work aims to reveal the differences of structures and properties between organo-montmorillonite(OMt) and organo-palygorskite (OPal) in oil-based drillingfluids. Organoclays are prepared in aqueoussolution and characterized by XRD, SEM and TEM. Surfactants can intercalate into the interlayer space ofMt while they coat only on the palygorskite surface. OMt can form “house of cards” structure while OPalforms “haystack” structure. Temperature rising promotes network structure and rheological properties oforganoclays in oil. The decline of rheological properties at high temperature is mainly caused by thedissolution of surfactants into oil, instead of thermal decomposition.
Active Fault Tolerant Control Scheme for Satellite Attitude Systems: Multiple Actuator Faults Case
Zhi-Feng Gao,Zepeng Zhou,Guoping Jiang,Mo-Shu Qian,Jin-Xing Lin 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.4
In this paper, an active fault tolerant control (FTC) design approach is proposed for the satellite attitude systems with exogenous disturbance and multiple actuator faults. Firstly, the nonlinear attitude system model of rigid satellite with multiple actuator faults is given. Next, an actuator fault diagnosis scheme, including a fault detection module and a fault estimation module, is given so as to detect the time of unknown actuator faults occurred and obtain their estimation values. Then, a terminal sliding mode-based fault tolerant attitude controller is designed using backstepping control technique, which guarantees that the closed-loop attitude systems of rigid satellite are asymptotically stable in the presence of multiple actuator faults. Numerical simulations illustrate the good performance of active FTC proposed in this study.
Strain rate effect of steel-concrete composite panel indented by a hemispherical rigid body
Weiyi Zhao,Lin Wang,Guotao Yang,Ziguo Wang,Zepeng Gao,Quanquan Guo 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.36 No.6
This paper presents numerical and theoretical investigations on the strain rate in steel-concrete composite (SC) panels under low-velocity impact of a hemispherical rigid body. Finite element analyses were performed on five specimens with different loading rates. The impact energy was kept constant to eliminate its influence by simultaneously altering the velocity and mass of the projectile. Results show that the strain rate in most parts of the specimens was low and its influence on bearing capacity and energy dissipation was limited in an average sense of space and time. Therefore, the strain rate effect can be ignored for the analyses of global deformation. However, the strain rate effect should be considered in local contact problems. Equations of the local strain and strain rate were theoretically derived.