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Enhance Transparency of Force Feedback Interaction Series Mechanism by SMC Strategy
Zhi Hu,Yueying Wang,Guohua Cui,Dan Zhang 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.7
To enhance the fidelity of virtual surgery, the force feedback interaction mechanism would simulatethe force information in real surgery. This paper first introduces evaluation methods of fidelity, then it exploresevaluation methods of force feedback fidelity, and put up the evaluation methods and indexes of force feedbackfidelity. In rigid force feedback interaction mechanism, fidelity is mainly shown as transparency. It means thetransfer function of the mechanism needs approach to 1, while friction, gravity, slip of the linear drive and otherfactors would affect transparency of the mechanism. This study introduces a 5-DOF (degree of freedom) forcefeedback series mechanism with long stroke. It discusses gravity compensation and simulation of typical virtualenvironment. It uses sliding mode control (SMC) to eliminate the effect of parameter variety, inaccurate modelingand other factors to improve system robustness. And it adds disturbance observer to the controller to eliminategravity inaccuracy. Finally, it evaluates the enhancement of force feedback fidelity.
Zhihu Yan,Caili Dai,Mingwei Zhao,Yongpeng Sun,Guang Zhao 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.37 No.-
Through extensive experiments, a reusable viscoelastic surfactant (rVES) fracturing fluid using a selfdesignedand synthesized surfactant was developed. Laboratory performance evaluation results showedthat various performances of rVES fracturing fluid are excellent. The most attractive aspect is the gellingand gel breaking of rVES fracturing fluid was achieved by altering the pH value. The recycled fracturingfluid still maintains good performances through three times cycles, which represents that it has goodprospects for re-use of flowback waters. In addition, large-scale coarse-grained molecular dynamics(CGMD) simulations results clearly revealed the formation mechanism of rVES fracturing fluid at themolecular level.
Flexible Iterative Learning Control Based Expert System and Its Application
Zuojun, Liu,Zhihu, Liu,Linan, Zu,Peng, Yang Korean Institute of Intelligent Systems 2009 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.9 No.3
A scheme of expert system based on iterative learning control is proposed. Iterative learning control can obtain control experience from the historical data to build the knowledge base of expert system. Considering some uncertain factors, a flexible measure is adopted in iterative learning control (ILC). Simulation proves the feasibility and effect of the air conditioning control expert system based on flexible iterative learning control (F-ILC). Finally, a feedback compensation unit is incorporated against irregular heavy disturbance.
Flexible Iterative Learning Control Based Expert System and Its Application
Liu Zuojun,Liu Zhihu,Zu Linan,Yang Peng 한국지능시스템학회 2009 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.9 No.3
A scheme of expert system based on iterative learning control is proposed. Iterative learning control can obtain control experience from the historical data to build the knowledge base of expert system. Considering some uncertain factors, a flexible measure is adopted in iterative learning control (ILC). Simulation proves the feasibility and effect of the air conditioning control expert system based on flexible iterative learning control (F-ILC). Finally, a feedback compensation unit is incorporated against irregular heavy disturbance.
Yifei Liu,Caili Dai,Kai Wangb,Mingwei Zhao,Guang Zhao,Shuai Yang,Zhihu Yan,Qing You 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.35 No.-
Aiming at water shut-off in high temperature reservoirs, the hydroquinone (HQ)–hexamethylenetetra-mine (HMTA) gel system was studied. The gelation performance and effects of various parameters weresystematically evaluated. With increase of the concentrations and temperature, gelation time decreasesand gel strength increases. In addition, gelation rate and gel strength were enhanced on adding acid. Moreover, the gel system shows good salt tolerance. The thermal stability measurement indicates thatthe gel can maintain stability up to 140 8C. Uniformly distributed three-dimensional network structurewas formed in the gel. At last, the gelation mechanism was proposed, illuminating the detailed gelationprocess clearly.
Jinliang Zhang,Dunbin Zhu,Wei Jian,Wentao Hu,Guosheng Peng,Yufeng Chen,Zhihu Wang 한국자동차공학회 2024 International journal of automotive technology Vol.25 No.2
Aiming at the sensitivity problems of uncertain factors such as parameter variation, external disturbance and friction for thepermanent magnet synchronous motor control system of electric vehicle, a fractional order complementary non-singular terminalsliding mode control method based on neural network is proposed. The mathematical model of permanent magnet synchronousmotor with uncertain factors was established. The sliding mode controller was designed by combining the generalized slidingmode surface and the complementary sliding mode surface, which shortened the arrival time from the state trajectory to slidingmode surface. The fractional calculus operator with fi ltering characteristics was used to improve the position tracking accuracyand reduce the chattering. As for the variety of uncertain disturbances, the neural network was used to estimate the system totaluncertainty and compensate online to further improve the dynamic response ability and anti-interference ability. Finally, thesimulation results verify the eff ectiveness and feasibility of the proposed method, which can provide theoretical and technicalsupport for improving the control accuracy of permanent magnet synchronous motor and the development of electric vehicles.