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Two New Families in the Stable Homotopy Groups of Sphere and Moore Spectrum

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Chinese Annals of Mathematics,Series B 2006年第3期27卷 311-328页

作者： jinkun LIN College of Mathematical Science and LPMC Nankai University Tianjin 300071 China

This paper proves the existence of an order p element in the stable homotopy group of sphere spectrum of degree p^nq ＋p^mq ＋ q- 4 and a nontrivial element in the stable homotopy group of Moore spectum of degree p^nq ＋ p^mq ＋ q - 3 which are represented by h0（hmbn-1 - hnbm-1） and ie（hohnhm） in the E2-terms of the Adams spectral sequence respectively, where p ≥ 7 is a prime, n ≥ m ＋ 2 ≥ 4, q = 2（p - 1）.

关键词： Stable homotopy groups of spheres Adams spectral sequence Toda spectrum

Adaptive formation control of quadrotor unmanned aerial vehicles with bounded control thrust

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Chinese Journal of Aeronautics 2017年第2期30卷 807-817页

作者： Wang Rui Liu jinkun School of Automation Science and Electrical Engineering Beihang University Beijing 100083 China

In this paper,the flight formation control problem of a group of quadrotor unmanned aerial vehicles（UAVs） with parametric uncertainties and external disturbances is *** are used to represent the attitudes of the quadrotor *** the model into a translational subsystem and a rotational subsystem,an intermediary control input is introduced to track a desired velocity and extract desired *** considering the internal parametric uncertainties and external disturbances of the quadrotor UAVs,the priori-bounded intermediary adaptive control input is designed for velocity tracking and formation keeping,by which the bounded control thrust and the desired orientation can be ***,an adaptive control torque input is designed for the rotational subsystem to track the desired *** the proposed control scheme,the desired velocity is tracked and a desired formation shape is built *** stability of the closed-loop system is proven via Lyapunov-based stability *** simulation results are presented to illustrate the effectiveness of the proposed control scheme.

关键词： Adaptive control Bounded input Formation control Parametric uncertainties Quadrotor UAV Unit-quaternions

QFT control based on zero phase error compensation for flight simulator

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Journal of Systems Engineering and Electronics 2007年第1期18卷 125-131页

作者： Liu jinkun He Yuzhu Dept. of Automatic Automatic Control Beijing Univ. of Aeronautics and Astronautics Beijing 100083 E R. China Dept. of Engineering System of Engineering Beijing Univ. of Aeronautics and Astronautics Beijing 100083 E R. China

To improve the robustness of high-precision servo systems, quantitative feedback theory （QFT） which aims to achieve a desired robust design over a specified region of plant uncertainty is proposed. The robust design problem can be solved using QFT but it fails to guarantee a high precision tracking. This problem is solved by a robust digital QFT control scheme based on zero phase error （ZPE） feed forward compensation. This scheme consists of two parts： a QFT controller in the closed-loop system and a ZPE feed-forward compensator. Digital QFT controller is designed to overcome the uncertainties in the system. Digital ZPE feed forward controller is used to improve the tracking precision. Simulation and real-time examples for flight simulator servo system indicate that this control scheme can guarantee both high robust performance and high position tracking precision.

关键词： Quantitative feedback theory Zero phase error Feed forward compensation Servo system Flight simulator

Construction of the Inference Engine of Blast Furnace Expert System

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Journal of Iron and Steel Research International 1998年第2期5卷 24-29页

作者： Liu jinkun Wang Shuqing State Key Laboratory of CAD & CG Zhejiang University

The expert system for judging blast furnace condition is built to realize automatic judgment of blast furnace conditions and standardization of blast furnace operation. This paper discusses the design and implementati... 详细信息

关键词： blast furnace expert system inference engine

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Distributed disturbance-observer-based vibration control for a flexible-link manipulator with output constraints

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Science China(Technological Sciences) 2018年第10期61卷 1528-1536页

作者： YANG HongJun LIU jinkun HE Wei State Key Laboratory of Management and Control for Complex System Institute of Automation Chinese Academy of Sciences School of Automation Science and Electrical Engineering Beihang University School of Automation and Electrical Engineering University of Science and Technology Beijing

The issue of output constraints is studied for a flexible-link manipulator in the presence of unknown spatially distributed disturbances. The manipulator can be taken as an Euler-Bernoulli beam and its dynamic is expressed by partial differential equations. On account of the uncertainty of disturbances, we present a disturbance observer to estimate infinite dimensional disturbances on the beam. The observer is proven exponentially stable. Considering the problem of output constraints in the practical engineering, we propose a novel distributed vibration controller based on the disturbance observer to fulfill the position regulation of the joint angle and suppress elastic deflections on the flexible link, while confining the regulating errors of output in a suitable scope that we can assign. The closed-loop system is demonstrated exponentially stable based on an integral-barrier Lyapunov function. Simulations validate the effectiveness of the design scheme.

关键词： flexible manipulator distributed vibration control disturbance observer partial differential equation output constraint distributed parameter system

FUZZY GLOBAL SLIDING MODE CONTROL BASED ON GENETIC ALGORITHM AND ITS APPLICATION FOR FLIGHT SIMULATOR SERVO SYSTEM

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Chinese Journal of Mechanical Engineering 2007年第3期20卷 13-17页

作者： LIU jinkun HE Yuzhu School of Automation Science ＆ Electrical Engineering Beihang University Beijing 100083 China Department of System Engineering of Engineering Technology Beihang University Beijing 100083 China

To alleviate the chattering problem, a new type of fuzzy global sliding mode controller （FGSMC） is presented. In this controller, the switching gain is estimated by fuzzy logic system based on the reachable conditions of sliding mode controller（SMC）, and genetic algorithm （GA） is used to optimize scaling factor of the switching gain, thus the switch chattering of SMC can be alleviated. Moreover, global sliding mode is realized by designing an exponential dynamic sliding surface. Simulation and real-time application for flight simulator servo system with Lugre friction are given to indicate that the proposed controller can guarantee high robust performance all the time and can alleviate chattering phenomenon effectively.

关键词： Sliding mode control Chattering free Fuzzy control Genetic algorithm Flight simulator

Control of a Spherical Robot: Path Following Based on Nonholonomic Kinematics and Dynamics

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Chinese Journal of Aeronautics 2011年第3期24卷 337-345页

作者： ZHENG Minghui ZHAN Qiang LIU jinkun CAI Yao Robotics Institute Beihang University Beijing 100191 China School of Automation Science and Electrical Engineering Beihang University Beijing 100191 China

This paper presents the controller design for the path following of a spherical mobile robot, BHQ-1. Firstly, a desired velocity for the reference path is deduced from the kinematic model, which cannot be transformed into the classic chained form. Secondly, a necessary torque for the desired velocity is obtained based on the dynamic model. As to the kinematics, a one-dimensional function is selected to measure the two-directional tracking error, and the velocity of rolling forward is reasonably assumed to be constant; therefore the multiple-input multiple-output （MIMO） system is transformed into a single-input single-output （SISO） system. As to the dynamics, both exact dynamics and inexact dynamics with modeling error as well as bounded unknown disturbance are taken into account, based on which a proportional-derivative （PD） controller and a sliding mode controller with adaptive parameters are proposed respectively. Finally, convergence analysis and simulation results are provided to validate these controllers.

关键词： spherical robot path following nonholonomic kinematics dynamics

Off-target effects of cytidine base editor and adenine base editor:What can we do?

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Journal of Genetics and Genomics 2019年第11期46卷 509-512页

作者： Puping Liang jinkun Wen Junjiu Huang Key Laboratory of Reproductive Medicine of Guangdong Province School of Life Sciencesand the First Affiliated HospitalSun Yat-sen UniversityGuangzhou510275China MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging Research SYSU-BCM Joint Research CenterSchool of Life SciencesSun Yat-sen UniversityGuangzhou510275China Jiangmen Central Hospital Affiliated Jiangmen Hospital of Sun Yat-sen UniversityGuangzhou510275China Key Laboratory of Reproductive Medicine of Guangdong Province The Third Affiliated Hospital of Guangzhou Medical UniversityGuangzhou510275China

DNA is the blueprint of life,instructing the growth,development,and reproduction of an *** sequencing uncovers the codes of life,whereas genome editing could rewrite the codes,thus then leads to revolutionary advances in all aspects of life sciences,such as uncovering regulatory network of life,increasing the production of crops,producing new breeds of livestock,and curing genetic disorders(Liu,2017).

关键词： Off-target effects editor

Zero phase error control based on neural compensation for flight simulator servo system

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Journal of Systems Engineering and Electronics 2006年第4期17卷 793-797页

作者： Liu jinkun He Peng Er Lianjie School of Automation Science & Electrical Engineering Beijing Univ. of Aeronautics and AstronauticsBeijing 100083 P.R.China Computing Lad Oxford Univ.Parks Road OxfordOX13QD U.K.

Using the future desired input value, zero phase error controller enables the overall system＇s frequency response exhibit zero phase shift for all frequencies and a small gain error at low frequency range, and based on this, a new algorithm is presented to design the feedforward controller. However, zero phase error controller is only suitable for certain linear system. To reduce the tracking error and improve robustness, the design of the proposed feedforward controller uses a neural compensation based on diagonal recurrent neural network. Simulation and real-time control results for flight simulator servo system show the effectiveness of the proposed approach.

关键词： zero phase error servo system neural network robust control flight simulator.