Portrait of Dr Xinggang Yan

Dr Xinggang Yan

Senior Lecturer in Control Engineering

About

Dr Xinggang Yan (严星刚) received his BSc degree from Shaanxi Normal University, in 1985,  MSc degree from Qufu Normal University in 1991, and PhD degree in engineering from Northeastern University, P. R. China in 1997. Currently, he is a Senior Lecturer in the University of Kent. He worked as a Research Fellow/Research Associate in the University of Leicester, United Kingdom, the University of Hong Kong, China, Nanyang Technological University, Singapore and Northwestern Polytechnical University, China. He was a Lecturer in Qingdao University, P. R. China from 1991 to 1994.  His research interests incluide nonlinear control, sliding mode control, decentralized control, fault detection and isolation,  observer design, time delay systems with applications in engineering systems.

New book: Xing-Gang Yan, Sarah Spurgeon and Edwards Christopher, Variable Structure Control of Complex Systems: Analysis and Design. Springer, 2017

Research interests

Dr Xinggang Yan's research interests, broadly speaking, lie in the control design and analysis of linear and nonlinear dynamical systems and large-scale interconnected systems with applications in real engineering systems. The problems investigated in his previous work are generally classified as: nonlinear control, observer design, decentralized control, fault detection and isolation, dynamical modeling, robust stabilization, tracking control and learning control etc, where not only state feedback but also output feedback is considered for varieties of systems; the matched and mismatched uncertainties are both dealt with. His frequently employed research approaches include Lyapunov analysis, sliding mode control, modern differential geometric approach, adaptive control and iterative learning control etc, which he has frequently made use of in the past and recent research works. The primary computational and simulation tool for the design and analysis is MATLAB with its toolboxes and Maple.

The developed theoretical results have been tested in some practical systems, through computer simulation, such as robot system, fight control system, electric power system, multimachine power systems and coupled inverted pendulum system etc.

Teaching

  • EL021   Calculus (Foundation Year)
  • EL318   Engineering Mathematics (First Year)
  • EL319   Engineering Analysis (First Year)
  • EL562   Computer Interfacing (2nd Year Group Project)
  • EL569   Signals and Systems (Second Year)
  • EL600   Third Year Engineering Project (3rd Yeara Individual Project)
  • EL676    Digital Control (Third year)
  • EL849    Research Methods & Project Design (MSc)
  • EL876   Advanced Control (MSc)
  • EL890   MSc Project

Supervision

Academic research visitors

  • Ms Jin Wang: 01/08/2018-31/01/2018,  Visiting Researcher, Funded by China Scholarship Council (CSC), Senior Engineer in ShangHai Space  Electronics Technology Institute, China.
  • Dr Ke Zhang:  Visiting Researcher, 01/05/2018-30/04/2019, Funded by China Scholarship Council (CSC), Associate Professor from Nanjing University of Areonauticas and Astronauticas, China. 
  • Mr Wenbo Tian: 10/05/2016-09/10/2016,  Visiting Researcher, Funded by China Scholarship Council (CSC), Senior Engineer in ShangHai Space  Electronics Technology Institute, China.
  • Dr Xiaolin Gong: 31/03/2016-30/03/2017, Visiting Researcher, Funded by China Scholarship Council (CSC), Lecturer in Beihang University.
  • Mr Qi Chen: 01/10/2015-30/03/2016 , Visiting PhD student, funded by Nanjing Science and Technolgy University, China
  • Dr Xiaofang Yuan: 19/10/2013-18/10/2014, Visiting Researcher, Hunan University, P.R. China. Funded by China Scholarship Council (CSC). Project: Intelligent control system theory and applications
  • Prof Qingling Zhang: 19/10/2013-19/01/2014, Visiting Professor, Northeastern University, P.R. China. Funded by Royal Acdemy of Engineering of the United Kingdom. Project: Variable structure control for complex singular systems with applications to industrial systems
  • Dr Yi Zhang: 19/10/2013-18/01/2014, Visiting Researcher, Shenyang University of Technology , P.R. China. Funded by Shenyang University of Technology. Project: Optimal Control for Prey-Predator Fishery Model Described by Differential and Algebraic Equations

Current PhD students

  • Mr KangKang Zhang (visiting PhD student) (28/10/2017-27/10/2018) funded by Chinese Scholarship Council.
  • Mr Adrian Emeka Onyeka. Variable structure control of time delay systems with applications
  • Mr Mokhtar S. Khalifa Mohamed. Nonlinear observer design with applications in fault detection and isolation

Previous PhD students

  • Mr. Jianqiu Mu.  Robust sliding mode control of complex systems with applications
  • Dr Mohammad Farhan Khan, Robustness and Resposiveness in Eukaryotic Protein Synthesis,
  • Dr Anet J. N. Anelone. A study of the synergies between control mechanisms in the immune system and the variable structure control paradigm
  • Dr Qi Chen (Visiting PhD student)  01/10/2015-30/03/2016,  funded by Nanjing Science and Technolgy University, China

Current MSc students

  • Miss Sonia Anne Abraham: Control design of a multi-link  robot system
  • Mr Andre Reis Rodrigues: Robust trajectory/output tracking control of a robot system

Previous MSc students

  • Mr Emmanuel Omotayo (2016-2017)
  • Mr. Peter Hogben (2016-2017)
  • Mr Francisco D.B. Soler Jorba (2015-2016)
  • Mr Yankun Yang (2015-2016)
  • Mr Anuo Yerawar (2015-2016)
  • Mr Junchi Chen (2014-2015)
  • Mr Benjamin M. Okochi (2014-2015)
  • Mr Mohammad Daoud Abbadi (2013-2014)
  • Miss Jingying Cao (2013-2014)
  • Mr Nithin Nagaraj (2013-2014)
  • Mr Jianqiu Mu (2012-2013)

Professional

Academic service

  • Editor-in-Chief of the International Journal of Engineering Research and Science & Technology, (ISSN 2319--5991,  http://ijerst.com/EditorialBoard.php)
  • Lead Guest Editor of the Special Issue on "Advanced Control of Complex Dynamical Systems with Applications" for the journal: Mathematical Problems in Engineering, 2016
  • Guest Editor of the Special Issue on "Advanced Control for Singular Systems with Applicationsfor the journal: Mathematical Problems in Engineering, 2017
  • Member of Editorial Board of Journals:  Complexity, Energies, Mathematical Problems in Engineering, Cogent Engineering, Annals of Robotics and Automation, International Journal of Electrical and Electronic Engineering & Telecommunications (IJEETC), SF Journal of Aviation and Aeronautical Science, Journal on Automation and Control Engineering(JACE), International Journal of Research Studies in Electrical and Electronics Engineering, Research in Applied Mathematics, etc.
  • Member of Technical Program Committee
    • The Second International Conference on Physics, Mathematics and Statistics (ICPMS2019) ,    Hangzhou, China, May 22-24, 2019.   http://www.pmsconf.org/Committee.aspx
    • The 2nd International Conference on Computer Science and Application (CASE 2018),  Hohhot, China, October 22 to 24, 2018.  http://www.csaeconf.org/Committee.aspx
    • The 3rd International Conference on Mechatronics and Electrical Systems (ICMES 2018), Bangkok, Thailand, October 12-14, 2018.  http://www.icmes.org/committees.html 
    • The Seventh International Conference on Smart Cities, Systems, Devices and Technologies SMART 2018,  Barcelona, Spain, July 22-26, 2018.   https://www.iaria.org/conferences2018/SMART18.html
    • The 2nd International Conference on Mechatronics and Electrical Systems (ICMES 2017) , Wuhan, China,Dec 22-25, 2017. http://www.icmes.org/committees.html
    • The 3rd Annual International Conference on Computer Science and Mechanical Automation (CSMA2017), Wuhan, China, November 10-12, 2017 http://www.csma2017.org/?op=committee
    • The 5th Annual 2017 International Conference on Mechanics and Mechatronics [ICMM2017] will be held on December 15th-17th, 2017, Xiamen, China. http://www.icmm2017.org/?op=committee
    • Member of Technical Program Committee of the 2nd international Conference on Mechatronics, Control and Automation Engineering (MCAE2017), Shenzhen, China,17-18, September 2017.  http://www.mcae2017.org/
  • Member of Executive Editorial Board of the International Conference on Industrial Electronics and Electrical Engineering (ICIEEE), 2017. ( http://ijieee.org.in/Conference2017/1/NewDelhi/ICIEEE/committee.php )

Publications

Showing 50 of 191 total publications in the Kent Academic Repository. View all publications.

Article

  • Xu, D. et al. (2019). Adaptive fuzzy sliding mode command-filtered backstepping control for islanded PV microgrid with energy storage system. Journal of the Franklin Institute [Online]. Available at: https://doi.org/10.1016/j.jfranklin.2019.01.012.
    This study focuses on the control of islanded photovoltaic (PV) microgrid and design of a controller for PV system. Because the system operates in islanded mode, the reference voltage and frequency of AC bus are provided by the energy storage system. We mainly designed the controller for PV system in this study, and the control objective is to control the DC bus voltage and output current of PV system. First, a mathematical model of the PV system was set up. In the design of PV system controller, command-filtered backstepping control method was used to construct the virtual controller, and the final controller was designed by using sliding mode control. Considering the uncertainty of circuit parameters in the mathematical model and the unmodeled part of PV system, we have integrated adaptive control in the
    controller to achieve the on-line identification of component parameters of PV system. Moreover, fuzzy control was used to approximate the unmodeled part of the system. In addition, the projection operator guarantees the boundedness of adaptive estimation. Finally, the control effect of designed controller was verified by MATLAB/Simulink software. By comparing with the control results of proportion-integral (PI) and other controllers, the advanced design of controller was verified.
  • Zhang, K. et al. (2019). Interval Sliding Mode Observer Based Incipient Sensor Fault Detection with Application to a Traction Device in China Railway High-speed. IEEE Transactions on Vehicular Technology [Online]. Available at: http://dx.doi.org/10.1109/TVT.2019.2894670.
    This paper proposes an interval sliding mode observer (ISMO) and an incipient sensor faults detection method for a class of nonlinear control systems with observer unmatched uncertainties. The interval bounds for continuous nonlinear functions and new injection functions are constructed to design ISMOs. An incipient fault detection framework with newly
    designed residual and threshold generators is proposed. The detectability is then studied, and a set of sufficient detectable conditions are presented. Applications to an electrical traction device used in China Railway High-speed (CRH) are presented to verify the effectiveness of the proposed incipient sensor fault detection methodology.
  • Liu, W. et al. (2019). Adaptive Fault-Tolerant Formation Control for Quadrotors with Actuator Faults. Asian Journal of Control [Online]. Available at: https:/dx./doi.org/10.1002/asjc.2008.
    In this paper, we investigate the fault-tolerant formation control of a group of quadrotor aircrafts with a leader. Continuous fault-tolerant formation control protocol is constructed by using adaptive updating mechanism and boundary layer theory to compensate actuator fault. Results show that the desired formation pattern and trajectory under actuator fault can be achieved using the proposed fault-tolerant formation control. A simulation is conducted to illustrate the effectiveness of the method.
  • Xu, D. et al. (2018). A novel adaptive command-filtered backstepping sliding mode control for PV grid-connected system with energy storage. Solar Energy [Online] 178:222-230. Available at: http://dx.doi.org/10.1016/j.solener.2018.12.033.
    In order to solve the problems of power fluctuation in the photovoltaic (PV) grid-connected system and the nonlinearity in the model of inverters, a projection-based adaptive backstepping sliding mode controller with command-filter is designed in the system to adjust the DC-link voltage and the AC side current in the PV gridconnected system. Firstly, the mathematical model of the inverter in PV system is established, then backstepping control method is applied to control it, and the command filter is added to the controller to eliminate the differential expansion of the backstepping controller. Furthermore, the adaptive law based on Lyapunov stability theory is designed to estimate the uncertain parameters in the grid-connected inverter. A projection algorithm is introduced into the adaptive controller due to the demand of guaranteeing the bounded estimated value. Additionally, a sliding mode controller is increased to improve its robustness in this system. Considering the influence of irradiation and temperature changes, a battery energy storage system (BESS) is applied on the DC side to suppress the fluctuation of the output power of the PV system. Finally, the simulation results demonstrate that the presented strategy can control precisely the grid-connected inverter.
  • Mao, Z. et al. (2018). Adaptive Actuator Compensation of Position Tracking for High-Speed Trains with Disturbances. IEEE Transactions on Vehicular Technology [Online] 67:5706-5717. Available at: http://dx.doi.org/10.1109/TVT.2018.2808360.
    In this paper, the adaptive fault compensation prob-lem is investigated for high-speed trains in the presence of time-varying system parameters, disturbances and actuator failures. To deal with the time-varying system parameters, a new time-varying indicator function instead of commonly used 0-1 function, is proposed to model the train dynamics as a piecewise model with unparameterizable time-varying disturbances, which can cover more time variations and help parametrization for adaptation. A backstepping adaptive controller is designed for the healthy system with unknown piecewise model parameters and known piecewise bounds on disturbances. For both the parameterizable and unparameterizable failures, the backstepping adaptive fail-ure compensation with the adaptive laws are derived to achieve the position tracking under the known bound disturbances. The adaptive failure compensation for unknown bounds on disturbances is also discussed under the parameterizable failure. Through introducing the nonlinear damping in the proposed controller, the failure compensation controller is proposed for the model with unparameterizable system parameters to achieve an arbitrary degree of position tracking accuracy. The stability of the corresponding closed-loop system and asymptotic state tracking are proved via Lyapunov direct method, and validated using a high-speed train model.
  • Liu, W. et al. (2018). Advanced Control for Singular Systems with Applications. Mathematical Problems in Engineering [Online]. Available at: https://doi.org/10.1155/2018/1819540.
  • Li, J. et al. (2018). Observer-Based Fuzzy Integral Sliding Mode Control For Nonlinear Descriptor Systems. IEEE Transactions on Fuzzy Systems [Online]. Available at: http://dx.doi.org/10.1109/TFUZZ.2018.2802458.
    This paper investigates observer-based stabilization for nonlinear descriptor systems using a fuzzy integral sliding mode control approach. Observer-based integral sliding mode control strategies for the T-S fuzzy descriptor systems are developed. A two step design is ?rst developed to obtain the observer gains and coef?cients in the switching function using linear matrix inequalities, and the results are used to facilitate the development of a single step design approach, which is seen to be convenient but introduces some conservatism in the design. The potential application to a class of mechanical systems is also considered. Since the descriptor system representation of mechanical systems is adopted, it is shown that in contrast to the existing fuzzy sliding mode control methods based on the normal system representation, the resulting T-S fuzzy system does not contain different input matrices for each local subsystem and the required number of fuzzy rules is consequently markedly reduced. Finally, the balancing problem of a pendulum on a car is numerically simulated to demonstrate the effectiveness of the proposed method.
  • Gong, X. et al. (2018). Unscented Particle Smoother and its Application to Transfer Alignment of Airborne Distributed POS. International Journal of Aerospace Engineering [Online]. Available at: http://dx.doi.org/10.1155/2018/3898734.
    This paper deals with the problem of state estimation for the transfer alignment of airborne distributed position and orientation system (distributed POS). For a nonlinear system, especially with large initial attitude errors, the performance of linear estimation methods will degrade. In this paper a nonlinear smoothing algorithm called the unscented particle smoother (UPS) is proposed and utilized in the off-line transfer alignment of airborne distributed POS. In this algorithm, the measurements are first processed by the forward unscented particle filter (UPF) and then a backward smoother is used to achieve the improved solution. The performance of this algorithm is compared with that of a similar smoother known as the Unscented Rauch-Tung-Striebel Smoother. The simulation results show that the UPS effectively improves the estimation accuracy and this work offers a new off-line transfer alignment approach of distributed POS for multi-antenna synthetic aperture radar and other airborne earth observation tasks.
  • Khan, M., Spurgeon, S. and Yan, X. (2018). Modelling and dynamic behaviour of eIF2 dependent regulatory system with disturbances. IEEE Transactions on NanoBioscience [Online]:1. Available at: https://ieeexplore.ieee.org/document/8478378.
    Eukaryotic initiation factor 2 (eIF2) is a central controller of the eukaryotic translational machinery. To sustain the on-going translation activity, eIF2 cycles between its GTP and GDP bound states. However, in response to cellular stresses, the phosphorylation of eIF2 takes place, which acts as an inhibitor of the guanine nucleotide exchange factor eIF2B and switches the translation activity on physiological timescales. The main objec-tive of this work is to investigate the stability of the regulatory system under nominal conditions, parametric fluctuations and structural damages. In this paper, a mathematical model of eIF2 dependent regulatory system is used to identify the stability-conferring features within the system with the help of direct and indirect methods of Lyapunov stability theory. To investigate the impact of intrinsic fluctuations and structural damages on the stability of regulatory system, the mathematical model has been linearised around feasible equilibrium point and the variation of system poles have been observed. The investigations have revealed that the regulatory model is stable and able to tolerate the intrinsic stressors but becomes unstable when particular complex is targeted to override the undesirable interaction. Our analyses indicate that, the stability is a collective property and damage in the structure of the system changes the stability of the system.
  • Mohamed, M. et al. (2018). Adaptive Sliding Mode Observer for Nonlinear Interconnected Systems with Time Varying Parameters. Asian Journal of Control [Online]. Available at: https://dx.doi.org/10.1002/asjc.1960.
    In this paper, a class of nonlinear interconnected systems with uncertain time varying parameters (TVPs) is considered. Both the interconnections and the isolated subsystems are nonlinear. Sliding mode control method and adaptive techniques are employed together to design an observer to estimate the state variables of the systems in presence of unknown TVPs. The Lyapunov direct method is used to analysis the stability of the sliding motion and it is not required to solve the so-called constrained Lyapunov problem (CLP). A set of conditions is developed under which the augmented systems formed by the error dynamical systems and the designed adaptive laws, are globally uniformly ultimately bounded. A simulation example is presented and the results show that the method proposed in this paper is effective.
  • Zhang, K. et al. (2018). Incipient Fault Detection for Traction Motors of High-Speed Railways Using an Interval Sliding Mode Observer. IEEE Transactions on Intelligent Transportation Systems [Online]. Available at: http://dx.doi.org/10.1109/TITS.2018.2878909.
    This paper proposes a stator-winding incipient shorted-turn fault detection method for the traction motors used in China high-speed railways. Firstly, a mathematical description for incipient shorted-turn faults is given from the quantitative point of view to preset the fault detectability requirement. Then, an interval sliding mode observer is proposed to deal with uncertainties caused by measuring errors from motor speed sensors. The active robust residual generator and the corresponding passive robust threshold generator are proposed based on this particularly designed observer. Furthermore, design parameters are optimized to satisfy the fault detectability requirement. This developed technique is applied to an electrical traction motor to verify its effectiveness and practicability.
  • Xu, Z. et al. (2017). A Novel Adaptive Neural Network Constrained Control for Multi-Area Interconnected Power System with Hybrid Energy Storage. IEEE Transactions on Industrial Electronics [Online] PP:1-1. Available at: http://dx.doi.org/10.1109/TIE.2017.2767544.
    This paper concentrates on the problem of control of a hybrid energy storage system (HESS) for an improved and optimized operation of load-frequency control (LFC) applications. The HESS consists of a supercapacitor served as the main power source, and a fuel cell served as the auxiliary power source. Firstly, a Hammerstein-type neural network (HNN) is proposed to identify the HESS system, which formulates the Hammerstein model with a nonlinear static gain in cascade with a linear dynamic block. It provides the model information for the controller to achieve the adaptive performance. Secondly, a feedforward neural network based on back-propagation training algorithm is designed to formulate the PID-type neural network (PIDNN), which is used for the adaptive control of HESS system. Meanwhile, a dynamic anti-windup signal is designed to solve the operational constraint of the HESS system. Then, an appropriate power reference signal for HESS can be generated. Thirdly, the stability and the convergence of the whole system are proved based on the Lyapunov stability theory. Finally, simulation experiments are followed through on a four-area interconnected power system to demonstrate the effectiveness of the proposed control scheme.
  • Zhang, K. et al. (2017). Incipient Voltage Sensor Fault Isolation for Rectifier in Railway Electrical Traction Systems. IEEE Transactions on Industrial Electronics [Online] 64:6763-6774. Available at: http://dx.doi.org/10.1109/TIE.2017.2696463.
    This paper proposes a dc voltage incipient sensor fault isolation method for single-phase three-level rectifier devices in high-speed railway electrical traction systems. Different incipient fault modes characterizing locations and incipient fault types are parameterized nonlinearly by unknown fault parameters. A new incipient fault isolation method is developed by combining sliding mode technique with nonlinear parametrization adaptive estimation technique. A bank of particular adaptive sliding mode estimators is proposed, which facilitates to derive new isolation residuals and adaptive threshold intervals. The isolability is studied, and the isolable sufficient condition is derived using new functions. For the practical electrical traction system in CRH2 (China Railway High-Speed 2), simulation and experiment based on TDCS-FIB (a software) are presented to verify the effectiveness and feasibility of the proposed method.
  • Gong, X., Liu, H. and Yan, X. (2017). Deformation measuring methods based on inertial sensors for airborne distributed POS. International Journal of Aerospace Engineering [Online] 2017. Available at: http://dx.doi.org/10.1155/2017/9343215.
    This paper is focused on deformation measuring methods based on inertial sensors, which is used to achieve high accuracy motion parameters and the spatial distribution optimization of muti-slave systems in airborne distributed Position and Orientation System (POS) or other purposes. In practical application, the installation difficulty, cost and accuracy of measuring equipment are the key factors need to be considered synthetically. Motivated by these, the deformation measurement methods based on gyros and accelerometers are proposed respectively and compared with the traditional method based on Inertial Measurement Unit (IMU). The mathematical models of these proposed methods are built, and the detailed derivations of them are given. Based on the Kalman filtering estimation, flight simulation and semi-physical simulation based on vehicle experiment show that the method based on gyros can obtain the similar estimation accuracy with the method based on IMU, and the method based on accelerometers has an advantage in y-axis deformation angle estimation.
  • Mu, J. et al. (2017). Generalised regular form based SMC for nonlinear systems with application to a WMR. IEEE Transactions on Industrial Electronics [Online] 64:6714-6723. Available at: http://dx.doi.org/10.1109/TIE.2017.2711500.
    In this paper, a generalised regular form is proposed to facilitate sliding mode control (SMC) design for a class of nonlinear systems. A novel nonlinear sliding surface is designed using implicit function theory such that the resulting sliding motion is globally asymptotically stable. Sliding mode controllers are proposed to drive the system to the sliding surface and maintain a sliding mo-tion thereafter. Tracking control of a two-wheeled mobile robot is considered to underpin the developed theoretical results. Model-based tracking control of a wheeled mobile robot (WMR) is first transferred to a stabilisation problem for the corresponding tracking error system, and then the developed theoretical results are applied to show that the tracking error system is globally asymptotically stable even in the presence of matched and mismatched uncertainties. Both experimental and simulation results demonstrate that the developed results are practicable and effective.
  • Zhang, Q. et al. (2017). Sliding mode control for singular stochastic Markovian jump systems with uncertainties. Automatica [Online] 79:27-34. Available at: http://dx.doi.org/10.1016/j.automatica.2017.01.002.
    This paper considers sliding mode control design for singular stochastic Markovian jump systems with uncertainties. A suitable integral sliding function is proposed and the resulting sliding mode dynamics is an uncertain singular stochastic Markovian jump system. A set of new sufficient conditions is developed which not only guarantees the stochastic admissibility of the sliding mode dynamics, but is also constructive and determines all the parameter matrices in the integral sliding function. A set of new sufficient conditions is developed which not only guarantees the stochastic admissibility of the sliding mode dynamics, but also determines all the parameter matrices in the integral sliding function. Then, a sliding mode control law is synthesized such that reachability of the specified sliding surface can be ensured. Finally, three examples are given to demonstrate the effectiveness of the results.
  • Mu, J. et al. (2017). Nonlinear sliding mode control of a two-wheeled mobile robot system. International Journal of Modelling, Identification and Control [Online] 27. Available at: http://doi.org/10.1504/IJMIC.2017.10003912.
    This paper presents a trajectory tracking control scheme for a two-wheeled mobile robot using sliding mode techniques. The stability of the designed sliding mode dynamics is analysed and reachability of the sliding mode is guaranteed in a given region with the proposed controller. A robot system including a micro-controller, the Arduino Due based on the ARM Cortex-M3, is used to implement the proposed control algorithm. Two DC motors controlled by PWM signals are used as actuators to implement the proposed feedback control. Simulation results are presented and compared with the results of practical experiments.
  • Li, J. et al. (2017). Robust Stabilisation of T-S Fuzzy Stochastic Descriptor Systems via Integral Sliding Modes. IEEE Transactions on Cybernetics [Online]:1-14. Available at: http://dx.doi.org/10.1109/TCYB.2017.2749244.
    This paper addresses the robust stabilisation problem for T-S fuzzy stochastic descriptor systems using an integral sliding mode control paradigm. A classical integral sliding mode control scheme and a non-parallel distributed compensation (Non-PDC) integral sliding mode control scheme are presented. It is shown that two restrictive assumptions previously adopted developing sliding mode controllers for T-S fuzzy stochastic systems are not required with the proposed framework. A unified framework for sliding mode control of T-S fuzzy systems is formulated. The proposed Non-PDC integral sliding mode control scheme encompasses existing schemes when the previously imposed assumptions hold. Stability of the sliding motion is analysed and the sliding mode controller is parameterised in terms of the solutions of a set of linear matrix inequalities (LMIs) which facilitates design. The methodology is applied to an inverted pendulum model to validate the effectiveness of the results presented.
  • Mao, Z. et al. (2017). Adaptive Compensation of Traction System Actuator Failures for High-Speed Trains. IEEE Transactions on Intelligent Transportation Systems [Online]. Available at: http://dx.doi.org/10.1109/TITS.2017.2666428.
    In this paper, an adaptive failure compensation problem is addressed for high-speed trains with longitudinal dynamics and traction system actuator failures. Considered the time-varying parameters of the train motion dynamics caused by time-varying friction characteristics, a new piecewise constant model is introduced to describe the longitudinal dynamics with variable parameters. For both the healthy piecewise constant system and the system with actuator failures, the adaptive controller structure and conditions are derived to achieve the plant-model matching. The adaptive laws are designed to update the adaptive controller parameters, in the presence of the system piecewise constant parameters and actuator failure parameters which are unknown. Based on Lyapunov functions, the closed-loop stability and asymptotic state tracking are proved. Sim-ulation results on a high-speed train model are presented to illustrate the performance of the developed adaptive actuator failure compensation control scheme.
  • Zhang, K. et al. (2016). Sliding Mode Observer Based Incipient Sensor Fault Detection with Application to High-Speed Railway Traction Device. ISA Transactions [Online] 63:49-59. Available at: http://doi.org/10.1016/j.isatra.2016.04.004.
    This paper considers incipient sensor fault development detection issue for a class of nonlinear systems with “observer unmatched” uncertainties. A particular FD (fault detection) sliding mode observer is designed for the augmented system formed by the original system and incipient sensor faults. The parameters are obtained using LMI and line filter techniques to guarantee that the generated residuals
    are robust to uncertainties and that sliding motion is not destroyed by faults. Then, three levels of novel adaptive thresholds (incipient sensor fault thresholds, sensor fault thresholds and sensor failure thresholds) are proposed based on the reduced order sliding mode dynamics, which effectively improve the incipient sensor fault development detectability. Case study of on the traction system in CRH (China
    Railway High-speed) is presented to demonstrate the effectiveness of the proposed incipient sensor fault development and senor faults detection schemes.
  • Zhang, K. et al. (2016). Incipient sensor fault estimation and accommodation for inverter devices in electric railway traction systems. International Journal of Adaptive Control and Signal Processing [Online] 31:785-804. Available at: http://dx.doi.org/10.1002/acs.2730.
    This paper proposes an incipient sensor fault estimation and accommodation method for three-phase PWM inverter devices in electric railway traction systems. First, the dynamics of inverters and incipient voltage sensor faults are modelled. Then, for the augmented system formed by original inverter system and incipient sensor faults, an optimal adaptive unknown input observer is proposed to estimate the inverter voltages, currents and the incipient sensor faults. The designed observer guarantees that the estimation errors converge to the minimal invariant ellipsoid. Moreover, based on the output regulator via internal model principle, the fault accommodation controller is proposed to ensure that the vod and voq voltages track the desired reference voltages with the tracking error converging to the minimal invariant ellipsoid. Finally, simulations based on the traction system in CRH2 (China Railway High-speed) are presented to verify the effectiveness of the proposed method.
  • Mohamed, M. et al. (2016). Robust variable structure observer design for non-linear large-scale systems with non-linear interconnections. IMA Journal of Mathematical Control and Information [Online]. Available at: http://dx.doi.org/10.1093/imamci/dnw063.
    In this paper, a variable structure observer is designed for a class of non-linear large-scale interconnected systems in the presence of uncertainties and non-linear interconnections. The modern geometric approach is used to explore system structure and a transformation is employed to facilitate the observer design. Based on the Lyapunov direct method, a set of conditions are developed such that the proposed variable structure systems can be used to estimate the states of the original interconnected systems asymptotically. The internal dynamical structure of the isolated nominal subsystems as well as the structure of the uncertainties are employed to reduce the conservatism. The bounds on the uncertainties are non-linear and are employed in the observer design to reject the effect of the uncertainties. A numerical example is presented to illustrate the approach and the simulation results showthat the proposed approach is effective.
  • Li, J. et al. (2016). Integral Sliding Mode Control for Markovian Jump T-S Fuzzy Descriptor Systems Based on the Super-Twisting Algorithm. IEE Proceedings - Control Theory and Applications [Online] 11:1134-1143. Available at: http://dx.doi.org/10.1049/iet-cta.2016.0862.
    This paper investigates integral sliding mode control problems for Markovian jump T-S fuzzy descriptor systems via the super-twisting algorithm. A new integral sliding surface which is continuous is constructed and an integral sliding mode control scheme based on a variable gain super-twisting algorithm is presented to guarantee the well-posedness of the state trajectories between two consecutive switchings. The stability of the sliding motion is analyzed by considering the descriptor redundancy and the properties of fuzzy membership functions. It is shown that the proposed variable gain super-twisting algorithm is an extension of the classical single-input case to the multi-input case. Finally, a bio-economic system is numerically simulated to verify the merits of the method proposed.

Book

  • Yan, X., Spurgeon, S. and Edwards, C. (2017). Variable Structure Control of Complex Systems: Analysis and Design. [Online]. Springer, Cham. Available at: https://link.springer.com/book/10.1007%2F978-3-319-48962-9.

Book section

  • Zhao, D., Spurgeon, S. and Yan, X. (2018). An Adaptive Finite Time Sliding Mode Observer. in: Clempner, J. and Yu, W. eds. New Perspectives and Applications of Modern Control Theory. Springer, pp. 523-538. Available at: http://www.springer.com/gb/book/9783319624631.
    This chapter develops a novel adaptive ?nite time observer which can achieve ?nite time unmatched parameter estimation and ?nite time system state observation. The proposed approach has strong robustness and rapid convergence. A step by step proof is given which employs ?nite time stability and sliding mode principles. It is seen that the method also enables lumped matched uncertainty to be estimated. An illustrative example is used to validate the effectiveness of the proposed approach.
  • Mohamed, M. et al. (2018). Variable Structure Observers for Nonlinear Interconnected Systems. in: Li, S. et al. eds. Advances in Variable Structure Systems and Sliding Mode Control—Theory and Applications. Springer, pp. 195-221. Available at: http://dx.doi.org/10.1007%2F978-3-319-62896-7_8.
    In this chapter, a variable structure observer is designed for a class of nonlinear large-scale interconnected systems in the presence of uncertainties and nonlinear interconnections. The modern geometric approach is used to explore system structure and a transformation is employed to facilitate the observer design. Based on the Lyapunov direct method, a set of conditions are developed such that the proposed variable structure systems can be used to estimate the states of the original interconnected systems asymptotically. The internal dynamical structure of the isolated nominal subsystems as well as the structure of the uncertainties are employed to reduce conservatism. The bounds on the uncertainties are nonlinear and are employed in the observer design to enhance robustness. A numerical example is presented to illustrate the results and simulation studies show that the proposed approach is effective.
  • Yan, X., Spurgeon, S. and Edwards, C. (2017). Mathematical Background. in: Yan, X., Spurgeon, S. K. and Edwards, C. eds. Variable Structure Control of Complex Systems: Analysis and Design. Springer, pp. 27-41. Available at: https://doi.org/10.1007/978-3-319-48962-9_2.
    This chapter presents the fundamental results which underpin the theoretical analysis presented in this book. Lipschitz functions, comparison functions, Lyapunov stability theory including uniform ultimate boundedness, the Razumikhin theorem, linear output sliding surface design, and the geometric structure of nonlinear systems are covered. Some preliminary mathematical results developed by the authors are also provided.
  • Yan, X., Spurgeon, S. and Edwards, C. (2017). Reduced-Order Compensator-Based Feedback Control of Large-Scale Systems. in: Yan, X., Spurgeon, S. K. and Edwards, C. eds. Variable Structure Control of Complex Systems: Analysis and Design. Springer, pp. 113-158. Available at: https://doi.org/10.1007/978-3-319-48962-9_5.
    Chapter 5 continues to consider dynamical output feedback controller design. However, compared with Chapter 4, Chapter 5 focuses on large-scale interconnected systems and uses reduced-order compensators in the feedback loop which is particularly important for large scale systems to avoid ‘the curse of dimensionality’. Sliding mode dynamics are established and the stability is analysed using an equivalent control approach and a local coordinate transformation. A robust decentralised output feedback sliding mode control scheme is synthesized such that the interconnected system can be driven to the pre-designed sliding surface. This approach allows both the nominal isolated subsystem and the whole nominal system to be nonminimum phase. In a second approach, a similar structure is introduced to identify a class of nonlinear large-scale interconnected systems. By exploiting the system structure of similarity, the proposed nonlinear reduced-order control schemes allow more general forms of uncertainties. The study shows that similar structures can simplify the analysis and reduce computation. Case studies on the HIRM aircraft and coupled inverted pendula, and a numerical simulation example are provided respectively to illustrate the results developed.
  • Yan, X., Spurgeon, S. and Edwards, C. (2017). Delay Independent Output Feedback Control. in: Yan, X., Spurgeon, S. K. and Edwards, C. eds. Variable Structure Control of Complex Systems: Analysis and Design. Springer, pp. 213-261. Available at: https://doi.org/10.1007/978-3-319-48962-9_7.
    In Chapter 7, complex control systems with time delay are considered. It is not required that the time delay is known. A Lyapunov Razumikhin approach is used to deal with the time delay throughout this chapter. All the developed results consider time varying delay and there is no limitation on the rate of change of time delay. A local stabilisation problem is considered for affine nonlinear control systems with uncertainties using a Lyapunov based approach and sliding mode control techniques. It is not assumed that the nominal system is either linearisable or partially linearisable. Stabilisation of a class of large scale systems with nonlinear interconnections is also considered. A decentralised static output feedback variable structure control is synthesised and a set of conditions is developed to guarantee that the considered large scale interconnected systems are stabilised uniformly asymptotically. Examples are provided to demonstrate the theoretical results.
  • Yan, X., Spurgeon, S. and Edwards, C. (2017). Static Output Feedback Variable Structure Control. in: Yan, X., Spurgeon, S. K. and Edwards, C. eds. Variable Structure Control of Complex Systems: Analysis and Design. Springer, pp. 43-79. Available at: https://doi.org/10.1007/978-3-319-48962-9_3.
    Chapter 3 considers static output feedback controller design for both nonlinear systems and interconnected systems. For a class of fully nonlinear systems, a variable structure control based Lyapunov method is proposed to drive the system to a ‘small’ region of the origin and maintain motion in the region thereafter. Then, in the region, the nonlinear system is linearised and a sliding mode control is designed to stabilise the system asymptotically. Both the controllers combined to stabilise the system globally. For interconnected systems, decentralised control schemes are developed and output variables embedded in the nonlinear terms are separated and used in the control design to reduce conservatism. Case studies based on a mass–spring system, coupled inverted pendulums and a flight control system are provided to show the developed control methodologies.
  • Yan, X., Spurgeon, S. and Edwards, C. (2017). Concluding Remarks. in: Yan, X., Spurgeon, S. K. and Edwards, C. eds. Variable Structure Control of Complex Systems: Analysis and Design. Springer, pp. 315-321. Available at: https://doi.org/10.1007/978-3-319-48962-9_10.
    Some examples, as an echo of the discussion about the source of complexity in Chapter 1 at the beginning of the book, are presented to further confirm the complexity of the systems considered in this book. Some suggestions for future work are presented. It is shown that study of complex control systems is a long term task for researchers and control engineers.
  • Yan, X., Spurgeon, S. and Edwards, C. (2017). Sliding Mode Observer-Based Fault Detection and Isolation. in: Yan, X., Spurgeon, S. K. and Edwards, C. eds. Variable Structure Control of Complex Systems: Analysis and Design. Springer, pp. 263-296. Available at: https://doi.org/10.1007/978-3-319-48962-9_8.
    This chapter considers fault detection and isolation (FDI) for nonlinear systems with uncertainties using particular sliding mode observers for which the parameters can be obtained using LMI techniques. A sliding mode observer based approach is presented to estimate system faults using bounds on the uncertainty, and as a special case, a fault reconstruction scheme is available where the reconstructed signal can approximate the fault signal to any accuracy. Sensor FDI for nonlinear systems is considered where a nonlinear diffeomorphism is introduced to exploit the system structure and a simple filter is presented to ‘transform’ the sensor fault into a pseudo-actuator fault scenario. Both fault estimation and reconstruction are considered. Case studies on a robotic arm and a mass spring system are given to demonstrate the effectiveness of the proposed schemes.
  • Yan, X., Spurgeon, S. and Edwards, C. (2017). Application of Decentralised Sliding Mode Control to Multimachine Power Systems. in: Yan, X., Spurgeon, S. K. and Edwards, C. eds. Variable Structure Control of Complex Systems: Analysis and Design. Springer, pp. 297-313. Available at: https://doi.org/10.1007/978-3-319-48962-9_9.
    This chapter provides a decentralised strategy for the excitation control problem of multimachine power systems formed from an interconnected set of lower order systems through a network transmission. Both mismatched uncertainties in the interconnections and parametric uncertainties in the direct axis transient short circuit time constants, which affect the subsystem input distribution matrix, are considered. The proposed approach can deal with interconnection terms and parametric disturbances with large magnitude. The results obtained hold in a large region of operation if the control gain is high enough. This allows the operating point of the multimachine power system to vary to satisfy different load demands. Simulations on a three-machine power system are presented.
  • Yan, X., Spurgeon, S. and Edwards, C. (2017). Introduction. in: Yan, X., Spurgeon, S. K. and Edwards, C. eds. Variable Structure Control of Complex Systems: Analysis and Design. Springer, pp. 1-25. Available at: https://doi.org/10.1007/978-3-319-48962-9_1.
    Complex control systems and some preliminary background knowledge of variable structure control are introduced in this chapter. Some of the sources of system complexity dealt with in this book are discussed. Specifically, the basic concepts and fundamental methodology of sliding mode control and decentralised control are provided. Core notions are clarified based on the authors’ many years of research in these areas. Several practical examples are introduced to illustrate complex systems.
  • Yan, X., Spurgeon, S. and Edwards, C. (2017). Delay Dependent Output Feedback Control. in: Yan, X., Spurgeon, S. K. and Edwards, C. eds. Variable Structure Control of Complex Systems: Analysis and Design. Springer, pp. 159-212. Available at: https://doi.org/10.1007/978-3-319-48962-9_6.
    Chapter 6 considers complex control systems with time delay under the assumption that the time delay is precisely known. A Lyapunov Razumikhin approach is employed to deal with time delay throughout this chapter. All the developed results consider time varying delay and there is no limitation on the rate of change of time delay. This is in contrast with the Lyapunov Krasovskii approach. Since the time delay is precisely known, it can be used in both the controller and observer design, and the developed results have high robustness. Both static and dynamical output feedback control schemes are presented for complex time delay systems. In addition, decentralised static output feedback sliding mode controllers are designed to stabilise a class of complex interconnected time delay systems where delay exists in both the interconnections and the isolated subsystems. Numerical examples and a case study of river pollution control are provided to demonstrate the developed results.
  • Yan, X., Spurgeon, S. and Edwards, C. (2017). Dynamical Output Feedback Variable Structure Control. in: Yan, X., Spurgeon, S. K. and Edwards, C. eds. Variable Structure Control of Complex Systems: Analysis and Design. Springer, pp. 81-111. Available at: https://doi.org/10.1007/978-3-319-48962-9_4.
    Chapter 4 considers dynamical output feedback control design for systems with mismatched uncertainties/disturbances. Compared with Chapter 3, all the uncertainties involved in this chapter are bounded by nonlinear functions of the system state variables instead of the output variables. The bounding functions are assumed to be known and thus it is possible to use them for system analysis and control design to reduce the effects of uncertainties on the systems. A sliding surface is designed which is independent of the designed observer, and then a sliding mode control is synthesised based on the designed observer and system outputs. The controller design and the observer design are separated which means that the designed controller can be used with any observer but the developed approach requires that the considered system is minimum phase. In a second approach, a dynamical compensator is designed first. A sliding surface is then designed for the augmented system formed by the considered system and the error dynamics. It is not required that the nominal system is minimum phase. Applications to control of the High Incidence Research Model (HIRM) aircraft are given. Both longitudinal and lateral aircraft dynamics based on different trim values of Mach number and height are employed in the simulation study.

Conference or workshop item

  • Zhang, K. et al. (2018). State and Parameter Estimation for a Class of Nonlinearly Parameterized Systems Using Sliding Mode Techniques. in: 2018 Annual American Control Conference (ACC). IEEE, pp. 2378-5861. Available at: http://dx.doi.org/10.23919/ACC.2018.8430753.
    In this study, a class of nonlinear parameterized systems is considered where the unknown parameters are parameterized nonlinearly. A stability criteria for time-varying systems is developed based on Perron-Frobenius theorem, and used for designing observers. A particular sliding mode observer with an update law, which can ensure that the sliding motion converges to zero asymptotically, is designed to estimate states and unknown parameters. The developed result is applied to a three-phase inverter system used by China high-speed trains to verify the effectiveness.
  • Onyeka, A. et al. (2018). Decentralized Sliding Mode LFC for Nonlinear Interconnected Power System with Time Delay. in: 2018 Annual American Control Conference (ACC). IEEE. Available at: https://ieeexplore.ieee.org/abstract/document/8430844/.
    This paper considers a decentralised sliding mode load frequency control (LFC) for multi-area power system with uncertain time-varying parameters and delay. Since delays can exert a destabilizing effect on the overall system, it is necessary to maximize the delay bound in order to regularize the deviation in frequency and tie-line power. Robustness is improved by taking advantage of the system structure and uncertainty bounds. A sliding surface is designed, which guarantees the stability of the sliding motion and the stability of the sliding motion is analyzed based on Lyapunov-Razumikhin function which has a fast changing rate. A delay dependent decentralized sliding mode control is synthesized to drive the system to the sliding surface in finite time, and maintain a sliding motion afterward. The effectiveness of the proposed method is tested
    via a two-area interconnected power system.
  • Mao, Z. et al. (2017). Adaptive Position Tracking Compensation for High-Speed Trains with Actuator Failures. in: 20th World Congress of the International Federation of Automatic Control (IFAC). Elsevier, pp. 14266-14271. Available at: https://doi.org/10.1016/j.ifacol.2017.08.1835.
    In this paper, an adaptive failure compensation is proposed for high-speed trains with traction system actuator failures to achieve the position tracking. To deal with the time-varying parameters of the train motion dynamics, the piecewise constant model is introduced to describe the train dynamics with variable parameters. For the system with actuator failures, the adaptive controller with the adaptive laws is designed to achieve the position tracking, in the presence of the system piecewise constant parameters and actuator failure parameters which are unknown. Simulation results on a high-speed train model are presented to illustrate the performance of the developed adaptive actuator failure compensation control scheme.
  • Zhang, K. et al. (2017). Interval Sliding Mode Observer Based Incipient Fault Detection with Application to a High-Speed Railway Traction Device. in: 4th IEEE International Symposium on Robotics and Intelligent Sensors (IEEE IRIS2016). Institute of Electrical and Electronics Engineers, pp. 157-162. Available at: https://doi.org/10.1109/IRIS.2016.8066083.
    In this paper, a novel interval sliding mode observer is designed to detect incipient faults for a class of non-Lipschitz nonlinear systems with mismatched uncertainties. The interval estimation concept is introduced to design interval estimator for the nonlinear subsystem with uncertainties bounded by known intervals. Then novel injection functions are designed to ensure that the sliding motion takes place and maintains thereafter. At last, new residual generators and adaptive threshold generators are designed, and the corresponding fault detectability is studied. Case study on a traction device in CRH (China Railway High-Speed) is presented to demonstrate the effectiveness of proposed incipient fault detection scheme.
  • Onyeka, A., Yan, X. and Mu, J. (2017). Sliding Mode Control of Time-Delay Systems with Delayed Nonlinear Uncertainties. in: 20th World Congress of the International Federation of Automatic Control (IFAC). Elsevier, pp. 2696-2701. Available at: https://doi.org/10.1016/j.ifacol.2017.08.555.
    This paper considers a class of time delay systems with delayed states and non-linear uncertainties using sliding mode techniques. In order to improve robustness, matched and mismatched disturbances are considered and assumed to be nonlinear functions of system states and delayed states. A sliding function is designed and a set of su?cient conditions is derived to guarantee the stability of the corresponding sliding motion by using Lyapunov-Razumikhin approach which allows large time varying delay with fast changing rate. A delay dependent sliding mode control is synthesized to drive the system to the sliding surface in ?nite time and maintain a sliding motion thereafter. E?ectiveness of the proposed method is tested via a case study on a continuous stirred tank reactor system.
  • Zhang, B. et al. (2017). Sliding Mode Control for Nonlinear Manipulator Systems. in: 20th World Congress of the International Federation of Automatic Control (IFAC). Elsevier, pp. 5127-5132. Available at: https://doi.org/10.1016/j.ifacol.2017.08.781.
    A sliding mode control is developed for nonlinear manipulator systems. An improved version of the exponential reaching law is presented to ensure the states converge to the sliding surface in finite time. In the presence of system uncertainty and external disturbances, the system states converge to a small region centered at the origin within a finite time and thereafter will asymptotically converge to the equilibrium point. The robustness and convergence properties of the proposed approach are demonstrated from both the theoretical point of view and also using simulation studies.
  • Mohamed, M. et al. (2017). Adaptive observer design for a class of nonlinear interconnected systems with uncertain time varying parameters. in: 20th World Congress of the International Federation of Automatic Control (IFAC). Elsevier, pp. 1421-1426. Available at: https://doi.org/10.1016/j.ifacol.2017.08.284.
    In this paper, a class of nonlinear interconnected systems with uncertain time varying parameters is considered, in which both the interconnections and the isolated subsystems are nonlinear. The di?erence between the unknown time varying parameter and its corresponding nominal value is assumed to be bounded where the nominal value is not required to be known. A dynamical system is proposed and then, the error systems between the original interconnected system and the designed dynamical systems are analysed based on the Lyapunov direct method. A set of conditions is developed such that the augmented systems formed by the error dynamical systems and the designed adaptive laws, are globally uniformly bounded. Speci?cally, the estimation errors are asymptotically convergent to zero using LaSalle-Yoshizawa Theorem. Case study on a coupled inverted pendulum system is presented to demonstrate the developed methodology, and simulation shows that the proposed approach is e?ective and practicable.
  • Zhang, K. et al. (2017). Incipient Fault Detection Based on Robust Threshold Generators: A Sliding Mode Interval Estimation Approach. in: 20th World Congress of the International Federation of Automatic Control (IFAC). Elsevier, pp. 5067-5072. Available at: https://doi.org/10.1016/j.ifacol.2017.08.953.
    This paper presents an incipient fault detection framework for systems with process disturbances and sensor disturbances based on a novel proposed threshold generator. Firstly, the definition of incipient faults is given using the H? from the quantitative point of view. Then, from the generated residuals and RMS evaluation function, the threshold generator is proposed based on sliding mode interval estimation module to ensure that the RMS evaluation of residuals is less than the generated threshold. By using recent results of the bounded real lemma for internally positive systems, a set of su?cient conditions to detect incipient faults via linear matrix inequality (LMI) is presented. Case study on an electrical traction device is presented to verify the e?ectiveness of the proposed method.
  • Mao, Z. et al. (2017). Adaptive position tracking control of high-speed trains with piecewise dynamics. in: 2017 American Control Conference. Institute of Electrical and Electronics Engineers, pp. 2453-2458. Available at: http://dx.doi.org/10.23919/ACC.2017.7963321.
    This paper addresses the adaptive position track-ing control problem for high-speed trains with time-varying resistances and mass in the motion dynamics. To handel these time-varying parameters with piecewise constant characteris-tics, a piecewise constant model with unknown parameters is in-troduced for different train operation conditions. An integrated adaptive controller structure is constructed to have the capacity to achieve plant-model matching with known parameters and complete system parametrization with unknown parameters, which is desirable for adaptive tracking control. For the train position tracking requirement, the reference model system is speci?cally chosen. Stable adaptive laws are designed to update the adaptive controller parameters in the presence of the unknown piecewise constant system parameters. Closed-loop stability and asymptotic state tracking are proved. Simulation results on a high-speed train model are presented to illustrate the desired adaptive position tracking control performance.
  • Mu, J. et al. (2017). Decentralised sliding mode control for nonlinear interconnected systems in the generalised regular form. in: 20th World Congress of the International Federation of Automatic Control (IFAC). Elsevier, pp. 8850-8855. Available at: https://doi.org/10.1016/j.ifacol.2017.08.1541.
    In this paper, a decentralised control strategy based on sliding mode techniques is proposed for a class of nonlinear interconnected systems in generalised regular form. All the isolated subsystems and interconnections are fully nonlinear. It is not required that the nominal isolated subsystems are either linearizable or partially linearizable. The uncertainties are nonlinear and bounded by known functions. Under mild conditions, sliding mode controllers for each subsystem are designed by only employing local information. Su?cient conditions are developed under which information on the interconnections is employed for decentralised controller design to reduce the e?ects of the interconnections on the entire systems. The bounds on the uncertainties have more general forms compared with previous work. A simulation example is used to demonstrate the e?ectiveness of the proposed method.
  • Zhang, K. et al. (2017). Incipient Sensor Fault Detection for Inverter Devices in Electric Railway Traction Systems. in: 36th Chinese Control Conference. IEEE, pp. 7482-7487. Available at: http://dx.doi.org/10.23919/ChiCC.2017.8028538.
    This paper proposes an incipient sensor fault detection method for three-phase PWM inverter devices in electric railway traction systems. An adaptive and sliding mode unknown input observer is designed for sensor faulty inverter system. The invariant ellipsoid is used to generate threshold. The parameters of the observer are particularly designed such that the estimation errors converge to the threshold invariant ellipsoid before the sensor fault develops to incipient fault degree, and the estimation errors exceed the threshold after the sensor fault develops to incipient fault degree. Finally, simulations based on the traction system in CRH2 (China Railway High-speed) are presented to verify the effectiveness of the proposed method.
  • Zhao, D., Spurgeon, S. and Yan, X. (2016). Adaptive output feedback finite time control for a class of second order nonlinear systems. in: the 14th International Workshop on Variable Structure Systems (VSS 2016).. Available at: http://dx.doi.org/10.1109/VSS.2016.7506890.
    This paper develops a finite time output feedback based control scheme for a class of nonlinear second order systems. The system representation includes both model uncertainty and uncertain parameters. A finite time parameter estimator is developed. This facilitates the design of a finite time observer based on the well-established step-by-step sliding mode observer design approach. A terminal sliding mode control scheme is then developed using the corresponding state estimates. The methodology is applied to a continuous stirred tank reactor system to validate the effectiveness of the proposed approach.
  • Mohamed, M. et al. (2016). Variable structure observer for a class of nonlinear large-scale interconnected systems with uncertainties. in: the 14th International Workshop on Variable Structure Systems (VSS 2016).. Available at: http://dx.doi.org/10.1109/VSS.2016.7506949.
    In this paper, a variable structure observer design approach is proposed for a class of nonlinear, large-scale interconnected systems in the presence of unstructured uncertainty. The modern geometric approach is exploited to explore the system structure and a transformation is developed to facilitate observer design. Using the Lyapunov direct method, a robust asymptotic observer is presented which exploits the internal dynamic structure of the system as well as the structure of the uncertainties. The bounds on the uncertainties are nonlinear and are employed in the observer design to reject the effect of the uncertainties. A numerical example is presented to illustrate the approach and the simulation results show that the proposed approach is effective.

Forthcoming

  • Onyeka, A. et al. (2018). Stabilisation of Time Delay Systems with Nonlinear Disturbances Using Sliding Mode Control. International Journal of Modelling, Identification and Control.
    This paper focuses on a class of control systems with delayed states and nonlinear disturbances using sliding mode techniques. Both matched and mismatched uncertainties are considered which are assumed to be bounded by known nonlinear functions. The bounds are used in the control design and analysis to reduce conservatism. A sliding function is designed and a set of sufficient conditions is derived to guarantee the asymptotic stability of the corresponding sliding motion by using the Lyapunov-Razumikhin approach which allows large time varying delay with fast changing rate. A delay dependent sliding mode control is synthesised to drive the system to the sliding surface in finite time and maintain a sliding motion thereafter. Effectiveness of the proposed method is demonstrated via a case study on a continuous stirred tank reactor system.
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