Dear Editor,This letter studies finite-time stability (FTS) of impulsive and switched hybrid systems with delay-dependent impulses. Some conditions, based on Lyapunov method, are proposed for ensuring FTS and estimati...Dear Editor,This letter studies finite-time stability (FTS) of impulsive and switched hybrid systems with delay-dependent impulses. Some conditions, based on Lyapunov method, are proposed for ensuring FTS and estimating settling-time function (STF) of the hybrid systems.When switching dynamics are FTS and impulsive dynamics involve destabilizing delay-dependent impulses, the FTS is retained if the impulses occur infrequently.展开更多
The problem of admissibility analysis and control synthesis of discrete-time switched linear singular （SLS） systems for arbitrary switching laws is solved. By using the switched Lyapunov function approach, some new ...The problem of admissibility analysis and control synthesis of discrete-time switched linear singular （SLS） systems for arbitrary switching laws is solved. By using the switched Lyapunov function approach, some new sufficient conditions under which the SLS system is admissible for arbitrary switching laws are derived in terms of linear matrix inequalities （LMIs）. Based on the admissibility results, control synthesis is then to design switched state feedback and static output feedback controllers, guaranteeing that the resulting closed-loop system is admissible. The presented results can be viewed as the extensions of previous works on switched Lyapunov function approach from the regular switched systems to singular switched cases. Examples are provided to demonstrate the reduced conservatism and effectiveness of the proposed conditions.展开更多
Switched Reluctance Motors(SRMs),outfitted with rugged construction,good speed range,high torque density,and rare earth-free nature that outweigh induction motors(IM)and permanent magnet synchronous motor(PMSM),afford...Switched Reluctance Motors(SRMs),outfitted with rugged construction,good speed range,high torque density,and rare earth-free nature that outweigh induction motors(IM)and permanent magnet synchronous motor(PMSM),afford a broad range of applications in the domain of electric vehicles(EVs).Standard copper magnetic wire and low-carbon steel laminations are used to construct SRMs,which give them high efficiency in the range of 85-95%.Despite SRM's desirable features over traditional motor-speed drives,high torque ripples and radial distortions constrain their deployment in EVs.Precise rotor position is imperative for effective management of the speed and torque of SRMs.This paper provides an illustrative compendium on review of the torque-speed control and ripple mitigation techniques using design enhancements and control methods for SRM drives for EV applications.The various schemes were evaluated on their performance metricsoperational speed range,control complexity,practical realization,need for pre-stored parameters(look-up tables of current,inductance and torque profiles)and motor controller memory requirements.The findings provide valuable insights into balancing the gains and trade-offs associated with EV applications.Furthermore,they pinpoint opportunities for enhancement by analyzing the cost and technical aspects of different SRM controllers.展开更多
Switched systems play an imperative role in modeling many real industrial systems with abrupt changes.Due to possible exposure to unreliable and complex physical environments,switching dynamics may simultaneously face...Switched systems play an imperative role in modeling many real industrial systems with abrupt changes.Due to possible exposure to unreliable and complex physical environments,switching dynamics may simultaneously face multiple faults,including the unexpected controller disconnect,the temporary mismatch between subsystems and desired corresponding controllers,and the intermittent disordering of mode transitions.These commonly arising faults may result in severe and detrimental impacts on the reliability and convergence of the closed-loop solution,thereby bringing significant yet challenging issues to be tackled.This paper provides the first attempt to investigate the stabilization problem for a class of constrained switched linear systems with multiple faults under mode-dependent dwell time(MDT).From a set-theory perspective,we demonstrate a critical necessary and sufficient stability condition for switched systems without uncertainties.Moreover,the non-conservative stability criterion is further extended to the perturbed switched systems with rigorous proof.A switching communication network example verifies the validity of the theoretical result and demonstrates their advantages.展开更多
In this paper,we present a high peak power passively Q-switched intracavity frequency-doubled green laser based on an efficient LED-pumped Nd:YAG dual-rod laser module.In quasi-continuous wave(QCW)running operation,th...In this paper,we present a high peak power passively Q-switched intracavity frequency-doubled green laser based on an efficient LED-pumped Nd:YAG dual-rod laser module.In quasi-continuous wave(QCW)running operation,the average output power of the fundamental laser at 1064 nm reaches as high as 20.98 W at a repetition rate of 50 Hz with a maximum single pulse energy of 419.6 mJ,corresponding to a maximum optical conversion efficiency of 38.8%and a slope efficiency of 41%.展开更多
We demonstrated a new type of MAX phase material,chromium titanium aluminum carbide(Cr_(2)TiAlC_(2)) polymer film,to generate a passively Q-switched erbium-doped fiber laser(EDFL).The film thickness was measured to be...We demonstrated a new type of MAX phase material,chromium titanium aluminum carbide(Cr_(2)TiAlC_(2)) polymer film,to generate a passively Q-switched erbium-doped fiber laser(EDFL).The film thickness was measured to be around 45 μm,which was fabricated using the embedding method with polyvinyl alcohol(PVA) polymer as hoster.The saturable absorber(SA) film demonstrates a dual-wavelength passively Q-switched EDFL which operates at 1 531 nm and 1 560.19 nm,respectively.The Q-switching pulse duration could be varied from 2.46 μs to 770 ns,while the repetition rate varied from 92.76 kHz to 106.6 kHz with an increasing input pumping range from 154 mW to 300 mW.The maximum output power and pulse energy of 15.05 mW and 141.18 nJ were obtained at the maximum input power of 300 mW,respectively.展开更多
Sensorless control of switched reluctance motors(SRMs) often requires a hybrid mode combining low-speed pulse injection methods and high-speed model-based estimation.However,pulse injection causes unwanted audible noi...Sensorless control of switched reluctance motors(SRMs) often requires a hybrid mode combining low-speed pulse injection methods and high-speed model-based estimation.However,pulse injection causes unwanted audible noises and torque ripples.This article proposes an enhanced model-based sensorless approach to extend downwards the speed range in which sensorless control can work without injection.An inertial phase-locked loop (IPLL) based on a stator flux observer is introduced for position estimation.Compared to the conventional phase-locked loop scheme,the IPLL offers a more robust disturbance rejection capability and thus reduces the flux model errors at lower speeds.Experimental results substantiate the feasibility of the extended low-speed operation using the model-based sensorless control approach.展开更多
The robust admissibility analysis of a class of uncertain discrete-time switched linear singular（SLS） systems for arbitrary switching laws is addressed. The parameter uncertainty is assumed to be norm-bounded. First...The robust admissibility analysis of a class of uncertain discrete-time switched linear singular（SLS） systems for arbitrary switching laws is addressed. The parameter uncertainty is assumed to be norm-bounded. First, by using the switched Lyapunov function approach, some new sufficient conditions ensuring the nominal discrete-time SLS system to be regular, casual and asymptotically stable for arbitrary switching laws are derived in terms of linear matrix inequalities. Then, the robust admissibility condition for the uncertain discrete-time SLS systems is presented. The obtained results can be viewed as an extension of previous works on the switched Lyapunov function approach from the regular switched linear systems to the switched linear singular cases. Numerical examples show the reduced conservatism and effectiveness of the proposed conditions.展开更多
This paper investigates L2-gain analysis and anti-windup compensation gains design for a class of discrete-time switched systems with saturating actuators and L2 bounded disturbances by using the switched Lyapunov fun...This paper investigates L2-gain analysis and anti-windup compensation gains design for a class of discrete-time switched systems with saturating actuators and L2 bounded disturbances by using the switched Lyapunov function approach.For a given set of anti-windup compensation gains,we firstly give a sufficient condition on tolerable disturbances under which the state trajectory starting from the origin will remain inside a bounded set for the corresponding closed-loop switched system subject to L2 bounded disturbances.Then,the upper bound on the restricted L2-gain is obtained over the set of tolerable disturbances.Furthermore,the antiwindup compensation gains aiming to determine the largest disturbance tolerance level and the smallest upper bound of the restricted L2-gain are presented by solving a convex optimization problem with linear matrix inequality(LMI) constraints.A numerical example is given to illustrate the effectiveness of the proposed design method.展开更多
A new model of dynamical systems is proposed which consists of singular systems with impulsive effects, i.e., switched and impulsive singular systems （SISS）. By using the switched Lyapunov functions method, a suffic...A new model of dynamical systems is proposed which consists of singular systems with impulsive effects, i.e., switched and impulsive singular systems （SISS）. By using the switched Lyapunov functions method, a sufficient condition for the solvability of the H-infinity control problem for SISSs is given which generalizes the H-infinity control theory for singular systems to switched singular systems with impulsive effects. Then the sufficient condition of solvablity of the H-infinity control problem is presented in terms of linear matrix inequalities. Finally, the effectiveness of the developed aooroach for switched and imoulsive singular svstems is illustrated by a numerical example.展开更多
The problem of observer-based robust H-infinity control is addressed for a class of linear discrete-time switched systems with time-varying norm-bounded uncertainties by using switched Lyapunov function method. None o...The problem of observer-based robust H-infinity control is addressed for a class of linear discrete-time switched systems with time-varying norm-bounded uncertainties by using switched Lyapunov function method. None of the individual subsystems is assumed to be robustly H-infinity solvable. A novel switched Lypunov function matrix with diagonal-block form is devised to overcome the difficulties in designing switching laws. For robust H-infinity stability analysis, two linear-matrix-inequality-based sufficient conditions are derived by only using the smallest region function strategy if some parameters are preselected. Then, the robust H-infinity control synthesis is studied using a switching state feedback and an observer-based switching dynamical output feedback. All the switching laws are simultaneously constructively designed. Finally, a simulation example is given to illustrate the validity of the results.展开更多
The problems of robust stability and stabilization via memoryless state feedback for a class of discrete-time switched singular systems with time-varying delays and linear fractional uncertainties are investigated.By ...The problems of robust stability and stabilization via memoryless state feedback for a class of discrete-time switched singular systems with time-varying delays and linear fractional uncertainties are investigated.By constructing a novel switched Lyapunov-Krasovskii functional,a delay-dependent criterion for the unforced system to be regular,causal and uniformly asymptotically stable is established in terms of linear matrix inequalities（LMIs）.An explicit expression for the desired memoryless state feedback stabilization controller is also given.The merits of the proposed criteria lie in their less conservativeness and relative simplicity,which are achieved by considering additionally useful terms（ignored in previous methods） when estimating the upper bound of the forward difference of the Lyapunov-Krasovskii functional and by avoiding utilizing any model augmentation transformation.Some numerical examples are provided to illustrate the validity of the proposed methods.展开更多
A wavelet collocation method with nonlinear auto companding is proposed for behavioral modeling of switched current circuits.The companding function is automatically constructed according to the initial error distri...A wavelet collocation method with nonlinear auto companding is proposed for behavioral modeling of switched current circuits.The companding function is automatically constructed according to the initial error distribution obtained through approximating the input output function of the SI circuit by conventional wavelet collocation method.In practical applications,the proposed method is a general purpose approach,by which both the small signal effect and the large signal effect are modeled in a unified formulation to ease the process of modeling and simulation.Compared with the published modeling approaches,the proposed nonlinear auto companding method works more efficiently not only in controlling the error distribution but also in reducing the modeling errors.To demonstrate the promising features of the proposed method,several SI circuits are employed as examples to be modeled and simulated.展开更多
In this paper, observer-based static output feedback control problem for discrete-time uncertain switched systems is investigated under an arbitrary switching rule. The main method used in this note is combining switc...In this paper, observer-based static output feedback control problem for discrete-time uncertain switched systems is investigated under an arbitrary switching rule. The main method used in this note is combining switched Lyapunov function （SLF） method with Finsler＇s Lemma. Based on linear matrix inequality （LMI） a less conservative stability condition is established and this condition allows extra degree of freedom for stability analysis. Finally, a simulation example is given to illustrate the efficiency of the result.展开更多
A control strategy of switched reluctance motor (SRM)for electric vehicle applications is proposed. In electric vehicle application, the switched reluctance motor is a good choice with its flexible control method, com...A control strategy of switched reluctance motor (SRM)for electric vehicle applications is proposed. In electric vehicle application, the switched reluctance motor is a good choice with its flexible control method, compactness, robustness, high efficiency and high starting torque. In this paper, the control strategy of motoring and regenerative braking for electric vehicle application is presented. Computer simulations are employed to analyze the steady state behavior of SRM propulsion system. Experimental results in electric motorcycle are provided to demonstrate the validity of SRM propulsion system.展开更多
In conformity with a fifth order RLC elliptic filter circuit prototype, it is easy to conceive the corresponding RC active filter circuit. Simple and feasible method presented here can be used to contrive...In conformity with a fifth order RLC elliptic filter circuit prototype, it is easy to conceive the corresponding RC active filter circuit. Simple and feasible method presented here can be used to contrive the equivalent switched capacitor filter circuit and switched current filter circuit. Consulting the technique data manual, we can expediently design a specific RLC filter. Therefore, it is of great convenience to design the switched current filter, which has the same performances. Such a kind of technology is useful in the domain of analogue sampled data signal processing.展开更多
This paper addresses the cooperative output regulation problem of a class of multi-agent systems （MASs）. Each agent is a switched linear system. We propose an agent-dependent multiple Lyapunov function （MLF） appro...This paper addresses the cooperative output regulation problem of a class of multi-agent systems （MASs）. Each agent is a switched linear system. We propose an agent-dependent multiple Lyapunov function （MLF） approach to design the switching law for each switched agent. The distributed controller for each agent is constructed based on a dynamic compensator. A sufficient condition for the solvability of the output regulation problem of switched agent networks is presented by distributed controllers and agent-dependent multiple Lyapunov function approach. Finally, simulation results demonstrate the effectiveness of our theory.展开更多
Power generation becomes the need of developed, developing and under developed countries to meet their increasing power requirements. When affordability increases their requirement of power increases, this happens whe...Power generation becomes the need of developed, developing and under developed countries to meet their increasing power requirements. When affordability increases their requirement of power increases, this happens when increased per capita consumption. The existing power scenario states that highest power is produced using firing of coals called thermal energy. A high efficiency Switched Reluctance Generator (SRG) based high frequency switching scheme to enhance the output for grid connectivity is designed, fabricated and evaluated. This proposed method generates the output for the low wind speed. It provides output at low speed because of multi-level DC-DC converter and storage system. It is an efficient solution for low wind power generation. The real time readings and results are discussed.展开更多
Based on the switched nonlinear system, a switched adaptive Active Disturbance Rejection Control(ADRC) law is proposed for the Variable Structure Near Space Vehicle(VSNSV) with unknown uncertainties and external distu...Based on the switched nonlinear system, a switched adaptive Active Disturbance Rejection Control(ADRC) law is proposed for the Variable Structure Near Space Vehicle(VSNSV) with unknown uncertainties and external disturbances. The reduced-order Extended State Observers(ESOs) are constructed for the attitude angle system and the angular rate system to estimate the total disturbance in real time. With the extended state introduced to counteract the effects of uncertainties and disturbances, a systematic procedure is presented for the synthesis of the switched adaptive ADRC strategy. Rigorous proof shows that the estimation errors of the reduced-order ESOs would converge to a small neighborhood of zero in finite time, and that the output of the closedloop system can track a given signal stably for a class of switching signals with average dwell time via the proposed approach. The variable gain control strategy based on Adaptive Dynamic Programming(ADP) with the actor-critic structure is also designed to improve the dynamic performance of the system. Simulation results verify the effectiveness and advantage of the proposed control scheme.展开更多
An adaptive robust attitude tracking control law based on switched nonlinear systems is presented for a variable structure near space vehicle （VSNSV） in the presence of uncertainties and disturbances. The adaptive f...An adaptive robust attitude tracking control law based on switched nonlinear systems is presented for a variable structure near space vehicle （VSNSV） in the presence of uncertainties and disturbances. The adaptive fuzzy systems are employed for approximating unknown functions in the flight dynamic model and their parameters are updated online. To improve the flight robust performance, robust controllers with adaptive gains are designed to compensate for the approximation errors and thus they have less design conservation. Moreover, a systematic procedure is developed for the synthesis of adaptive fuzzy dynamic surface control （DSC） approach. According to the common Lyapunov function theory, it is proved that all signals of the closed-loop system are uniformly ultimately bounded by the continuous controller. The simulation results demonstrate the effectiveness and robustness of the proposed control scheme.展开更多
基金supported by the National Natural Science Foundation of China(61833005)
文摘Dear Editor,This letter studies finite-time stability (FTS) of impulsive and switched hybrid systems with delay-dependent impulses. Some conditions, based on Lyapunov method, are proposed for ensuring FTS and estimating settling-time function (STF) of the hybrid systems.When switching dynamics are FTS and impulsive dynamics involve destabilizing delay-dependent impulses, the FTS is retained if the impulses occur infrequently.
基金supported partly by the National Natural Science Foundation of China(6057400660835001)+1 种基金the Key Project of Chinese Ministry of Education(108060)the Jiangsu Planned Projects for Postdoctoral Research Funds(0802010c).
文摘The problem of admissibility analysis and control synthesis of discrete-time switched linear singular （SLS） systems for arbitrary switching laws is solved. By using the switched Lyapunov function approach, some new sufficient conditions under which the SLS system is admissible for arbitrary switching laws are derived in terms of linear matrix inequalities （LMIs）. Based on the admissibility results, control synthesis is then to design switched state feedback and static output feedback controllers, guaranteeing that the resulting closed-loop system is admissible. The presented results can be viewed as the extensions of previous works on switched Lyapunov function approach from the regular switched systems to singular switched cases. Examples are provided to demonstrate the reduced conservatism and effectiveness of the proposed conditions.
基金supported in part by the Universitat Politècnica de València under grant PAID-10-21supported through AMRITA Seed Grant(Proposal ID:ASG2022188)。
文摘Switched Reluctance Motors(SRMs),outfitted with rugged construction,good speed range,high torque density,and rare earth-free nature that outweigh induction motors(IM)and permanent magnet synchronous motor(PMSM),afford a broad range of applications in the domain of electric vehicles(EVs).Standard copper magnetic wire and low-carbon steel laminations are used to construct SRMs,which give them high efficiency in the range of 85-95%.Despite SRM's desirable features over traditional motor-speed drives,high torque ripples and radial distortions constrain their deployment in EVs.Precise rotor position is imperative for effective management of the speed and torque of SRMs.This paper provides an illustrative compendium on review of the torque-speed control and ripple mitigation techniques using design enhancements and control methods for SRM drives for EV applications.The various schemes were evaluated on their performance metricsoperational speed range,control complexity,practical realization,need for pre-stored parameters(look-up tables of current,inductance and torque profiles)and motor controller memory requirements.The findings provide valuable insights into balancing the gains and trade-offs associated with EV applications.Furthermore,they pinpoint opportunities for enhancement by analyzing the cost and technical aspects of different SRM controllers.
基金supported in part by the Natural Sciences and Engineering Research Council of Canada(NSERC)supported by the National Natural Science Foundation of China under Grant 62303403Zhejiang Provincial Natural Science Foundation of China under Grants LR25F030004 and LQ24F030022。
文摘Switched systems play an imperative role in modeling many real industrial systems with abrupt changes.Due to possible exposure to unreliable and complex physical environments,switching dynamics may simultaneously face multiple faults,including the unexpected controller disconnect,the temporary mismatch between subsystems and desired corresponding controllers,and the intermittent disordering of mode transitions.These commonly arising faults may result in severe and detrimental impacts on the reliability and convergence of the closed-loop solution,thereby bringing significant yet challenging issues to be tackled.This paper provides the first attempt to investigate the stabilization problem for a class of constrained switched linear systems with multiple faults under mode-dependent dwell time(MDT).From a set-theory perspective,we demonstrate a critical necessary and sufficient stability condition for switched systems without uncertainties.Moreover,the non-conservative stability criterion is further extended to the perturbed switched systems with rigorous proof.A switching communication network example verifies the validity of the theoretical result and demonstrates their advantages.
基金supported by the Nanjing University of Posts and Telecommunications Foundation,China(Grant Nos.JUH219002 and JUH219007)the Key R&D Program of Shandong Province,China(Grant No.2021CXGC010202)。
文摘In this paper,we present a high peak power passively Q-switched intracavity frequency-doubled green laser based on an efficient LED-pumped Nd:YAG dual-rod laser module.In quasi-continuous wave(QCW)running operation,the average output power of the fundamental laser at 1064 nm reaches as high as 20.98 W at a repetition rate of 50 Hz with a maximum single pulse energy of 419.6 mJ,corresponding to a maximum optical conversion efficiency of 38.8%and a slope efficiency of 41%.
文摘We demonstrated a new type of MAX phase material,chromium titanium aluminum carbide(Cr_(2)TiAlC_(2)) polymer film,to generate a passively Q-switched erbium-doped fiber laser(EDFL).The film thickness was measured to be around 45 μm,which was fabricated using the embedding method with polyvinyl alcohol(PVA) polymer as hoster.The saturable absorber(SA) film demonstrates a dual-wavelength passively Q-switched EDFL which operates at 1 531 nm and 1 560.19 nm,respectively.The Q-switching pulse duration could be varied from 2.46 μs to 770 ns,while the repetition rate varied from 92.76 kHz to 106.6 kHz with an increasing input pumping range from 154 mW to 300 mW.The maximum output power and pulse energy of 15.05 mW and 141.18 nJ were obtained at the maximum input power of 300 mW,respectively.
基金supported in part by the National Natural Science Foundation of China 52307069in part by 2024 Tertiary Education Scientific Research Project of Guangzhou Municipal Education Bureau under Grant2024312176in part by the Project of Hetao Shenzhen-Hong Kong Science and Technology Innovation Cooperation Zone under Grant HZQB-KCZYB-2020083。
文摘Sensorless control of switched reluctance motors(SRMs) often requires a hybrid mode combining low-speed pulse injection methods and high-speed model-based estimation.However,pulse injection causes unwanted audible noises and torque ripples.This article proposes an enhanced model-based sensorless approach to extend downwards the speed range in which sensorless control can work without injection.An inertial phase-locked loop (IPLL) based on a stator flux observer is introduced for position estimation.Compared to the conventional phase-locked loop scheme,the IPLL offers a more robust disturbance rejection capability and thus reduces the flux model errors at lower speeds.Experimental results substantiate the feasibility of the extended low-speed operation using the model-based sensorless control approach.
基金The National Natural Science Foundation of China(No.60835001)the Key Project of Ministry of Education of China (No.108060)
文摘The robust admissibility analysis of a class of uncertain discrete-time switched linear singular（SLS） systems for arbitrary switching laws is addressed. The parameter uncertainty is assumed to be norm-bounded. First, by using the switched Lyapunov function approach, some new sufficient conditions ensuring the nominal discrete-time SLS system to be regular, casual and asymptotically stable for arbitrary switching laws are derived in terms of linear matrix inequalities. Then, the robust admissibility condition for the uncertain discrete-time SLS systems is presented. The obtained results can be viewed as an extension of previous works on the switched Lyapunov function approach from the regular switched linear systems to the switched linear singular cases. Numerical examples show the reduced conservatism and effectiveness of the proposed conditions.
基金supported by National Natural Science Foundation of China (Nos.61174073 and 90816028)
文摘This paper investigates L2-gain analysis and anti-windup compensation gains design for a class of discrete-time switched systems with saturating actuators and L2 bounded disturbances by using the switched Lyapunov function approach.For a given set of anti-windup compensation gains,we firstly give a sufficient condition on tolerable disturbances under which the state trajectory starting from the origin will remain inside a bounded set for the corresponding closed-loop switched system subject to L2 bounded disturbances.Then,the upper bound on the restricted L2-gain is obtained over the set of tolerable disturbances.Furthermore,the antiwindup compensation gains aiming to determine the largest disturbance tolerance level and the smallest upper bound of the restricted L2-gain are presented by solving a convex optimization problem with linear matrix inequality(LMI) constraints.A numerical example is given to illustrate the effectiveness of the proposed design method.
基金the National Natural Science Foundation of China (No.60574013)the Science and Technology Foundation of theEducation Department of Liaoning Province (No.20060823)
文摘A new model of dynamical systems is proposed which consists of singular systems with impulsive effects, i.e., switched and impulsive singular systems （SISS）. By using the switched Lyapunov functions method, a sufficient condition for the solvability of the H-infinity control problem for SISSs is given which generalizes the H-infinity control theory for singular systems to switched singular systems with impulsive effects. Then the sufficient condition of solvablity of the H-infinity control problem is presented in terms of linear matrix inequalities. Finally, the effectiveness of the developed aooroach for switched and imoulsive singular svstems is illustrated by a numerical example.
基金This work was supported by the National Natural Science Foundation of China (No. 60274009, 60574013)
文摘The problem of observer-based robust H-infinity control is addressed for a class of linear discrete-time switched systems with time-varying norm-bounded uncertainties by using switched Lyapunov function method. None of the individual subsystems is assumed to be robustly H-infinity solvable. A novel switched Lypunov function matrix with diagonal-block form is devised to overcome the difficulties in designing switching laws. For robust H-infinity stability analysis, two linear-matrix-inequality-based sufficient conditions are derived by only using the smallest region function strategy if some parameters are preselected. Then, the robust H-infinity control synthesis is studied using a switching state feedback and an observer-based switching dynamical output feedback. All the switching laws are simultaneously constructively designed. Finally, a simulation example is given to illustrate the validity of the results.
基金supported by the National Natural Science Foundation of China(6090402060835001)the Jiangsu Planned Projects for Postdoctoral Research Funds(0802010C)
文摘The problems of robust stability and stabilization via memoryless state feedback for a class of discrete-time switched singular systems with time-varying delays and linear fractional uncertainties are investigated.By constructing a novel switched Lyapunov-Krasovskii functional,a delay-dependent criterion for the unforced system to be regular,causal and uniformly asymptotically stable is established in terms of linear matrix inequalities（LMIs）.An explicit expression for the desired memoryless state feedback stabilization controller is also given.The merits of the proposed criteria lie in their less conservativeness and relative simplicity,which are achieved by considering additionally useful terms（ignored in previous methods） when estimating the upper bound of the forward difference of the Lyapunov-Krasovskii functional and by avoiding utilizing any model augmentation transformation.Some numerical examples are provided to illustrate the validity of the proposed methods.
文摘A wavelet collocation method with nonlinear auto companding is proposed for behavioral modeling of switched current circuits.The companding function is automatically constructed according to the initial error distribution obtained through approximating the input output function of the SI circuit by conventional wavelet collocation method.In practical applications,the proposed method is a general purpose approach,by which both the small signal effect and the large signal effect are modeled in a unified formulation to ease the process of modeling and simulation.Compared with the published modeling approaches,the proposed nonlinear auto companding method works more efficiently not only in controlling the error distribution but also in reducing the modeling errors.To demonstrate the promising features of the proposed method,several SI circuits are employed as examples to be modeled and simulated.
基金This work was supported by Doctorate Foundation of Shenyang Normal University of China (No. 054-554405-01)
文摘In this paper, observer-based static output feedback control problem for discrete-time uncertain switched systems is investigated under an arbitrary switching rule. The main method used in this note is combining switched Lyapunov function （SLF） method with Finsler＇s Lemma. Based on linear matrix inequality （LMI） a less conservative stability condition is established and this condition allows extra degree of freedom for stability analysis. Finally, a simulation example is given to illustrate the efficiency of the result.
文摘A control strategy of switched reluctance motor (SRM)for electric vehicle applications is proposed. In electric vehicle application, the switched reluctance motor is a good choice with its flexible control method, compactness, robustness, high efficiency and high starting torque. In this paper, the control strategy of motoring and regenerative braking for electric vehicle application is presented. Computer simulations are employed to analyze the steady state behavior of SRM propulsion system. Experimental results in electric motorcycle are provided to demonstrate the validity of SRM propulsion system.
文摘In conformity with a fifth order RLC elliptic filter circuit prototype, it is easy to conceive the corresponding RC active filter circuit. Simple and feasible method presented here can be used to contrive the equivalent switched capacitor filter circuit and switched current filter circuit. Consulting the technique data manual, we can expediently design a specific RLC filter. Therefore, it is of great convenience to design the switched current filter, which has the same performances. Such a kind of technology is useful in the domain of analogue sampled data signal processing.
基金supported by National Natural Science Foundation of China(Nos.61304058 and 61233002)IAPI Fundamental Research Funds(No.2013ZCX03-01)General Project of Scientific Research of the Education Department of Liaoning Province(No.L2015547)
文摘This paper addresses the cooperative output regulation problem of a class of multi-agent systems （MASs）. Each agent is a switched linear system. We propose an agent-dependent multiple Lyapunov function （MLF） approach to design the switching law for each switched agent. The distributed controller for each agent is constructed based on a dynamic compensator. A sufficient condition for the solvability of the output regulation problem of switched agent networks is presented by distributed controllers and agent-dependent multiple Lyapunov function approach. Finally, simulation results demonstrate the effectiveness of our theory.
文摘Power generation becomes the need of developed, developing and under developed countries to meet their increasing power requirements. When affordability increases their requirement of power increases, this happens when increased per capita consumption. The existing power scenario states that highest power is produced using firing of coals called thermal energy. A high efficiency Switched Reluctance Generator (SRG) based high frequency switching scheme to enhance the output for grid connectivity is designed, fabricated and evaluated. This proposed method generates the output for the low wind speed. It provides output at low speed because of multi-level DC-DC converter and storage system. It is an efficient solution for low wind power generation. The real time readings and results are discussed.
基金supported by the National Natural Science Foundation of China(Nos.61374012,61403028)Aeronautical Science Foundation of China(No.2016ZA51011)
文摘Based on the switched nonlinear system, a switched adaptive Active Disturbance Rejection Control(ADRC) law is proposed for the Variable Structure Near Space Vehicle(VSNSV) with unknown uncertainties and external disturbances. The reduced-order Extended State Observers(ESOs) are constructed for the attitude angle system and the angular rate system to estimate the total disturbance in real time. With the extended state introduced to counteract the effects of uncertainties and disturbances, a systematic procedure is presented for the synthesis of the switched adaptive ADRC strategy. Rigorous proof shows that the estimation errors of the reduced-order ESOs would converge to a small neighborhood of zero in finite time, and that the output of the closedloop system can track a given signal stably for a class of switching signals with average dwell time via the proposed approach. The variable gain control strategy based on Adaptive Dynamic Programming(ADP) with the actor-critic structure is also designed to improve the dynamic performance of the system. Simulation results verify the effectiveness and advantage of the proposed control scheme.
基金co-supported by National Natural Science Foundation of China (Nos. 91116017, 60974106 and 11102080)Funding for Outstanding Doctoral Dissertation in NUAA (No. BCXJ10-04)
文摘An adaptive robust attitude tracking control law based on switched nonlinear systems is presented for a variable structure near space vehicle （VSNSV） in the presence of uncertainties and disturbances. The adaptive fuzzy systems are employed for approximating unknown functions in the flight dynamic model and their parameters are updated online. To improve the flight robust performance, robust controllers with adaptive gains are designed to compensate for the approximation errors and thus they have less design conservation. Moreover, a systematic procedure is developed for the synthesis of adaptive fuzzy dynamic surface control （DSC） approach. According to the common Lyapunov function theory, it is proved that all signals of the closed-loop system are uniformly ultimately bounded by the continuous controller. The simulation results demonstrate the effectiveness and robustness of the proposed control scheme.
