In order to enhance the safety of autonomous driving vehicles,this work focuses on the issue of automatic-to-manual mode transition in the column electric power steering(C-EPS)system.First,we utilized an extended stat...In order to enhance the safety of autonomous driving vehicles,this work focuses on the issue of automatic-to-manual mode transition in the column electric power steering(C-EPS)system.First,we utilized an extended state observer to estimate the driver's steering torque and designed a steering mode transition unit.Second,we validated the mode switching function through an experimental platform.The results indicated that when using the extended state observer for torque estimation,the steering wheel angle and lower input angle errors were approximately±0.5%.The input and observed torque curves were closely aligned,demonstrating excellent tracking capability of the system.In addition,by adopting a steering mode conversion unit,the switch from autonomous control to manual control has been obtained,achieving a smooth and minimal change in steering wheel angle without significant bumps.The experimental results demonstrate that the designed mode switching strategy has the advantages of speed and smoothness,and has strong practical value.展开更多
With the advancement of more electric aircraft(MEA)technology,the application of electro-hydrostatic actuators(EHAs)in aircraft actuation systems has become increasingly prevalent.This paper focuses on the modeling an...With the advancement of more electric aircraft(MEA)technology,the application of electro-hydrostatic actuators(EHAs)in aircraft actuation systems has become increasingly prevalent.This paper focuses on the modeling and mode switching analysis of EHA used in the primary flight control actuation systems of large aircraft,addressing the challenges associated with mode switching.First,we analyze the functional architecture and operational characteristics of multi-mode EHA,and sumarize the operating modes and implementation methods.Based on the EHA system architecture,we then develop a theoretical mathematical model and a simulation model.Using the simulation model,we analyze the performance of the EHA during normal operation.Finally,the performance of the EHA during mode switching under various functional switching scenarios is investigated.The results indicate that the EHA meets the performance requirements in terms of accuracy,bandwidth,and load capacity.Additionally,the hydraulic cylinder operates smoothly during the EHA mode switching,and the response time for switching between different modes is less than the specified threshold.These findings validate the system performance of multi-mode EHA,which helps to improve the reliability of EHA and the safety of aircraft flight control systems.展开更多
The photovoltaic(PV)output process is inherently complex,often disrupted by a multitude of meteoro-logical factors,while conventional detection methods at PV power stations prove inadequate,compromising prediction acc...The photovoltaic(PV)output process is inherently complex,often disrupted by a multitude of meteoro-logical factors,while conventional detection methods at PV power stations prove inadequate,compromising prediction accuracy.To address this challenge,this paper introduces a power prediction method that leverages modal switching(MS),weight factor adjustment(WFA),and parallel long short-term memory(PALSTM).Initially,historical PV power station data is categorized into distinct modes based on global horizontal irradiance and converted solar angles.Correlation analysis is then employed to evaluate the impact of various meteorological factors on PV power,selecting those with strong correlations for each specific mode.Subsequently,the weights of meteorological parameters are optimized and adjusted,and a PALSTM neural network is constructed,with its parallel modal parameters refined through training.Depending on the prediction time and input data mode characteristics,the appropriate mode channel is selected to forecast PV power station generation.Ultimately,the feasibility of this method is validated through an illustrative analysis of measured data from an Australian PV power station.Comparative test results underscore the method’s advantages,particularly in scenarios where existing detection methods are lacking and meteorological factors frequently fluctuate,demonstrating its superior prediction accuracy and stability.展开更多
In classical IPOA, the communication of two users between local AsynchronousTransfer Mode (ATM) ports needs a VCC, however, it is not an elegant solution to the ATM accessequipments design when the performance of the ...In classical IPOA, the communication of two users between local AsynchronousTransfer Mode (ATM) ports needs a VCC, however, it is not an elegant solution to the ATM accessequipments design when the performance of the whole system is considered. Thus, we investigate theway to provide the improved IPOA protocol that uses switching way in local ports. And it is fullycompatible with the CIPOA by using the same protocol for ARP and IP forwarding. In addition, we alsopresent the design of one 10/100 Mbit/s auto adaptive IPOA client board with local switch abilityidea and CAM mechanism for our project.展开更多
This article proposes a novel approach combining exponential-reaching-law-based equivalent control law with radial basis function (RBF) network-based switching law to strengthen the sliding mode control (SMC) tracking...This article proposes a novel approach combining exponential-reaching-law-based equivalent control law with radial basis function (RBF) network-based switching law to strengthen the sliding mode control (SMC) tracking capacity for systems with uncertainties and disturbances. First, SMC discrete equivalent control law is designed on the basis of the nominal model of the system and the adaptive exponential reaching law, and subsequently, stability of the algorithm is analyzed. Second, RBF network is used to f...展开更多
This paper explores and proposes a design solution of an integrated skip cycle mode （SCM） control circuit with a simple structure. The design is simulated and implemented with XD10H-1.0μm modular DIMOS 650 V proces...This paper explores and proposes a design solution of an integrated skip cycle mode （SCM） control circuit with a simple structure. The design is simulated and implemented with XD10H-1.0μm modular DIMOS 650 V process. In order to meet the requirement of a wide temperature range and high yields of products, the schematic extracted from the layout is simulated with five process corners at 27℃ and 90℃. Simulation results demonstrate that the proposed integrated circuit is immune to noise and achieves skipping cycle control when switching mode power supply （SMPS） works with low load or without load.展开更多
Based on analyzing the structure and working principle on electric vehicles （EVs） with dual motors coupled by planetarY gears, the control strategy of mode switching was proposed. The power interruption problem on E...Based on analyzing the structure and working principle on electric vehicles （EVs） with dual motors coupled by planetarY gears, the control strategy of mode switching was proposed. The power interruption problem on EVs with automatic mechanical transmission （AMT） shifting was resolved. Based on the speed-torque characteristics of the planetary gears and the principle of the auxiliary motor＇ s zero speed braking, control features of mode switching were introduced. The mode shifting between the main motor mode and dual motors coupled driving were studied. Matlab/Simulink was adopted as a platform to develop the simulation model of EVs with dual motors drive system and 3 gears AMT. Simulation results demonstrated that the power interruption of dual motors drive system was solved during mode switching. The power requirements of EVs were satisfied, too.展开更多
A power train dynamics model of a coaxial parallel hybrid electric vehicle （HEV） was built for different clutch operating states. With the state vector constituted by the motor rotation speed and the clutch transmit...A power train dynamics model of a coaxial parallel hybrid electric vehicle （HEV） was built for different clutch operating states. With the state vector constituted by the motor rotation speed and the clutch transmitting torque at two successive time steps, a discrete state space model for estimating the clutch transmitting torque was built, and the Kalman filtering algorithm was used to estimate the clutch transmitting torque. The Matlab/Simulink was employed to simulate the clutch transmitting torque for two mode-switch processes. Estimation errors were analyzed through compa- ring the estimated and simulated values of the clutch torque. Impact of the noise covariance and the sample time on clutch torque estimation errors were explored. The results show that the developed estimation method can be used to estimate the clutch transmitting torque for HEV with good accura- cy. The results are useful for torque direct control of automatic diaphragm clutches.展开更多
We first experimentally demonstrate a laser-diode end-pumped self-Q-switched and mode-locked Nd,Cr：YAG green laser with a KTP crystal as the intra-cavity frequency doubler. The device produces an average output power...We first experimentally demonstrate a laser-diode end-pumped self-Q-switched and mode-locked Nd,Cr：YAG green laser with a KTP crystal as the intra-cavity frequency doubler. The device produces an average output power of 680 mW at 532 nm. The corresponding pulse width of the Q-switched envelope of the green laser is 170 ＋ 20 ns. The mode-locked pulses have a repetition rate of approximately 183 MHz and the average pulse duration is estimated to be around sub-nanosecond. It is found that the intra-cavity frequency doubling greatly improves the modulation depth and stability of the mode-locked pulses within the Q-switched envelope.展开更多
To improve locomotion and operation integration, this paper presents an integrated leg-arm quadruped robot(ILQR) that has a reconfigurable joint. First, the reconfigurable joint is designed and assembled at the end of...To improve locomotion and operation integration, this paper presents an integrated leg-arm quadruped robot(ILQR) that has a reconfigurable joint. First, the reconfigurable joint is designed and assembled at the end of the legarm chain. When the robot performs a task, reconfigurable configuration and mode switching can be achieved using this joint. In contrast from traditional quadruped robots, this robot can stack in a designated area to optimize the occupied volume in a nonworking state. Kinematics modeling and dynamics modeling are established to evaluate the mechanical properties for multiple modes. All working modes of the robot are classified, which can be defined as deployable mode, locomotion mode and operation mode. Based on the stability margin and mechanical modeling, switching analysis and evaluation between each mode is carried out. Finally, the prototype experimental results verify the function realization and switching stability of multimode and provide a design method to integrate and perform multimode for quadruped robots with deployable characteristics.展开更多
By applying switch-signal theory, the interaction between MOS transmission switch-ing transistor and current signal in current-mode CMOS circuits is analyzed, and the theory oftransmission current-switches which is su...By applying switch-signal theory, the interaction between MOS transmission switch-ing transistor and current signal in current-mode CMOS circuits is analyzed, and the theory oftransmission current-switches which is suitable to current-mode CMOS circuits is proposed. Thecircuits, such as ternary full-adder etc., designed by using this theory have simpler circuit struc-tures and correct logic functions. It is confirmed that this theory is efficient in guiding the logicdesign of current-mode CMOS circuits at switch level.展开更多
In this paper, the effect of injected energy on low energy single longitudinal mode (SLM) pre-lase Q-switched is analyzed and the optimization procedure is shown in detail. Here, taking the Pr:YLF laser as an example ...In this paper, the effect of injected energy on low energy single longitudinal mode (SLM) pre-lase Q-switched is analyzed and the optimization procedure is shown in detail. Here, taking the Pr:YLF laser as an example of low energy laser, and the parameters of Pr:YLF laser by using pre-lase have been shown. Compared with normal Q-switched laser, the single pulse energy reaches 60.16% and the pulse width exceeds 39.73% when the same maximum energy is injected and SLM is achieved in pre-lase. The analysis results show that pre-lase is suitable for low energy laser to obtain SLM and there be an optimal performance to achieve the optimal energy output.展开更多
The mode switching between spatial multiplexing （SM） and space-time block code （STBC） diversity is investigated for the multiple-input multiple-output （MIMO） automatic repeat request （ARQ） system. Five importa...The mode switching between spatial multiplexing （SM） and space-time block code （STBC） diversity is investigated for the multiple-input multiple-output （MIMO） automatic repeat request （ARQ） system. Five important practical factors are considered in the proposed switching scheme： transmit correlation, ARQ technique, packet loss probability （PLP） constraint, discrete rate transmission （DRT） and channel coding. Under the spatially correlated channel, the distributions of the post signal-to-interference-plus- noise ratio （SiNR） for the SM mode and the STBC mode are obtained by using Gamma approximations. Then this paper derives the closed-form expressions of the PLP and the throughput for different modes when the ARQ technique is employed, based on which the mode switching algorithm is proposed to improve the spectral efficency. In the simulation, the correction of the expressions is first verified. Then, the significant gain observed by the proposed algorithm is presented. Since the switching point is the key parameter to implement the mode switching, this paper also shows how the switching point is affected by the practical factors considered.展开更多
This paper proposes a high-speed nonsingular terminal switched sliding mode control(HNT-SSMC) strategy for robot manipulators. The proposed approach enhances the control system performance by switching among appropria...This paper proposes a high-speed nonsingular terminal switched sliding mode control(HNT-SSMC) strategy for robot manipulators. The proposed approach enhances the control system performance by switching among appropriate sliding mode controllers according to different control demands in different regions of the state space. It is shown that the highspeed nonsingular terminal switched sliding mode(HNT-SSM)which is the representation of different control demands and enforced by the HNT-SSMC has the property of global highspeed convergence compared with the nonsingular fast terminal sliding mode(NFTSM), and provides the global non-singularity.The simulation study of an application example is carried out to validate the effectiveness of the proposed strategy.展开更多
This paper presents a new four-dimensional（4 D） autonomous chaotic system which has first Lyapunov exponent of about 22 and is comparatively larger than many existing three-dimensional（3 D） and 4 D chaotic systems...This paper presents a new four-dimensional（4 D） autonomous chaotic system which has first Lyapunov exponent of about 22 and is comparatively larger than many existing three-dimensional（3 D） and 4 D chaotic systems.The proposed system exhibits hyperbolic curve and circular paraboloid types of equilibria.The system has all zero eigenvalues for a particular case of an equilibrium point.The system has various dynamical behaviors like hyperchaotic,chaotic,periodic,and quasi-periodic.The system also exhibits coexistence of attractors.Dynamical behavior of the new system is validated using circuit implementation.Further an interesting switching synchronization phenomenon is proposed for the new chaotic system.An adaptive global integral sliding mode control is designed for the switching synchronization of the proposed system.In the switching synchronization,the synchronization is shown for the switching chaotic,stable,periodic,and hybrid synchronization behaviors.Performance of the controller designed in the paper is compared with an existing controller.展开更多
This paper develops a new method to deal with the robust H-infinity control problem for a class of uncertain switched nonlinear systems by using integral sliding mode control.A robust H-infinity integral sliding surfa...This paper develops a new method to deal with the robust H-infinity control problem for a class of uncertain switched nonlinear systems by using integral sliding mode control.A robust H-infinity integral sliding surface is constructed such that the sliding mode is robust stable with a prescribed disturbance attenuation level γ for a class of switching signals with average dwell time.Furthermore,variable structure controllers are designed to maintain the state of switched system on the sliding surface from the initial time.A numerical example is given to illustrate the effectiveness of the proposed method.展开更多
The results are presented of an experimental investigation of heat transfer in an air-liquid cooling system for a Switch-Mode Power Supply (SMPS) for TV digital power amplifiers. Since these SMPSs are characterized by...The results are presented of an experimental investigation of heat transfer in an air-liquid cooling system for a Switch-Mode Power Supply (SMPS) for TV digital power amplifiers. Since these SMPSs are characterized by high power and high compactness, thereby making the standard cooling techniques difficult to be used, a new cooling system is developed, using water and air as the cooling media. The active components (MOSFETs) are cooled with a liquid cold-plate, the passive ones (condensers, transformers, coils) with an air flow, in turn cooled by the cold-plate. By inserting the cooling system in an experimental tool where it is possible to control the cooling water, measurements are made of temperature in the significant points of the SMPS. The electric efficiency is also measured. The evaluation of the thermal performance of this cooling system is useful in order to limit its maximum operational temperature. The efficacy of the cooling system is demonstrated;the trends of efficiency and power dissipation are evidenced.展开更多
基金Supported by the National Natural Science Foundation of China(52172324)Key Research and Development Plan of Shaanxi Province(2021GY-285,2021SF-483)+1 种基金Science and Technology Project of Shaanxi Provincial Department of Transport(21-20K,20-38T)Fundamental Research Funds for the Central Universities,CHD(300102323501)。
文摘In order to enhance the safety of autonomous driving vehicles,this work focuses on the issue of automatic-to-manual mode transition in the column electric power steering(C-EPS)system.First,we utilized an extended state observer to estimate the driver's steering torque and designed a steering mode transition unit.Second,we validated the mode switching function through an experimental platform.The results indicated that when using the extended state observer for torque estimation,the steering wheel angle and lower input angle errors were approximately±0.5%.The input and observed torque curves were closely aligned,demonstrating excellent tracking capability of the system.In addition,by adopting a steering mode conversion unit,the switch from autonomous control to manual control has been obtained,achieving a smooth and minimal change in steering wheel angle without significant bumps.The experimental results demonstrate that the designed mode switching strategy has the advantages of speed and smoothness,and has strong practical value.
基金supported by the Chinese Civil Aircraft Project(No.MJ-2017-S49).
文摘With the advancement of more electric aircraft(MEA)technology,the application of electro-hydrostatic actuators(EHAs)in aircraft actuation systems has become increasingly prevalent.This paper focuses on the modeling and mode switching analysis of EHA used in the primary flight control actuation systems of large aircraft,addressing the challenges associated with mode switching.First,we analyze the functional architecture and operational characteristics of multi-mode EHA,and sumarize the operating modes and implementation methods.Based on the EHA system architecture,we then develop a theoretical mathematical model and a simulation model.Using the simulation model,we analyze the performance of the EHA during normal operation.Finally,the performance of the EHA during mode switching under various functional switching scenarios is investigated.The results indicate that the EHA meets the performance requirements in terms of accuracy,bandwidth,and load capacity.Additionally,the hydraulic cylinder operates smoothly during the EHA mode switching,and the response time for switching between different modes is less than the specified threshold.These findings validate the system performance of multi-mode EHA,which helps to improve the reliability of EHA and the safety of aircraft flight control systems.
基金This work was supported in part by the Natural Science Foundation of Henan Province,and the specific grant number is 232300420301the initial of author is P.L.,the URL to the sponsors’websites is https://kjt.henan.gov.cn/(accessed on 09 February 2025)And this work was also supported in part by the Fundamental Research Funds for the Universities of Henan Province,and the specific grant number is NSFRF220425,the initial of author is P.L.,the URL to sponsors websites is http://app.hnkjt.gov.cn/web/index.do(accessed on 09 February 2025).
文摘The photovoltaic(PV)output process is inherently complex,often disrupted by a multitude of meteoro-logical factors,while conventional detection methods at PV power stations prove inadequate,compromising prediction accuracy.To address this challenge,this paper introduces a power prediction method that leverages modal switching(MS),weight factor adjustment(WFA),and parallel long short-term memory(PALSTM).Initially,historical PV power station data is categorized into distinct modes based on global horizontal irradiance and converted solar angles.Correlation analysis is then employed to evaluate the impact of various meteorological factors on PV power,selecting those with strong correlations for each specific mode.Subsequently,the weights of meteorological parameters are optimized and adjusted,and a PALSTM neural network is constructed,with its parallel modal parameters refined through training.Depending on the prediction time and input data mode characteristics,the appropriate mode channel is selected to forecast PV power station generation.Ultimately,the feasibility of this method is validated through an illustrative analysis of measured data from an Australian PV power station.Comparative test results underscore the method’s advantages,particularly in scenarios where existing detection methods are lacking and meteorological factors frequently fluctuate,demonstrating its superior prediction accuracy and stability.
文摘In classical IPOA, the communication of two users between local AsynchronousTransfer Mode (ATM) ports needs a VCC, however, it is not an elegant solution to the ATM accessequipments design when the performance of the whole system is considered. Thus, we investigate theway to provide the improved IPOA protocol that uses switching way in local ports. And it is fullycompatible with the CIPOA by using the same protocol for ARP and IP forwarding. In addition, we alsopresent the design of one 10/100 Mbit/s auto adaptive IPOA client board with local switch abilityidea and CAM mechanism for our project.
文摘This article proposes a novel approach combining exponential-reaching-law-based equivalent control law with radial basis function (RBF) network-based switching law to strengthen the sliding mode control (SMC) tracking capacity for systems with uncertainties and disturbances. First, SMC discrete equivalent control law is designed on the basis of the nominal model of the system and the adaptive exponential reaching law, and subsequently, stability of the algorithm is analyzed. Second, RBF network is used to f...
文摘This paper explores and proposes a design solution of an integrated skip cycle mode （SCM） control circuit with a simple structure. The design is simulated and implemented with XD10H-1.0μm modular DIMOS 650 V process. In order to meet the requirement of a wide temperature range and high yields of products, the schematic extracted from the layout is simulated with five process corners at 27℃ and 90℃. Simulation results demonstrate that the proposed integrated circuit is immune to noise and achieves skipping cycle control when switching mode power supply （SMPS） works with low load or without load.
基金Supported by Doctoral Fund of Ministry of Education of China(20101101110012)the National Natural Science Foundationof China(51175040)
文摘Based on analyzing the structure and working principle on electric vehicles （EVs） with dual motors coupled by planetarY gears, the control strategy of mode switching was proposed. The power interruption problem on EVs with automatic mechanical transmission （AMT） shifting was resolved. Based on the speed-torque characteristics of the planetary gears and the principle of the auxiliary motor＇ s zero speed braking, control features of mode switching were introduced. The mode shifting between the main motor mode and dual motors coupled driving were studied. Matlab/Simulink was adopted as a platform to develop the simulation model of EVs with dual motors drive system and 3 gears AMT. Simulation results demonstrated that the power interruption of dual motors drive system was solved during mode switching. The power requirements of EVs were satisfied, too.
基金Supported by the National High Technology Research and Development Program of China(863Program)(2012AA111104)
文摘A power train dynamics model of a coaxial parallel hybrid electric vehicle （HEV） was built for different clutch operating states. With the state vector constituted by the motor rotation speed and the clutch transmitting torque at two successive time steps, a discrete state space model for estimating the clutch transmitting torque was built, and the Kalman filtering algorithm was used to estimate the clutch transmitting torque. The Matlab/Simulink was employed to simulate the clutch transmitting torque for two mode-switch processes. Estimation errors were analyzed through compa- ring the estimated and simulated values of the clutch torque. Impact of the noise covariance and the sample time on clutch torque estimation errors were explored. The results show that the developed estimation method can be used to estimate the clutch transmitting torque for HEV with good accura- cy. The results are useful for torque direct control of automatic diaphragm clutches.
基金Project supported by the National Natural Science Foundation of China （Grant Nos 60278024 and 60438020）.
文摘We first experimentally demonstrate a laser-diode end-pumped self-Q-switched and mode-locked Nd,Cr：YAG green laser with a KTP crystal as the intra-cavity frequency doubler. The device produces an average output power of 680 mW at 532 nm. The corresponding pulse width of the Q-switched envelope of the green laser is 170 ＋ 20 ns. The mode-locked pulses have a repetition rate of approximately 183 MHz and the average pulse duration is estimated to be around sub-nanosecond. It is found that the intra-cavity frequency doubling greatly improves the modulation depth and stability of the mode-locked pulses within the Q-switched envelope.
基金Supported by National Natural Science Foundation of China (Grant Nos. 52375003, 52205006)National Key R&D Program of China (Grant No. 2019YFB1309600)。
文摘To improve locomotion and operation integration, this paper presents an integrated leg-arm quadruped robot(ILQR) that has a reconfigurable joint. First, the reconfigurable joint is designed and assembled at the end of the legarm chain. When the robot performs a task, reconfigurable configuration and mode switching can be achieved using this joint. In contrast from traditional quadruped robots, this robot can stack in a designated area to optimize the occupied volume in a nonworking state. Kinematics modeling and dynamics modeling are established to evaluate the mechanical properties for multiple modes. All working modes of the robot are classified, which can be defined as deployable mode, locomotion mode and operation mode. Based on the stability margin and mechanical modeling, switching analysis and evaluation between each mode is carried out. Finally, the prototype experimental results verify the function realization and switching stability of multimode and provide a design method to integrate and perform multimode for quadruped robots with deployable characteristics.
基金Supported by National Natural Science Foundation of China
文摘By applying switch-signal theory, the interaction between MOS transmission switch-ing transistor and current signal in current-mode CMOS circuits is analyzed, and the theory oftransmission current-switches which is suitable to current-mode CMOS circuits is proposed. Thecircuits, such as ternary full-adder etc., designed by using this theory have simpler circuit struc-tures and correct logic functions. It is confirmed that this theory is efficient in guiding the logicdesign of current-mode CMOS circuits at switch level.
文摘In this paper, the effect of injected energy on low energy single longitudinal mode (SLM) pre-lase Q-switched is analyzed and the optimization procedure is shown in detail. Here, taking the Pr:YLF laser as an example of low energy laser, and the parameters of Pr:YLF laser by using pre-lase have been shown. Compared with normal Q-switched laser, the single pulse energy reaches 60.16% and the pulse width exceeds 39.73% when the same maximum energy is injected and SLM is achieved in pre-lase. The analysis results show that pre-lase is suitable for low energy laser to obtain SLM and there be an optimal performance to achieve the optimal energy output.
基金supported by the Chinese Important National Science and Technology Specific Project(2010ZX03002-003-01)
文摘The mode switching between spatial multiplexing （SM） and space-time block code （STBC） diversity is investigated for the multiple-input multiple-output （MIMO） automatic repeat request （ARQ） system. Five important practical factors are considered in the proposed switching scheme： transmit correlation, ARQ technique, packet loss probability （PLP） constraint, discrete rate transmission （DRT） and channel coding. Under the spatially correlated channel, the distributions of the post signal-to-interference-plus- noise ratio （SiNR） for the SM mode and the STBC mode are obtained by using Gamma approximations. Then this paper derives the closed-form expressions of the PLP and the throughput for different modes when the ARQ technique is employed, based on which the mode switching algorithm is proposed to improve the spectral efficency. In the simulation, the correction of the expressions is first verified. Then, the significant gain observed by the proposed algorithm is presented. Since the switching point is the key parameter to implement the mode switching, this paper also shows how the switching point is affected by the practical factors considered.
基金supported partially by the Research Program of Science and Technology at Universities of Inner Mongolia Autonomous Region(NJZY13279)
文摘This paper proposes a high-speed nonsingular terminal switched sliding mode control(HNT-SSMC) strategy for robot manipulators. The proposed approach enhances the control system performance by switching among appropriate sliding mode controllers according to different control demands in different regions of the state space. It is shown that the highspeed nonsingular terminal switched sliding mode(HNT-SSM)which is the representation of different control demands and enforced by the HNT-SSMC has the property of global highspeed convergence compared with the nonsingular fast terminal sliding mode(NFTSM), and provides the global non-singularity.The simulation study of an application example is carried out to validate the effectiveness of the proposed strategy.
基金supported by the National Natural Science Foundation of China(Grant No.11772306)
文摘This paper presents a new four-dimensional（4 D） autonomous chaotic system which has first Lyapunov exponent of about 22 and is comparatively larger than many existing three-dimensional（3 D） and 4 D chaotic systems.The proposed system exhibits hyperbolic curve and circular paraboloid types of equilibria.The system has all zero eigenvalues for a particular case of an equilibrium point.The system has various dynamical behaviors like hyperchaotic,chaotic,periodic,and quasi-periodic.The system also exhibits coexistence of attractors.Dynamical behavior of the new system is validated using circuit implementation.Further an interesting switching synchronization phenomenon is proposed for the new chaotic system.An adaptive global integral sliding mode control is designed for the switching synchronization of the proposed system.In the switching synchronization,the synchronization is shown for the switching chaotic,stable,periodic,and hybrid synchronization behaviors.Performance of the controller designed in the paper is compared with an existing controller.
基金supported by the National Natural Science Foundation of China(No.60874024,60574013)
文摘This paper develops a new method to deal with the robust H-infinity control problem for a class of uncertain switched nonlinear systems by using integral sliding mode control.A robust H-infinity integral sliding surface is constructed such that the sliding mode is robust stable with a prescribed disturbance attenuation level γ for a class of switching signals with average dwell time.Furthermore,variable structure controllers are designed to maintain the state of switched system on the sliding surface from the initial time.A numerical example is given to illustrate the effectiveness of the proposed method.
文摘The results are presented of an experimental investigation of heat transfer in an air-liquid cooling system for a Switch-Mode Power Supply (SMPS) for TV digital power amplifiers. Since these SMPSs are characterized by high power and high compactness, thereby making the standard cooling techniques difficult to be used, a new cooling system is developed, using water and air as the cooling media. The active components (MOSFETs) are cooled with a liquid cold-plate, the passive ones (condensers, transformers, coils) with an air flow, in turn cooled by the cold-plate. By inserting the cooling system in an experimental tool where it is possible to control the cooling water, measurements are made of temperature in the significant points of the SMPS. The electric efficiency is also measured. The evaluation of the thermal performance of this cooling system is useful in order to limit its maximum operational temperature. The efficacy of the cooling system is demonstrated;the trends of efficiency and power dissipation are evidenced.
