A full-order sliding mode control based on a fuzzy extended state observer is proposed to control the uncertain chaos in the permanent magnet synchronous motor. Through a simple coordinate transformation, the chaotic ...A full-order sliding mode control based on a fuzzy extended state observer is proposed to control the uncertain chaos in the permanent magnet synchronous motor. Through a simple coordinate transformation, the chaotic PMSM model is transformed into the Brunovsky canonical form, which is more suitable for the controller design. Based on the fuzzy control theory, a fuzzy extended state observer is developed to estimate the unknown states and uncertainties, and the restriction that all the system states should be completely measurable is avoided. Thereafter, a full-order sliding mode controller is designed to ensure the convergence of all system states without any chattering problem. Comparative simulations show the effectiveness and superior performance of the proposed control method.展开更多
This paper presents a robust sixth-order Discrete-time Extended Sliding Mode Observer (DESMO) for sensorless control of PMSM in order to estimate the currents, speed, rotor position, load torque and stator resistance....This paper presents a robust sixth-order Discrete-time Extended Sliding Mode Observer (DESMO) for sensorless control of PMSM in order to estimate the currents, speed, rotor position, load torque and stator resistance. The satisfying simulation results on Simulink/Matlab environment for a 1.6 kW PMSM demonstrate the good performance and stability of the proposed ESMO algorithm against parameter variation, modeling uncertainty, measurement and system noises.展开更多
This article proposes an innovative strategy to the problem of non-linear estimation of states for electrical machine systems. This method allows the estimation of variables that are difficult to access or that are si...This article proposes an innovative strategy to the problem of non-linear estimation of states for electrical machine systems. This method allows the estimation of variables that are difficult to access or that are simply impossible to measure. Thus, as compared with a full-order sliding mode observer, in order to reduce the execution time of the estimation, a reduced-order discrete-time Extended sliding mode observer is proposed for on-line estimation of rotor flux, speed and rotor resistance in an induction motor using a robust feedback linearization control. Simulations results on Matlab-Simulink environment for a 1.8 kW induction motor are presented to prove the effectiveness and high robustness of the proposed nonlinear control and observer against modeling uncertainty and measurement noise.展开更多
In this study,a composite strategy based on sliding-mode control( SMC) is employed in a permanent-magnet synchronous motor vector control system to improve the system robustness performance against parameter variation...In this study,a composite strategy based on sliding-mode control( SMC) is employed in a permanent-magnet synchronous motor vector control system to improve the system robustness performance against parameter variations and load disturbances. To handle the intrinsic chattering of SMC,an adaptive law and an extended state observer( ESO) are utilized in the speed SMC controller design. The adaptive law is used to estimate the internal parameter variations and compensate for the disturbances caused by model uncertainty. In addition,the ESO is introduced to estimate the load disturbance in real time. The estimated value is used as a feed-forward compensator for the speed adaptive sliding-mode controller to further increase the system's ability to resist disturbances. The proposed composite method,which combines adaptive SMC( ASMC) and ESO,is compared with PI control and ASMC. Both the simulation and experimental results demonstrate that the proposed method alleviates the chattering of SMC systems and improves the dynamic response and robustness of the speed control system against disturbances.展开更多
Through the analysis of the sliding failure form of soil mass under the bearing push-extend reamed of Push-extend Multi-under-reamed Pile, in the paper, the law of coulomb-Mohr is used to establish a stress function a...Through the analysis of the sliding failure form of soil mass under the bearing push-extend reamed of Push-extend Multi-under-reamed Pile, in the paper, the law of coulomb-Mohr is used to establish a stress function and the theory of the sliding line is used to establish Prandtl regional stress field, which determines the stress calculating mode of soil mass and provides a theoretical basis for a further study of this type of pile ultimate bearing capacity of soil mass.展开更多
This paper presents a novel non-singular fast terminal sliding mode control(NFTSMC)based on the deep flux weakening switching point tracking method in order to improve the control performance of permanent interior mag...This paper presents a novel non-singular fast terminal sliding mode control(NFTSMC)based on the deep flux weakening switching point tracking method in order to improve the control performance of permanent interior magnet synchronous motor(IPMSM)drive systems.The mathematical model of flux weakening(FW)control is established,and the deep flux weakening switching point is calculated accurately by analyzing the relationship between the torque curve and voltage decline curve.Next,a second-order NFTSMC is designed for the speed loop controller to ensure that the system converges to the equilibrium state in finite time.Then,an extended sliding mode disturbance observer(ESMDO)is designed to estimate the uncertainty of the system.Finally,compared with both the PI control and sliding mode control(SMC)by simulations and experiments with different working conditions,the method proposed has the merits of accelerating convergence,improving steady-state accuracy,and minimizing the current and torque pulsation.展开更多
The problem of linear time-varying（LTV） system modal analysis is considered based on time-dependent state space representations, as classical modal analysis of linear time-invariant systems and current LTV system mo...The problem of linear time-varying（LTV） system modal analysis is considered based on time-dependent state space representations, as classical modal analysis of linear time-invariant systems and current LTV system modal analysis under the ＂frozen-time＂ assumption are not able to determine the dynamic stability of LTV systems. Time-dependent state space representations of LTV systems are first introduced, and the corresponding modal analysis theories are subsequently presented via a stabilitypreserving state transformation. The time-varying modes of LTV systems are extended in terms of uniqueness, and are further interpreted to determine the system＇s stability. An extended modal identification is proposed to estimate the time-varying modes, consisting of the estimation of the state transition matrix via a subspace-based method and the extraction of the time-varying modes by the QR decomposition. The proposed approach is numerically validated by three numerical cases, and is experimentally validated by a coupled moving-mass simply supported beam exper- imental case. The proposed approach is capable of accurately estimating the time-varying modes, and provides anew way to determine the dynamic stability of LTV systems by using the estimated time-varying modes.展开更多
A new kind of reactive toughening accelerator for epoxy resin, amine-teminated hyperbranched polymer (H2O-NMe2) was synthesized and characterized by FT-IR spectroscopy. Dynamic mechanical analysis (DMA) was used to st...A new kind of reactive toughening accelerator for epoxy resin, amine-teminated hyperbranched polymer (H2O-NMe2) was synthesized and characterized by FT-IR spectroscopy. Dynamic mechanical analysis (DMA) was used to study the glass transition temperature (Tg), loss factor (tanδ) and activation energy (Ea) by using multiplexing frequency. The results show that the Ea at glassy relaxation process of modified system is about 70-80 kJ/mol higher than that of unmodified system, and the high modulus and good thermal properties are still maintained.展开更多
This paper proposes a novel composite dual-control bycombing the integral sliding mode control （ISMC） method basedon the finite time convergence theory with extended state observer（ESO） for a tracking problem of a...This paper proposes a novel composite dual-control bycombing the integral sliding mode control （ISMC） method basedon the finite time convergence theory with extended state observer（ESO） for a tracking problem of a missile with tail fins and reactionjetcontrol system （RCS）. First, the ISMC method based on finitetime convergence is utilized to design the control law of tail fins andthe pulse control of RCS for the dual-control system, ensuring thesystem with rapid response and high accuracy of tracking. Then,ESO is employed for the estimation of aerodynamic disturbancesinfluenced by the airflow of thruster jets. With the characteristicof high accuracy estimation of ESO, the chattering free trackingperformance of the attack angle command and the robustnessof the control law are achieved. Meanwhile, the stability of thedual-control system is analyzed based on finite time convergencestability theorem and Lyapunov’s theorem. Finally, numerical simulationsdemonstrate the effectiveness of the proposed design.展开更多
Vegetative propagation by stem cutting is an important technique applied for agricultural production where rooting success is one of the major aspects. A study to assess the effects of mode of application of rooting h...Vegetative propagation by stem cutting is an important technique applied for agricultural production where rooting success is one of the major aspects. A study to assess the effects of mode of application of rooting hormones (IBA) on adventitious root formation of V. paradoxa stem cuttings was conducted. Accordingly, four application methods were investigated in a 4 × 3 factorial experiment using a Completely Randomized Design (CRD). The application methods were: 24-hour extended soak, foliar spraying, basal quick dip and delayed IBA application method. Thus, the parameters used to determine rooting success were mean root length and root number. The effect of these application methods on occurrence of bud break was also considered. On the whole, root length was observed to be a function of IBA concentration, whereby root length increased significantly (P ≤ 0.05) with an increment in IBA concentration. Stem cuttings subjected to 24-h extended soak at 100 ppm rooted best (59.5% ± 8.33%), where as foliar sprayed stem cuttings exhibited the worst rooting success (11.9 ± 3.06 - 23.8% ± 4.16%). Bud break appeared to decrease with increasing IBA concentration and delaying IBA application enhanced rooting percentage of the quick dip method by 7.1%, 9.5% and 11.9% at 2500 ppm, 3500 ppm and 4500 ppm, respectively. The extended soak method of IBA application at 80 ppm shows potential for large scale production of V. paradoxa through stem cuttings.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.61403343 and 61433003)the Scientific Research Foundation of Education Department of Zhejiang Province,China(Grant No.Y201329260)the Natural Science Foundation of Zhejiang University of Technology,China(Grant No.1301103053408)
文摘A full-order sliding mode control based on a fuzzy extended state observer is proposed to control the uncertain chaos in the permanent magnet synchronous motor. Through a simple coordinate transformation, the chaotic PMSM model is transformed into the Brunovsky canonical form, which is more suitable for the controller design. Based on the fuzzy control theory, a fuzzy extended state observer is developed to estimate the unknown states and uncertainties, and the restriction that all the system states should be completely measurable is avoided. Thereafter, a full-order sliding mode controller is designed to ensure the convergence of all system states without any chattering problem. Comparative simulations show the effectiveness and superior performance of the proposed control method.
文摘This paper presents a robust sixth-order Discrete-time Extended Sliding Mode Observer (DESMO) for sensorless control of PMSM in order to estimate the currents, speed, rotor position, load torque and stator resistance. The satisfying simulation results on Simulink/Matlab environment for a 1.6 kW PMSM demonstrate the good performance and stability of the proposed ESMO algorithm against parameter variation, modeling uncertainty, measurement and system noises.
文摘This article proposes an innovative strategy to the problem of non-linear estimation of states for electrical machine systems. This method allows the estimation of variables that are difficult to access or that are simply impossible to measure. Thus, as compared with a full-order sliding mode observer, in order to reduce the execution time of the estimation, a reduced-order discrete-time Extended sliding mode observer is proposed for on-line estimation of rotor flux, speed and rotor resistance in an induction motor using a robust feedback linearization control. Simulations results on Matlab-Simulink environment for a 1.8 kW induction motor are presented to prove the effectiveness and high robustness of the proposed nonlinear control and observer against modeling uncertainty and measurement noise.
基金Supported by the National Natural Science Foundation of China(No.11603024)
文摘In this study,a composite strategy based on sliding-mode control( SMC) is employed in a permanent-magnet synchronous motor vector control system to improve the system robustness performance against parameter variations and load disturbances. To handle the intrinsic chattering of SMC,an adaptive law and an extended state observer( ESO) are utilized in the speed SMC controller design. The adaptive law is used to estimate the internal parameter variations and compensate for the disturbances caused by model uncertainty. In addition,the ESO is introduced to estimate the load disturbance in real time. The estimated value is used as a feed-forward compensator for the speed adaptive sliding-mode controller to further increase the system's ability to resist disturbances. The proposed composite method,which combines adaptive SMC( ASMC) and ESO,is compared with PI control and ASMC. Both the simulation and experimental results demonstrate that the proposed method alleviates the chattering of SMC systems and improves the dynamic response and robustness of the speed control system against disturbances.
文摘Through the analysis of the sliding failure form of soil mass under the bearing push-extend reamed of Push-extend Multi-under-reamed Pile, in the paper, the law of coulomb-Mohr is used to establish a stress function and the theory of the sliding line is used to establish Prandtl regional stress field, which determines the stress calculating mode of soil mass and provides a theoretical basis for a further study of this type of pile ultimate bearing capacity of soil mass.
基金supported by the Natural Science Foundation of China under Grant No.61733004the Scientific Research Fund of the Hunan Provincial Education Department under Grand No.18A267.
文摘This paper presents a novel non-singular fast terminal sliding mode control(NFTSMC)based on the deep flux weakening switching point tracking method in order to improve the control performance of permanent interior magnet synchronous motor(IPMSM)drive systems.The mathematical model of flux weakening(FW)control is established,and the deep flux weakening switching point is calculated accurately by analyzing the relationship between the torque curve and voltage decline curve.Next,a second-order NFTSMC is designed for the speed loop controller to ensure that the system converges to the equilibrium state in finite time.Then,an extended sliding mode disturbance observer(ESMDO)is designed to estimate the uncertainty of the system.Finally,compared with both the PI control and sliding mode control(SMC)by simulations and experiments with different working conditions,the method proposed has the merits of accelerating convergence,improving steady-state accuracy,and minimizing the current and torque pulsation.
基金Supported by the China Scholarship Council,National Natural Science Foundation of China(Grant No.11402022)the Interuniversity Attraction Poles Programme of the Belgian Science Policy Office(DYSCO)+1 种基金the Fund for Scientific Research–Flanders(FWO)the Research Fund KU Leuven
文摘The problem of linear time-varying（LTV） system modal analysis is considered based on time-dependent state space representations, as classical modal analysis of linear time-invariant systems and current LTV system modal analysis under the ＂frozen-time＂ assumption are not able to determine the dynamic stability of LTV systems. Time-dependent state space representations of LTV systems are first introduced, and the corresponding modal analysis theories are subsequently presented via a stabilitypreserving state transformation. The time-varying modes of LTV systems are extended in terms of uniqueness, and are further interpreted to determine the system＇s stability. An extended modal identification is proposed to estimate the time-varying modes, consisting of the estimation of the state transition matrix via a subspace-based method and the extraction of the time-varying modes by the QR decomposition. The proposed approach is numerically validated by three numerical cases, and is experimentally validated by a coupled moving-mass simply supported beam exper- imental case. The proposed approach is capable of accurately estimating the time-varying modes, and provides anew way to determine the dynamic stability of LTV systems by using the estimated time-varying modes.
基金Project (0447053) supported by the Natural Science Foundation of Guangxi Province, China Project(50473060) supported by the National Natural Science Foundation of China Project ([2004]20) supported by the Department of Education of Gunangxi Province, China
文摘A new kind of reactive toughening accelerator for epoxy resin, amine-teminated hyperbranched polymer (H2O-NMe2) was synthesized and characterized by FT-IR spectroscopy. Dynamic mechanical analysis (DMA) was used to study the glass transition temperature (Tg), loss factor (tanδ) and activation energy (Ea) by using multiplexing frequency. The results show that the Ea at glassy relaxation process of modified system is about 70-80 kJ/mol higher than that of unmodified system, and the high modulus and good thermal properties are still maintained.
基金supported by the National Natural Science Foundation of China(11202024)
文摘This paper proposes a novel composite dual-control bycombing the integral sliding mode control （ISMC） method basedon the finite time convergence theory with extended state observer（ESO） for a tracking problem of a missile with tail fins and reactionjetcontrol system （RCS）. First, the ISMC method based on finitetime convergence is utilized to design the control law of tail fins andthe pulse control of RCS for the dual-control system, ensuring thesystem with rapid response and high accuracy of tracking. Then,ESO is employed for the estimation of aerodynamic disturbancesinfluenced by the airflow of thruster jets. With the characteristicof high accuracy estimation of ESO, the chattering free trackingperformance of the attack angle command and the robustnessof the control law are achieved. Meanwhile, the stability of thedual-control system is analyzed based on finite time convergencestability theorem and Lyapunov’s theorem. Finally, numerical simulationsdemonstrate the effectiveness of the proposed design.
文摘Vegetative propagation by stem cutting is an important technique applied for agricultural production where rooting success is one of the major aspects. A study to assess the effects of mode of application of rooting hormones (IBA) on adventitious root formation of V. paradoxa stem cuttings was conducted. Accordingly, four application methods were investigated in a 4 × 3 factorial experiment using a Completely Randomized Design (CRD). The application methods were: 24-hour extended soak, foliar spraying, basal quick dip and delayed IBA application method. Thus, the parameters used to determine rooting success were mean root length and root number. The effect of these application methods on occurrence of bud break was also considered. On the whole, root length was observed to be a function of IBA concentration, whereby root length increased significantly (P ≤ 0.05) with an increment in IBA concentration. Stem cuttings subjected to 24-h extended soak at 100 ppm rooted best (59.5% ± 8.33%), where as foliar sprayed stem cuttings exhibited the worst rooting success (11.9 ± 3.06 - 23.8% ± 4.16%). Bud break appeared to decrease with increasing IBA concentration and delaying IBA application enhanced rooting percentage of the quick dip method by 7.1%, 9.5% and 11.9% at 2500 ppm, 3500 ppm and 4500 ppm, respectively. The extended soak method of IBA application at 80 ppm shows potential for large scale production of V. paradoxa through stem cuttings.
