This paper is concerned with a method for forming distributed measurement and control system.A three-layer structure model based on network,physical node layer and func-tion node layer is discussed.It is designed on o...This paper is concerned with a method for forming distributed measurement and control system.A three-layer structure model based on network,physical node layer and func-tion node layer is discussed.It is designed on object-oriented software method.The model has a fine application prospect.展开更多
The primary issue regarding the plasma synthetic jet actuator(PSJA)is its performance attenuation at high frequencies.To solve this issue,a self-supplementing,dual-cavity,plasma synthetic jet actuator(SD-PSJA)is desig...The primary issue regarding the plasma synthetic jet actuator(PSJA)is its performance attenuation at high frequencies.To solve this issue,a self-supplementing,dual-cavity,plasma synthetic jet actuator(SD-PSJA)is designed,and the static properties of the SD-PSJA are investigated through experiments and numerical simulations.The pressure measurement shows that the SD-PSJA has two saturation frequencies(1200 Hz and 2100 Hz),and the experimental results show that both the saturation frequencies decrease as the volume of the bottom cavity of the SD-PSJA increases.As the size of the supplement hole increases,the first saturation frequency increases continuously,while the second saturation frequency shows a trend of first decreasing and then increasing.Numerical simulations show that the working process of the SD-PSJA is similar to that of the PSJA,but the volume of the cavity in the SD-PSJA is smaller than that of the PSJA;the SD-PSJA can supplement air to the top cavity through two holes,thus reducing the refresh time and effectively improving the jet intensity of the actuator at high frequencies.展开更多
The distribution of the Jurassic coal measures in the northern Qaidam Basin is obviously controlled by the regional structures. Based on the existing data of coalfield exploration and combined with the analysis of coa...The distribution of the Jurassic coal measures in the northern Qaidam Basin is obviously controlled by the regional structures. Based on the existing data of coalfield exploration and combined with the analysis of coalfield basement structures, features of the main faults, and the distribution of coal measures, this paper brings forward a scheme of coalfield tectonic divisional units and the definition of the coal-controlling structural styles in the northern Qaidam Basin. The structure control of the distribution of coal measures is further discussed. Several stages of regional tectonic activities since the Indosinian has led to the distribution of coal measures into the characteristics of zonation from the north to south and block from east to west. The results indicate that the structural deformations are the most intense in the front of the three uplifted belts, which are characterized by the combination of thrusts. The coal measures are uplifted to the shallow formations, and are easy to be exploited, but the scale of mines is small because of serious damages by the coal distribution. On the contrary, the stress and strain are weak in the three depressions, with the coal-controlling structural styles being mainly the thrust-fold and thrust-monocline combinations. The distribution of coals in the depressions is relatively stable. The shallower part of the depression will become the key areas for exploration and development of coal resources in the northern Qaidam Basin.展开更多
We present a scheme for remotely preparing a state via the controls of many agents in a network.In thescheme,the agents' controls are achieved by utilizing quantum key distribution.Generally,the original state can...We present a scheme for remotely preparing a state via the controls of many agents in a network.In thescheme,the agents' controls are achieved by utilizing quantum key distribution.Generally,the original state can berestored by the receiver with probability 1/2 if all the agents collaborate.However,for certain type of original states therestoration probability is unit.展开更多
The modelling of one kind of nonlinear parabolic distributed parameter control system with moving boundary, which had extensive applications was presented, Two methods were used to investigate the basic characteristic...The modelling of one kind of nonlinear parabolic distributed parameter control system with moving boundary, which had extensive applications was presented, Two methods were used to investigate the basic characteristics of the system: I) transforming the system it? the variable domain into that in the fixed domain; 2) transforming the distributed parameter system into the lumped parameter system. It is found that there are two critical values for the control variable : the larger one determines whether or not the boundary would move, while the smaller one determines whether or not the boundary, would atop automatically. For one-dimensional system of planar, cylindrical and spherical cases the definite solution problem can be expressed as a unified form. By means of the computer simulation the open-loop control system and close-cycle feedback control system have been investigated. Numerical results agree well with theoretical results. The computer simulation shows that the system is well posed, stable, measurable and controllable.展开更多
For a class of nonlinear systems whose states are immeasurable, when the outputs of the system are sampled asynchronously, by introducing a state observer, an output feedback distributed model predictive control algor...For a class of nonlinear systems whose states are immeasurable, when the outputs of the system are sampled asynchronously, by introducing a state observer, an output feedback distributed model predictive control algorithm is proposed. It is proved that the errors of estimated states and the actual system's states are bounded. And it is guaranteed that the estimated states of the closed-loop system are ultimately bounded in a region containing the origin. As a result, the states of the actual system are ultimately bounded. A simulation example verifies the effectiveness of the proposed distributed control method.展开更多
This paper is focused on a distributed optimal control design for a class of nonlinear timedelay systems with delayed measurements and communication disruptions.The innovation lies in three aspects.The distributed opt...This paper is focused on a distributed optimal control design for a class of nonlinear timedelay systems with delayed measurements and communication disruptions.The innovation lies in three aspects.The distributed optimal control method which includes an optimal controller and a bounded controller is designed based on Lyapunov function.The availability of data transmitted through the communication channel depends on a feasibility problem.And a sufficient condition to guarantee ultimate boundedness of the system is given based on appropriate assumptions.The significance of this paper is that this distributed optimal control method is applied to time-delay system.Finally,a simulation example is given to verify the effectiveness of the proposed method.展开更多
The traditional measurement method was inaccurate to evaluate the motor controller efficiency,which the measurement efficiency value could be more than 100%in practical testing experiments.To deal with this issue,an i...The traditional measurement method was inaccurate to evaluate the motor controller efficiency,which the measurement efficiency value could be more than 100%in practical testing experiments.To deal with this issue,an improved electrical measurement method for the motor controller efficiency is proposed in this paper,which is established by analyzing the power loss distribution and phase currents of the motor controller.It is demonstrated that the SiC MOSFET chips are the main power loss devices in the motor controller,accounting for more than 93.1%of the total power loss.The accuracy of the proposed method is compared with the traditional method in simulation.It shows that the test error of the efficiency obtained by the traditional method fluctuates on a large scale,which varied from 0.094%to 1.911%.Compared with the traditional method,the test error of the proposed method appears to be less than 0.083%,which provides significant guidance for the motor controller efficiency test and design.展开更多
由于DCS控制器中电表传感器在计量检测过程中,传统的B-MAC-DCS协议能耗和丢包率较高,无法缓解汇聚节点的漏斗效应,导致在远程抄表过程中传感器计量误差增大。提出一种机械电表接触传感器计量误差检测方法。采用小波基函数对DCS控制器中...由于DCS控制器中电表传感器在计量检测过程中,传统的B-MAC-DCS协议能耗和丢包率较高,无法缓解汇聚节点的漏斗效应,导致在远程抄表过程中传感器计量误差增大。提出一种机械电表接触传感器计量误差检测方法。采用小波基函数对DCS控制器中的接触传感器计量数据抗干扰处理,并通过动态选取阈值的方法,对经过小波变换后的数据去除噪声。使用低功耗自适应集簇分层型(low energy adaptive clustering hierarchy,LEACH)协议分簇代替传统的B-MAC协议;根据簇内监测值,引入阈值分析方法获取传感器计量指标,并将其作为判定依据进行误差检测,根据计量指标的变化情况判断是否存在计量误差。实验结果表明,所提方法可以准确且有效检测出机械电表接触传感器计量误差,解决DCS中机械电表的运行隐患问题。展开更多
An array of distributed round synthetic jets was used to control a fully developed turbulent boundary layer.The study focused on the related skin friction drag reduction and mechanisms involved.The control effects wer...An array of distributed round synthetic jets was used to control a fully developed turbulent boundary layer.The study focused on the related skin friction drag reduction and mechanisms involved.The control effects were analyzed by measuring the streamwise velocities using a hot-wire anemometer downstream of the array.A reduction in the skin friction was observed both in the regions downstream of the orifices and in the regions between two adjacent orifices.A statistical analysis with the variable-interval time-averaging(VITA)technique demonstrated a weakened bursting intensity with synthetic jet in the near-wall region.The streamwise vortices were lifted by the upwash effect caused by synthetic jet and induced less low-speed streaks.The control mechanism acted in a way to suppress the dynamic interaction between the streamwise vortices and low-speed streaks and to attenuate the turbulence production in the near-wall region.The forcing frequency was found to be a more relevant parameter when synthetic jet was applied in turbulent boundary layer flow control.A higher forcing frequency induced a higher reduction in the skin friction.The power spectral density and autocorrelation of the fluctuating velocities showed that the synthetic jets gradually decayed in the streamwise direction,having an effect as far as 34.5 times the displacement thickness that was on the trailing edge of the distributed synthetic jets array.展开更多
文摘This paper is concerned with a method for forming distributed measurement and control system.A three-layer structure model based on network,physical node layer and func-tion node layer is discussed.It is designed on object-oriented software method.The model has a fine application prospect.
基金National Natural Science Foundation of China(No.61971345)the Foundation for Key Laboratories of National Defense Science and Technology of China(No.614220120030810).
文摘The primary issue regarding the plasma synthetic jet actuator(PSJA)is its performance attenuation at high frequencies.To solve this issue,a self-supplementing,dual-cavity,plasma synthetic jet actuator(SD-PSJA)is designed,and the static properties of the SD-PSJA are investigated through experiments and numerical simulations.The pressure measurement shows that the SD-PSJA has two saturation frequencies(1200 Hz and 2100 Hz),and the experimental results show that both the saturation frequencies decrease as the volume of the bottom cavity of the SD-PSJA increases.As the size of the supplement hole increases,the first saturation frequency increases continuously,while the second saturation frequency shows a trend of first decreasing and then increasing.Numerical simulations show that the working process of the SD-PSJA is similar to that of the PSJA,but the volume of the cavity in the SD-PSJA is smaller than that of the PSJA;the SD-PSJA can supplement air to the top cavity through two holes,thus reducing the refresh time and effectively improving the jet intensity of the actuator at high frequencies.
文摘The distribution of the Jurassic coal measures in the northern Qaidam Basin is obviously controlled by the regional structures. Based on the existing data of coalfield exploration and combined with the analysis of coalfield basement structures, features of the main faults, and the distribution of coal measures, this paper brings forward a scheme of coalfield tectonic divisional units and the definition of the coal-controlling structural styles in the northern Qaidam Basin. The structure control of the distribution of coal measures is further discussed. Several stages of regional tectonic activities since the Indosinian has led to the distribution of coal measures into the characteristics of zonation from the north to south and block from east to west. The results indicate that the structural deformations are the most intense in the front of the three uplifted belts, which are characterized by the combination of thrusts. The coal measures are uplifted to the shallow formations, and are easy to be exploited, but the scale of mines is small because of serious damages by the coal distribution. On the contrary, the stress and strain are weak in the three depressions, with the coal-controlling structural styles being mainly the thrust-fold and thrust-monocline combinations. The distribution of coals in the depressions is relatively stable. The shallower part of the depression will become the key areas for exploration and development of coal resources in the northern Qaidam Basin.
基金Supported by the program for New Century Excellent Talents at the University of China under Grant No.NCET-06-0554the National Natural Science Foundation of China under Grant Nos.60677001,50672001,10874122,and 10747146+2 种基金the Science-Technology Fund of Anhui Province for Outstanding Youth under Grant No.06042087the Key Fund of the Ministry of Education of China under Grant No.206063the Natural Science Foundation of Guangdong Province under Grant Nos.06300345 and 7007806
文摘We present a scheme for remotely preparing a state via the controls of many agents in a network.In thescheme,the agents' controls are achieved by utilizing quantum key distribution.Generally,the original state can berestored by the receiver with probability 1/2 if all the agents collaborate.However,for certain type of original states therestoration probability is unit.
文摘The modelling of one kind of nonlinear parabolic distributed parameter control system with moving boundary, which had extensive applications was presented, Two methods were used to investigate the basic characteristics of the system: I) transforming the system it? the variable domain into that in the fixed domain; 2) transforming the distributed parameter system into the lumped parameter system. It is found that there are two critical values for the control variable : the larger one determines whether or not the boundary would move, while the smaller one determines whether or not the boundary, would atop automatically. For one-dimensional system of planar, cylindrical and spherical cases the definite solution problem can be expressed as a unified form. By means of the computer simulation the open-loop control system and close-cycle feedback control system have been investigated. Numerical results agree well with theoretical results. The computer simulation shows that the system is well posed, stable, measurable and controllable.
文摘For a class of nonlinear systems whose states are immeasurable, when the outputs of the system are sampled asynchronously, by introducing a state observer, an output feedback distributed model predictive control algorithm is proposed. It is proved that the errors of estimated states and the actual system's states are bounded. And it is guaranteed that the estimated states of the closed-loop system are ultimately bounded in a region containing the origin. As a result, the states of the actual system are ultimately bounded. A simulation example verifies the effectiveness of the proposed distributed control method.
基金supported by the National Natural Science Foundation of China under Grant Nos.61374004,61773237,61473170Rizhao Science and Technology Innovation Special Plan(2019cxzx2212)。
文摘This paper is focused on a distributed optimal control design for a class of nonlinear timedelay systems with delayed measurements and communication disruptions.The innovation lies in three aspects.The distributed optimal control method which includes an optimal controller and a bounded controller is designed based on Lyapunov function.The availability of data transmitted through the communication channel depends on a feasibility problem.And a sufficient condition to guarantee ultimate boundedness of the system is given based on appropriate assumptions.The significance of this paper is that this distributed optimal control method is applied to time-delay system.Finally,a simulation example is given to verify the effectiveness of the proposed method.
基金Supported by National Key Research and Development Program of China(2016YFB0100605)。
文摘The traditional measurement method was inaccurate to evaluate the motor controller efficiency,which the measurement efficiency value could be more than 100%in practical testing experiments.To deal with this issue,an improved electrical measurement method for the motor controller efficiency is proposed in this paper,which is established by analyzing the power loss distribution and phase currents of the motor controller.It is demonstrated that the SiC MOSFET chips are the main power loss devices in the motor controller,accounting for more than 93.1%of the total power loss.The accuracy of the proposed method is compared with the traditional method in simulation.It shows that the test error of the efficiency obtained by the traditional method fluctuates on a large scale,which varied from 0.094%to 1.911%.Compared with the traditional method,the test error of the proposed method appears to be less than 0.083%,which provides significant guidance for the motor controller efficiency test and design.
文摘由于DCS控制器中电表传感器在计量检测过程中,传统的B-MAC-DCS协议能耗和丢包率较高,无法缓解汇聚节点的漏斗效应,导致在远程抄表过程中传感器计量误差增大。提出一种机械电表接触传感器计量误差检测方法。采用小波基函数对DCS控制器中的接触传感器计量数据抗干扰处理,并通过动态选取阈值的方法,对经过小波变换后的数据去除噪声。使用低功耗自适应集簇分层型(low energy adaptive clustering hierarchy,LEACH)协议分簇代替传统的B-MAC协议;根据簇内监测值,引入阈值分析方法获取传感器计量指标,并将其作为判定依据进行误差检测,根据计量指标的变化情况判断是否存在计量误差。实验结果表明,所提方法可以准确且有效检测出机械电表接触传感器计量误差,解决DCS中机械电表的运行隐患问题。
基金The authors would like to acknowledge the financial support received from the project“Drag Reduction via Turbulent Boundary Layer Flow Control(DRAGY)”.The DRAGY project(April 2016-March 2019)is a China-EU Aeronautical Cooperation project,which is co-funded by Ministry of Industry and Information Technology(MIIT),China,and Directorate-General for Research and Innovation(DG RTD),European Commission.
文摘An array of distributed round synthetic jets was used to control a fully developed turbulent boundary layer.The study focused on the related skin friction drag reduction and mechanisms involved.The control effects were analyzed by measuring the streamwise velocities using a hot-wire anemometer downstream of the array.A reduction in the skin friction was observed both in the regions downstream of the orifices and in the regions between two adjacent orifices.A statistical analysis with the variable-interval time-averaging(VITA)technique demonstrated a weakened bursting intensity with synthetic jet in the near-wall region.The streamwise vortices were lifted by the upwash effect caused by synthetic jet and induced less low-speed streaks.The control mechanism acted in a way to suppress the dynamic interaction between the streamwise vortices and low-speed streaks and to attenuate the turbulence production in the near-wall region.The forcing frequency was found to be a more relevant parameter when synthetic jet was applied in turbulent boundary layer flow control.A higher forcing frequency induced a higher reduction in the skin friction.The power spectral density and autocorrelation of the fluctuating velocities showed that the synthetic jets gradually decayed in the streamwise direction,having an effect as far as 34.5 times the displacement thickness that was on the trailing edge of the distributed synthetic jets array.
