The increasing demands on safety, emission and fuel consumption require more accurate control models of micro internal combustion swing engine （MICSE）. The objective of this paper is to investigate the constant spee...The increasing demands on safety, emission and fuel consumption require more accurate control models of micro internal combustion swing engine （MICSE）. The objective of this paper is to investigate the constant speed control models of four-stroke MICSE The operation principle of the four-stroke MICSE is presented based on the description of MICSE prototype. A two-level Petri net based hybrid mode/ is proposed to mode/ the four-stroke MICSE engine cycle. The Petri net subsystem at the upper level controls and synchronizes the four Petri net subsystems at the lower level. The continuous sub-models, including breathing dynamics of intake manifold, thermodynamics of the chamber and dynamics of the torque generation, are investigated and integrated with the discrete model in MATLAB Simulink. Through the comparison of experimental data and simulated DC voltage output, it is demonstrated that the hybrid model is valid for the four-stroke MICSE system. A nonlinear model is obtained from the cycle average data via the regression method, and it is linearized around a given nominal equilibrium point for the controller design. The feedback controller of the spark timing and valve duration timing is designed with a sequential loop closing design approach. The simulation of the sequential loop closure control design applied to the hybrid model is implemented in MATLAB. The simulation results show that the system is able to reach its desired operating point within 0.2 s, and the designed controller shows good MICSE engine performance with a constant speed. This paper presents the constant speed control models of four-stroke MICSE and carries out the simulation tests, the models and the simulation results can be used for further study on the precision control of four-stroke MICSE.展开更多
The influence of the axial relative motion between the target and the source on ghost imaging(GI) is investigated.Both the analytical and experimental results show that the transverse resolution of GI is reduced as th...The influence of the axial relative motion between the target and the source on ghost imaging(GI) is investigated.Both the analytical and experimental results show that the transverse resolution of GI is reduced as the deviation of the target’s center position from the optical axis or the axial motion range increases. To overcome the motion blur,we propose a deblurring method based on speckle-resizing and speed retrieval, and we experimentally validate its effectiveness for an axially moving target with an unknown constant speed. The results demonstrated here will be very useful to forward-looking GI remote sensing.展开更多
An inexpensive MC4044-based phase locked loop for constant speed control of a DC motor is discussed. It operates on a principle similar to that of a frequency synthesizer. The paper introduces the system configuration...An inexpensive MC4044-based phase locked loop for constant speed control of a DC motor is discussed. It operates on a principle similar to that of a frequency synthesizer. The paper introduces the system configuration with a detailed description of its operating principle, some practical design considerations are discussed with an experimental study to test the control performance of the newly designed system. The experimental result shows that the phase locked control system can regulate the speed of a DC torque motor with a precision up to 0.0022%(1).[展开更多
The traditional large electroslag remelting furnaces have many shortages,such as high short-network impedance and inductance,long maintenance time for electrode replacement,low stiffness of driveline,and low control a...The traditional large electroslag remelting furnaces have many shortages,such as high short-network impedance and inductance,long maintenance time for electrode replacement,low stiffness of driveline,and low control accuracy of remelting speed.The present research was aimed to solve these problems through structure modification and constant remelting speed control for a 120-t electroslag remelting(ESR) furnace.Based on the technique of three-phase double electrodes in series,the short-network system and the structure of the 120-t ESR furnace were improved;and a continuous feeding system for the self-consumption electrode was proposed.A selfdesigned fully hydraulic driveline system with three degrees of freedom was successfully applied to the 120-t ESR furnace.An electrode auto-replacement system and the S-style speed-control curve of electrode-feeding system were designed on the basis of the soft measurement/sensing model on the remaining electrode length so as to obtain a high accuracy control system for constant remelting speed.The experiment products showed good surface quality and cross-sectional results,indicating good system control,and verifying the effectiveness of the structure modification of the furnace.展开更多
Based on the characteristic of AC-excited variable speed constant frequency(VSCF)wind power generation,the vector control technique was applied in a doubly fed induction generator(DFIG).Maximum wind energy or maximum ...Based on the characteristic of AC-excited variable speed constant frequency(VSCF)wind power generation,the vector control technique was applied in a doubly fed induction generator(DFIG).Maximum wind energy or maximum output power point can be tracked by decoupling control of active power and reactive power.The research result shows that the net power of generation system delivered to grid in maximum wind energy tracking mode is not the most.We presented a novel maximum power point tracking(MPPT)control strategy by analyzing the DFIG mathematic model and power relations which delivered the maximum power to the grid.The maximum power point could be tracked automatically without measuring wind speed in the control strategy and the control was independent of optimal turbine power curve,which had excellent dynamic and static performances and robustness.Simulation and experimental results testify the accuracy and validity of the control strategy.展开更多
In general,Variable-Speed Constant Frequency (VSCF)Wind generation system is controlled by stator voltage orientation method which based on the mathematic model of VSCF Wind generation system and discussed the control...In general,Variable-Speed Constant Frequency (VSCF)Wind generation system is controlled by stator voltage orientation method which based on the mathematic model of VSCF Wind generation system and discussed the control strategy.Present the whole dynamic control model of variable-speed wind generator system in MATLAB/ Simulink,and the simulation results confirm the validity and effectiveness of the proposed control strategy.展开更多
Every four years the Committee on Data for Science and Technology (CODATA) supplies a self-consistent set of values of the basic constants and conversion factors of physics recommended for international use. In 2013, ...Every four years the Committee on Data for Science and Technology (CODATA) supplies a self-consistent set of values of the basic constants and conversion factors of physics recommended for international use. In 2013, the World-Universe Model (WUM) proposed a principally different depiction of the World as an alternative to the picture of the Big Bang Model. This article: 1) Gives the short history of Classical Physics before Special Relativity;2) Calculates Fundamental Physical Constants based on experimentally measured Rydberg constant, Electrodynamic constant, Electron Charge-to-Mass Ratio, and Planck constant;3) Discusses Electrodynamic constant and Speed of Light;4) Considers Dimensionless Fundamental Parameters (Dirac Large Number Q and Dimensionless Rydberg Constant α);5) Calculates Newtonian Constant of Gravitation based on the Inter-connectivity of Primary Physical Parameters;6) Makes a detailed analysis of the Self-consistency of Fundamental Physical Constants and Primary Physical Parameters through the prism of WUM. The performed analysis suggests: 1) Discontinuing using the notion “Vacuum” and its characteristics (Speed of Light in Vacuum, Characteristic Impedance of Vacuum, Vacuum Magnetic Permeability, Vacuum Electric Permittivity);2) Accepting the exact numerical values of Electrodynamic constant, Planck constant, Elementary charge, and Dimensionless Rydberg Constant α. WUM recommends the predicted value of Newtonian Constant of Gravitation in 2018 to be considered in CODATA Recommend Values of the Fundamental Physical Constants 2022.展开更多
We previously revealed that the speed of light in vacuum c, the gravitational constant G, the vacuum permittivity ε, and the vacuum permeability μ can be defined by the temperature T (or the expected average frequen...We previously revealed that the speed of light in vacuum c, the gravitational constant G, the vacuum permittivity ε, and the vacuum permeability μ can be defined by the temperature T (or the expected average frequency f) of cosmic microwave background (CMB) radiation. Given that CMB is continuously cooling, that is, T is continuously decreasing, we proposed that the above “constants” are variable and their values at some space-time with CMB temperature T (c<sub>T</sub>, G<sub>T</sub>, ε<sub>T</sub>, and μ<sub>T</sub>) can be described using their values (c<sub>0</sub>, G<sub>0</sub>, ε<sub>0</sub>, and μ<sub>0</sub>) and the temperature (T<sub>0</sub>) of CMB at present space-time. Based on the above observation, a number of physical equations related with these constants are re-described in this study, including relativity equation, mass-energy equation, and Maxwell’s equations, etc.展开更多
This study purposes an in situ testing method on quality assessment of soil improvement.Factual drilling data includes the spatial distribution and in situ strength of untreated and treated soil along three different ...This study purposes an in situ testing method on quality assessment of soil improvement.Factual drilling data includes the spatial distribution and in situ strength of untreated and treated soil along three different drillholes measured by on-site drilling monitoring method.These factual drilling data can characterize the degree of soil improvement by penetration injection with permeable polyurethane.Result from on-site drilling monitoring shows that the linear zones represent constant drilling speeds shown in the plot of drill bit advancement vs.net drilling time,which indicates the spatial distributions of soil profile.The soil profile at the study site is composed of four layers,which includes fill,untreated silty clay,treated silty clay,and mucky soil.The results of soil profile are verified by the parallel site loggings.The constant drilling speeds profile the coring-resistant strength of drilled soils.By comparing with the untreated silty clay,the constant drilling speeds of the treated silty clay have been decreased by 13.0-62.8%.Two drilling-speed-based indices of 61.2%and 65.6%are proposed to assess the decreased average drilling speed and the increased in situ strength of treated silty clay.Laboratory tests,i.e.uniaxial compressive strength(UCS)test,have been performed with core sample to investigate and characterize in situ strength by comparing that with drilling speeds.Results show that the average predicted strengths of treated silty clay are 2.4-6.9 times higher than the average measured strength of untreated silty clay.The UCS-based indices of 374.5%and 344.2%verified the quality assessment(QA)results by this new in situ method.This method provides a cost-effective tool for quality assessment of soil improvement by utilizing the digital drilling data.展开更多
基金Supported by National Natural Science Foundation of China(Grant No.51475422)Science Fund for Creative Research Groups of National Natural Science Foundation of China(Grant No.51221004)
文摘The increasing demands on safety, emission and fuel consumption require more accurate control models of micro internal combustion swing engine （MICSE）. The objective of this paper is to investigate the constant speed control models of four-stroke MICSE The operation principle of the four-stroke MICSE is presented based on the description of MICSE prototype. A two-level Petri net based hybrid mode/ is proposed to mode/ the four-stroke MICSE engine cycle. The Petri net subsystem at the upper level controls and synchronizes the four Petri net subsystems at the lower level. The continuous sub-models, including breathing dynamics of intake manifold, thermodynamics of the chamber and dynamics of the torque generation, are investigated and integrated with the discrete model in MATLAB Simulink. Through the comparison of experimental data and simulated DC voltage output, it is demonstrated that the hybrid model is valid for the four-stroke MICSE system. A nonlinear model is obtained from the cycle average data via the regression method, and it is linearized around a given nominal equilibrium point for the controller design. The feedback controller of the spark timing and valve duration timing is designed with a sequential loop closing design approach. The simulation of the sequential loop closure control design applied to the hybrid model is implemented in MATLAB. The simulation results show that the system is able to reach its desired operating point within 0.2 s, and the designed controller shows good MICSE engine performance with a constant speed. This paper presents the constant speed control models of four-stroke MICSE and carries out the simulation tests, the models and the simulation results can be used for further study on the precision control of four-stroke MICSE.
基金supported by the Hi-Tech Research and Development Program of China under Grant Project No. 2013AA122901
文摘The influence of the axial relative motion between the target and the source on ghost imaging(GI) is investigated.Both the analytical and experimental results show that the transverse resolution of GI is reduced as the deviation of the target’s center position from the optical axis or the axial motion range increases. To overcome the motion blur,we propose a deblurring method based on speckle-resizing and speed retrieval, and we experimentally validate its effectiveness for an axially moving target with an unknown constant speed. The results demonstrated here will be very useful to forward-looking GI remote sensing.
文摘An inexpensive MC4044-based phase locked loop for constant speed control of a DC motor is discussed. It operates on a principle similar to that of a frequency synthesizer. The paper introduces the system configuration with a detailed description of its operating principle, some practical design considerations are discussed with an experimental study to test the control performance of the newly designed system. The experimental result shows that the phase locked control system can regulate the speed of a DC torque motor with a precision up to 0.0022%(1).[
基金financially supported by the National Science and Technology Major Project of the Eleventh Five-Year Plan of China(2009ZX04006-032)
文摘The traditional large electroslag remelting furnaces have many shortages,such as high short-network impedance and inductance,long maintenance time for electrode replacement,low stiffness of driveline,and low control accuracy of remelting speed.The present research was aimed to solve these problems through structure modification and constant remelting speed control for a 120-t electroslag remelting(ESR) furnace.Based on the technique of three-phase double electrodes in series,the short-network system and the structure of the 120-t ESR furnace were improved;and a continuous feeding system for the self-consumption electrode was proposed.A selfdesigned fully hydraulic driveline system with three degrees of freedom was successfully applied to the 120-t ESR furnace.An electrode auto-replacement system and the S-style speed-control curve of electrode-feeding system were designed on the basis of the soft measurement/sensing model on the remaining electrode length so as to obtain a high accuracy control system for constant remelting speed.The experiment products showed good surface quality and cross-sectional results,indicating good system control,and verifying the effectiveness of the structure modification of the furnace.
基金Funded by the National Natural Science Foundation of China(No.60974049)the Science and Technology Support Industrial Project of Jiangsu Province(No.BZ2008031,No.BE2008074,and No.BE2009090)+1 种基金the Nantong International Cooperative Project(No.W2009003)the Natural Science Foundation of Nantong University(No.08Z022 and No.08Z025).
文摘Based on the characteristic of AC-excited variable speed constant frequency(VSCF)wind power generation,the vector control technique was applied in a doubly fed induction generator(DFIG).Maximum wind energy or maximum output power point can be tracked by decoupling control of active power and reactive power.The research result shows that the net power of generation system delivered to grid in maximum wind energy tracking mode is not the most.We presented a novel maximum power point tracking(MPPT)control strategy by analyzing the DFIG mathematic model and power relations which delivered the maximum power to the grid.The maximum power point could be tracked automatically without measuring wind speed in the control strategy and the control was independent of optimal turbine power curve,which had excellent dynamic and static performances and robustness.Simulation and experimental results testify the accuracy and validity of the control strategy.
文摘In general,Variable-Speed Constant Frequency (VSCF)Wind generation system is controlled by stator voltage orientation method which based on the mathematic model of VSCF Wind generation system and discussed the control strategy.Present the whole dynamic control model of variable-speed wind generator system in MATLAB/ Simulink,and the simulation results confirm the validity and effectiveness of the proposed control strategy.
文摘Every four years the Committee on Data for Science and Technology (CODATA) supplies a self-consistent set of values of the basic constants and conversion factors of physics recommended for international use. In 2013, the World-Universe Model (WUM) proposed a principally different depiction of the World as an alternative to the picture of the Big Bang Model. This article: 1) Gives the short history of Classical Physics before Special Relativity;2) Calculates Fundamental Physical Constants based on experimentally measured Rydberg constant, Electrodynamic constant, Electron Charge-to-Mass Ratio, and Planck constant;3) Discusses Electrodynamic constant and Speed of Light;4) Considers Dimensionless Fundamental Parameters (Dirac Large Number Q and Dimensionless Rydberg Constant α);5) Calculates Newtonian Constant of Gravitation based on the Inter-connectivity of Primary Physical Parameters;6) Makes a detailed analysis of the Self-consistency of Fundamental Physical Constants and Primary Physical Parameters through the prism of WUM. The performed analysis suggests: 1) Discontinuing using the notion “Vacuum” and its characteristics (Speed of Light in Vacuum, Characteristic Impedance of Vacuum, Vacuum Magnetic Permeability, Vacuum Electric Permittivity);2) Accepting the exact numerical values of Electrodynamic constant, Planck constant, Elementary charge, and Dimensionless Rydberg Constant α. WUM recommends the predicted value of Newtonian Constant of Gravitation in 2018 to be considered in CODATA Recommend Values of the Fundamental Physical Constants 2022.
文摘We previously revealed that the speed of light in vacuum c, the gravitational constant G, the vacuum permittivity ε, and the vacuum permeability μ can be defined by the temperature T (or the expected average frequency f) of cosmic microwave background (CMB) radiation. Given that CMB is continuously cooling, that is, T is continuously decreasing, we proposed that the above “constants” are variable and their values at some space-time with CMB temperature T (c<sub>T</sub>, G<sub>T</sub>, ε<sub>T</sub>, and μ<sub>T</sub>) can be described using their values (c<sub>0</sub>, G<sub>0</sub>, ε<sub>0</sub>, and μ<sub>0</sub>) and the temperature (T<sub>0</sub>) of CMB at present space-time. Based on the above observation, a number of physical equations related with these constants are re-described in this study, including relativity equation, mass-energy equation, and Maxwell’s equations, etc.
基金supported by grants from the Research Grant Council of the Hong Kong Special Administrative Region,PR China(Project Nos.HKU 17207518 and R5037-18).
文摘This study purposes an in situ testing method on quality assessment of soil improvement.Factual drilling data includes the spatial distribution and in situ strength of untreated and treated soil along three different drillholes measured by on-site drilling monitoring method.These factual drilling data can characterize the degree of soil improvement by penetration injection with permeable polyurethane.Result from on-site drilling monitoring shows that the linear zones represent constant drilling speeds shown in the plot of drill bit advancement vs.net drilling time,which indicates the spatial distributions of soil profile.The soil profile at the study site is composed of four layers,which includes fill,untreated silty clay,treated silty clay,and mucky soil.The results of soil profile are verified by the parallel site loggings.The constant drilling speeds profile the coring-resistant strength of drilled soils.By comparing with the untreated silty clay,the constant drilling speeds of the treated silty clay have been decreased by 13.0-62.8%.Two drilling-speed-based indices of 61.2%and 65.6%are proposed to assess the decreased average drilling speed and the increased in situ strength of treated silty clay.Laboratory tests,i.e.uniaxial compressive strength(UCS)test,have been performed with core sample to investigate and characterize in situ strength by comparing that with drilling speeds.Results show that the average predicted strengths of treated silty clay are 2.4-6.9 times higher than the average measured strength of untreated silty clay.The UCS-based indices of 374.5%and 344.2%verified the quality assessment(QA)results by this new in situ method.This method provides a cost-effective tool for quality assessment of soil improvement by utilizing the digital drilling data.
