Instead of establishing mathematical hydraulic system models from physical laws usually done with the problems of complex modelling processes, low reliability and practicality caused by large uncertainties, a novel mo...Instead of establishing mathematical hydraulic system models from physical laws usually done with the problems of complex modelling processes, low reliability and practicality caused by large uncertainties, a novel modelling method for a highly nonlinear system of a hydraulic excavator is presented. Based on the data collected in the excavator＇s arms driving experiments, a data-based excavator dynamic model using Simplified Refined Instrumental Variable （SRIV） identification and estimation algorithms is established. The validity of the proposed data-based model is indirectly demonstrated by the performance of computer simulation and the.real machine motion control exoeriments.展开更多
A simple control structure in servo system is occasionally needed for simple industrial application which precise and high control performance is not exessively important so that the cost production can be reduced eff...A simple control structure in servo system is occasionally needed for simple industrial application which precise and high control performance is not exessively important so that the cost production can be reduced efficiently. Simplified vector control, which has simple control structure, is utilized as the permanent magnet synchronous motor control algorithm and genetic algorithm is used to tune three PI controllers used in simplified vector control. The control performance is obtained from simulation and investigated to verify the feasibility of the algorithm to be applied in the real application. Simulation results show that the speed and torque responses of the system in both continuous time and discrete time can achieve good performances. Furthermore, simplified vector control combined with genetic algorithm has a similar perfofmance with conventional field oriented control algorithm and possible to be realized into the real simple application in the future.展开更多
The simplified algorithm for out-of-plane ultimate loadcarrying capacity of concrete-filled steel tubular( CFST) solid-rib arches under uniform vertical load was studied. The experimentally validated finite element mo...The simplified algorithm for out-of-plane ultimate loadcarrying capacity of concrete-filled steel tubular( CFST) solid-rib arches under uniform vertical load was studied. The experimentally validated finite element model was developed. The out-of-plane equivalent length coefficients of solid-rib arches were obtained using out-of-plane elastic eigenvalue buckling analysis. Then the out-ofplane elastic stability coefficient was plotted against the normalized slenderness ratio,and the out-of-plane eigenvalue buckling load or elastic buckling capability of arches was calculated. Lastly effects of different parameters on the out-of-plane ultimate load-carrying capacity of CFST solid-rib arches were determined using geometric and material nonlinear finite element analysis, and a simplified algorithm was established by fitting the out-of-plane elastic-plastic stability coefficient and normalized slenderness ratio using PerryRobertson formula. Ratio of the elastic stability coefficient to the elastic-plastic counterpart was plotted against the out-of-plane normalized slenderness ratio,from which the out-of-plane elasticplastic ultimate load-carrying capacity was determined according to the corresponding elastic buckling load. Results show that the proposed simplified algorithm can accurately predict the out-of-plane eigenvalue buckling load and the elastic-plastic ultimate loadcarrying capacity of the CFST solid-rib arches.展开更多
In almost all frozen soil models used currently, three variables of temperature, ice content and moisture content are used as prognostic variables and the rate term, accounting for the contribution of the phase change...In almost all frozen soil models used currently, three variables of temperature, ice content and moisture content are used as prognostic variables and the rate term, accounting for the contribution of the phase change between water and ice, is shown explicitly in both the energy and mass balance equations. The models must be solved by a numerical method with an iterative process, and the rate term of the phase change needs to be pre-estimated at the beginning in each iteration step. Since the rate term of the phase change in the energy equation is closely related to the release or absorption of the great amount of fusion heat, a small error in the rate term estimation will introduce greater error in the energy balance, which will amplify the error in the temperature calculation and in turn, cause problems for the numerical solution convergence. In this work, in order to first reduce the trouble, the methodology of the variable transformation is applied to a simplified frozen soil model used currently, which leads to new frozen soil scheme used in this work. In the new scheme, the enthalpy and the total water equivalent are used as predictive variables in the governing equations to replace temperature, volumetric soil moisture and ice content used in many current models. By doing so, the rate terms of the phase change are not shown explicitly in both the mass and energy equations and its pre-estimation is avoided. Secondly, in order to solve this new scheme more functionally, the development of the numerical scheme to the new scheme is described and a numerical algorithm appropriate to the numerical scheme is developed. In order to evaluate the new scheme of the frozen soil model and its relevant algorithm, a series of model evaluations are conducted by comparing numerical results from the new model scheme with three observational data sets. The comparisons show that the results from the model are in good agreement with these data sets in both the change trend of variables and their magnitude values, and the new scheme, together with the algorithm, is more efficient and saves more computer time.展开更多
The aim of this paper is to simplify the design of fractional-order PID controllers.Because the analytical expressions and operations of fractional-order systems are complex,numerical approximation tool is needed for ...The aim of this paper is to simplify the design of fractional-order PID controllers.Because the analytical expressions and operations of fractional-order systems are complex,numerical approximation tool is needed for the simulation analysis and engineering practice of fractional-order control systems.The key to numerical approximation tool is the exact approximation of the fractional calculus operator.A commonly used method is to approximate the fractional calculus operator with an improved Oustaloup^recursive filter.Based on the modified Oustaloup5s recursive filter,a mathematical simplification method is proposed in this paper,and a simplified fractional-order PID controller(SFOC)is designed.The controller parameters are tuned by using genetic algorithm(GA).Effectiveness of the proposed control scheme is verified by simulation.The performance of SFOC has been compared with that of the integer-order PID controller and conventional fractional-order PID controller(CFOC).It is observed that SFOC requires smaller effort as compared with its integer and conventional fractional counterpart to achieve the same system performance.展开更多
The dominant error source of mobile terminal location in wireless sensor networks （WSNs） is the non-line-of-sight （NLOS） propagation error. Among the algorithms proposed to mitigate the influence of NLOS propagati...The dominant error source of mobile terminal location in wireless sensor networks （WSNs） is the non-line-of-sight （NLOS） propagation error. Among the algorithms proposed to mitigate the influence of NLOS propagation error, residual test （RT） is an efficient one, however with high computational complexity （CC）. An improved algorithm that memorizes the light of sight （LOS） range measurements （RMs） identified memorize LOS range measurements identified residual test （MLSI-RT） is presented in this paper to address this problem. The MLSI-RT is based on the assumption that when all RMs are from LOS propagations, the normalized residual follows the central Chi-Square distribution while for NLOS cases it is non-central. This study can reduce the CC by more than 90%.展开更多
饲草等粗饲料是反刍动物日粮纤维的主要来源。中性洗涤纤维(NDF)是衡量饲草纤维含量的重要指标,其消化率是评估饲草质量、动物干物质采食量的关键参数。目前常用体外48 h NDF消化率(NDFD_(48))评估饲草NDF的可消化情况。准确测定粗饲料N...饲草等粗饲料是反刍动物日粮纤维的主要来源。中性洗涤纤维(NDF)是衡量饲草纤维含量的重要指标,其消化率是评估饲草质量、动物干物质采食量的关键参数。目前常用体外48 h NDF消化率(NDFD_(48))评估饲草NDF的可消化情况。准确测定粗饲料NDFD_(48)值对精准平衡动物日粮具有指导意义。目前粗饲料NDFD_(48)可用瘤胃尼龙袋法、实验室半体内法测定或近红外快速检测,但通常受测定试验条件和仪器设备等制约。基于NDFD_(48)的生物学意义,旨在拟合构建估测NDFD_(48)的计算方法。利用奶牛营养需要(NASEM,2021)中饲草纤维指标[NDF和酸性洗涤纤维(ADF)]及消化率指标(NDFD_(48))作为测试集,构建了NDFD_(48)模型,并选取Journal of Dairy Science期刊中14篇文章的相关指标及本实验室实测指标作为2套验证集,对模型进行了验证。结果发现,NDFD_(48)计算值与2套NDFD_(48)实测值均具有显著相关性(P<0.001),R^(2)分别为0.89和0.85。利用一致性相关系数(CCC)对模型进行验证,相关性达到0.93和0.91。此模型检测指标少,计算简便,精准度高。模型评估表明,该模型可为生产应用及饲草营养预判提供理论参考。展开更多
This paper describes a simplified algorithm of PLS regression, which can obviously reduce the computation of some parameters and simplify the computing procedure. Moreover, the new optimistic rule of this method provi...This paper describes a simplified algorithm of PLS regression, which can obviously reduce the computation of some parameters and simplify the computing procedure. Moreover, the new optimistic rule of this method provides a new explanation to the result of PLS regression.展开更多
This paper employs an efficacious analytical tool,adaptive simplified human learning optimization(ASHLO)algorithm,to solve optimal power flow(OPF)problem in AC/DC hybrid power system,considering valve-point loading ef...This paper employs an efficacious analytical tool,adaptive simplified human learning optimization(ASHLO)algorithm,to solve optimal power flow(OPF)problem in AC/DC hybrid power system,considering valve-point loading effects of generators,carbon tax,and prohibited operating zones of generators,respectively.ASHLO algorithm,involves random learning operator,individual learning operator,social learning operator and adaptive strategies.To compare and analyze the computation performance of the ASHLO method,the proposed ASHLO method and other heuristic intelligent optimization methods are employed to solve OPF problem on the modified IEEE 30-bus and 118-bus AC/DC hybrid test system.Numerical results indicate that the ASHLO method has good convergent property and robustness.Meanwhile,the impacts of wind speeds and locations of HVDC transmission line integrated into the AC network on the OPF results are systematically analyzed.展开更多
DEMON and LOFAR have been proved the powerful means in underwater acoustic signal processing, especially in weak signal detection and target noise classification. Sometimes one need to know the fine structure of frequ...DEMON and LOFAR have been proved the powerful means in underwater acoustic signal processing, especially in weak signal detection and target noise classification. Sometimes one need to know the fine structure of frequency spectrum of received signal. It is necessary to take a very long data to get high frequency resolution. This is not always possible due to the hardware and software limitation. Zoom FFT is one of the trade-off consideration for solving high frequency resolution problem, if we are only focus on some special frequency bins. Previous discussions mainly bifurcate into two different representations, the Complex Modulation and Cascade FFT. The former one traditionally needs some kind of special treatments, such as the complex modulation, Lowpass filtering, down-sampling. While the latter achieves the same result by two cascade FFT, with necessary modifications in phase and amplitude, thus is feasible for real-time implementation. Based on some theoretical analysis, a relationship between the complex moduIation and cascade FFT has been described in this paper. In addition, the selection of parameters such as windows function, sample rate, overlap factor have been discussed. Finally, the algorithm is presented and some simulation results are illustrated展开更多
文摘Instead of establishing mathematical hydraulic system models from physical laws usually done with the problems of complex modelling processes, low reliability and practicality caused by large uncertainties, a novel modelling method for a highly nonlinear system of a hydraulic excavator is presented. Based on the data collected in the excavator＇s arms driving experiments, a data-based excavator dynamic model using Simplified Refined Instrumental Variable （SRIV） identification and estimation algorithms is established. The validity of the proposed data-based model is indirectly demonstrated by the performance of computer simulation and the.real machine motion control exoeriments.
文摘A simple control structure in servo system is occasionally needed for simple industrial application which precise and high control performance is not exessively important so that the cost production can be reduced efficiently. Simplified vector control, which has simple control structure, is utilized as the permanent magnet synchronous motor control algorithm and genetic algorithm is used to tune three PI controllers used in simplified vector control. The control performance is obtained from simulation and investigated to verify the feasibility of the algorithm to be applied in the real application. Simulation results show that the speed and torque responses of the system in both continuous time and discrete time can achieve good performances. Furthermore, simplified vector control combined with genetic algorithm has a similar perfofmance with conventional field oriented control algorithm and possible to be realized into the real simple application in the future.
基金National Natural Science Foundation of China(No.51178119)
文摘The simplified algorithm for out-of-plane ultimate loadcarrying capacity of concrete-filled steel tubular( CFST) solid-rib arches under uniform vertical load was studied. The experimentally validated finite element model was developed. The out-of-plane equivalent length coefficients of solid-rib arches were obtained using out-of-plane elastic eigenvalue buckling analysis. Then the out-ofplane elastic stability coefficient was plotted against the normalized slenderness ratio,and the out-of-plane eigenvalue buckling load or elastic buckling capability of arches was calculated. Lastly effects of different parameters on the out-of-plane ultimate load-carrying capacity of CFST solid-rib arches were determined using geometric and material nonlinear finite element analysis, and a simplified algorithm was established by fitting the out-of-plane elastic-plastic stability coefficient and normalized slenderness ratio using PerryRobertson formula. Ratio of the elastic stability coefficient to the elastic-plastic counterpart was plotted against the out-of-plane normalized slenderness ratio,from which the out-of-plane elasticplastic ultimate load-carrying capacity was determined according to the corresponding elastic buckling load. Results show that the proposed simplified algorithm can accurately predict the out-of-plane eigenvalue buckling load and the elastic-plastic ultimate loadcarrying capacity of the CFST solid-rib arches.
基金the National Natural Science Foun-dation of China under Grant Nos. 40575043 and 40605024as well as 40730952the National Basic Research Program of China under Grant No. 2009CB421405The Innovation Project of the Chinese Academy of Sci-ences (Grant No. KZCX2-YW-220)
文摘In almost all frozen soil models used currently, three variables of temperature, ice content and moisture content are used as prognostic variables and the rate term, accounting for the contribution of the phase change between water and ice, is shown explicitly in both the energy and mass balance equations. The models must be solved by a numerical method with an iterative process, and the rate term of the phase change needs to be pre-estimated at the beginning in each iteration step. Since the rate term of the phase change in the energy equation is closely related to the release or absorption of the great amount of fusion heat, a small error in the rate term estimation will introduce greater error in the energy balance, which will amplify the error in the temperature calculation and in turn, cause problems for the numerical solution convergence. In this work, in order to first reduce the trouble, the methodology of the variable transformation is applied to a simplified frozen soil model used currently, which leads to new frozen soil scheme used in this work. In the new scheme, the enthalpy and the total water equivalent are used as predictive variables in the governing equations to replace temperature, volumetric soil moisture and ice content used in many current models. By doing so, the rate terms of the phase change are not shown explicitly in both the mass and energy equations and its pre-estimation is avoided. Secondly, in order to solve this new scheme more functionally, the development of the numerical scheme to the new scheme is described and a numerical algorithm appropriate to the numerical scheme is developed. In order to evaluate the new scheme of the frozen soil model and its relevant algorithm, a series of model evaluations are conducted by comparing numerical results from the new model scheme with three observational data sets. The comparisons show that the results from the model are in good agreement with these data sets in both the change trend of variables and their magnitude values, and the new scheme, together with the algorithm, is more efficient and saves more computer time.
基金the National Natural Science Foundation of China(No.61603411)。
文摘The aim of this paper is to simplify the design of fractional-order PID controllers.Because the analytical expressions and operations of fractional-order systems are complex,numerical approximation tool is needed for the simulation analysis and engineering practice of fractional-order control systems.The key to numerical approximation tool is the exact approximation of the fractional calculus operator.A commonly used method is to approximate the fractional calculus operator with an improved Oustaloup^recursive filter.Based on the modified Oustaloup5s recursive filter,a mathematical simplification method is proposed in this paper,and a simplified fractional-order PID controller(SFOC)is designed.The controller parameters are tuned by using genetic algorithm(GA).Effectiveness of the proposed control scheme is verified by simulation.The performance of SFOC has been compared with that of the integer-order PID controller and conventional fractional-order PID controller(CFOC).It is observed that SFOC requires smaller effort as compared with its integer and conventional fractional counterpart to achieve the same system performance.
基金supported by the State Key Program of National Natural Science of China (Grant No.60532030)the New Century Excellent Talents in University (Grant No.NCET-08-0333)the Natural Science Foundation of Shandong Province (Grant No.Y2007G10)
文摘The dominant error source of mobile terminal location in wireless sensor networks （WSNs） is the non-line-of-sight （NLOS） propagation error. Among the algorithms proposed to mitigate the influence of NLOS propagation error, residual test （RT） is an efficient one, however with high computational complexity （CC）. An improved algorithm that memorizes the light of sight （LOS） range measurements （RMs） identified memorize LOS range measurements identified residual test （MLSI-RT） is presented in this paper to address this problem. The MLSI-RT is based on the assumption that when all RMs are from LOS propagations, the normalized residual follows the central Chi-Square distribution while for NLOS cases it is non-central. This study can reduce the CC by more than 90%.
文摘饲草等粗饲料是反刍动物日粮纤维的主要来源。中性洗涤纤维(NDF)是衡量饲草纤维含量的重要指标,其消化率是评估饲草质量、动物干物质采食量的关键参数。目前常用体外48 h NDF消化率(NDFD_(48))评估饲草NDF的可消化情况。准确测定粗饲料NDFD_(48)值对精准平衡动物日粮具有指导意义。目前粗饲料NDFD_(48)可用瘤胃尼龙袋法、实验室半体内法测定或近红外快速检测,但通常受测定试验条件和仪器设备等制约。基于NDFD_(48)的生物学意义,旨在拟合构建估测NDFD_(48)的计算方法。利用奶牛营养需要(NASEM,2021)中饲草纤维指标[NDF和酸性洗涤纤维(ADF)]及消化率指标(NDFD_(48))作为测试集,构建了NDFD_(48)模型,并选取Journal of Dairy Science期刊中14篇文章的相关指标及本实验室实测指标作为2套验证集,对模型进行了验证。结果发现,NDFD_(48)计算值与2套NDFD_(48)实测值均具有显著相关性(P<0.001),R^(2)分别为0.89和0.85。利用一致性相关系数(CCC)对模型进行验证,相关性达到0.93和0.91。此模型检测指标少,计算简便,精准度高。模型评估表明,该模型可为生产应用及饲草营养预判提供理论参考。
基金National Natural Science Foundation ( No.79970 0 53)
文摘This paper describes a simplified algorithm of PLS regression, which can obviously reduce the computation of some parameters and simplify the computing procedure. Moreover, the new optimistic rule of this method provides a new explanation to the result of PLS regression.
基金supported by National Natural Science Foundation of China(No.51377103)the technology project of State Grid Corporation of China:Research on Multi-Level Decomposition Coordination of the Pareto Set of Multi-Objective Optimization Problem in Bulk Power System(No.SGSXDKYDWKJ2015-001)the support from State Energy Smart Grid R&D Center(SHANGHAI)
文摘This paper employs an efficacious analytical tool,adaptive simplified human learning optimization(ASHLO)algorithm,to solve optimal power flow(OPF)problem in AC/DC hybrid power system,considering valve-point loading effects of generators,carbon tax,and prohibited operating zones of generators,respectively.ASHLO algorithm,involves random learning operator,individual learning operator,social learning operator and adaptive strategies.To compare and analyze the computation performance of the ASHLO method,the proposed ASHLO method and other heuristic intelligent optimization methods are employed to solve OPF problem on the modified IEEE 30-bus and 118-bus AC/DC hybrid test system.Numerical results indicate that the ASHLO method has good convergent property and robustness.Meanwhile,the impacts of wind speeds and locations of HVDC transmission line integrated into the AC network on the OPF results are systematically analyzed.
文摘DEMON and LOFAR have been proved the powerful means in underwater acoustic signal processing, especially in weak signal detection and target noise classification. Sometimes one need to know the fine structure of frequency spectrum of received signal. It is necessary to take a very long data to get high frequency resolution. This is not always possible due to the hardware and software limitation. Zoom FFT is one of the trade-off consideration for solving high frequency resolution problem, if we are only focus on some special frequency bins. Previous discussions mainly bifurcate into two different representations, the Complex Modulation and Cascade FFT. The former one traditionally needs some kind of special treatments, such as the complex modulation, Lowpass filtering, down-sampling. While the latter achieves the same result by two cascade FFT, with necessary modifications in phase and amplitude, thus is feasible for real-time implementation. Based on some theoretical analysis, a relationship between the complex moduIation and cascade FFT has been described in this paper. In addition, the selection of parameters such as windows function, sample rate, overlap factor have been discussed. Finally, the algorithm is presented and some simulation results are illustrated
