The dynamic model of a novel electric power steering （EPS） system integrated with active front steering function （the novel EPS system） is built. The concepts and quantitative expressions of the steering road feel...The dynamic model of a novel electric power steering （EPS） system integrated with active front steering function （the novel EPS system） is built. The concepts and quantitative expressions of the steering road feel, steering sensibility, and steering operation stability are introduced. Based on quality engineering theory, the optimization algorithm is proposed by integrating the Monte Carlo descriptive sampling, elitist non-dominated sorting genetic algorithm （NSGA-II） and 6-sigma design method. With the steering road feel and the steering portability as optimization targets, the system parameters are optimized by the proposed optimization algorithm. The simulation results show that the system optimized based on quality engineering theory can improve the steering road feel, guarantee steering stability and steering portability and thus provide a theoretical basis for the design and optimization of the novel electric power steering system.展开更多
At present,equivalent water depth truncated mooring system optimization design is regarded as the priority of hybrid model testing for deep sea platforms,and will replace the full depth system test in the future.Compa...At present,equivalent water depth truncated mooring system optimization design is regarded as the priority of hybrid model testing for deep sea platforms,and will replace the full depth system test in the future.Compared with the full depth system,the working depth and span are smaller in the truncated one,and the other characteristics maintain more consistency as well.In this paper,an inner turret moored floating production storage ＆ offloading system（FPSO） which works at a water depth of 320m,was selected to be a research example while the truncated water depth was 80m.Furthermore,an improved non-dominated sorting genetic algorithm（INSGA-II） was selected to optimally calculate the equivalent water depth truncated system,considering the stress condition of the total mooring system in both the horizontal and vertical directions,as well as the static characteristic similarity of the representative single mooring line.The results of numerical calculations indicate that the mathematical model is feasible,and the optimization method is fast and effective.展开更多
Difference systems of sets (DSSs) are combinatorial configurations which were introduced in 1971 by Levenstein for the construction of codes for synchronization. In this paper, we present two kinds of constructions of...Difference systems of sets (DSSs) are combinatorial configurations which were introduced in 1971 by Levenstein for the construction of codes for synchronization. In this paper, we present two kinds of constructions of difference systems of sets by using disjoint difference families and a special type of difference sets, respectively. As a consequence, new infinite classes of optimal DSSs are obtained.展开更多
With the level of short-circuit current of power systems growing increasingly higher,optimal allocation of current limiters has received considerable attention in recent years,especially in China.This paper analyzes t...With the level of short-circuit current of power systems growing increasingly higher,optimal allocation of current limiters has received considerable attention in recent years,especially in China.This paper analyzes two kinds of common used current limiters based on the increment of bus impedance matrix and proposes a multi-objective current limiters configuration model considering the investment of limiters,the level of short-circuit current,as well as the transient stability of power system.An innovative search space reduction technique based on sensitivity factor is introduced to choose better candidate locations for current limiters so as to avoid the curse of dimensionality.The elitist non-dominated sorting genetic algorithm II is used to search the Pareto-optimal solutions of the proposed model.In order to further improve optimization efficiency,master-slave parallel modification of NSGA-II program structure is implemented.The satisfactory case study results demonstrate the feasibility of the proposed multi-objective method in power system current limiters allocation associated with cost,security and stability.展开更多
基金Projects(51005115,51205191)supported by the National Natural Science Foundation of ChinaProject(QC201101)supported by the Visiting Scholar Foundation of the Automobile Engineering Key Laboratory of Jiangsu Province,China+1 种基金Project(SKLMT-KFKT-201105)supported by the Visiting Scholar Foundation of the State Key Laboratory of Mechanical Transmission in Chongqing University,ChinaProjects(NS2013015,NS2012086)supported by the Funds from the Postgraduate Creative Base in Nanjing University of Areonautics and Astronautics,and NUAA Research Funding,China
文摘The dynamic model of a novel electric power steering （EPS） system integrated with active front steering function （the novel EPS system） is built. The concepts and quantitative expressions of the steering road feel, steering sensibility, and steering operation stability are introduced. Based on quality engineering theory, the optimization algorithm is proposed by integrating the Monte Carlo descriptive sampling, elitist non-dominated sorting genetic algorithm （NSGA-II） and 6-sigma design method. With the steering road feel and the steering portability as optimization targets, the system parameters are optimized by the proposed optimization algorithm. The simulation results show that the system optimized based on quality engineering theory can improve the steering road feel, guarantee steering stability and steering portability and thus provide a theoretical basis for the design and optimization of the novel electric power steering system.
基金Supported by the National Natural Science Foundation of China （Grant No. 10602055）Natural Science Foundation of Zhejiang Province （Grant No. Y6110243）
文摘At present,equivalent water depth truncated mooring system optimization design is regarded as the priority of hybrid model testing for deep sea platforms,and will replace the full depth system test in the future.Compared with the full depth system,the working depth and span are smaller in the truncated one,and the other characteristics maintain more consistency as well.In this paper,an inner turret moored floating production storage ＆ offloading system（FPSO） which works at a water depth of 320m,was selected to be a research example while the truncated water depth was 80m.Furthermore,an improved non-dominated sorting genetic algorithm（INSGA-II） was selected to optimally calculate the equivalent water depth truncated system,considering the stress condition of the total mooring system in both the horizontal and vertical directions,as well as the static characteristic similarity of the representative single mooring line.The results of numerical calculations indicate that the mathematical model is feasible,and the optimization method is fast and effective.
基金supported by National Natural Science Foundation of China (Grant Nos.10771051,10831002)
文摘Difference systems of sets (DSSs) are combinatorial configurations which were introduced in 1971 by Levenstein for the construction of codes for synchronization. In this paper, we present two kinds of constructions of difference systems of sets by using disjoint difference families and a special type of difference sets, respectively. As a consequence, new infinite classes of optimal DSSs are obtained.
文摘With the level of short-circuit current of power systems growing increasingly higher,optimal allocation of current limiters has received considerable attention in recent years,especially in China.This paper analyzes two kinds of common used current limiters based on the increment of bus impedance matrix and proposes a multi-objective current limiters configuration model considering the investment of limiters,the level of short-circuit current,as well as the transient stability of power system.An innovative search space reduction technique based on sensitivity factor is introduced to choose better candidate locations for current limiters so as to avoid the curse of dimensionality.The elitist non-dominated sorting genetic algorithm II is used to search the Pareto-optimal solutions of the proposed model.In order to further improve optimization efficiency,master-slave parallel modification of NSGA-II program structure is implemented.The satisfactory case study results demonstrate the feasibility of the proposed multi-objective method in power system current limiters allocation associated with cost,security and stability.
