Obtaining the optimal values of the parameters for th e design of a required mould and the operation of the moulding process are diffi cult, this is due to the complexity of product geometry and the variation of pla s...Obtaining the optimal values of the parameters for th e design of a required mould and the operation of the moulding process are diffi cult, this is due to the complexity of product geometry and the variation of pla stic material properties. The typical parameters for the mould design and mouldi ng process are melt flow length, injection pressure, holding pressure, back pres sure, injection speed, melt temperature, mould temperature, clamping force, inje ction time, holding time and cooling time. This paper discusses the difficulties of using the current computer aided optimization methods to acquire the values of the parameters. A method that is based on the concept of genetic algorithm is proposed to overcome the difficulties. The proposed method describes in details on how to attain the optimal values of the parameters form a given product geom etry.展开更多
Satellite constellation design for space optical systems is essentially a multiple-objective optimization problem. In this work, to tackle this challenge, we first categorize the performance metrics of the space optic...Satellite constellation design for space optical systems is essentially a multiple-objective optimization problem. In this work, to tackle this challenge, we first categorize the performance metrics of the space optical system by taking into account the system tasks（i.e., target detection and tracking）. We then propose a new non-dominated sorting genetic algorithm（NSGA） to maximize the system surveillance performance. Pareto optimal sets are employed to deal with the conflicts due to the presence of multiple cost functions. Simulation results verify the validity and the improved performance of the proposed technique over benchmark methods.展开更多
Pointing at naval ship projects creation and evaluation at stage of naval ship concept design,in the mechanism of integrated design based on naval ship synthesis model,ship projects creation and intelligent fuzzy eval...Pointing at naval ship projects creation and evaluation at stage of naval ship concept design,in the mechanism of integrated design based on naval ship synthesis model,ship projects creation and intelligent fuzzy evaluation method is researched,thus the applicability of each algorithm is obtained.Firstly,the naval ship synthesis model is introduced to design process,value and application status of synthesis model in integrated design is then exposed.Then the applicability of single target and multi targets SA algorithm is improved,and the quick generation of naval ship projects is done.After that,multiple projects evaluation method based on Vague fuzzy set is introduced to established the intelligent evaluation model,which can integrate effectively the quantitative and qualitative indexes.At last,the analysis of results comparison shows the advancement and rationality of each method.The example shows the integrated design process researched in this paper can be a great orientation of naval ship project design,and can also be used in other parts of naval ship development.展开更多
针对大型汽车覆盖件修边工序模具设计步骤多、周期长、重复度高等问题,采用归纳总结法,尝试将修边模具辅助结构设计过程中遇到的隐性知识显性化、定性知识数值化、经验知识算法化。首先,对修边模具辅助结构智能化设计推理规则进行了研究...针对大型汽车覆盖件修边工序模具设计步骤多、周期长、重复度高等问题,采用归纳总结法,尝试将修边模具辅助结构设计过程中遇到的隐性知识显性化、定性知识数值化、经验知识算法化。首先,对修边模具辅助结构智能化设计推理规则进行了研究,以修边镶块辅助结构自动生成算法为例,研究了力学准则和几何准则,给出了实现隐性知识显性化的量化算法。其次通过经验的总结与准则的研究,在技术路线层面搭建辅助结构的自动化设计推理规则,实现了修边工序辅助结构智能化和少交互式设计,并基于NX OPEN API进行算法实现,验证技术路线可行性。结果表明,通过历史工艺复用,对经验设计的汽车模具零部件制定量化的力学准则和几何准则,便可以进行智能算法推理设计,减少修边模具开发周期。展开更多
半倾转构型是电驱动垂直起降飞行器(Electric vertical take‑off and landing,eVTOL)的一种常用构型,因此需要对其总体参数设计规律、总体参数优化方法以及过渡飞行功率特性进行研究。首先,提出了一种使用纵向配平框架的半倾转构型性能...半倾转构型是电驱动垂直起降飞行器(Electric vertical take‑off and landing,eVTOL)的一种常用构型,因此需要对其总体参数设计规律、总体参数优化方法以及过渡飞行功率特性进行研究。首先,提出了一种使用纵向配平框架的半倾转构型性能算法,采用升力旋翼和平尾融合算法解决操纵冗余问题。然后,通过试验数据对比,验证了算法的精度。接下来,使用该性能算法并结合重量模型,分析了各项总体参数、电池能量密度的变化对空机重量、重量效率的影响,并针对特定需求得到了一套满足要求的总体参数。最后,使用半倾转构型性能算法对过渡状态下的功率、迎角、加速度进行扫描,通过分析计算结果,定性选择过渡路径,并通过优化加速度降低过渡过程的能量消耗,得到了过渡过程中剩余功率的变化趋势,为半倾转构型eVTOL的设计与工程研制提供了可参考的研究思路。展开更多
文摘Obtaining the optimal values of the parameters for th e design of a required mould and the operation of the moulding process are diffi cult, this is due to the complexity of product geometry and the variation of pla stic material properties. The typical parameters for the mould design and mouldi ng process are melt flow length, injection pressure, holding pressure, back pres sure, injection speed, melt temperature, mould temperature, clamping force, inje ction time, holding time and cooling time. This paper discusses the difficulties of using the current computer aided optimization methods to acquire the values of the parameters. A method that is based on the concept of genetic algorithm is proposed to overcome the difficulties. The proposed method describes in details on how to attain the optimal values of the parameters form a given product geom etry.
文摘Satellite constellation design for space optical systems is essentially a multiple-objective optimization problem. In this work, to tackle this challenge, we first categorize the performance metrics of the space optical system by taking into account the system tasks（i.e., target detection and tracking）. We then propose a new non-dominated sorting genetic algorithm（NSGA） to maximize the system surveillance performance. Pareto optimal sets are employed to deal with the conflicts due to the presence of multiple cost functions. Simulation results verify the validity and the improved performance of the proposed technique over benchmark methods.
基金supported by “The Fundamental Research Funds for the Central Universities”(3132014318)
文摘Pointing at naval ship projects creation and evaluation at stage of naval ship concept design,in the mechanism of integrated design based on naval ship synthesis model,ship projects creation and intelligent fuzzy evaluation method is researched,thus the applicability of each algorithm is obtained.Firstly,the naval ship synthesis model is introduced to design process,value and application status of synthesis model in integrated design is then exposed.Then the applicability of single target and multi targets SA algorithm is improved,and the quick generation of naval ship projects is done.After that,multiple projects evaluation method based on Vague fuzzy set is introduced to established the intelligent evaluation model,which can integrate effectively the quantitative and qualitative indexes.At last,the analysis of results comparison shows the advancement and rationality of each method.The example shows the integrated design process researched in this paper can be a great orientation of naval ship project design,and can also be used in other parts of naval ship development.
文摘针对大型汽车覆盖件修边工序模具设计步骤多、周期长、重复度高等问题,采用归纳总结法,尝试将修边模具辅助结构设计过程中遇到的隐性知识显性化、定性知识数值化、经验知识算法化。首先,对修边模具辅助结构智能化设计推理规则进行了研究,以修边镶块辅助结构自动生成算法为例,研究了力学准则和几何准则,给出了实现隐性知识显性化的量化算法。其次通过经验的总结与准则的研究,在技术路线层面搭建辅助结构的自动化设计推理规则,实现了修边工序辅助结构智能化和少交互式设计,并基于NX OPEN API进行算法实现,验证技术路线可行性。结果表明,通过历史工艺复用,对经验设计的汽车模具零部件制定量化的力学准则和几何准则,便可以进行智能算法推理设计,减少修边模具开发周期。
文摘半倾转构型是电驱动垂直起降飞行器(Electric vertical take‑off and landing,eVTOL)的一种常用构型,因此需要对其总体参数设计规律、总体参数优化方法以及过渡飞行功率特性进行研究。首先,提出了一种使用纵向配平框架的半倾转构型性能算法,采用升力旋翼和平尾融合算法解决操纵冗余问题。然后,通过试验数据对比,验证了算法的精度。接下来,使用该性能算法并结合重量模型,分析了各项总体参数、电池能量密度的变化对空机重量、重量效率的影响,并针对特定需求得到了一套满足要求的总体参数。最后,使用半倾转构型性能算法对过渡状态下的功率、迎角、加速度进行扫描,通过分析计算结果,定性选择过渡路径,并通过优化加速度降低过渡过程的能量消耗,得到了过渡过程中剩余功率的变化趋势,为半倾转构型eVTOL的设计与工程研制提供了可参考的研究思路。
