塑料注射机双曲肘合模机构优化设计的研究

本文结合实例通过对注塑机双曲肘合模机构优化设计的研究，指出并以功效系数最大建立的优化建模属非线性规划、非凸类型，具有多解性，文中还详细讨论了设计变量与目标骖数间的关系，指出＋θ，－ｒ方案比现行的＋θ，＋ｒ方案好得多。     

基于 ADAMS 的模切机双肘杆机构优化设计研究

利用MSC.ADAMS对模切机双肘杆机构进行了参数化建模,通过建立双肘杆机构优化目标函数,实现了双肘杆机构的结构尺寸参数化优化分析,并进行了相关的运动学、动力学仿真。优化结果表明,减小动平台与水平方向的震动偏角和在水平方向的位移,将大大提高模切速度、精度和整机的稳定性。     

微机械陀螺结构的稳健优化设计

本文提出一种基于容差分析的微机械陀螺稳健设计方法,开发了相应的稳健优化设计流程.该方法采用估算目标函数和约束的名义值与扰动值来定义系统稳健性,同时将最坏情况容差作为设计参数的扰动.在集成了器件建模和优化工具的设计环境中开发了相应的自动化设计流程,可用于微机械陀螺的结构设计.优化算法使用遗传算法.讨论了不同的稳健设计方法,结果表明本文的方法能以合适的计算成本获得高质量的结果.系统敏感性分析表明,稳健优化设计结果对误差是不敏感的.采用蒙特卡洛分析检验稳健设计的产出率,结果表明有88%的试验样本是可接受的,而对于确定性优化,仅有50%的可接受样本.微结构已经采用键合-深反应离子刻蚀工艺加工出来.     

基于田口方法的柔性铰链柔度稳健优化设计

柔顺机构柔度稳健性是柔性机构在微机电系统与精密工程等领域广泛应用的前提和基础,但在实际工程中传统设计方法未充分考虑其稳健性.引入田口稳健优化设计方法,选取柔性铰链各结构参数为可控因素,工作载荷为噪声因子,通过正交试验数据分析得出各个可控因素的信噪比和贡献率,进而选出最佳的参数水平组合,并对柔度综合稳健性能的最优方案进行了验证.算例表明,采用田口稳健优化设计的柔性铰链柔度稳健性比传统方法信噪比水平提高了4.68dB,降低了其质量损失,实现了柔性铰链柔度稳定性优化.田口稳健优化设计方法具有普适性,在实际工程应用中具有较高参考价值.     

碳纤维增强复合材料螺旋铣孔切削力及加工质量研究

针对传统钻孔方法加工复合材料时易导致分层、撕裂等缺陷的问题,采用螺旋铣作为新的制孔技术,根据飞机装配现场的实际加工条件,构建以机器人为移动载体、螺旋铣孔终端执行器为加工单元、螺旋铣孔专用刀具为切削工具的加工系统,采用该加工系统对碳纤维增强复合材料(CFRP)螺旋铣孔关键工艺参数进行正交试验,并讨论了刀具主轴转速、每齿进给量和轴向切削深度等工艺参数对切削力的影响规律;通过对加工缺陷的监测,探讨了切削力与CFRP分层、撕裂等缺陷之间的关系;最后对工艺参数进行优化,经试验验证,优化后轴向切削力较优化前降低26%以上,孔入口及出口处均无撕裂、毛刺,加工质量最优。     

激光用于LCD板ITO膜修复的研究

对激光修复LCD板ITO膜的过程及影响因素进行了理论分析和计算。设计并加工出一套激光聚焦系统，由一个用于扩束和压缩发散角的倒置开普勒望运镜和聚焦透镜组成，其聚焦光斑为15μm。优化了调Q基模Nd：YAG激光器的参数，并用其进行了实验研究。结果表明，能修复各种不同厚度的ITO膜，打的孔小于20μm，位置漂移量小于3μm。     

基于公理设计和相容决策支持问题法的稳健优化设计方法

 针对多目标稳健优化问题,建立了多目标稳健优化的损失函数,利用灵敏度分析方法确定各设计变量对各设计目标的影响程度,确定主要的设计参数,便于调整和控制设计参数的公差.根据信息公理与损失函数的一致性关系,建立以最小化各目标的总损失函数为目标函数.并在相容决策支持问题法框架基础上,提出一种基于公理设计和相容决策支持问题法的多目标稳健优化设计模型.实例分析表明,提出的方法是可行的.     

小型汽油机进气系统声学性能优化设计

随着车辆舒适性要求的不断提高,对发动机进气系统的声学性能要求也越来越高.以声学理论为基础,建立小型汽油机滤清器的参数化数值模型.首先,通过小型汽油机直管管口噪声模拟,获得进气系统插入损失的目标值;其次,结合插入损失的目标值确定小型汽油机进气系统传递损失的目标值,应用滤清器的数值模型优化滤清器的结构参数.小型汽油机进气系统声学性能优化设计方法具有很高的工程应用价值,并为滤清器的参数化设计提供了理论依据.     

基于实验测试分析的刀版布置优化研究

通过对双肘杆机构的平压平模切机在实际工况下的振动分析,利用丹麦BK振动测试系统及FBD压力测试系统,得到了模切刀痕线及橡胶条的压力大小,并比较得出了平衡刀的数量是影响模切压力均匀性的重要因素。根据研究结论,可确定模切版的刀版布置优化方案,进而保证模切压力的均匀性,提高模切精度。     

汽车排气系统振动和吊耳疲劳性能的稳健优化

由于加工、测量、安装、老化等原因,排气系统吊耳和波纹管的真实刚度通常在其名义设计值附近波动,使得排气系统真实的静、动态性能与其名义设计值之间存在偏差。为提升汽车排气系统振动及橡胶吊耳疲劳耐久性能的稳健性,以吊耳和波纹管动刚度为正态随机设计变量,以吊耳隔振量不小于20 dB为约束条件,以挂钩垂向动态反力最大值及其标准差、吊耳的静变形量及预载力标准差为目标函数,建立了某乘用车排气系统振动和吊耳疲劳性能的多目标稳健优化模型。结果表明,与确定性优化方案相比,排气系统静、动态性能对稳健优化方案的灵敏度降低,实施稳健优化方案将使得排气系统的振动和吊耳疲劳性能更加稳健。稳健优化方法对改善排气系统振动和吊耳疲劳耐久性的稳健优化有较重要参考价值。     

Multiresponse optimization using multivariate process capability index

Robust design is an efficient method for product and process improvement which combines experimentation with optimization to create a system that is less sensitive to uncontrollable variation. In this article, a simple and integrated modeling methodology for robust design is proposed. This methodology achieves the robustness objective function and input variables constraints simultaneously. The objective function is written in terms of the multivariate process capability vector (MC_pm) of several competing features of the system under study. The proposed methodology is applicable to general functions of the system performance with random variables. The effectiveness of the methodology is verified using two real‐world examples which are compared with those of other robust design methods. Copyright © 2010 John Wiley & Sons, Ltd.     

Product Robust Design and Process Robust Design: Are They the Same? (No.)

Taguchi's ideas of robust parameter design motivated the development of the dual-response approach, where both the mean and the variance of the quality response are modeled in terms of the design parameters and noise factors. These are then used to identify optimal settings that achieve the dual objective of optimizing the signal (the mean) and minimizing variation. While much research has been published recently with regard to how to solve the dual-response problem (DRP), relatively little attention has been given to the unique characteristics of process robust design, like the existence of systematic variation or intercorrelations among the process “controllable” variables. These properties indeed put process robust design in a category of its own (separate from product robust design). In this paper, we first expound these unique properties and develop a general formulation of the DRP as it applies to process robust design. We then report on an implementation to an industrial process in a high-tech corporation.     

造船液压机压头锁紧碟簧疲劳寿命稳健优化设计

 碟簧(碟形弹簧)的材料特性、几何特性、载荷等因素发生较小的波动,就会导致碟簧特性的变化,使其实际使用寿命与设计寿命出现较大偏差.针对碟形弹簧的疲劳寿命受不确定性因素影响而波动较大的问题,采用分析性稳健设计方法,对移动回转压头造船液压机压头锁紧碟簧的疲劳寿命与不确定性因素的关系进行了研究;以碟簧疲劳寿命的波动方差最小为目标函数,疲劳寿命均值等于预期寿命为等式约束,碟簧组轴向力大于允许值为不等式约束,建立碟簧疲劳寿命稳健优化模型,并获得了稳健设计解.稳健优化后的结果与优化前相比,在满足性能约束的条件下使不确定性因素的变化对碟簧疲劳寿命的影响降到最低,碟簧的疲劳寿命稳定在目标值附近,提高了设计的经济性和可靠性.     

Robust topology optimization of phononic crystals with random field uncertainty

The uncertain spatial variation of material properties can remarkably affect the band gap characteristics of phononic crystals (PnCs). It is necessary to consider this issue when designing and manufacturing PnC materials/structures. This paper investigates a robust topology optimization method for designing the microstructures of PnCs by considering random‐field material properties. Herein, the spatial distribution of the material properties is first represented by a random field and then discretized into uncorrelated stochastic variables with the expansion optimal linear estimation method; stochastic band gap analysis is then conducted with polynomial chaos expansion. Furthermore, a robust topology optimization formulation of PnCs is proposed on the basis of the relative elemental density, where a weighted objective function handles the compromise of the mean value and standard deviation of the PnC band gap. The band gap response is analyzed, employing the finite element method for each sample of polynomial chaos expansion. In this context, the sensitivities of the stochastic band gap behaviors to the design variables are also derived. Numerical examples demonstrate that the proposed method can generate meaningful optimal topologies of PnCs with a relatively large width and less sensitive band gap. Additionally, the effects of the weight factors in the objective function and the variation coefficient of material properties are discussed.     

飞机总体设计中的一种多目标鲁棒优化方法

 提出一种基于灵敏度的多目标鲁棒优化方法。针对各维设计变量存在扰动的情况，在原约束多目标优化模型上，附加偏差目标函数，并采用最差估计法对约束条件进行鲁棒可行性调整。采用全局敏度方程方法来计算目标函数和约束函数对设计变量的敏度，进而采用Pareto遗传算法搜索约束多目标优化问题的非劣解集，设计者可以根据不同的设计准则从中选择合适的设计点。将上述方法用于飞机总体参数优化设计，并与采用常规优化方法所得的优化结果进行了分析和比较。     

概率及非概率不确定性条件下结构鲁棒设计方法

提出了在概率不确定性和非概率不确定性同时存在时的约束函数鲁棒性和目标函数鲁棒性的实现策略及结构鲁棒设计方法。将传统优化设计问题的约束条件改造成为能同时反映两类不确定性量波动变化影响的约束条件,以实现约束函数的鲁棒性;在传统优化设计问题目标函数中增加若干个关于目标函数灵敏度的新目标函数,构成一个多目标函数设计问题,以实现目标函数的鲁棒性。所提方法应用于一个10杆桁架结构设计,采用宽容排序法求解。计算结果表明,在相同的结构总质量限制条件下,目标函数鲁棒性程度随着变量不确定性程度的增加而降低;在相同的变量不确定性程度条件下,增加结构总质量能提高目标函数鲁棒性的程度。     

Development of a simple and efficient method for robust optimization

Robust optimization problems are newly formulated and an efficient computational scheme is proposed. Both design variables and design parameters are considered as random variables about their nominal values. To ensure the robustness of objective performance, we introduce a new performance index bounding the performance together with a constraint limiting the performance variation. The constraint variations are regulated by considering the probability of feasibility. Each probability constraint is transformed into a sub‐optimization problem by the advanced first‐order second moment (AFOSM) method for computational efficiency. The proposed robust optimization method has the advantages that the mean value and the variation of the performance function are controlled simultaneously and rationally and the second‐order sensitivity information is not required even in case of gradient‐based optimization process. The suggested method is examined by solving three examples and the results are compared with those for the deterministic case and those available in the literature. Copyright © 2002 John Wiley & Sons, Ltd.     

A mathematical optimization methodology for the optimal design of a planar robotic manipulator

A general optimization methodology for the optimal design of robotic manipulators is presented and illustrated by its application to a realistic and practical three‐link revolute‐joint planar manipulator. The end‐effector carries out a prescribed vertical motion for which, respectively, the average torque requirement from electrical driving motors, and the electric input energy to the driving motors are minimized with respect to positional and dimensional design variables. In addition to simple physical bounds placed on the variables, the maximum deliverable torques of the driving motors and the allowable joint angles between successive links represent further constraints on the system. The optimization is carried out via a penalty function formulation of the constrained problem to which a proven robust unconstrained optimization method is applied. The problem of singularities (also known as degeneracy or lock‐up), which may occur for certain choices of design variables, is successfully dealt with by means of a specially proposed procedure in which a high artificial objective function value is computed for such ‘lock‐up trajectories’. Designs are obtained that are feasible and practical with reductions in the objective functions in comparison to that of arbitrarily chosen infeasible initial designs. Copyright © 1999 John Wiley & Sons, Ltd.     

基于健壮设计原理的产品设计方法研究

分析了健壮设计理论及其模型的建立,并结合黑箱子模型进行功能简化,在健壮模型中找出性能参数、设计参数和噪声参数。论述了健壮设计模型的构造,进而分析了健壮设计的设计哲学。提出了在健壮设计理论指导下如何指导实际的设计,在实际设计中如何分析其功能模型,找出影响其性能的噪声变量,对其外在的设计变量进行选择和变更,设计出性能稳定的健壮性产品。     

汽车动力总成悬置系统鲁棒优化算法

应用鲁棒优化设计理论,考虑设计变量的不确定性对优化设计结果的影响,建立鲁棒优化模型。以动力总成悬置系统能量解耦为目标,悬置刚度参数为设计变量,考虑设计目标的均值和标准差,建立动力总成悬置系统的鲁棒优化模型。针对粒子群算法求解容易陷入局部最优解的问题,采用混合粒子群算法对动力总成悬置系统的悬置刚度参数进行鲁棒优化,并用Monte Carlo方法进行分析,以考察设计值的变化对目标函数的影响。结果表明,优化方法可以有效提高悬置系统的鲁棒性。