基于ADAMS的某型越野车悬架仿真与优化研究

以ADAMS/Car车辆动力学仿真软件为基础,根据双横臂独立悬架关键硬点坐标,建立某型越野车双横臂式独立前悬架动力学模型,并对前悬架系统进行车轮跳动仿真。在ADAMS/Insight中对前悬架定位参数进行灵敏度分析。根据前轮定位参数的变化规律和灵敏度分析结果,选取悬架的8个关键硬点坐标为设计变量,对4个悬架定位参数进行优化设计。仿真结果表明,优化后的双横臂独立悬架的运动学特性得到改善。     

ADAMS/Car与Insight在双横臂悬架优化设计中的应用

运用ADAMS/Car初步建立了某特种车的双横臂式前悬架,并通过双轮平行跳动仿真分析了轮跳对前轮定位参数的影响,选出需要优化的参数。通过ADAMS/Insight对悬架硬点进行灵敏度分析,找到影响性能较大的硬点坐标。对于灵敏度较大的设计参数建立车轮定位参数在轮跳过程中最大变化量的二阶响应面近似数学模型,利用MATLAB编程拟合出近似模型并进行优化求解与可靠性分析。修改优化后的悬架硬点坐标再次进行仿真试验比较优化前后的试验结果,验证优化的合理性。     

基于近似模型的车轮定位参数优化设计研究

为改善某车型前悬架优化设计中其运动学特性,解决前轮胎磨损较严重问题,提出一种基于近似模型应用改进响应面法对车轮定位参数进行优化设计。首先,应用ADAMS/Car软件建立了麦弗逊式前悬架仿真分析模型,并在ADAMS/Insight中对悬架部分设计硬点参数进行灵敏度分析。然后,针对灵敏度大的设计参数建立车轮定位参数在跳动过程中最大变化量的二阶响应面近似数学模型,并利用Matlab编程对拟合出的近似模型优化求解与可靠性分析。最后,将优化后车轮定位参数最优值代入悬架模型中,在ADAMS/Car中再次进行轮跳仿真试验,对比应用传统响应面优化方法优化悬架前后试验结果表明,该优化设计方法具有较好的优化效果。     

基于ADAMS/Insight的客车悬架动力学仿真与优化

旨在研究结构硬点坐标对城市客车悬架性能的影响,并对双横臂悬架进行优化。运用ADAMS/Car,建立客车前悬架的动力学模型,研究该悬架系统的KC特性,分析车轮定位参数随着车轮跳动的变化规律;开展灵敏度分析与试验优化设计,通过ADAMS/Insight多次迭代求解最优方案。结果表明:通过改变构件硬点的坐标,外倾角和前束角随车轮跳动的变化幅度分别降低了23.6%和8.5%,其它的车轮定位参数(如主销内倾角)相应得到了不同程度的优化。     

前悬架硬点优化设计

针对前悬架性能的优化问题,提出一种基于近似模型并用响应面法和改进NSGA-Ⅱ遗传算法相结合的方法对前悬架进行优化设计。利用ADAMS/Car建立双叉臂前悬架动力学仿真分析模型,在Insight中对悬架的硬点参数进行灵敏度分析,选择出灵敏度大的设计参数,并建立响应面近似模型,运用改进NSGA-Ⅱ算法对悬架进行硬点优化设计。结果表明,优化后的前轮定位参数在车轮跳动过程中的变化量明显减小,悬架的性能得到很好的提高,该设计方法实现了悬架硬点的优化,为悬架的优化设计提供了依据。     

某样车前悬特性分析及优化方法研究

利用ADAMS/CAR软件对某样车麦弗逊前悬架建立仿真模型,并对车轮定位参数和车轮跳动量进行仿真。通过对仿真结果和样车悬架同工况K&C台架试验数据进行比较,验证了所建模型的准确性。同时,应用ADAMS/insight软件对该悬架部分硬点坐标进行敏感度分析以及回归分析,并对模型进行硬点优化求解。对比优化前后的仿真结果可知,优化后车轮外倾角、车轮前束角变化量更小,主销内倾角、主销后倾角略有变化,有利于整车操纵稳定性,验证了该优化方法的可行性。     

四连杆式独立前悬架的优化设计

四连杆式悬架可以保证车辆良好的直线行驶性能,是目前最好的被动悬架形式之一。运用ADAMS/CAR软件建立了四连杆式独立前悬架的系统模型,并对各项车轮定位参数进行了仿真分析。运用ADAMS/INSIGHT软件对悬架的结构硬点进行了优化,将优化前后的车轮定位参数进行运动学对比分析,得到良好的悬架运动学特性。     

基于Kriging近似模型的某轿车前悬架不确定性优化

针对前悬架确定性优化没有考虑参数不确定性时存在的问题,提出了一种考虑不确定性因素的前悬架不确定性优化方法。应用ADAMS/Car建立了某轿车麦弗逊式前悬架模型,在ADAMS/In-sight中进行了悬架设计硬点参数的灵敏度分析,针对灵敏度较大的设计硬点参数和所考虑的不确定性量,建立了车轮定位参数在车轮跳动过程中的Kriging近似模型,简化了优化过程。针对该近似模型进行了动力学分析,运用经过改进的非支配排序遗传算法(NSGA-Ⅱ)和隔代遗传算法(IP-GA)进行了多目标不确定性优化求解。优化结果表明,该不确定性优化方法具有较高的有效性和精确性。与确定性优化结果的对比表明,不确定性优化具有更好的鲁棒性。     

基于ADAMS/Insight某型电动车悬架仿真优化研究

以ADAMS/Car车辆动力学仿真软件为基础,建立某型电动车双横臂式独立前悬架动力学模型,选取悬架的8个关键硬点坐标为设计变量,5个悬架定位参数为优化目标,联合ADAMS/Insight对悬架进行仿真分析和优化迭代计算。对优化前后悬架定位参数的变化进行了分析。     

基于ADAMS的方程式赛车前悬架分析与优化

针对某型大学生方程式赛车前悬架系统进行分析与优化。利用动力学软件ADAMS/CAR建立该赛车前悬架多柔体模型,并在弹性运动学模式下进行仿真。分析了双轮平行跳动时悬架运动特性和赛车制动时的转向轻便性与抗点头性,结果显示主销内倾角、车轮外倾角、转向盘力矩与磨胎半径变化规律不符合设计要求。运用ADAMS/INSIGHT对原系统进行多目标优化,最终各参数均得到优化,改善了悬架系统的运动学特性与赛车的转向轻便性。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

Fifth International Summer School on Screw-Theory Based Methods in Robotics

正3-11 September,2014University of Bologna,Bologna,Italy www.summerscrews.org summerscrews2014.ing.unibo.it SUMMER 20SCREWS 14In 2014,our screw-theory school comes to the world's oldest university.In early September,Summer Screws'14 will gather six experts in the application of screw theory in robotics and up to 40 participants at the University of Bologna,Bologna,Italy.The school will teach attendees how to apply existing methods and empower them to develop new ones in their own research.The basic theoretical notions will be introduced in a rigorous manner,emphasizing examples,applications,and exercises.Scholarships are available.     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

INDUSTRIAL ENGINEERING AND VISUALISATION-A PRODUCT DEVELOPMENT PERSPECTIVE

Taking the actual project of teaching and researching process for example, the relationship between the industrial engineering and product development is discussed. And use the novel visualization technology to support the industrial engineering and product development. How to use the new computer modeling and simulating technologies to support the product development and industrial engineering, is introduced especially. The support includes both domestic products and industrial systems. The visualization and computer technologies take a very important role in some system or multi-direction modeling, those technologies mentioned above can help the industrial engineers study the effect of design on the whole life circle, including the producing steps. So the engineers can avoid making the wrong decision which may cause bad effects on the whole industrial engineering.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...