车厢可卸式垃圾车拉臂系统的刚柔耦合仿真分析

针对车厢可卸式垃圾车拉臂系统存在的所受负载不断变化、工况较多的问题,对拉臂系统在满载装卸过程中油缸力、拉臂作用力以及拉臂应力、应变的动态变化规律进行了研究,采用刚柔耦合的分析方法,通过机械系统动力学软件ADAMS和有限元分析软件ANSYS,建立了以拉臂为柔性体的刚柔耦合仿真系统,并进行了联合仿真分析,得到了拉臂系统所受作用力在不同拉臂转角、举升角时的变化值以及拉臂最大应力、应变发生的位置,验证了拉臂装配体强度及刚度要求符合设计要求.研究结果表明,刚柔耦合仿真能有效地模拟拉臂系统受力情况,与典型的工况方法相比,考虑动载对强度分析的影响,能更准确确定拉臂系统的危险工况,从而为拉臂系统的结构优化提供较为可靠的依据.     

垃圾车拉臂装置的有限元分析与结构优化

为改善拉臂式垃圾车的性能,优化拉臂装置结构,建立了各工况下拉臂所受载荷的数学模型,利用COSMOSWorks软件对拉臂进行结构有限元分析,获得了该结构在各种实际工况下的应力应变分布,在此基础上以拉臂质量最小值为目标函数进行结构优化设计,使其性能得到了改善,在满足结构强度要求的前提下,拉臂质量减少了20.4%。     

旋转式拉臂车性能研究

建立了旋转式拉臂车的数学模型，并对它的运动学与力学进行了详细地分析。计算表明，与普通拉臂车相比，旋转式拉臂车不仅有效地减小了液压缸所受的作用力，而且还减小了作业过程中集装箱的倾斜角度，其综合性能得到了显著的提高。     

拉臂机构力学特性分析及结构优化

拉臂机构作为拉臂式垃圾车的关键部位,直接决定整车的可靠运行与人员操作体验,文中在分析拉臂机构的力学特性基础上,计算出在装卸工况下的载荷,利用有限元分析软件,对拉臂机构关键部位进行静态有限元分析与模态分析,分析结果表明拉臂机构符合动态性能要求,但其工作时强度不足,需对此进行结构优化。通过对拉臂机构进行局部修改,采取必要的辅助措施,使其达到符合静态性能要求的目的。在满足拉臂机构静动态性能要求上,装箱工况最大应力降低了23.3%,卸箱工况最大应力降低了24.9%,较好地达到了提高拉臂机构安全性能的目的。     

拉臂式压缩垃圾车车厢结构的载荷表达与优化设计

由于压缩程度不同,拉臂式压缩垃圾车车厢内的压缩垃圾是变密度的。首先建立车厢内压缩垃圾的变密度函数,基于该变密度函数给出车厢内压缩垃圾自重、惯性、压缩、挤入载荷的数学表达,再叠加上对拉臂车进行动力学分析得到的拉臂与汽车底盘对车厢的作用力,组成各危险工况车厢所承受的载荷。在对拉臂式压缩垃圾车车厢进行结构有限元分析的基础上采用以ANSYS为分析器的导重法对车厢结构进行优化设计,在满足结构强度要求的前提下,使结构质量减少31%。     

拉臂式压缩垃圾车车厢结构的有限元分析与优化设计

由于压缩程度不同,拉臂式压缩垃圾车车厢内的压缩垃圾是变密度的.首先建立车厢内压缩垃圾的变密度函数,基于该变密度函数给出车厢内压缩垃圾自重、惯性、压缩、挤入载荷的教学表这,再叠加上对拉臂车进行动力学分析得到的拉臂与汽车底盘对车厢的作用力,组成各危险工况车厢所承受的载荷.在时拉臂式压缩垃圾车车厢进行结构有限元分析的基础上采用以ANSYS为分析器的导重法对车厢结构进行优化设计,在满足结构强度要求的前提下,使结构质量减少31%.     

伸缩式拉臂机构的结构参数优化设计

拉臂机构是车厢可卸式汽车的关键系统.以伸缩式拉臂机构为研究对象,以举升油缸的最大拉力最小和最大推力最小为目标函数,建立伸缩式拉臂机构的数学模型,使用ADAMS软件,对其结构尺寸进行了优化设计.     

拉臂车工作动态仿真分析

近年来,虚拟样机技术作为一种新兴的设计手段,被越来越多地应用于工程设计和机械系统性能研究。本研究根据某汽车厂提供的14吨级拉臂车设计图纸为依据,利用机械系统动力学仿真分析软件ADAMS建立拉臂车工作系统虚拟样机模型,对工作系统作业过程进行联合仿真分析,求出相关特征部位的力和位移变化特性,为利用ANSYS进行的拉臂车零部件的强度、刚度分析提供依据。     

基于有限元法的高空作业车伸缩臂接触分析

接触问题属于边界非线性问题。当用有限元程序进行接触分析时,计算时间较长,收敛与否依赖于模型的复杂程度以及接触刚度等因素。在有限元分析中,节点自由度耦合分析方法为线性分析,不存在收敛问题。为了研究这两种方法在高空作业车伸缩臂结构分析中的差异,在有限元软件ANSYS中建立了伸缩臂接触模型和节点自由度耦合模型。结果表明:在模拟滑块接触时,自由度耦合方法得到的结果接近接触模型;但在铰接支座处由于这两种模型差异较大,两者结果相差很大。     

基于ANSYS的混凝土胶带布料车伸缩臂的有限元分析

本文应用ANSYS有限元分析软件,对胶带布料车伸缩臂建立有限元模型,进行数值模拟分析,得到了不同工况下伸缩臂的变形情况和应力分布,精确确定出应力危险区,为工程设计提供了理论依据。     

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.     

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。     

基于多目标非支配解提取法的电力系统无功优化

针对传统的电力系统多目标粒子群优化算法采用权重系数法将多目标转化为单目标,从而忽视了各目标函数间的竞争关系这一问题,提出将非支配解提取法运用到电力系统多目标无功优化中,并设定了一套提取规则,以电力系统中的有功网损、电压偏差和电压稳定裕度为目标,使目标在充分竞争的情况下得出Pareto最优解,利用IEEE-14节点系统对多目标非支配解提取法的电力系统无功优化进行了仿真测试。研究结果表明,该算法一次运行可以得出多组非支配解,既有偏向单个目标的解也有兼顾所有目标的解,克服了权重系数法的盲目性和单一性,可使电力决策者根据实际问题选择最优解,具有较好的灵活性与多样性。     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

RLS and LMS blind adaptive multi-user detection method and comparison in acoustic communication

RLS and LMS blind adaptive multi-user detection algorithm and multi-user detector was proposed to solve the problem of multi-user signal detection problem encountered in underwater acoustic communication networks.In simulation analysis,RLS and the LMS blind adaptive multi-user detector were designed and tested for synchronous and asynchronous multi-user communication process.The results of SIR comparison and MMSE comparison show that,both of the two methods can realize blind adaptive detection when any user change in multi-user communication,during this process,the training communication sequences are not needed.The RLS algorithm has about 5 dB higher in SIR compared with LMS algorithm,and the convergence velocity of RLS algorithm is also higher than LMS algorithm when the communication users change.RLS algorithm has better ability in multi-user detection than that of LMS algorithm,and it has great attraction and guiding significance for solving the problem of multiple access interference(MAI) in multi-user communication.     

Robust Impedance Control of Robots Using an Adaptive Interaction Force Observer

For robot interaction control,the interaction force between the robot and the manipulated object or environment should be monitored.Impedance control is a type ...     

Research on key techniques of expendable conductivity temperature depth measuring system

This paper analysis the developing of expendable conductivity temperature depth measuring system(XCTD)and introduce its principle of measuring about temperature,salinity and depth of ocean.Some key techniques are put forward.According to the real needs of XCTD,conductivity sensor with high sensitivity is designed by principle of electromagnetic induce,the ocean conductivity from induced electromotive force has been calculated.Adding temperature correction circuit would help to reduce error of conductivity measurement because of sharply changing temperature.Advanced temperature measuring circuit of high precision and the constant current source is used to weaken effect of self-heating of resistance and fluctuation of the source.On respect of remote data transmission,LVDS is a good choice for the purpose of guarantee the quality of data transmitted and the transmission distance is reaching to thousand meters in the seawater.Modular programming method is also brought into this research aimed at improve the stability,reliability and maintainability of the whole measuring system.In February,2015,the trials in South China Sea demonstrate that the developed XCTD realize effective measurement at a speed of 6 knots and detection depth at 800 m.The consistency coefficient of the acquired data is greater than 0.99 and the success rate of probe launching is above 90%.