不确定环境下再制造加工车间生产调度优化方法

针对再制造加工车间工况兼具随机性与模糊性,采用模糊随机变量表示废旧件加工时间,以描述再制造加工车间工况的双重不确定性;在不确定理论的基础上,建立基于模糊随机机会约束的再制造加工车间生产调度问题模型,并提出求解该问题混合智能优化算法:基于Arena仿真平台应用模糊随机模拟技术产生输入和输出数据,利用粒子群优化算法训练径向基函数神经网络以逼近不确定函数,将训练好的神经网络嵌入至遗传算法中优化再制造加工车间生产调度问题;通过仿真实例验证该混合智能优化算法解决加工时间为模糊随机变量的不确定环境下再制造加工车间生产调度问题的有效性和合理性。     

基于模糊机会约束规划的再制造装配车间调度优化方法

针对再制造零部件质量的不确定性导致工位装配时间波动范围大和调度模型难以准确描述的问题,采用基于可信性测度的模糊变量表示再制造零部件的装配时间,建立基于置信水平下的模糊机会约束规划调度模型,并提出求解该模型的混合智能优化算法：应用模糊模拟技术产生样本数据;利用反向传播算法训练多层前向神经网络逼近不确定函数;将训练后的神经网络与遗传算法相结合,以优化再制造装配车间调度问题。实例验证了该模型和算法的可行性。     

多品种汽车发动机两阶段模糊再制造生产计划

针对多品种发动机再制造生产过程中存在的不确定性因素,以最小化生产成本为目标,基于可信性理论建立了不确定环境下汽车发动机两阶段模糊再制造生产计划模型。该模型考虑多品种产品回收情况下,拆解零件的再制造加工数量、加工成本、新零件采购数量以及市场需求的不确定性对再制造加工生产计划的影响,将生产过程分为两个阶段,并采用补偿函数逼近方法,将具有无限支撑的无限维优化模型转化为有限维优化问题进行求解,设计了基于逼近方法的粒子群算法来求解两阶段模糊生产计划问题。以曲轴飞轮总成为仿真实例,验证了该混合智能优化算法解决两阶段模糊规划问题的有效性和合理性。     

不确定环境下再制造发动机曲轴轴向间隙优化控制

再制造发动机曲轴轴向间隙既是影响再制造发动机性能的重要因素,也是不确定环境下再制造发动机装配过程质量控制的难点。以再制造发动机装配过程中曲轴轴向间隙优化控制为研究目标,分析不确定环境下再制造发动机曲轴轴向间隙影响因素,并构建基于信息熵的装配尺寸不确定测度模型,进而研究再制造发动机装配过程中曲轴轴向间隙质量耦合内在关系;在确保再制造发动机曲轴轴向间隙装配尺寸熵不大于新品的前提下,通过数学公式推导出再制造曲轴第一轴颈宽度和缸体轴承座宽度分级选配尺寸公差宽放系数;提出基于分级选配的再制造发动机曲轴轴向间隙优化控制方法;通过某再制造发动机企业的实例验证了该方法的有效性和可行性。     

再制造曲轴径向跳动不确定性的内涵与测度

再制造曲轴径向跳动不确定性是影响再制造发动机质量稳定性和服役安全性的关键因素之一。从回收废旧曲轴失效形式不同、再制造修复工艺各异导致径向跳动存在差异的角度,分析再制造曲轴径向跳动不确定性的内涵;根据径向跳动不确定性产生的原因将其归结为随机不确定性和模糊不确定性;应用“随机熵”测度径向跳动的随机不确定性,运用“模糊熵”测度径向跳动的模糊不确定性,建立基于积空间P×M的复合熵模型,定量化描述曲轴径向跳动的整体不确定度;以某重型发动机再制造企业WD615系列68型曲轴再制造为例,对测度方法进行实例验证,结果证明了方法的有效性和实用性,研究内容为再制造不确定优化决策提供了理论依据。     

基于改进模糊神经网络的废旧零部件再制造工艺方案决策方法

鉴于废旧零部件损伤状况及其再制造质量要求的差异性导致再制造工艺方案具有不确定性和模糊性,为确定最优再制造工艺方案,在对废旧零部件再制造工艺过程特征问题进行描述的基础上,建立了再制造工艺方案优化决策模型;提出一种基于改进T-S模糊神经网络的再制造工艺方案决策方法,并对该模型进行了求解。将所提出的方法应用到某机床厂废旧机床主轴再制造中,运用MATLAB编程实现了再制造工艺方案的优化决策,并通过与传统模糊神经网络方法进行性能对比,验证了所提出方法的有效性。     

再制造系统的自适应调度原理

废旧品回收的数量、时间、质量以及拆解顺序、深度等诸多不确定性使得传统的调度理论难以直接应用于再制造系统。为此,提出了再制造系统的自适应调度原理,采用调度方法匹配识别、专家推理、新调度问题建模求解和调度方法评价相结合的方法生成最终的调度方案。最后,对再制造系统自适应调度的原型系统框架及其关键技术进行了阐述。     

面向再制造的基于Pro/Toolkit的拆卸仿真

产品拆卸是再制造工程中重要的环节,拆卸的好坏直接影响产品再制造性。通过研究Pro/Toolkit二次开发的方法,得到拆卸仿真系统开发的流程:建立产品拆卸模型,提取模型拆卸信息,规划产品拆卸序列,进行产品再制造拆卸评估。研究了层次概率模糊认知图的数学模型规化拆卸序列的方法,得出了实现变速箱目标拆卸的最优拆卸序列。分析了拆卸仿真系统的再制造拆卸评估准则,给出了从零件的拆卸时间、拆卸费用、环境性影响、经济性、可拆卸度性、再制造性、回收价值性、零件耐用性、再制造工艺性、技术稳定性等方面进行产品再制造评估的改进算法。最后使用MFC对话框设计技术设计再制造拆卸仿真系统的对话框,得到面向再制造的拆卸仿真系统。     

基于不确定性测度的再制造曲轴平衡性控制方法

再制造发动机平衡性是影响再制造发动机使用性能的重要因素之一。分析影响再制造发动机曲轴平衡性的关键因素,探究曲轴主轴颈径向跳动、直径、圆柱度及曲轴端面跳动、弯曲度等因素不确定性的内涵;考虑各个因素测量值的离散程度及测量值与理想值的偏差程度,构建因素不确定性定量化测度模型;在以上研究基础上,提出基于改进BP神经网络(BPNN)的发动机曲轴再制造平衡性质量控制方法,其中,网络模型采用梯度下降法对输入层到隐层之间的权值和阈值进行调整,采用支持向量机调整隐层到输出层之间的权值和阈值;通过某企业再制造曲轴的质量数据表明,方法能够有效提高再制造曲轴平衡性合格率,降低曲轴加工废品率,应用实例验证了提出方法的可行性和有效性。     

基于收益概率的不确定环境下的产品拆卸序列优化

为了研究拆卸过程中存在的许多不确定因素对拆卸收益产生的影响,利用拆卸网络图得到目标零部件的可行拆卸序列,综合考虑拆卸时间随机、零部件质量不确定等因素,提出拆卸收益的计算方法;基于拆卸收益概率,建立了不确定环境下产品拆卸序列优化模型,并设计了基于随机模拟的求解方法。结合实例进行分析,验证了所提模型的可行性和方法的有效性,通过改变参数比较优化结果说明了参数变化对拆卸序列优化的影响。     

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。     

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%.     

CHARACTERISTCS OF FLUID FILM IN OPTIMIZED SPIRAL GROOVE MECHANICAL SEAL

In order to investigate the sealing performance variation resulted from the thermal deformation of the end faces, the equations to calculate the fluid film pressure distribution, the bearing force and the leakage rate are derived, for the fluid film both in parallel gap and in wedgy gap. The geometrical parameters of the sealing members are optimized by means of heat transfer analysis and complex method. The analysis results indicate that the shallow spiral grooves can generate hydrodynamic pressure while the rotating ring rotates and the bearing force of the fluid film in spiral groove end faces is much larger than that in the flat end faces. The deformation increases the bearing force of the fluid film in flat end faces, but it decreases the hydrodynamic pressure of the fluid film in spiral groove end faces. The gap dimensions which determine the characteristics of the fluid film is obtained by coupling analysis of the frictional heat and the thermal deformation in consideration of the equilibrium condition of the bearing force and the closing force. For different gap dimensions, the relationship between the closing force and the leakage rate is also investigated, based on which the leakage rate can be controlled by adjusting the closing force.     

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...     

OPTIMIZATION METHOD ON IMPELLER MERIDIONAL CONTOUR AND 3D BLADE

An optimization method for 3D blade and meridional contour of centrifugal or mixed-flow impeller based on the 3D viscous computational fluid dynamics (CFD) analysis is proposed. The blade is indirectly parameterized using the angular momentum and calculated by inverse design method. The design variables are separated into two categories: the meridional contour design variables and the blade design variables. Firstly, only the blade is optimized using genetic algorithm with the meridional contour remained constant. The artificial neural network (ANN) techniques with the training sample data schemed according to design of experiment theory are adopted to construct the response relation between the blade design variables and the impeller performance. Then, based on the ANN approximated relation between the meridional contour design variables and impeller performance, the meridional contour is optimized. Fewer design variables and less calculation effort is required in this method that may be widely used in the optimization of three-dimension impellers. An optimized impeller in a mixed-flow pump, where the head and the efficiency are enhanced by 12.9% and 4.5% respectively, confirms the validity of this newly proposed method.