随机工时下的多目标柔性作业车间鲁棒调度问题

针对工时不确定条件下的多目标柔性作业车间调度问题,采用2个不确定参数描述随机工时的波动程度和约束条件允许违背程度,将不确定条件下的柔性作业车间调度问题模型转换成确定条件下的鲁棒对等问题模型。在算法设计中采用全局非支配解集保存每代进化过程中产生的非支配解,并选择全局非支配解集中的个体参与变异操作。在交叉和变异操作之后,设计了一种基于变邻域结构的局部搜索策略。最后,运用该算法求解经典基准算例,验证了其有效性。     

加工时间不确定的柔性作业车间鲁棒调度方法

针对中小批量环境下加工时间不确定的柔性作业车间调度问题,采用冗余处理方法构建了以最大完工时间为目标的鲁棒调度模型。为降低算法的搜索规模和提高算法的求解速度,提出了顺序搜索机制,并设计两阶段遗传算法,分阶段获取冗余状态和最优结果。采用某柔性生产线的数据进行正交试验,优化了算法关键参数,并构建了柔性生产线仿真模型,对调度结果的鲁棒性和优化目标性能进行了分析。结果表明,该算法在目标性能和鲁棒性上都显著优于标准遗传算法,能有效处理加工时间不确定的柔性作业车间调度问题。     

订单不确定下双资源约束多装配线鲁棒调度

考虑生产过程中的订单不确定等因素,建立了以最大化交付满意度、最大化装配线平衡率及最小化完工时间跨度为目标的鲁棒调度模型,基于差分进化算法和粒子群算法提出了对模型进行求解的混合优化算法,并通过算例验证了混合优化算法求解该鲁棒调度模型的可行性和有效性。最后综合分析PTCN公司二厂多装配线生产车间的实际生产情况,将所建立的鲁棒调度模型和提出的混合优化算法应用于实际的多装配线生产过程,获得了较优的调度结果。     

鲁棒优化与多智能体协调的电梯群控调度

针对电梯群控调度过程中交通流不确定和优化求解复杂性的问题,提出一种混合鲁棒优化方法和多智能体协调的电梯群控调度方法。分析了电梯群控调度中的交通流不确定问题,建立了解决该不确定问题的电梯调度决策鲁棒优化模型。为了弥补模型求解复杂度过高的不足,进一步提出鲁棒优化和多智能体调度结合的混合调度决策方法。仿真结果表明,该方法能有效改善群控调度的性能,提高群控调度对交通模式的适应性。     

带缓冲时间的不确定性作业车间鲁棒调度研究

对机器故障下的作业车间鲁棒调度问题进行了研究。根据威布尔概率分布函数和故障浴盆曲线将不确定的机器故障转化为定量化的故障区间,建立带缓冲时间的性能鲁棒调度优化模型。用遗传算法求解该模型过程中,确立带缓冲时间的鲁棒解码规则,且交叉片段在整个父代中搜索与片段对等的基因,有利于扩大交叉范围。最后的仿真实验表明,优化模型保证了调度的鲁棒性,提出的改进遗传算法对问题求解的有效性。     

一类已知概率分布下的混合车间鲁棒调度问题研究

为解决一类产品生产需经上游作业车间的零部件加工和下游流水车间的零部件总装的调度问题,在研究生产调度文献的基础上,给出了混合车间调度问题;给出一类已知概率分布下的混合车间鲁棒调度方法,并建立鲁棒调度模型;采用遗传算法求解鲁棒调度模型。最后进行了实证研究,证明所建模型以及遗传算法在求解混合车间调度问题上是有效的。     

机器混合故障下柔性作业车间鲁棒调度方法

柔性作业车间机器在生产过程中时常发生退化故障和突发故障，针对这种混合故障，考虑用预防性维护来防止退化故障，通过插入缓冲时间的方式来吸收突发故障的影响。分别以工序最终完工时间期望值和各工序加工完成时间的延迟总和期望值为质和解的鲁棒性指标，建立柔性作业车间鲁棒性调度优化模型，并设计引入混合故障概率矩阵的改进遗传算法对模型求解，联合决策工序加工顺序、预防性维护位置和缓冲时间位置，同时优化调度方案的鲁棒性。最后通过数值实验与对比分析验证了此鲁棒调度方法能有效应对车间混合故障造成的扰动。     

面向能耗的多工艺路线柔性作业车间分批优化调度模型

合理的调度方案能有效降低柔性作业车间总能耗。针对柔性作业车间中加工工件种类多、单批工件数量大、加工工艺路线柔性大等问题,研究一种面向能耗的多工艺路线柔性作业车间分批优化调度模型。分析柔性作业车间中工件加工过程能耗特性,以车间总能耗最低和完工时间最小为优化目标建立了多工艺路线柔性作业车间分批优化调度模型,并采用多目标模拟退火算法对模型进行优化求解。通过算法优化得到的调度方案与经验调度方案的对比分析,验证了该模型的有效性和实用性。     

任务工时不确定的模具车间前摄性调度研究

由于模具生产属于非重复性生产模式,各工序的工时具有很强的随机不确定性,这给模具车间制定合理可行的作业计划带来了一定的困难。针对这一实际问题,提出了一种考虑任务工时不确定性的前摄性车间调度算法。首先,分析了模具精加工环节的两道关键工序对制造系统稳定性的影响,并基于工序的工时不确定特性,建立了任务工时不确定的离散概率模型;然后,以调度方案的稳定度作为优化目标,构建了两阶段流水车间前摄性调度模型,针对该模型,提出了一种变宽集束搜索求解算法;最后,将该算法与定宽集束搜索算法进行对比分析,结果表明该算法能很好地兼顾求解质量和计算时间。     

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。     

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.