Multilevel hierarchical production planning architecture for engineer-to-order enterprises

The critical materials and critical parts are keys to the production at Engineer to Order (ETO) enterprises implies that the control of plans for critical materials and critical parts is essential to the control of all plans at ETO enterprises. A mixed mode of hierarchical network planning/MRP (NP/MRP) is proposed to generate network plans for critical materials or critical parts from project networks and the plans for non critical parts produced by MRP are constrained by the related project networks. The multilevel hierarchical network planning/MRP mixed planning (MHNM) architecture proposed is the extension of the hierarchical NP/MRP to the supply chain based on the temporal constraints of multilevel project networks for critical materials or critical parts. A general model is formulated for scheduling tasks on machines at work centers as well.

The Allocation of Production orders to offshore Plants in the Clothing Industry: Part 2-Prototype System Supporting Order Allocation Decisions

This part demonstrates a prototype system which has been constructed to enable the allocation of orders of different product types to different manufacturing locations . ’ What - if’ experiments using this system show that different allocation rules would provide different outcomes in terms of the number of unallocated orders. A high number of unallocated orders will have a direct Impact on workload. Further research effort is necessary to channel into the exercbe of production order allocation with particular reference to allocation rules.

The Allocation of Production Orders to Offshore Plants in the Clothing Industry:Part1-Model Conceptualisation

As a rough cut planning exercise,production order allo-cation for offshore manu facturing sites in the clothingindustry has received little attention as does other typesof planning like production planning.This paper outlinesan investigation into the exercise of production order al-location in the clothing industry.We have identified thatpractitioners involving in this exercise are not unanimousin the selection of offshore sites.Part 1 presents thebackground,objectives,process and conceptual model ofproduction order allocation.

The Planning and Scheduling of Business Process in Agile Supply Chain System

The rapidly developing global competition is leadin g to the worldwide enterprise alliance, with which the geographical dispersion of production, assembly and distribution operations comes into being. Supply chain system is such a kind of enterprise alliance, managing the material and informat ion flows both in and between enterprises, such as vendors, manufacturing and assembly plants and distribution centers. In the present research work, we can see that supply chain system can quickly respond to customer needs and adapt to the dynamic change of the market so as to improve the competence of enterprises in the chain. Thus, in supply chain system, it’s most important to enhance the speed with which the products are produced and distributed to the customers who order them and reduce the operating costs at the same time. However, because of the special characteristics, such as dynamic and distributed , etc., often in Agile Supply Chain System (ASCS), there are many dynamic tasks, and many urgent changes of the processes, which make the planning work and mana gement become very difficult and complex. Thus, in Agile Supply Chain System, we first need an efficient planning work, which can program the processes properly to get a primary scheme. And then the local scheduling work based on the primar y scheme will play a important role to deal with the dynamic and distributed pro blems in the business process in ASCS. So, this paper will be organized as below . At the first of this paper, we will discuss the situation in which Agile Suppl y Chain System is applied, and then we will elaborate the characteristics of Agi le Supply Chain System. With that, the shortcomings of the process managements t hat are, at present, used in Supply Chain Systems will be displayed clearly. Sec ond, we will introduce the planning methods in our research work. And then, the local scheduling will be discussed in detail, based on the primarily planned wor kflow. To realize the goal, first we build the mathematic model to describe the scheduling goal of system optimum, based on the categories of the cooperating-r elation among the operation nodes, which we defined in our research work, in Agi le Supply Chain System. And then the optimized algorithm to solve the model woul d be introduced, in succession. At the final of this paper, we will introduce some knowledge of the process mana gement and the realization of ASCS and summarize our work.

Motion Planning of Humanoid Robot for Obstacle Negotiation

The motion planning for obstacle negotiation by humanoid robot BHR-2 through stepping over or stepping on/off the wide and flat obstacle at known locations is presented. In the trajectory generation method, first the constraints of the foot motion parameters which include obstacle dimensions and the distance of obstacle from the humanoid robot is formulated. By varying the values of the constraint parameters, different types of foot motion for different obstacles can be produced. In this method, first the foot trajectory is generated, and then the waist trajectory is computed by using cubic spline interpolation without first calculating the zero moment point （ZMP） trajectory . The dynamic stability during the execution of stepping over and stepping on/off trajectories are ensured by incorporating the ZMP criterion. The effectiveness of the proposed method is confirmed by simulations and experiments on humanoid robot BHR-2.

基于改进蚁群算法的农业机器人多田块路径规划方法与试验

[目的]针对丘陵地区因田块碎片化和障碍物影响农业机器人作业的情况,提出一种基于改进蚁群算法和A算法相结合的多田块路径规划方法。[方法]通过无人机构建农田遥感影像,利用栅格法对农田进行环境建模,再进行子区的划分与合并,在蚁群算法中引入区域启发函数,对不同区域内的移动代价作区分,通过人工增加最优路径中的信息素浓度并建立自适应信息素挥发系数,对信息素更新方法进行改进,以此求解作业子区间的最优遍历顺序,利用具有启发式搜索功能的A算法进行子区连接路径规划,最终实现多田块路径规划。[结果]MATLAB仿真试验结果表明,在子区数量为40时,采用改进蚁群算法进行规划的平均路径长度比传统的蚁群算法减少了3.19%,平均迭代收敛次数减少了79.5%;在路径遍历仿真试验中,农业机器人遍历路径覆盖率能达到100%,路径重复率为6.48%。利用农田无人机遥感影像和田间作业参数进行自然环境的仿真试验,进一步验证了该方法的有效性。[结论]本研究提出的方法能有效解决丘陵地区农业机器人多田块路径规划问题,可为丘陵地区农业机器人大面积作业提供路径参考与技术支持。

计及电-气双向耦合的综合能源配电网优化重构

综合能源系统是实现电网、气网以及热网等多种能源系统深度融合,利用能量耦合互补等优势提升整个系统能源利用效率的有效形式。为提升综合能源系统优化运行能力,文章首先基于电转气技术与天然气发电技术,构建了的电-气双向耦合综合能源系统总体模型。进而考虑配电网重构技术(Distribution Network Reconfiguration Technology,DNR)中拓扑结构灵活可控这一特性,在配电子系统中引入开关变量、系统运行总费用最低这一目标函数及网络辐射状拓扑结构等约束,建立了配电子系统重构模型。从降低模型求解复杂性的角度,应用二阶锥松弛、乘积变量线性化及分段线性化等方法,将原始综合能源配电网重构非凸非线性模型转化为混合整数二阶锥规划(Mixed Integer Second-Order Cone Programming,MISOCP)问题求解。仿真结果表明,在电-气双向耦合的综合能源系统中应用配电网重构技术,能够降低综合能源系统运行费用,同时有效支撑了配电子系统电压与配气子系统气压。

面向关隘地形的分层调度多机器人路径规划

针对关隘地形下多机器人路径规划存在的高度耦合性,引入调度次序优化思想构造了分层的多机器人路径求解与优化算法。首先,在优化层采用遗传算法生成所有机器人的调度次序,并根据适应度对调度次序进行迭代和进化。其次,根据优化层制定的调度次序,在规划层采用改进的层级协作A*(IHCA*)算法进行路径求解,并将求解结果返回上层以对该次序的适应度进行更新。最后,通过上下层相互配合,逐步提升问题求解成功率并降低路径耗时。此外,提出搜索熔断机制,避免原始HCA*算法在关隘地形中陷于反复无效搜索的状态,可进一步提升求解效率。研究结果表明,所提算法在高耦合关隘环境下具有较高的求解成功率,且路径总耗时更少。

RSS和AOA融合的单站低空无线电辐射源定位算法

提出一种在低空场景下基于接收信号强度(Rcecived Signal Strength,RSS)与到达角度(Angle of Arrival,AOA)信息融合的单站无源定位算法。该算法采用单架无人机设备虚拟多站设备接收无线电辐射源信号,融合RSS估计的距离信息与AOA方向角信息,依据最小二乘准则(LS)构造算法的优化目标函数,采用凸松弛技术将目标函数等价为二阶锥规划(SOCP)问题并通过内点法求解。实验结果表明,该算法的定位精度在2 km范围内可达20 m,其定位性能优于单站无源定位算法,且由于采用单架无人机采集信号,其设备复杂度相较于多站无源定位较低。

改进人工势场法解决局部最小值路径规划研究

当移动机器人在行进过程中使用传统人工势场法(artificial potential field method, APF)进行路径规划时,通常会陷入局部最优困境,无法顺利到达目标点。为解决这一问题,首先,对APF算法规划路径失败原因进行分析,其次设置情况判断条件,判断当机器人陷入局部最小值时,通过在合适位置增加临时引导点的方法,引导其跳出局部极小值点;其次,引入分数阶微积分思想方法结合APF算法,提出混合阶次的分数阶梯度下降法进行位置信息迭代,优化算法的收敛速度和收敛精度;最后,用MATLAB软件对该方法进行仿真,实验结果表明提出的方法可以有效解决局部最小值问题,而且在速度、精度上都有明显的提高,且能适应较为复杂的多障碍物环境,验证了改进方法的有效性、正确性。

考虑订单拆分策略的AGV拣选效率优化方法

为提高智能仓库系统中AGV的拣选效率,针对AGV订单拣选优化问题分为AGV-货架任务分配、多AGV无冲突路径规划两个子问题进行研究,根据订单特点引入订单拆分策略,并以最小化AGV完成所有订单的总时间为目标构建数学模型。首先,设计了确定货架优先级的AGV-货架任务分配算法(AGV-shelf task allocation algorithm, ASTA)求解匹配问题。然后,提出一种带有贪婪参数并嵌入冲突消解策略的改进Q-Learning算法,得到拆分策略下最优无冲突拣选路径方案。最后,通过在40 m×40 m仓库布局中的订单集数值实验对比分析,所提算法与现有的两种算法对比结果显示,AGV完成所有订单的总时间分别平均减少11.63%和26.74%,验证了拆分策略的有效性,并且通过AGV使用数量、完成订单时间和路径冲突等待时间占比三个指标的对比验证了拆分策略和所提算法能有效缓解拥堵情况,减少行驶路径长度,提高拣选效率。此外,针对AGV数量灵敏度分析,在不同数量的AGV对行驶时间和路径冲突等待时间的影响方面,发现19台AGV数量是最佳配置,验证了模型的可行性和算法的有效性。

基于n阶S形曲线的SCARA多目标运动规划

为了对SCARA机器人运动过程中产生的振动进行有效抑制,首先,建立了SCARA机器人的简化浮动坐标法动力学模型;然后,利用n阶S形曲线构造了同时对定位时间和SCARA机器人受到的冲击进行优化的多目标优化模型;最后,采用基于Kriging模型的NSGA-Ⅱ算法对优化问题进行求解。得到的多目标优化问题的Pareto前沿表明,四阶S形曲线的定位时间与三阶S形曲线大致相当,但是引起的冲击远小于三阶S形曲线。对优化结果的仿真也表明,以四阶S形曲线驱动的SCARA机器人运行过程更平滑,产生的残余振动也远小于三阶S形曲线。研究表明,四阶S形曲线具备比三阶S形曲线更加优良的振动抑制性能,在工程中具有广泛的应用价值。

拖挂式移动机器人的多约束避障轨迹规划

基于七次多项式曲线研究了拖挂式移动机器人多约束避障轨迹规划问题,建立了具有非完整约束特性拖挂式移动机器人的前向和后向运动学模型。在速度、加速度、急动度、曲率和曲率导数等多约束条件下,提出基于七次多项式曲线的避障轨迹规划方法。考虑平稳性、舒适性和交通效率等设计了优化目标函数,对七次多项式曲线参数进行优化。仿真结果表明,所提出的基于七次多项式曲线的避障轨迹规划方法,能够得到多约束条件下满足最优避障时间和最优避障距离的避障轨迹规划结果。

上海市产业园区“三线一单”和规划环评跟踪评估

产业园区既是产业高质量发展的承载区,也是环境污染治理和风险防范的重点区域,落实“三线一单”和规划环评的生态环境管控是产业园区提高环境综合管理水平的重要抓手。连续5年的跟踪评估试点显示,上海市产业园区生态环境分区管控和规划环评效力不断提升,约90%的入园项目可以简化环评手续,营商环境优化明显,有力助推市域产业的高质量发展。跟踪评估试点工作具有显著的借鉴意义,值得全国推广。

“语言治理”诸关系及其轻重缓急

“语言治理”在当前是一个前沿问题,主要涉及政治学、管理学、语言学等学科,可以看作是语言规划研究的一个组成部分。“语言治理”的前提是社会中存在着某些“语言问题”。当前,各类“语言问题”多发,需要进行治理。“语言治理”与“语言管理”不同。“语言治理”需要照顾到国家的“语言安全”问题。治理的轻重缓急问题是“语言治理”的本质问题,我们应该坚持“无问题不治理”的原则。

考虑等效循环放电深度约束的配电网储能规划

储能作为新能源系统中的一部分,因其优秀的调节作用在配电网中得到了广泛应用。但储能寿命会受其运行特性的影响,导致规划结果不准确,为了解决这个问题,提出了一种考虑循环放电深度约束的配电网储能规划模型。首先介绍了雨流计数法的基本原理,结合分段线性化思想建立了放电深度与储能寿命的对应关系,并在此基础上提出了一种考虑等效循环放电深度约束的储能寿命模型。然后,以总成本最小为目标函数建立了考虑储能寿命的规划模型。其次,针对模型中的非凸项进行凸化处理,并转化为二阶锥规划模型。最后,在改进的Portugal54算例系统上进行仿真验证,验证了所提模型的有效性。

基于改进变色龙群算法的移动机器人路径规划

针对变色龙群算法在解决移动机器人路径规划问题时算法收敛速度慢、寻优精度低和易陷入局部最优等问题,提出一种分数阶变色龙群算法。首先,在算法初始化时采用Tent混沌映射丰富种群多样性,以提高算法的全局搜索能力。其次,加入分数阶更改变色龙攻击猎物时舌头的速度更新公式,以避免算法陷入局部最优并加快算法的收敛速度。最后,采用三次B样条曲线对路径进行平滑操作,以提高移动机器人实际路径的平滑性。仿真结果表明,改进后的变色龙群算法相比于其他算法收敛速度更快,能避开障碍物,寻找到最优路径。

基于有序聚类分析的武夷山国家公园森林旅游景观类型划分

依托武夷山国家公园森林景观资源的连贯性和完整性,采用Fisher有序聚类法,结合现场访谈信息数据,提取旅游景观观测因子并对观测因子进行编号建立空间矩阵,寻找最优分割聚类后确定各个景观段落的主题。结果表明,武夷山国家公园森林旅游景观可划分为8个单元段,即坡地草坪景观段、山谷阔叶林景观段、山谷针阔混交林景观段、山脊阔叶林景观段、坡地针阔混交林景观段、山谷茶田景观段、阔叶林溪流景观段和岩石溪流游景观段。

PCB制造中OLT计算模型与APS预排功能的协同优化

在PCB(Printed Circuit Board,印制电路板)制造领域,准确的交期预测对于提升客户满意度和市场竞争力至关重要。文章将OLT(Order Lead Time,订单周期)科学计算模型与AP S(Advanced Planning and Scheduling,高级计划与排程)系统的订单预排功能相结合,以提高PCB工厂的交期预测准确性和订单交付效率。首先,分析了现有OLT计算方法的局限性。基于此,本文根据业务流程对OLT进行细化,并引入一种考虑在制数量和资源分配的加工周期计算模型。进一步,阐述APS系统的订单预排功能的算法逻辑,并利用该功能模拟多订单、多资源、多目标下的排产,估算订单的排程与交期。最后,通过案例展示了在实际生产环境中两者的交叉验证和结合应用,突显了本文方法在科学预测生产周期、提升订单履行率和增强客户满意度方面的显著优势。

基于二阶锥规划的配电网源-网-荷-储联合规划方法设计

随着高比例分布式光伏接入配电网,如何对线路进行规划与源-储定址定容成为无法避免的问题。提出了配电网源-网-荷-储双层联合扩展规划策略,上层以配电网系统网络年投资费用最小和网损惩罚费用最小为目标建立线路规划模型,实现对配电网线路走向的改进;下层针对源、荷的不确定性以配电网运行收益最大为目标建立配电网源-储定址定容模型,同时引入不确定性参数对源-荷不确定性集的范围进行约束。针对所建双层规划模型非线性、难求解问题,基于二阶锥松弛算法将上述非凸、非线性优化规划模型转换为二阶锥优化模型,进而获得全局最优解,以此得到分布式光伏以及储能的最佳接入位置和容量。仿真结果表明,该方法可有效降低配电网的规划成本,促进分布式电源的消纳。