人机协同的生产调度实验平台

生产调度一直以来都是生产管理的难题,同以往单纯采用算法由机器来获得调度最优解的思路不同的是,采用人机协同的思想开展对调度问题的研究,将调度任务进行分派,使凋度员和机器协同完成调度任务,建立了人机协同的生产调度实验平台.实例表明,该实验平台提供了一个训练调度员调度能力的工具,利用该实验平台,调度员和机器可较好地协同得到满意的调度解.     

数字化车间物料动态配送规划研究

目的 针对数字化生产车间工位物料需求时间的不确定,导致物料配送不准确、不及时的问题,提出一种动态物料配送策略。方法 首先,根据工位关联度和变动时间窗确定实时的配送工位和协同配送工位,设计基于工位排序的动态物料配送路径优化策略。其次,建立以配送成本和时间窗偏离惩罚成本综合最小为目标函数的数学模型。最后,提出并采用系统动力学仿真与蚁群遗传融合算法联合的方法对模型进行求解。结果 模拟算例表明,与静态物料配送优化策略相比,该策略的平均时间成本减少率为30.1%,平均库存减少率为14.86%。结论 该策略能够根据动态时间窗确定配送工位和协同工位,并实时调整配送顺序,实现物料配送的动态自适应性调整,降低总配送成本。融合算法在迭代次数、收敛性、最优解质量方面有明显优越性。     

面向订单的生产计划与调度的综合优化

研究了一个多订单环境下的生产计划与调度集成优化问题,以实现准时生产为目标,综合考虑产品装配结构约束的订单任务计划与订单产品零部件的加工调度,采用直接面向客户订单的工序调度模式建立了计划和调度的综合优化整数规划模型.设计了带精英策略的蚁群算法作为该数学模型的求解方法,并通过对比试验为该算法选取最佳的搜索参数.实例仿真结果表明,所建模型的正确性以及蚁群算法求解该问题的可行性和有效性.     

供应链管理中生产和运输集成的排序问题

分析了供应链管理中多制造商、多客户的生产和运输集成起来的排序(调度)问题.建立了集成排序模型,在研究解的最优性条件基础上,用工件的总流程时间作为排序目标,解决使总费用达到最小的问題,给出相应的动态规划算法,并分析算法的复杂性.     

面向“货到人”拣选系统的一种随机调度策略

通过“货到人”拣选系统作业流程分析,提出了在分批下发订单任务的情况下的一种随机调度策略。以AGV (automated guided vehicle)完成所有任务的总时间最短为目标函数,以任务分配为决策变量,考虑进行调度时AGV所处的状态以及在完成任务过程中AGV在拣选台的排队等待时间,建立随机调度策略的数学规划模型。利用遗传算法进行求解,通过实例仿真,验证了随机调度策略较调度空闲AGV策略具有更高的拣选效率,同时解决了AGV调度与拣选序列问题,对AGV数量配置具有指导作用。     

模具企业生产调度管理系统的研究

为适应模具企业新的生产方式,本文提出了一种结合合同网协议、GPGP协同机制和TAEMS任务描述语言的任务分配和调度方法,并建立层/级结构的整体框架和各级调度策略.该方法从整体的角度分析问题,提高了调度结果的一致性和优化性.初步的验证表明该方法是有效的.     

数字孪生驱动的物联型混单包装线多工位联动优化

目的 解决生产扰动给混单包装线带来的交货期延误、成本额外增加等问题.方法 将传统的混单包装线物联网化,实现生产资源的实时感知,及时获取生产现场的真实信息;面向物联型混单包装线的生产环境,基于数字孪生体系构建起物理世界与数字世界的联系,通过物联网的实体感知和网络的信息传输形成孪生数据集,建立孪生数据驱动的混单包装线多工位联动优化的信息架构;依据包装任务的工序约束,建立起多个工位的动态关联,实现工位间生产信息的实时协调,进而通过算法实现工位任务队列的联动式智能优化.结果 通过在某摩托车外胎包装生产线上的应用,优化后工序任务队列的目标函数值相比最高值下降了36.1％,验证了文中提出的物联型混单包装线多工位联动优化方法的有效性和可行性.结论 文中提出的混单包装线物联网化能为智能制造的实时提供硬件支撑,基于数字孪生的多工位联动优化提供了智能化决策工具支持.     

基于改进变邻域搜索算法的多批次协同任务规划

目的 对多批次协同任务进行分析与建模,并研究任务规划的求解算法。方法 以车载装备多批次协同执行任务为例,综合考虑时间协同、任务区域协同和补给区域协同约束,以暴露时间最短为目标函数建立模型,并提出一种改进变邻域搜索算法进行求解,该方法根据邻域的优化能力自动调整迭代时选择该邻域的概率。结果 仿真结果表明,改进策略在不降低最优解质量的情况下,能够避免标准变邻域搜索算法后期易出现某些邻域长时间无法寻找到最优解的情况,有效提高了算法的效率。结论 变邻域搜索算法可以解决多批次任务规划问题,改进后的算法减少了后期对优化能力不强的邻域的搜索次数,有效提升了算法效率。     

机械协同设计任务的规划探讨

对于机械设计,实现某一功能的载体比较多,非标准件也很多,需要的人工干预较大,设计中涉及的知识范围很广,因此造成的协商活动复杂.而且协同设计过程中存在的迭代与反复现象造成了设计任务总量和设计过程的不确定性.另外任务之间存在串行、并行、并发等各种复杂的执行依赖关系,所以还需要对设计过程进行良好的规划.设计任务的规划是协同设计能够顺利进行的关键环节.     

基于供应链协同的物流配送路径调度优化

在分析供应链协同运作机制的基础上,针对3级供应链协同网络的物流配送路径问题进行研究.在考虑回程空载及任务时间限制等影响因素的基础上,以整体成本最小化为目标,建立基于供应链协同的物流配送路径调度模型.通过案例分析,运用CEGA算法进行编程计算,快速有效地得到调度模型最优解,所建模型的实用性和有效性得到验证.     

A multiple-criteria real-time scheduling approach for multiple-load carriers subject to LIFO loading constraints

This paper studies the problem of scheduling a multiple-load carrier subject to last-in-first-out loading constraints in an automobile assembly line. Two scheduling criteria, the throughput of the assembly line and the material handling distance, are considered in order to maximise the profit of the assembly line. Different from other studies, the product mix and weights of the scheduling criteria are considered to be variable. A scheduling approach is proposed for the problem. At moments when the product mix or weights of the scheduling criteria change, the scheduling approach can select an appropriate rule from a set of given rules. In this study, the proposed approach is compared with other approaches by simulation in order to verify the performance of the proposed approach. The results indicate that, when the product mix and weights of the scheduling criteria are variable, the proposed scheduling approach outperforms other approaches.     

Integrated Production Planning and Scheduling on Automobile Assembly Lines

We address the closely related problems of production planning and scheduling on mixed model automobile assembly lines. We propose an integrated solution, in which a production plan that is feasible with respect to aggregate capacity constraints is developed and then a sequence that is feasible with respect to this plan is sought. We propose three tabu-search-based algorithms that explore the solution spaces for both problems to different degrees to find a combination of a production plan and schedule that are feasible and that approximately optimize the objective function (involving the overproduction and underproduction of finished automobiles, the set-up cost, the idle times of work-cells on the line, the makespan and the load deviations among work-cells). Simulation is used to evaluate alternative schedules. Stochastic extensions are proposed and the complexities of these algorithms are discussed. Example runs comparing the algorithms are presented for deterministic cases, stochastic cases, types of automobiles, buffer sizes and number of work-cells. The results show that an embedded tabu search algorithm is suitable for solving small scale problems, an alternate tabu search algorithm for the medium scale and a serial tabu search algorithm for the large scale.     

Lagrangean relaxation approach to joint optimization for production planning and scheduling of synchronous assembly lines

This paper focuses on simultaneous optimisation of production planning and scheduling problem over a time period for synchronous assembly lines. Differing from traditional top-down approaches, a mixed integer programming model which jointly considers production planning and detailed scheduling constraints is formulated, and a Lagrangian relaxation method is developed for the proposed model, whereby the integrated problem is decomposed into planning, batch sequencing, tardiness and earliness sub-problems. The scheduling sub-problem is modelled as a time-dependent travelling salesman problem, which is solved using a dynasearch algorithm. A proposition of Lagrangian multipliers is established to accelerate the convergence speed of the proposed algorithm. The average direction strategy is employed to solve the Lagrangian dual problem. Test results demonstrate that the proposed model and algorithm are effective and efficient.     

A heuristic procedure for the automobile assembly-line sequencing problem considering multiple product options

Mixed-model assembly nowadays is a common practice in the automobile industry. In an automobile assembly plant, many car options often need to be considered in sequencing an assembly line, for example, the multiple sequencing objectives that consider a pattern, blocking, spacing, and smoothing of options. A general heuristic procedure is developed in this paper for sequencing automobile assembly lines considering multiple options. The procedure obtains an initial sequence by an enhanced constructive procedure, swaps orders for the most deteriorating category of objectives, and performs re-sequencing attempting to improve the swapped sequence. The heuristic procedure was shown to frequently improve the initial sequences by swapping and re-sequencing when swapping opportunities exist. A further improvement step is also proposed to perform a limited search based on the swapped solution. The limited-search improvement step was shown to be effective in further improving solutions from the heuristic procedure in the computational experimentation. Solutions from the heuristic procedure in conjunction with the limited-search improvement step were compared to those from the simulated annealing procedure for large-size problems and showed relatively positive results.     

生产调度干扰管理模型构建及智能算法研究

在现代企业生产经营过程中,生产调度的作用日益突出。它是生产管理领域内的关键生产环节。干扰管理是近些年来学者提出的一种新的处理生产过程中突发事件的思想和方法,已在供应链、物流以及某些特定领域的调度方面有所应用。流水车间调度问题(Flow-shopScheduling Problem,FSP)是一类复杂且极有代表性的流水线生产调度问题的简化模型,它无论是在离散制造工业还是在流程工业中都具有广泛的应用,具有一定的代表性。构建了流水车间调度问题以及干扰为工件到达的流水车间调度干扰管理模型,其经典目标函数为最大完工时间和干扰目标函数为干扰时间差相混合。     

基于Lingo的汽车装配线建模与平衡研究

本文对汽车装配线的两类平衡问题进行研究，通过线性规划，建立了装配线平衡的数学模型；并将所建立的数学模型应用于某汽车集团的汽车底盘装配线。具体步骤为：将装配内容转化为作业顺序优先关系图，并将相关装配数据存入文本文件，然后利用LING08．0根据以上两个数学模型进行编程，分别求出了最小工位数和最优生产节拍，最后用平衡延迟指标进行判断，从而确定是否满足平衡要求。     

Solving the response time variability problem by means of the electromagnetism-like mechanism

The response time variability problem (RTVP) is an NP-hard combinatorial scheduling problem that has been recently formalised in the literature. The RTVP has a wide range of real-life applications such as in the automobile industry, when models to be produced on a mixed-model assembly line have to be sequenced under a just-in-time production. The RTVP occurs whenever products, clients or jobs need to be sequenced so as to minimise variability in the time between the instants at which they receive the necessary resources. In two previous studies, three metaheuristic algorithms (a multi-start, a GRASP and a PSO algorithm) were proposed to solve the RTVP. We propose solving the RTVP by means of the electromagnetism-like mechanism (EM) metaheuristic algorithm. The EM algorithm is based on an analogy with the attraction-repulsion mechanism of the electromagnetism theory, where solutions are moved according to their associated charges. In this paper we compare the proposed EM metaheuristic procedure with the three metaheuristic algorithms aforementioned and it is shown that, on average, the EM procedure improves strongly on the obtained results.     

Local scheduling problems submitted to global FIFO processing constraints

This paper deals with local scheduling problems as part of a global process management policy. The industrial context is an automotive assembly plant. An automobile manufacturing process creates a list that schedules orders so as to optimize production costs. Such a list must respect the vast majority of shop-related constraints, notably those of the assembly shop, which are the hardest to schedule. This list also allows one to provide information to suppliers regarding the parts they are required to deliver to the assembly plant. PSA Peugeot-Citroën has set the ambitious objective of ensuring compliance with all list entries upon arrival at the assembly plant. This objective is equivalent to instituting a global first-in, first-out (FIFO) management policy for all operations upstream of the assembly line (i.e. body shop, paint shop) and in particular it enables one to make significant reductions in component inventories.

However, FIFO-based flows are difficult to achieve. They first require setting up local production scheduling in the plant in order to satisfy constraints specific to each shop (body shop, paint shop, assembly line); this step will be referred to as ‘local scheduling’. Moreover, a number of disturbances intervene to change the initial order.

The aim of our work is to lay out a new policy for managing flows (called ‘reorderable scheduling’). The premise is to define the maximum scheduling level allowed upon input into each shop so as to guarantee restoration of the initial list order (i.e. reordering) at the assembly entrance.

We will start by studying, from a theoretical perspective, a very general base case and then we will characterize the maximum authorized local scheduling disturbance that enables us to fulfil the global management objective (i.e. FIFO). We will also show the implementation of this method in our industrial case within the context of an automotive assembly plant and finally perform the validation step by means of simulation.     

Research of Dynamic Material Handling in an Automobile General Assembly Line Based on Real-time Information

The status of material delivery of an automobile general assembly line is analyzed,and the technique to achieve the real-time tracking of assembly statas information is proposed based on RFID( Radio Frequency Identification) . Thus the consumption of line-side buffer is obtained dynamically,then the type and quantity of needed material are fed back to the subsystem of material handling; the algorithm for determining the best time departure time of delivery driver based on minimizing of total time penalty function is proposed. This approach makes the ma- terial amount of a single delivery trip maximized and improves the efficiency of delivery drivers significantly in the case of does not affect the assembly line normal throughput. Additionally,although this dynamic material handling method is developed for the automobile assembly plant,it should be pointed out that this method is also applicable to other mixed model assembly plants such as electronics,semiconductor and aerospace industry.     

Control logic verification for an automotive body assembly line using simulation

In this paper, an approach is proposed that verifies the controller logic processes for the automobile industry via simulation. For this purpose, a state-based object model that creates a virtual car body assembly line is proposed and a verification methodology using observed signal sequences during the simulation is proposed. This approach was applied to an assembly line controlled by a PLC and the effectiveness of the proposed system was explained in a case study.