共查询到17条相似文献,搜索用时 62 毫秒
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采用面向对象方法,使用统一建模语言进行炼油企业生产计划系统的需求分析和系统设计。首先描述了生产计划系统的功能需求,包括数据管理、模型管理、模型发生器和过程分析等,并且采用序列图初步分析了系统核心功能生产计划的实现过程。在此基础上,进行系统的数据模型设计,包括公用数据模型,装置数据模型和物流数据模型。上述数据模型描述了炼油企业生产流程的静态结构和生产计划活动的信息。最后开发了软件OpTechPlan,并且在中国北方某炼油企业得到了初步的应用。 相似文献
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炼油企业通常由生产过程和公用工程两个主要部分组成。将生产计划和公用工程集成优化,不仅获得真正的全局最优解,而且克服了传统生产计划人为制定生产过程与公用工程之间中间物流(各压力等级的蒸汽,瓦斯等)价格的缺陷,避免了蒸汽减温减压和放空,以及炼厂气放空的经济损失和环境破坏。首先采用IDEF0方法建立了生产计划与公用工程的功能模型,描述了两者之间的相互关系。接着建立了生产计划与公用工程集成的混合整数线性规划模型。模型描述了装置能耗不仅与加工量相关,而且与装置的生产方案相关,更真实地反映了生产过程与能量系统之间的定量关系。模型还在全厂范围内进行各压力等级蒸汽和燃料的平衡。最后,将建立的全厂集成优化模型应用于中国北方的某大型炼油厂,验证了模型的有效性。 相似文献
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传统的生产计划优化由于不考虑过程装置的操作优化,从而无法保证企业生产计划层与过程操作层的全局最优.为了在获得炼油企业最优生产计划的同时,确保计划优化中重点装置的操作条件可以实现,本文建立了集成装置工艺条件的炼油企业生产计划优化模型.该模型引入常减压装置侧线产品切割点温度、催化裂化装置转化率等过程工艺条件,基于物料质量平衡、产品质量指标约束等关系,进行厂级生产计划建模与求解,确定可达的装置操作条件.应用案例中重点通过与传统常减压装置侧线收率固定的生产计划方案比较,证明在满足可达的操作条件下,集成装置工艺条件操作范围的生产计划优化模型,可以实现更高的全厂利润与更优的装置收率分布,同时优化结果对炼厂实际生产更具有指导意义. 相似文献
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基于动态规划的生产计划优化模型研究与应用 总被引:1,自引:0,他引:1
动态规划是运筹学的一个分支,是一种多阶段决策过程,可用于解决多目标决策问题,以使系统的总效果最优.以某企业生产计划的优化安排为实例,在该企业产品的生产能力、生产成本、库存成本等约束条件下,利用动态规划方法建立生产计划安排模型,通过模型求解解决了该企业产品生产计划的优化问题,同时以精练的C++代码实现了相应程序. 相似文献
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讨论了多目标优化生产调度计划系统的结构功能和部分关键功能的设计,分析了该系统如何把多目标优化启发式算法、自定义式机台分布图及GANTT图仿真模型相结合,实现生产调度计划的优化编制、调度单的自动生成和实时跟单以及生产计划的合理制定。 相似文献
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应用并行工程方法对生产计划与能量系统的集成进行了分析,提出了用于确定业务流程和信息流的业务过程模型,明确了系统的并行特性,采用并行工程方法建立了并行业务过程模型,并确定了用于数据建模的数据流,从而为集成效据库管理和集成软件系统的开发奠定了基础。 相似文献
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棉纺织企业多目标优化计划调度系统开发 总被引:1,自引:0,他引:1
讨论了多目标优化生产调度计划系统的结构功能和部分关键功能的设计,分析了该系统如何把多目标优化启发式算法、自定义式机台分布图及GANTT图仿真模型相结合,实现生产调度计划的优化编制、调度单的自动生成和实时跟单以及生产计划的合理制定。 相似文献
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针对定点装配车间不合格品返工导致生产计划及调度不可行的情况,提出一种基于返工延后处理的定点装配车间生产计划与调度集成优化方法.首先制定返工延后处理的粗生产计划;下达计划生产后,将每周期产生的不合格品放入缓冲区,在下周期初时重新调整生产计划并求解新计划下的最优调度,判断其是否满足装配班组负载率要求,不断交替迭代生产计划与调度直至达到计划与调度的均衡和优化.最后通过算例验证了所提出方法的可行性和有效性. 相似文献
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Development of an Aggregate Production Plan (APP), the top most level in a hierarchical production planning system, is a difficult task, especially when input and other production planning parameters are uncertain because of their inherent impreciseness. This therefore makes generation of a master production schedule highly complex. Regarding this point, in this paper, we present a scheme of a multi-period and multi-product APP which is formulated as an integer linear programming model. The proposed approach uses a triangular possibility distribution for handling all the imprecise operating costs, demands, and also for the capacity data. The proposed approach uses the strategy of simultaneously minimizing the most possible value of the imprecise total costs, maximizing the possibility of obtaining lower total costs and minimizing the risk of obtaining higher total costs. A modified variant of a possibilistic environment based particle swarm optimization (PE-PSO) approach is used to solve the APP model. A numerical model for demonstrating the feasibility of the proposed model is also carried out. In the computational study, the considered case study data were experimented with and analyzed to evaluate the performance of the PE-PSO over both a standard genetic algorithm (GA) and a fuzzy based genetic algorithm (FBGA). The experimental results demonstrate that the PE-PSO variant provides better qualities in the aspects of its accuracy when compared to the other two algorithms. 相似文献
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《Expert systems with applications》2014,41(6):3069-3077
Particle swarm optimization (PSO) originated from bird flocking models. It has become a popular research field with many successful applications. In this paper, we present a scheme of an aggregate production planning (APP) from a manufacturer of gardening equipment. It is formulated as an integer linear programming model and optimized by PSO. During the course of optimizing the problem, we discovered that PSO had limited ability and unsatisfactory performance, especially a large constrained integral APP problem with plenty of equality constraints. In order to enhance its performance and alleviate the deficiencies to the problem solving, a modified PSO (MPSO) is proposed, which introduces the idea of sub-particles, a particular coding principle, and a modified operation procedure of particles to the update rules to regulate the search processes for a particle swarm. In the computational study, some instances of the APP problems are experimented and analyzed to evaluate the performance of the MPSO with standard PSO (SPSO) and genetic algorithm (GA). The experimental results demonstrate that the MPSO variant provides particular qualities in the aspects of accuracy, reliability, and convergence speed than SPSO and GA. 相似文献
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Most algorithms in probabilistic sampling-based path planning compute collision-free paths made of straight line segments lying in the configuration space. Due to the randomness of sampling, the paths make detours that need to be optimized. The contribution of this paper is to propose a basic gradient-based algorithm that transforms a polygonal collision-free path into a shorter one. While requiring only collision checking, and not any time-consuming obstacle distance computation nor geometry simplification, we constrain only part of the configuration variables that may cause a collision, and not entire configurations. Thus, parasite motions that are not useful for the problem resolution are reduced without any assumption. Experimental results include navigation and manipulation tasks, eg a manipulator arm-filling boxes and a PR2 robot working in a kitchen environment. Comparisons with a random shortcut optimizer and a partial shortcut have also been studied. 相似文献
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针对多产品生产部件串联系统的生产和维修问题进行了研究,提出了基于二阶段时间延迟的联合优化模型。首先,基于生产周期分段理论,将整个周期等分成若干单位时间段,生产与维修共用每段时间,且若干时间段后采取一次预防维修。其次,考虑生产系统的实际生产时间、可用生产时间和维修耗费时间,建立了生产计划与维修计划总成本模型。其中,维修计划考虑缺陷和故障维修费用、维修检查费用,以及非正常状态下设备运行可能产生的不合格产品损失费用;生产计划考虑生产成本、库存成本、延期未交货成本和维修停机后恢复生产的设备启动成本。最后,通过算例分析,计算最优预防维修周期和各单位时间段各产品产量,验证了模型的有效性。 相似文献
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一种障碍环境下机器人路径规划的蚁群粒子群算法 总被引:8,自引:3,他引:5
针对机器人在障碍环境下寻找最优路径问题, 提出了一种障碍环境下机器人路径规划的蚁群粒子群算法.该方法有效地结合了粒子群算法和蚁群算法的优点, 采用栅格法进行环境建模, 利用粒子群算法的快速简洁等特点得到蚁群算法初始信息素分布, 以减少迭代次数, 加快算法的收敛速度; 同时利用蚁群算法之间的可并行性, 采用分布式技术实现蚂蚁之间的并行搜索, 求解精度高等优点, 求精确解. 仿真实验结果证明了该方法的有效性, 是机器人路径规划的一种较好的方法. 相似文献
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Assembly sequence planning of complex products is difficult to be tackled, because the size of the search space of assembly sequences is exponentially proportional to the number of parts or components of the products. Contrasted with the conventional methods, the intelligent optimization algorithms display their predominance in escaping from the vexatious trap. This paper proposes a chaotic particle swarm optimization (CPSO) approach to generate the optimal or near-optimal assembly sequences of products. Six kinds of assembly process constraints affecting the assembly cost are concerned and clarified at first. Then, the optimization model of assembly sequences is presented. The mapping rules between the optimization model and the traditional PSO model are given. The variable velocity in the traditional PSO algorithm is changed to the velocity operator (vo) which is used to rearrange the parts in the assembly sequences to generate the optimal or near-optimal assembly sequences. To improve the quality of the optimal assembly sequence and increase the convergence rate of the traditional PSO algorithm, the chaos method is proposed to provide the preferable assembly sequences of each particle in the current optimization time step. Then, the preferable assembly sequences are considered as the seeds to generate the optimal or near-optimal assembly sequences utilizing the traditional PSO algorithm. The proposed method is validated with an illustrative example and the results are compared with those obtained using the traditional PSO algorithm under the same assembly process constraints. 相似文献