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虚拟流水线生产系统及Petri网建模技术研究 总被引:2,自引:0,他引:2
根据船舶生产模式和特点,提出了船舶产品中曲面分段加工的虚拟流水线作业模式.研究了虚拟流水线生产系统的原理和特点,并对虚拟流水线生产关键技术中的作业负荷均衡技术和准时化生产控制技术进行研究.利用面向对象Petri网技术建立虚拟流水线生产系统模型,并将系统决策规则融于模型中,为系统仿真和调度研究创造了条件. 相似文献
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虚拟流水线生产系统及Petri网建模技术研究 总被引:2,自引:0,他引:2
根据船舶生产模式和特点,提出了船舶产品中曲面分段加工的虚拟流水线作业模式。研究了虚拟流水线生产系统的原理和特点,并对虚拟流水线生产关键技术中的作业负荷均衡技术和准时化生产控制技术进行研究。利用面向对象Petri网技术建立虚拟流水线生产系统模型,并将系统决策规则融于模型中,为系统仿真和调度研究创造了条件。 相似文献
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为了提高船舶中小组立等中间产品建造作业调度能力,提升船舶建造效率,提出面向多约束的船舶组立建造作业调度方法。首先,分析船舶组立建造的工艺流程和作业调度方法,综合考虑机器小组、工艺和交货期等多种约束条件,以建造周期最短为调度目标,建立船舶组立建造作业调度数学模型;其次,综合运用算法分解策略及调度规则,设计改进的最短作业优先调度算法实现模型求解;最后,以某船厂建造车间一定生产周期(17天)的中小组立先行中日程计划为对象,验证该方法的有效性和实用性。研究结果表明,所提出的面向多约束的船舶组立建造作业调度方法相较于当前的调度方法,排产周期压缩22小时,即缩短了原有周期的16.18%,有效提高了生产计划排产和作业调度效率。 相似文献
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《中国航海》2018,(3)
在清淤作业中清淤设备的工作状况和能耗等级与设备所完成的动作密切相关,为评估清淤设备的这些参数,将核心的连续作业动作准确地从总作业过程中识别出来是重要的手段之一。将多个三维混合传感器分别安装于机械臂的各主要部分上,采集大量清淤作业时机械臂的运动数据,并建立挖斗型机械臂的模型。通过对数据进行分析,提出一种用于动作分割的复合特征。在完成动作分割的基础上,通过分析分割出的时间间隔内的连续动作,提出一种位移特征,并采用数据作为特征参数的BP(Back Propagation)神经网络进行动作判定。经过对试验数据验证,该方法的对于挖-移-卸这一连续动作的识别率达到98. 5%。 相似文献
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针对传统的船舶信息管理任务调度模型的调度平均等待时间长的问题,研究群智能优化算法的船舶信息管理任务批量流水调度模型。根据群智能优化算法理论,将调度过程中的船舶看作粒子,根据实际调度需求设定调度模型的参数。为缩短船舶调度平均等待时间,规划船舶调度的目标函数以及约束条件。计算粒子适应度,将粒子与任务分配一一映射,根据船舶可信度计算得到局部粒子最优解,更新粒子位置直至出现最优调度解,完成船舶信息管理任务批量流水调度模型的构建。通过与传统调度模型的对比仿真实验,验证构建的基于群智能优化算法的船舶调度模型能够缩短传统调度模型2/3的平均调度等待时间,提高了调度效率。 相似文献
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针对现阶段舰船嵌入式系统,采用单一传统数据加密方法,存在安全性降低的问题。提出基于调度模型的舰船嵌入式系统关键数据反馈加密方法,通过利用3GR加密字串分割算法,对舰船关键数据加密源字串进行分割化运算。创建AEHA综合加密认证单元,对分割后的字串做精简数优化,加速认证。对比实验证明,提出的基于调度模型的舰船嵌入式系统关键数据反馈加密方法,能够快速对舰船嵌入式系统关键反馈数据进行实时瞬态加密,加密数据抗攻击性与反破解能力都优于传统加密方法 相似文献
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Increasing demand for containerization compels container terminals to improve their performance. Uncoordinated scheduling of operations is one of the main factors accounting for poor performance at automated container terminals (ACTs). To increase land utilization efficiency and lower operational times, a new storage system called the split-platform automated storage/retrieval system (SP-AS/RS) has been introduced for temporary storage of containers. This paper describes a multi-objective mixed-integer programming (MIP) model that is based on a combination of multiple interacting sub-tasks. It is aimed at optimizing the integrated scheduling of handling and storage operations in ACTs. The MIP model objective function is to minimize delays in the loading/unloading tasks of the cranes and the travel time of vehicles and platforms in the SP-AS/RS. At the same time, a simulated annealing algorithm (SAA) that provides near-optimal solutions for the problem in a reasonable computation time is appraised. The results of this study show that the objective function of the MIP model is, on average, 58 % lower than that of the non-integrated scheduling method. On the other hand, the best objective function values obtained by the SAA indicate only a 3.7 % disadvantage in comparison with optimal values determined by the MIP model, demonstrating that the SAA is able to provide near-optimal solutions for the integrated scheduling of handling and storage operations. 相似文献
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In a previous article by the same authors, we described the operational, short term tanker scheduling problem, focusing on the Chevron Shipping Company case study. We developed a model for the scheduling situation and described an integer programming formulation for schedule optimization. In this paper, we describe the scheduling system implementation on the University of Michigan IBM 3090-600E computer. The system generates feasible schedules for each vessel and then uses integer programming to attempt to solve for the optimal overall schedule. Use of the system and the potential for cost savings is demonstrated with a realistic scheduling situation based on Chevron Shipping Company information. 相似文献
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连续泊位调度与岸桥配置协同优化 总被引:1,自引:0,他引:1
连续泊位调度与岸桥配置协同优化是集装箱码头提升竞争力的关键因素.针对该问题构建一个混合整数规划模型,以构造算法为核心,通过调整船舶的分配次序,设计了一个新的启发式算法.通过VB6.0软件编程,进行了四组大规模仿真算例实验,结果显示60%的算例在新算法下可获得更优的解,平均改进7.37%,证明了模型和算法的有效性. 相似文献
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We describe the operational tanker scheduling problem in detail, as it relates to Chevron Shipping Company. We review the literature and current Chevron practice. We develop a model for the scheduling situation, and describe an integer programming formulation for schedule optimization, including the feasible schedule generation process, for a realistic representation of the company scheduling practices. 相似文献
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以集装箱码头船舶装卸作业调度问题为研究对象,综合考虑港口多种装卸资源和流程,在船舶泊位占有时间确定的条件下,以装卸运输作业总成本最低为目标,提出单船装卸作业调度模型;用蚁群算法对所建立的模型进行求解和仿真,并结合实际问题给出具体调度结果。此模型和方法考虑了生产效率和作业成本之间的平衡,保证以较低的成本完成规定作业。 相似文献
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Nowadays, shipyards are making every effort to efficiently manage their resources such as gantry cranes, transporters, and
block stock yards. The scheduling of block lifting for a gantry crane has been manually performed by an expert shipyard manager
for many years. Such a practice, however, can lead to an undesirably long time to produce scheduling plans. In addition, the
quality of the scheduling plans may not be optimal. To improve the overall process, a block lifting scheduling system for
a gantry crane was developed in this study by using optimization techniques. A block lifting scheduling problem was first
formulated as a multiobjective optimization problem. For a gantry crane, minimization of the traveling distance while unloaded
and wire and shackle replacement between block lifting was considered. An optimization algorithm based on the genetic algorithm
was then proposed and implemented so as to solve the problem. To evaluate the efficiency and applicability of the developed
system, the system was applied to an actual block lifting scheduling problem in a shipyard. Compared to results achieved by
manual scheduling by an expert manager, the results of this work show that blocks can be more efficiently lifted by a gantry
crane when the developed system is applied. 相似文献