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借助数字化船坞系统对温度变化导致的船体分段变形作了研究,在理论计算和实测数据分析研究的基础上,给出了基于温度场变化的船坞搭载定位作业的建议。 相似文献
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船体分段合拢面的精度检测是分段总组合拢过程中的重要环节。在船体分段合拢面的精度检测方面,三维扫描仪相对全站仪有着巨大优势。然而,三维扫描仪在扫描过程中会记录很多与合拢面无关的点,因此本文对三维扫描仪扫描出的点云数据,进行合拢面的智能识别。通过采用深度学习理论对PointNet++点云网络进行适合本文的改进,使用CAD模型导出的点云数据构建有标注的船体分段点云数据集,进而使用Adam优化算法对网络进行优化训练。最终网络模型对分段合拢面的识别在验证集上获得精确率73%,召回率90%的效果。 相似文献
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Shoji Takechi Kazuhiro Aoyama Toshiharu Nomoto 《Journal of Marine Science and Technology》1998,3(4):194-200
Accuracy management concerns various aspects of all assembly industries, e.g., final product quality, manufacturing efficiency,
and manufacturing costs. In the near future, accuracy management will be even more important in manufacturing systems because
of mechanization and automation. This paper considers the concept of computer-aided accuracy management systems, which are
based on the concept of integrated manufacturing systems. We propose two management systems, accuracy planning and accuracy
estimation, and concentrate on accuracy planning. A model of welding deformations and an easy estimation method for such deformations
by computer analysis using the finite element method (FEM) are described. A prototype system based on the accuracy management
concept was implemented in the authors' integrated manufacturing systems, and some examples of estimating welding deformations
are given here.
Translation of an article that appeared in the Journal of The Society of Naval Architects of Japan, vol. 181 (1997): The original
article won the SNAJ prize, which is awarded annually to the best papers selected from the SNAJ Journal, JMST, or other quality
journals in the field of naval architecture and ocean engineering. 相似文献
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Process planning for a hull structure defines the assembly sequence of the hull block. Although this activity is very important
because the working strategy defines the production costs, to date it has been done manually. To raise the efficiency of this
process, we developed a practical computer-aided process planning system. It has been developed using deliverables obtained
from advanced computer integrated manufacturing system (CIM; ACIM) for shipbuilding projects sponsored by the Ship and Ocean
Foundation (SOF). The system has a knowledge base which contains the know-how of skilled designers as well as design practices,
and allows the assembly sequence of hull parts and intermediate products to be defined automatically. The system has been
integrated with the shipyard CAD system MATES, and put to practical use.
Received: August 19, 2002 / Accepted: November 25, 2002
Address correspondence to: Y. Sasaki (yuuichi_sasaki@mhi.co.jp)
Updated from the Japanese original, which won the 2002 SNAJ prize (J Soc Nav Archit Jpn 2001;189:309–315) 相似文献
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船舶分段制造计划系统是一个多任务的管理系统,周期相当长而且有着相当大的不确定性。该文建立了船舶分段制造计划系统管理框架,运用关键链技术分析和优化了船体分段计划系统。介绍了运用关键链方法后,对船舶分段制造采用工艺改进和管理措施改进所取得的效果,并对关键链方法未来的发展前景进行了展望。 相似文献
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在某大型集装箱船建造过程中,面临与船坞坞底改造工程同期施工的特殊工况。引入双岛不移位式建造工艺,突破场地条件限制。针对双岛建造精度管理的难点,经科学策划和全过程跟踪,确保全船精度指标完全符合建造标准,实现船坞坞底改造与总段连续搭载同步进行的目标。双岛不移位式建造工艺和精度管理方法可拓展至类似船舶的船坞搭载。 相似文献
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Dimensional control is one of the most important challenges in the shipbuilding industry.In order to predict assembly dimensional variation in hull flat block construction,a variation stream model based on state space was presented in this paper which can be further applied to accuracy control in shipbuilding.Part accumulative error,locating error,and welding deformation were taken into consideration in this model,and variation propagation mechanisms and the accumulative rule in the assembly process were analyzed.Then,a model was developed to describe the variation propagation throughout the assembly process.Finally,an example of flat block construction from an actual shipyard was given.The result shows that this method is effective and useful. 相似文献
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基于数据驱动的船体板件数控等离子切割精度控制 总被引:1,自引:1,他引:0
摘 要:船体板件切割的尺寸误差直接影响船体分段制造的尺寸精度,造成分段精度难以满足整船装配精度要求。为提升船体板件的数控等离子切割精度水平,本文首先基于板材切割过程的大量精度数据,引入统计过程控制(Statistical Process Control, SPC)方法,评价了数控等离子切割的精度状况;然后再结合现场工艺过程分析精度数据的过程控制图,确定了影响切割精度的主要因素;同时,针对主要影响因素提出了相关改进措施,并借助过程控制图对切割精度进行循环控制;最后使用假设检验的方法,从样本到整体验证了切割精度的提升。 相似文献
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为解决船体分段任务包工时定额的计算过度依赖线性公式而忽略工时定额与工艺参数之间的非线性关系的问题,提高工时定额计算的效率和精确度,将PSO-BP神经网络技术应用到船体分段任务包工时定额中。通过对影响船体分段中间产品额定工时的工艺参数进行分析,建立多输入单输出的PSO-BP神经网络模型,并应用实际数据对PSO-BP神经网络进行训练,测试仿真结果与实际值之间的误差在允许范围内。验证结果表明,采用PSO-BP神经网络建立船体分段任务包工时定额模型,能对任务包作业工时进行准确预测。 相似文献
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ZHAN Yi-ting JI Zhuo-shang LIU Yin-dong 《船舶与海洋工程学报》2007,6(2):37-43
Methods used for digital ship design were studied and formed the basis of a proposed frame model suitable for ship construction modeling. Based on 3-D modeling software, a digital design system for hull structures was developed. Basic software systems for modeling, modifying, and assembly simulation were developed. The system has good compatibility, and models created by it can be saved in different 3-D file formats, and 2D engineering drawings can be output directly. The model can be modified dynamically, overcoming the necessity of repeated modifications during hull structural design. Through operations such as model construction, intervention inspection, and collision detection, problems can be identified and modified during the hull structural design stage. Technologies for centralized control of the system, database management, and 3-D digital design are integrated into this digital model in the preliminary design stage of shipbuilding. 相似文献
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The shipbuilding industry has adopted IT convergence as a new engine for growth encompassing conventional production know-how and economies of scale. Brand new solutions for enterprise IT, such as three-dimensional (3D) computer-aided design (CAD) systems, enterprise resource planning systems, and product lifecycle management systems have been adopted and customized to shipyards and contribute to productivity enhancement. As part of IT convergence in the shipbuilding industry, we examine the adoption of business process management (BPM) for the ship hull production design process. Ship hull production design, a process-based task, requires the most man-hours among all ship design processes and is directly coupled with ship production; thus, improvements in this task can contribute hugely toward enhancing productivity. First, we explain the concept of the executable model, which is an essential condition for executing defined processes in a business process management system (BPMS). In addition, we analyze the hull production design task and use this as the basis of a process to build executable BPM models. Thus, we present detailed implementations and the expected effects for the BPM execution of the hull production design process. The executable BPM model of the hull production design process is implemented using Bonita Open-Solution 5.5, a representative open-source BPMS. 相似文献
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针对北方某重力式方块码头工程设计及施工过程中存在的构件碰撞、工程量计算精度低、技术交底效率低等问题,进行BIM技术在重力式方块码头工程设计施工中的应用研究.通过创建三维信息模型进行碰撞检查、工程算量、进度模拟以及可视化工艺技术交底,有效解决了以上问题,得出如下结论:BIM技术可视化降低了沟通成本,为工程精细化管理提供了技术手段;利用BIM技术在设计阶段解决碰撞问题,降低施工时的返工风险;基于BIM模型的工程算量更加直观,具有完整、快捷、精确等特点;利用BIM技术对施工进度计划进行可视化预演,可辅助施工技术人员对施工方案进行优化. 相似文献