Equipment selection and on-site utilization for heavy industrial projects

油砂产业是目前加拿大经济最强劲的驱动力之一。最近的统计数据表明，加拿大是世界第三大石油储量，仅次于沙特阿拉伯和委内瑞拉，估计储量为1740亿桶，其中1700亿桶位于艾伯塔省，以油砂的形式存在(艾伯塔省政府，2012年)。由于艾伯塔省北部以严寒和漫长的冬季而闻名，重型建筑面临着严格的时间限制，因此模块化建筑成为大型项目的解决方案。然而，随着模块逐渐变得更重(有时超过500吨)和更大的体积，他们的现场组装需要移动式起重机。由于行业接受了模块化的概念，重型建筑的挑战从制造转移到了组装，从而使起重机操作成为可能影响效率的关键因素之一。对起重机操作的仔细检查，特别是从从业者的角度来看，表明路径规划是一项具有挑战性的任务，特别是对于大型项目来说，这使得其自动化必不可少，以确保对工作订单或项目范围内的变化做出快速反应。这项拟议的研究旨在开发一种整合了现场布局、路径规划和模块组装排序的起重机作业的整体方法。拟议的研究与以前关于两个主要要素的工作有所不同：(I)与用折线表示路径的其他研究不同，拟议的研究建立了诸如旋转和平移序列之类的轨迹，这是起重机唯一的基本运动；(Ii)由于安装的模块可能成为后续升降的障碍，因此重要的是分析模块的组装顺序，以便最大限度地扩大可移动起重机的机动区域。这导致更好地利用移动起重机，因为模块的最佳排序减少了起重机行走或重新分配的需要，而当找不到无障碍路径时就会发生这种情况。然而，为了完成这项研究，拟议的研究还解决了起重机在负重时需要行走的情况下的路径规划问题。

The oil sands industry is currently one of the strongest driving forces of Canadian economy. Recent statistics indicate that Canada is the third-largest oil reserves in the world, after Saudi Arabia and Venezuela with an estimated reserve of 174 billion barrels of which 170 billion are located in Alberta in the form of oil sands (Alberta Government, 2012). Because the Northern part of Alberta is known for its harsh and long winter, heavy construction faces stringent time constraints and because of that modular construction emerged as the solution of choice for large scale projects. However, as modules evolved to be heavier (sometimes in excess of 500 metric tons) and more voluminous their on-site assembly requires mobile crane. As a result of the industry embracing the concept of modularization, the challenge of heavy construction shifted from fabrication to assembly thus making crane operations one of the critical factors that could impact efficiency. A close examination of crane operations, especially from the view point of practitioners, shows that path planning is a challenging task especially for large scale projects which makes its automation indispensable to ensure fast responses to change in work orders or in the scope of the project. The proposed research aims at developing a holistic methodology to crane operations which integrates site layout, path planning and module assembly sequencing. The proposed research departs from previous work on two main elements: (i) in contrast to other studies in which paths are represented by polylines, the proposed research builds such trajectories as a sequence of rotations and translations which are the only fundamental motions of cranes; (ii) because installed modules may become obstacles for subsequent lifts, it is important to analyse the order in which modules are assembled so to maximize the area where a mobile crane can maneuver. This leads to a better utilization of mobile cranes since an optimal sequencing of modules reduces the need for crane walking or re-allocation which occurs when obstacle-free paths could not be found. However, to be complete the proposed research also addresses the issues of path planning in the case where the crane is required to walk while carrying the load.