Equipment selection and on-site utilization for heavy industrial projects

油砂工业是目前加拿大经济最强大的驱动力之一。最近的统计数据表明，加拿大是世界上第三大石油储量国，仅次于沙特阿拉伯和委内瑞拉，估计储量为1 740亿桶，其中1 700亿桶以油砂的形式位于阿尔伯塔省（阿尔伯塔政府，2012年）。由于阿尔伯塔的北方地区以其严酷而漫长的冬季而闻名，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首选解决方案。然而，随着模块发展到更重（有时超过500公吨）和更大体积，其现场组装需要移动的起重机。由于该行业采用模块化概念，重型建筑的挑战从制造转向组装，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，这使得其自动化不可或缺，以确保对工作订单或项目范围的变化做出快速响应。本研究旨在发展一套完整的起重机作业方法，整合现场布局、路径规划与模组组装排序。本文的研究与以往的研究主要有两个方面的不同：（1）与其他研究中用折线表示的路径不同，本文的研究将起重机的运动轨迹建立为一系列的旋转和平移运动，这是起重机唯一的基本运动;（ii）由于已安装的模块可能成为随后升降的障碍，重要的是分析组装模块的顺序，以使移动的起重机可以操纵的区域最大化。这导致了更好地利用移动的起重机，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，这发生在无障碍路径无法找到。然而，要完成所提出的研究还解决了路径规划的问题，在这种情况下，起重机需要走，同时携带负载。

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.