Path Planning Penalty-based Optimization for Mobile Cranes

Boshen Lin; Ahmed Bouferguene; Mohamed Al-Hussein

Abstract:

Modern construction projects are increasingly complex to a point where scheduling analyses can no longer be performed manually using pencil and paper as they once were. As a result, not only do we need to rely on computer technology to model the large number of parameters (degrees of freedom) but more importantly new algorithms may need to be elaborated in order to handle the spatial complexity of construction sites. In this respect, when cranes are used to move loads from their pick locations to their final destinations, it is paramount to have a minute understanding of the trajectories of each payload. Modern heavy construction industry relies heavily on cranes since projects are often in terms of modules that are prefabricated off-site and front-loaded with as many functionalities as possible to minimize on-site activities. Front-loading modules increases their weights thus making high-capacity mobile cranes indispensable for on-site assembly. To add to the complexity of the lifting problem, it is important to mention that nowadays construction sites can be congested right from the start, which makes path analysis and planning even more critical to projects' success. Building on the success of A* algorithm, which has been used mostly to represent 2D crane trajectories, a variant of this algorithm is proposed to represent 3D trajectories. However, users are allowed to introduce penalties to take into account elements that could be related to efficiency or safety. The results illustrate the ability of the proposed algorithm to balance the length of the trajectory with other user-defined criteria that can lead to smoother or safer trajectories.