Potential of Time-of-Flight Range Imaging for Object Identification and Manipulation in Construction

In this paper, we examine the potential of a range camera in construction material sorting applications. By utilizing the depth information from a time-of-flight (TOF) camera, we identify and classify objects placed on a conveyor belt. The motivation stems from the fact that object manipulation and identification are two primary problems associated with automated handling and sorting of material objects moving on a conveyor belt. Such a problem may arise in the construction industry for handling objects such as formwork when it is returned to the distribution facility. We present algorithms and experimental results using the depth information from a TOF range camera for two distinct tasks: (1) object attribute measurement and (2) object identification. Experiments and results for both tasks indicate a potential benefit for the use of TOF range cameras in construction automation and robotic arm tasks as they relate, for example, to sorting applications in the construction-formwork business.