Monitoring Lifting Equipment for Automated Progress Control: A Feasibility Study

Reliable and timely information describing up-to-date performance is a prerequisite for effective management of construction. Existing methods for on-site data collection are labor-intensive, subjective, and the data are frequently available only after activities have been completed. Monitoring of the main lifting equipment on construction sites can provide real-time, low-cost and objective data for interpretation within an APPC system. This paper reports on a field study conducted monitoring a tower crane employed in construction of a hybrid cast-in-place and precast concrete structure. Data describing the load weight, the hook height and the position of the hook in the building have been collected for multiple occurrences of different activity/building element combinations (including column formwork, slab formwork, pouring concrete beams, pouring concrete slabs, and reinforcing columns). A set of distinguishing characteristics of crane operations has been identified for computer-automated identification of the construction activities performed using the crane. A rigorous comparison of the potential values of each characteristic, for each activity type, has led to the conclusion that the characteristic values alone are insufficient for distinguishing between different activities. However, when the activity location is considered in the context of the building’s geometry and construction schedule, the activity can be identified almost all of the time. The geometry and schedule are provided in the format of an electronic Building Project Model. In this way, a set of interpretation rules capable of interpreting the data monitored in real time can be compiled. Useful information concerning the construction process can be reported, including the overall actual start and finish times of an activity, its duration, and the net time that the crane was employed for it.