Visual Tracking of Construction Jobsite Workforce and Equipment with Particle Filtering

Tracking workforce and equipment at construction jobsites has attracted considerable interest, considering its importance for productivity analysis, safety monitoring, and dynamic site layout planning, for example. Several real-time locating systems (RTLSs) are commercially available, but their requirements for attaching sensors or tags to a workers or equipment raise privacy concerns. Recently, the idea of using video cameras statically placed at construction jobsites to track workers and equipment has been proposed and tested. One challenge of visual tracking stems from jobsite occlusions, which significantly affect tracking performance. This paper presents a vision tracking method using particle filters to address the issue of occlusions at construction jobsites. The method includes two main phases. First, the worker or mobile equipment of interest is manually initiated with a rectangular window, and hundreds of particles are generated. Then each particle is propagated and its weight is calculated by measuring its observation likelihood. The particles are resampled based on their weights. This makes it possible to follow a worker or equipment of interest. The method has been tested at real construction jobsites in Quebec, and tracking results demonstrated its effectiveness.