Semantic trajectory insights for worker safety in dynamic environments

Existing literature reveals that unsafe worker movement behaviors are one of the major reasons of construction site fatalities resulting in serious collisions with site objects and machinery.

For capturing worker movements in dynamic construction environments which involves moving and changing objects, a solution based on semantic trajectories and Hidden Markov Model (HMM) is presented in the form of four subsystems. First, a real-time data collection and trajectory preprocessing subsystem is constructed for extracting multifaceted trajectory characteristics and stay locations of the workers using spatio-temporal data that will help in recognizing the important regions in the building for categorizing the worker movements. Second, to enable the desired semantic insights for better understanding the underlying meaningful worker movements using the contextual data related to the building environment, an ontology-based STriDE (Semantic Trajectories in Dynamic Environments) model is applied which has an ability to track information about the evolution of moving and changing building objects, and outputs semantic trajectories. The third subsystem uses the Hidden Markov Model (HMM) which is the most preferred probabilistic approach in the literature for describing the object behavior in time. An entire set of trajectories belonging to a stay location (a semantic region) is analyzed by categorizing the worker movements into four states using the HMMs along with the Viterbi algorithm. In the end, the output of the Viterbi algorithm is visualized using a BIM model for identifying the most probable high-risk locations involving sharp worker movements and rotations. The developed system will help safety managers in monitoring and controlling building activities remotely in dynamic environments by better understanding the worker behaviors for an improved safety management in day-to-day building operations as well as by preventing other workforce from accessing such hazardous locations which involve risky movements