Mohammadtaghi Safari - Department of Civil Engineering, Sadjad University, Mashhad, Iran
Iman Bagheri - Department of Electrical Engineering, Montazeri Technical and Vocational University

In construction projects, measuring labor input is crucial for on-site control and management since it's the primary predictor of project outcomes. However, traditional manual methods for measuring labor input are time-consuming, not done in real-time, and lack effectiveness. This study presents a novel solution to address this challenge. It utilizes Inertial Measurement Unit (IMU) sensors attached to hand tools during construction activities to measure labor input accurately and in real time. The approach consists of phases, identifying local specific structures, computing self-similarity matrices, and extracting temporal-spatial features. This approach provides a more precise and timely measurement of labor input, improving project control and management. This research also suggests that patterns of repetition in hand tool usage data can be automatically identified and then used to measure the amount of labor input. A working prototype and research study was developed, focusing on counting rotations for a screw-connection activity to test the idea. The goal is to assess the usability of this method in broader construction contexts. Experiments illustrate that IMU sensors on hand tools can measure labor input effectively and efficiently. The accuracy of the results was confirmed by comparing them to real-world data. We are currently working on improving the accuracy of activity segmentation and speeding up feature extraction. These improvements will reduce measurement errors and help us better understand construction behaviors on-site.

Civil Engineering, Construction, Monitoring, Measurement, IMU