Tracking worker and equipment positions with GPS receivers.
NOIRS 2003-Abstracts of the National Occupational Injury Research Symposium 2003, October 28-30, Pittsburgh, Pennsylvania. Pittsburgh, PA: National Institute for Occupational Safety and Health, 2003 Oct; :22
To quantify worker exposure to hazardous areas around operating construction equipment, the National Institute for Occupational Safety and Health (NIOSH) conducted a pilot test using global positioning system (GPS) to simultaneously track the positions of several workers and pieces of construction equipment. Recent advances in GPS receivers make it possible to locate positions with unprecedented levels of accuracy with off-the-shelf technology, although some error in the position identified by GPS still exists. The pilot testing was done during a paving operation at the Pittsburgh Research Laboratory which included milling, geotextile placement, and paving of base and wearing courses. Continuous positions of workers and equipment were collected using four different GPS receiver models. Additional static and roving tests were also conducted. The accuracy of GPS position and movement estimates is a function of the capabilities and therefore, the cost of the receiver, as well as factors ranging from errors in estimating satellite orbits to interference from obstacles (e.g., buildings) near the receiver. During the pilot test, the least expensive receivers located horizontal positions with a 68% precision of 2.l meters and a 95% precision of 4.4 meters, while the more expensive receivers located horizontal positions with a 68% precision of 0.7 meters and a 95% precision of 2.6 meters. The goal of this effort will be to estimate the probability that a worker is located within a predefined hazard area of a piece of equipment at a specific time so that overall exposure to the worker during the day can be estimated. Since strong correlation exists between the errors of GPS horizontal position estimates from two different receivers at the same point in time, errors in distance between two different GPS receivers will be less than the sum of the individual errors. Results from the pilot test indicate that the error in distance between two of the more expensive receivers has a 68% precision of 0.3 meters and a 95% precision of 1.7 meters. Results also indicate that the squared error distance can be reasonable estimated by a gamma distribution which wiIl allow monte-carlo simulations to be conducted to estimate the probability that a worker is in the hazard area of the specified piece of equipment. Based on these results, the more expensive receivers will be used for equipment and laborers whose tasks require them to work near operating equipment while the least expensive receivers will be used for workers who are not expected to work near operating equipment (e.g. foremen, inspectors, etc.), but who may on occasion approach operating equipment.
Construction-equipment; Construction-industry; Construction-workers; Occupational-exposure; Occupational-hazards; Models; Workers; Injuries; Injury-prevention; Traumatic-injuries; Accident-prevention; Monitoring-systems; Monitors
Abstract; Conference/Symposia Proceedings
Disease and Injury: Traumatic Injuries
NOIRS 2003-Abstracts of the National Occupational Injury Research Symposium 2003, October 28-30, Pittsburgh, Pennsylvania