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ABSTRACT: This paper describes an experiment to examine whether a visual warning system can improve detection of moving machine hazards that could result in struck-by or pinning accidents. Thirty-six participants, twelve each in one of three age groups, participated in the study. A visual warning system capable of providing four different modes of warning was installed on a continuous mining machine that is used to mine coal. The speed of detecting various machine movements was recorded with and without the visual warning system. The average speed of detection for forward and reverse machine movements was reduced by 75% when using the flashing mode of the visual warning system. This translated to 0.485 m of machine travel for the fast speed condition of 19.8 m/min, which is significant in the context of the confined spaces of a mine. There were no statistically significant differences among age groups in the ability to detect machine movements for the visual warning modes in this study. The visual warning system shows promise as a safety intervention for reducing struck-by or pinning accidents involving continuous mining machines. The methods and results of this study could be applied to other moving machinery used in mining or other industries where moving machinery poses struck-by or pinning hazards.
Applied ergonomics 04/2012; 43(6):1058-65. · 1.11 Impact Factor
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ABSTRACT: Researchers at the National Institute for Occupational Safety and Health (NIOSH) are investigating different lighting technologies with the objective of improving mine safety. This paper presents results from an ongoing study that compares discomfort glare for different LED cap lamps using the de Boer rating scale. The cap lamps tested included two commercially-available LED cap lamps and one NIOSH prototype LED cap lamp tested at three different illumination levels. Prior research indicated the NIOSH prototype enabled much better visual performance as compared to other LED cap lamps. It uses three LEDs that produce multiple illumination areas in comparison to commercially-available cap lamps that use one LED and project a narrow spot pattern. Across subjects and cap lamp test conditions, measured illuminances (averaged at both eyes) varied from 0.62 lux to 3.73 lux; whereas, the de Boer glare ratings varied from 4.86 to 7.71. An analysis of variance based on 15 subjects indicated a significant difference in discomfort glare due to cap lamps (F 4, 52 = 18.01, p <;0.001). Post hoc tests indicate that one of the commercially-available cap lamps exhibited lower discomfort scores, with no statistically significant differences detected between the others. Thus, the NIOSH prototype cap lamp does not cause.
Industry Applications Society Annual Meeting (IAS), 2010 IEEE; 11/2010
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ABSTRACT: This experiment investigated the effects of different machine mounted area lighting technologies on visual performance. The primary objective was to conduct a comparative evaluation of the lighting technologies based on the visual performance of thirty-six human subjects in a simulated underground mine environment. Incandescent (Incand), fluorescent (Fluor), and light-emitting diode (LED) technologies were used to create four lighting combinations. Visual performance was quantified for the detection of movement in the peripheral field of view and the identification of ground hazards. Measurements were made of the speed [response time measured in milliseconds (ms)], the accuracy (the number of targets and objects missed), and the subjective discomfort rating of the glare experienced for each lighting combination. A secondary objective explored the effects of aging on visual performance. The results indicate that lighting combinations which consisted of LED area lights significantly improved visual performance for the detection of hazards found in the peripheral field of view, as well as those found on the ground. They furthermore, indicate that age plays a significant role in visual performance.
Industry Applications Society Annual Meeting, 2009. IAS 2009. IEEE; 11/2009
