Open Cut » Occupational Health & Equipment Safety
In this project we have developed a prototype technology for measuring and reporting an individual's fatigue, with the intention that such a technology could be used to prevent fatigue-related injuries in the Australian coal mining industry. The technology, known as the Smart Cap system, resembles a typical baseball cap, yet contains sophisticated sensors capable of measuring EEG (brain waves) through hair, determining an individual's fatigue level, and reporting that to an in-cab display.
The development of the sensor technology went through a number of phases; the first of which was to develop the sensor capable of reading EEG without the need for conductive gel. Once this was proven, a more sophisticated circuit was developed that incorporated tuned filtering and digital signal processing allowing the brain wave data to be stored and communicated using Bluetooth wireless. The third and final phase, while incorporating more sophisticated features, was focussed on the embodiment of the sensor array into a baseball cap in order to allow long term use in a mining environment.
Two field trials of the Smart Cap fatigue detection system took place at surface coal mining operations in central Queensland during 2008. In total, 53 operators were involved in these trials for one or more shifts. Both day and night shifts were incorporated for operators of haul trucks, excavators, water trucks, dozers and graders. Infrared video footage of some operators was captured for comparison with the real-time EEG and fatigue information collected by the Smart Cap system. In particular, this footage allowed the calculation of the percentage of eye closure (PERCLOS) of eleven operators. Comparison of the PERCLOS measurements with operator fatigue levels shows good correlation in line with similar published research, providing some reassurance of the system's accuracy.
The robustness of the electronics in terms of noise rejection and connectivity were also tested. In all aspects, the Smart Cap system performed according to its design parameters. Specifically, we show that the sophisticated sensor array is capable of eliminating ambient electrical noise in the mine environment, and that the Bluetooth connectivity is secure in the event of intentional mismatching of equipment or close vehicle interactions.
Also presented is the response of the operators to this technology. In the majority, operators showed support for the Smart Cap system, and voluntarily participated in the field trial to a degree whereby volunteers had to be turned away. More importantly, support for the system's implementation was expressed, and only very minimal opposition was encountered.