Open Cut » Health and Safety
Long term exposure to whole body vibration causes a range of adverse health effects, particularly back disorders. Operators of surface mining earth- moving equipment are known to be exposed to significant whole-body vibration amplitudes. Workplace management of the risks associated with this hazard requires assessment of vibration amplitudes before devising and implementing appropriate control measures. High amplitude sudden impacts ie., jolts and jars, are also associated with acute injuries.
The aim of this project was to develop the WBV iOS application (developed in C23022) further, in conjunction with new server software, to allow continuous monitoring of equipment operator whole-body vibration through embedding an iOS device within the seats of earth-moving equipment.
Data were successfully transmitted in this way from trucks operating at a central Queensland site, however breaks in transmission occurred because the devices overheated when placed within the truck seats. The scope of the project included the development of measurement hardware including seat and floor mounted accelerometers connected to a Raspberry Pi (RPi) microcomputer installed in the equipment cab that continually transmitted acceleration and GPS data to a server via the mine's network. Software was written to allow off-line analysis of seat and floor accelerometer data. Data were also automatically sent to the company's asset health team.
The project has demonstrated the potential for such a system to allow efficient continuous collection of whole-shift data from earth-moving equipment in operation at surface coal mines. Measurements of whole-body vibration calculated for a total of 4538 shifts of operation across 17 rear dump trucks and a D11 Dozer are included in this report.
These data can be used to monitor whole-body vibration amplitudes as a function of shift, roadway standards, and examine the effectiveness of seating in attenuating the vibration transmitted from the floor to the equipment operator. Examining accelerometer measurements as a function of GPS data provides the opportunity to undertake targeted roadway maintenance. Differences between floor acceleration levels observed between trucks operating on the same roadways directs attention to potential truck maintenance issues. Shift to shift differences in seat effectiveness can identify operators who are having difficulty adjusting the seat suspension to suit their mass. High amplitude accelerations, potentially indicating jolts and jars associated with loading events, can be automatically identified for investigation, or the acceleration time series can be inspected in response to reported events.
Limitations were encountered in that site resources are required to install and maintain the accelerometers. In part, this is likely a consequence of the design of the system as a research tool / proof of concept without particular consideration being given to ensuring longevity of the system in the harsh mining environment. An opportunity exists for a vendor to undertake the design and fabrication of a more robust commercial system based on the learnings gained from this project.