Open Cut » Overburden Removal
The enhanced sensing of machine and operator performance is crucial to the automation of dragline operations and for improving safety in the dragline working area. The determination of a reliable and accurate measure of the terrain surfaces in the region around the dragline, provides:
- A comparison with mine plans.
- Real time feedback on (where to dig and dump.
- Analysis of volume of material moved.
- Improved overall visibility in dusty, foggy conditions.
- Improved safety .
- Up-to-date dig surface and spoil pile information, necessary to efficiently expedite the automation of swing component of the dragline cycle (ACARP Project 5003).
This project was undertaken to:
- Produce a prototype real-time terrain mapping system based on 3-dimensional mm wave radar technology; and
- Integrate radar generated data with mine planning software for data visualisation and assessment.
To achieve the specified objectives, the prototype 3D mm wave radar developed by CRCMining, was tested on a production machine at BMA, Peak Downs Mine. The radar terrain mapping system was shown to have the ability to automatically generate digital terrain maps of the dragline environment during normal operation and to integrate radar generated surfaces with mine planning software.
The reliability and accuracy of volume estimation using radar generated surfaces needs to be improved due to the complexity of the process. The challenges faced during volume estimation were related to the following areas:
1. Smoothness of the generated surface.
Volume overestimation results when the generated surfaces are too rough. Surfaces which are too smooth do not provide accurate representation of the dig area. The compromise could be realised by conducting testing under controlled conditions.
2. Partial illumination of scanned surfaces.
If the subsequent radar scans covered mutually exclusive dig areas, it is difficult to compare one scan to the other. This issue can be resolved by linking the radar visualisation system with the dragline monitoring system, which would trigger the complete scanning of the area prior to dragline operation.
3. Comparison of two surfaces to estimate volume using 3d-Dig.
This process is very difficult and time consuming due to high resolution and the constant need to rebuild the surface within 3d-Dig software. There are also multiple lines from the wire frames, making it difficult to distinguish one surface from another.
4. Slope limitations in volume estimation using 3d-Dig.
The software would not allow volume estimation where the slope of the cut was greater than 70°. Whilst this is good practise for mine planning purposes, it is an unnecessary restriction for comparing surfaces for volume estimation.