Past experience has shown that the automation of the dragline swing
motion requires real time monitoring of the bucket position. A current
project at the Centre for Mining Technology and Equipment (CMTE) is
aiming to achieve this using machine vision. The hardware platform is a
Datacube MaxVideo 200 system. The images are obtained by a fixed
camera installed on the dragline boom. The field of view is large enough
to include the bucket in all possible configurations. Standard chain
coding and run-length coding algorithms are used to process the video
image. The three-dimensional bucket position is calculated by combining
the output of the machine vision system with the rope length data
obtained from transducers installed on drag and hoist drums. This
information is then fed into a control computer which takes corrective
action to suppress bucket oscillations before they reach dangerous levels.