Stereo vision in LHD automation

This paper details work in applying stereo vision for the enhancement of safety and productivity in the operation of a load-haul-dump (LHD) vehicle in underground mining. The primary goal of this portion of the research is to provide three-dimensional (3-D) models of the LHD´s environment. Availability of these models facilitates performance of automated or teleoperated loading tasks and enhances safety through identification and location of humans in the path of the vehicle. Generation of an accurate 3-D model of the immediate surroundings of the LHD is accomplished through processing of stereo visual imagery. Stereo video is acquired using a pair of digital cameras mounted above the cab of the LHD. The video data are processed into a dense depth map plus confidence information. These depths and the stereo rig calibration data are then used to construct a 3-D surface model. We demonstrate useful models obtained under both well-illuminated and low-light conditions.