Comparison of cycle times for manual and semi-autonomous load haul dump (LHD) machines: an operational perspective at LKAB’s Kiirunavaara Mine

Automation of LHDs and their increasing use in mines make it critical to understand their performance in actual mining environments. Cycle times of semi-autonomous and manual LHDs were compared to determine their productivity differences. Manual LHDs had shorter cycle times in 57% of the areas, while the semi-autonomous were faster in 43% of the areas. Cycle time distributions were evaluated, and a log-logistic distribution was proposed to simulate the total cycle time, a lognormal distribution to simulate the loading duration, a logistic distribution to simulate the dumping duration, and a small extreme-value distribution to simulate the speed of semi-autonomous LHDs.