Assisted Tele-Remote Control of Wheel Loaders in Underground Mining

Abstract: Tele-remote operation of mobile earth-moving machines in underground mines supported byoperator assistance functions is attractive for safety and productivity reasons. This way, operatorscan avoid hazardous underground environments with poor air quality and the productivitycan, in principle, be improved by saving the time required to commute drivers to and fromthe operational areas. The infrastructure needed to do tele-remote control in the form of highcapacitywireless IP networks is nowadays being deployed in underground mines. In mineswith sufficiently high ceilings, wheel loaders are used in short loading cycles to load blastedrock onto dump trucks. Bucket filling on remote control is less efficient than manual operationdue to the loss of sensory perception resulting from not being in the actual environment.Automatic bucket filling algorithms have been developed earlier but, due to the complexity ofbucket-environment interactions, such algorithms have not produced satisfactory results and arenot commercially available. If tele-remote operation is enabled, it can also be used to rescuefuture autonomous machines, when they malfunction. This thesis presents the key challengesin automation and tele-remote operation of earth-moving machines, surveys the literature andavailable technologies to address these challenges. The key contributions of this thesis are highlightingimportant knowledge gaps based on a survey in the field of automation of earth-movingmachines and proposing a machine learning based framework for automatic bucket filling forfront-end loaders. The proposed machine learning based approach to automatic bucket fillinguses linear regression and classification models of lift and tilt actions, which are fitted to thebehavior of an expert driver filling the bucket with gravel pile. The models of operator behaviorfrom the recorded data reveals relationships between sensor data and operator actionsand shows that a learning based approach is feasible. A case study has been done on the useof wheel-loaders in underground mining presenting the use case of assisted tele-remote controlbased on audio-video and sensor feedback. A good communication setup, that considers requirementsof real-time video transmission, is important for tele-remote control. Furthermore,a simulation study evaluates two transport layer protocols with respect to video quality for teleremotecontrol over wireless IEEE 802.11 networks. It has been identified that adding operatorassistance functions to tele-remote control is a good approach towards autonomous operation ofearth moving equipment.i