LEAN SPEED OPTIMIZATION APPLIED TO A CYCLIC HAUL OPERATION

Cyclic haul operations are iterative transport operations, often performed by several haulers in a production work step. Cyclic haul operations are common in mining and quarry operations where the purpose of the haul work step is to move mass a relatively short distance e.g., from blasted rock supplies to the mass crushing and separation facility. The operation can include one or several haulers that perform the work simultaneously. When several haulers are used, they are generally not synchronized in an optimized way and operative variations and changes continuously affects the operation. An example of such variations can be that the driving speed and time required for certain maneuvers varies depending on driver skills and machine capacity. An operative change can be that the loading position is moved, leading to changed routes and varying distances. The operative characteristics of the haul work step indicates that there rarely exists a static state that the operators can learn to do efficiently. Our previous research has shown that haul operations can have a fuel reduction potential of up to 40%, depending on the operation characteristics and wastes such as unnecessary stops and waiting. This paper presents and assesses a system solution in a decentralized control system that calculates and advices operators with a speed for just in time arrival to a destination. The purpose of the system is to reduce fuel consumption with an obtained production rate. The system assessment shows that while production rate is obtained, fuel is reduced by up to 20% compared to base line operation in a simple quarry haul work step, including three haulers.