Popis: |
Improving the energy efficiency of mobile machines requires information about the initial state of the machine. This information includes knowledge of the systems and their components and of course, measurement data that is acquired during typical operation. Machine manufacturers and research institutes have carried out extensive measurement programs during the last decade. Usually, the published studies concentrated on one work cycle, the machines studied were operated by humans, and it is shown that productivity and fuel consumption are dependent on the machine design, work cycle and operator. This study concentrates on a detailed analysis of the energy consumption of a municipal loader during measured work tasks. The goal was to find out how much the driver and work cycle affect the machine’s energy consumption and energy distribution. To evaluate the real fuel consumption and energy distribution, the measurements consisted of two different work cycles that were driven by two drivers with different skill levels. The first cycle was the classic short wheel loader loading cycle, the Y-cycle. In this task, the loader was equipped with a bucket, and a pile of gravel was moved from pile A to pile B in a Y-pattern. The second cycle was the load and carry cycle in which the driver picked up a load with the forklift attachment and carried the load over a predefined distance. The major finding was that the impact of the driver and the work cycle is considerable in fuel consumption. The difference is also seen in the energy distribution in the hydraulic system and in losses and how the losses are divided. Therefore, it can be stated that test results with one driver or one cycle should not be generalized without concern and judgement of novel concepts requires several tests with different drivers and work cycles. |