Degree Type


Date of Award


Degree Name

Master of Science


Mechanical Engineering


Mechanical Engineering

First Advisor

Sourabh Bhattacharya


We address the harvesting-on-demand problem in which a group of grain carts unload multiple combine harvesters in an agricultural harvesting operation. In a general harvesting operation, combine harvesters are used to collect the grains from the field. Once the on board tank of any combine is filled, a grain cart is needed to unload the load from the combine so it could keep working. Currently, combines are served individually by a grain cart. In this work, we investigate the case when there are fewer grain

carts than combine harvesters.

Initially we introduce the formulation of the problem and required parameters of the combine harvesters, the grain carts and the field. We start the analysis of the problem with a simple case when there are multiple combines and a single grain cart. A scheduling strategy for the grain cart to serve all the combines without interrupting their work is proposed. Based on the analysis of the single grain cart

operation, we discuss the position of the depot to minimize the traveling distance of the grain cart to unload itself in a harvesting operation. Both cases when the field is and is not rectangular are considered. The path planning of the grain carts moving between combines is based on the numerical technique proposed by Mengzhe. In this work, we present a primitive based path planning method for the grain cart to obtain a sub-optimal path for the grain cart moving between any two combine harvesters. Then we generalize the scheduling strategy to a group of grain carts serving multiple combines when the number of grain carts is fewer than that of the combines. Two techniques are proposed, which are round-robin scheme and load balance scheme. In each of the techniques, two different approaches are presented.

The performance of round-robin and load balance strategy is compared so that the farmers can select the correct strategy to apply in their harvesting operation easily. Finally, we extend the strategies in scenarios when the grain carts are big enough so that no depot is required. An application of the proposed scheduling schemes with BOE-bots in Vicon environment is shown.


Copyright Owner

Yan Tian



File Format


File Size

57 pages

video.mp4 (9470 kB)