Follow the Leader
MU Student Creates System for Robotic Grain Carts
COLUMBIA, Mo. - While they may look like shiny toys found under the Christmas tree, Brian Kliethermes' two radio-controlled trucks are a little different.
Kliethermes, a senior in the University of Missouri agricultural systems management program from Tipton, Mo., outfitted two plastic toy trucks with a computer and Global Positioning System receivers that allow the trailing truck to "talk" to the lead truck and follow the same course, demonstrating how a low-cost GPS can be used to platoon unmanned vehicles for farming operations.
Farmers have used GPS on tractors or combines for parallel tracking, allowing straight passes across field without assistance from the operator. Such technology has made farming operations more productive by minimizing overlaps, reducing operator fatigue and cutting fuel costs.
"But, there is nothing on the market that allows the platooning, or traveling in unison, of two vehicles such as a combine and grain cart," Kliethermes said. "To travel in platoon, vehicles must communicate with each other and travel at a set or variable distance between them."
"Brian identified a challenge on his family farm that has been of interest to other farmers and machinery industry for a long time," said Brian Adams, assistant professor of agricultural systems management.
Kliethermes equipped the lead vehicle with a Bluetooth GPS receiver. The follower vehicle has a serial port GPS receiver and small computer. A GPS signal from the lead vehicle is transferred wirelessly to the follower vehicle, giving its location and speed to the follower. The computer on the follower vehicle compares the speed and location from the lead vehicle to its own and decides its own speed and course.
Kliethermes' key to keeping the pair of trucks in unison was his writing codes, or algorithms, that allowed the follower vehicle's computer to analyze a GPS signal from the lead vehicle, creating a system of coordinates that kept the follower the proper distance away.
The lead vehicle would typically be controlled by an operator. The follower, platoon, vehicle would trail by a set distance laterally and longitudinally.
"The follower vehicle will always be communicating with the lead vehicle to stay within the given distance," Kliethermes said.
Using such a system, combines would be able to travel a set distance apart and continue harvesting while unloading grain into a following grain cart. The system also could be used for silage harvesting where the harvester is the lead vehicle for a platoon silage wagon, he said. Today, such wagons and carts must be pulled by a tractor, requiring a second operator. That driver has the tedious task of maintaining the proper distance so grain or silage flows into the wagon.
