Phil Jennings of Kinze Manufacturing gets a big kick out of riding in their modified tractor when it’s hauling one of their grain carts during a real Iowa harvest. When the call goes out for the cart, the tractor starts chugging across the field to where the combine is working. Jennings just sits there and doesn’t even set a hand on the steering wheel. The tractor is autonomous. Guided by a computer, it sets off after the combine and runs the cart under the auger while the big harvester empties its hopper.
“I’ll tell you,” Jennings laughs, “it’s fun to sit in the cab when you know you don’t have to touch anything, and to see if it reacts the same way you would if you were the operator, or some of the ways it reacts differently. It’s been neat to see the system’s ability to do that.”
Jennings is the service manager for Kinze at its factory in Williamsburg, Iowa. There, the company has been working with Jaybridge Robotics of Cambridge, Mass. to integrate more capability into farm machinery. Its first major project is the autonomous tractor and grain cart.
Ever since the development of auto steer, there’s been a concerted effort to get farm machines to do more and more. Now, a number of factors have come together to help make this possible. Computers are smaller, cheaper and more powerful than ever. Navigating technology and geographic information systems such as GPS are more accessible and, while farms and machines get larger, the labour pool available to run them gets smaller. As well, farm operations such as seeding and harvest are highly time sensitive, so expenditures to improve logistics could pay off handsomely.
“If the guy who we need to run that extra piece of equipment or run that grain cart is not readily available, that labour is at a premium,” Jennings says. “Without that grain cart, I lose the efficiency of my combine and that’s really where your return on investment is going to be, not specifically in a paycheque for a person but in the efficiency of the harvest by keeping the combine moving.”
That’s why Kinze made its first demonstration video with a driverless tractor suddenly sputtering to life all on its own and scampering out over the field to meet a moving combine. The tractor manoeuvres alongside, places the cart directly under the auger, and a torrent of corn starts pouring out. Just after the four-minute mark, the real show begins as the combine goes into a series of tight turns in several different directions. In a strange ballet, the tractor matches the combine step for step and keeps the cart perfectly positioned right under the spout of the auger. Not one kernel of corn hits the ground, no matter how wildly the combine steers.
“We give that tractor its own vision from sensors all around it — and inside the combine there is a tablet,” Jennings says. “Essentially the combine operator still orchestrates that part of the operation, and all of its cues as to what it should be doing still come from the combine.”
The combine is the heart of the system and the driver possesses the brain, so it’s still a human being making the decisions and directing the operation. The tablet in the cab has a map of the field with all the different obstacles placed in position and this is transmitted to the tractor. It knows, according to the map, where the crop has been cut and where it’s still standing. It’s aware of tile outlets or any other structures in the field. The operator has the advantage of the high seat and, if unmapped obstacles appear, they can feed new information into the tablet while driving the combine.
“The push of the touch screen can enter any other obstacles,” Jennings says. “If you want to make sure that it goes around a creek or a ravine or something, you can just draw around it with your fingers like finger paint on the screen. You can say go here but don’t go there.”
The other thing an operator can do is tell the tractor to idle and stand where it is while the combine makes another pass around the crop. At the push of the screen button, the tractor will start up again and catch the combine.
“When the combine operator says, ‘Hey, I’m on a nice, fairly straight stretch and I’ve got two-thirds of a tank and I want to get it emptied,’ they can press a single push button that says, ‘Unload,’ and it will come up, pull around the side and sync with the speed and distance as well as front to back. The combine can dump the grain on the go.”
To fine tune the system even more, the tractor has a series of on-board sensors that also feed information into its own computer. There are cameras mounted on strategic points in front, behind and off to the sides. If it stops, it feeds real-time video into the combine’s tablet so the operator can see why the tractor isn’t moving. If there’s an obstacle not entered into the tablet, the tractor will spot it with its own set of eyes.
The tractor is fitted with a radar system that sends pulses of radio waves out and measures what bounces back. Radar can see metallic things like other machines or equipment, as well as anything containing water. Since living things, such as wildlife, livestock or people are largely water, the radar can see them and the computer tells the tractor to act accordingly.
Radar can’t see wood or plastic so fence posts or PVC pipe might go unnoticed if it weren’t for another set of eyes called lidar. Lidar is a laser beam that will register objects that radar can’t, so the tractor can see just about anything that might be in that field. It also has an inertial measurement and GPS unit that uses satellite information, accelerometers and gyroscopes to tell the tractor what direction it’s going in and how fast.
All this information is fed into that on-board computer which is “ruggedized” in order to withstand the jarring a tractor takes as it moves up and down a farm field. The computer calculates the tractor’s speed and direction as well as noting its surroundings. Since computers work as fast as they do, it can turn with the combine almost perfectly. Once it’s full it can be dispatched back to its starting point where a truck driver climbs into the tractor cab and unloads it into a truck.
“The other thing is that the system is always running in a safe mode and what that means is that if there’s ever any question whether it’s a distance from an object or if one of the sending units reads something that it doesn’t like or isn’t expected or normal, it shuts down,” Jennings says. “There’s also a number of different manual safety devices on the exterior so that if you’re in and out of the vehicle to load the truck or you’re on the road or something, whenever you roll the steps down to climb into it, it’s in manual mode and it can’t be taken out.”
There are visions of the future where farm machines programmed for complex tasks could work on their own without a human operator in the cab. There’s no denying that other operations such as swathing or seeding are a lot more complicated and will require a great deal more study. The grain cart was one of the simpler operations and a good place to start.
“The autonomous grain cart that we’re doing today has a relatively low input from an operator’s standpoint,” Jennings says. “As we look at machine functionality we’ll just grow on that and be able to add additional functionality for other machine types.”
You can have a look at the autonomous tractor and grain cart in action with this YouTube video.