New tractor pushes people out of the driver’s seat


PRINCETON, Ky. – One of the employees calls off work. Another employee is so tired he can’t keep his eyes open long enough to plant a straight row. The farmer is short-handed and there are too many acres and not enough manpower.

The solution might be an autonomous tractor – a tractor that operates by computer chip – with no driver needed.

Agricultural engineers at the University of Kentucky’s College of Agriculture are working out the kinks to get this newfangled driverless tractor up and in the field.

Upper hand. The advantage of these tractors is no longer having to deal with employees who are sick, tired or need time off. These little contraptions can work in the fields 24 hours a day, with no need for rest.

Although equipment manufacturers have experimented with this type of tractor, ag engineer Tim Stombaugh’s concept varies.

Rather than having a full-size autonomous tractor, Stombaugh and his colleagues are working on developing smaller driverless tractors. Although farmers will need several of them to do the work of one large tractor, they will be more cost efficient and if one needs repairs, the others can continue in the fields.

According to Stombaugh, a four-wheel drive tractor pulling a 24-row corn planter can be replaced by three of these small driverless tractors pulling 2-row planters, since the autonomous tractors are able to work 24 hours.

Cash flow. In addition, the driverless tractors may save money.

For example, a 235 horsepower tractor equipped with a 16-row planter costs $193,000. Three 30 horsepower tractors equipped with 2-row planters costs $50,000. This is a difference of $143,000, which can be invested in control systems for the smaller autonomous tractors.

Another possible benefit is that the tractors would save on manpower. Although the workforce could be reduced, Stombaugh said it is also possible that there will need to be a different type of workforce to “operate” the machines.

These operators may need to have enhanced knowledge of electronics and computer topics, which may mean the farmer has to pay more in wages or pay for employees’ advance training, Stombaugh said.

New era. Stombaugh stresses that farmers will still be essential to the operation.

“It won’t eliminate the farmer; it’ll just change his role,” he said.

Although the farmer will no longer be driving the tractor all day in the field, he or she will still have to watch for when the machines need gas, seed or repairs.

Guidance. A combination of a global positioning system, sensors and computers replaces the driver on these tractors.

Since Stombaugh began working on this idea a year and a half ago, the researchers have developed a prototype. It is similar in appearance to a “normal” tractor, however, there isn’t a seat or human controls.

The global positioning system on the tractors has an accuracy rate of 1 inch. This means seeds, fertilizer and other inputs are applied at a precise rate.

“It has little controllers that control each function on the machine and they talk to each other through a computer network,” Stombaugh said. “These little components are fairly inexpensive. That is our final goal – to have a system without a lot of expense.”

He said his focus is to find a low-cost alternative to today’s tractors so that everyone from small-scale to large-scale farmers can afford a driverless model.

Stumbling block. The biggest hurdle that Stombaugh and Scott Shearer, another ag engineer working on the project, face are the liability issues. Stombaugh said this is the major issue that needs to be worked out before full-scale production.

In addition, there are safety issues to address.

What about children or animals that dart in front of the tractor? There isn’t an actual person in the driver’s seat to apply the brakes.

Stombaugh said that is an issue they haven’t addressed yet but knows they will have to in the near future.

One thing in his favor is that there are different safety issues when dealing with a smaller, 2,000-pound tractor vs. a large 18,000-pound machine.

The unknown. With no human controls, steering wheel, seat or cab, the tractor may look odd plowing the soil, but strange-looking tractors may become more common.

Since drivers won’t be needed on these vehicles, researchers are rethinking the whole concept of how tractors are designed.

Today’s tractors have large back wheels and smaller front wheels so the operator can see, Stombaugh said. But there won’t be an operator on these tractors, so this means the design of tractors can be changed to operate more efficiently autonomously.

Ways to attach implements to these tractors are also being rethought, however, standard equipment can be used.

A standard planter with fewer row units is being used with the driverless prototype.

Fruition. Stombaugh is hoping the tractor will hit the commercial market within the next four or five years.

As of now, he has no idea what the cost of this novel tractor will be when it goes on sale. With the current technology, today the tractor would cost $100,000 beyond the price of the tractor itself, Stombaugh said.

“It’s cost prohibitive at this point,” he said. “We’re working to reduce this and make it competitive with just buying a new tractor.”

(You can contact Kristy Alger at 1-800-837-3419, ext. 23, or by e-mail at


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