Small electric, autonomous tractors build big-time

A California startup is building three models of autonomous tractors fit with electric drive trains, with the smallest already in production and deliveries to American farmers expected this year.

“The Bearcub-24 model has a 24 kilowatt-hour battery, and it’s the equivalent to let’s say around 30 horsepower,” said Bakur Kvezereli, founder of Ztractor.

Each model is based on a two-track system that comes standard with a 540 rpm power takeoff and a three-point hitch, which makes them compatible with existing farm implements.

The Bearcub-24 weighs 2,100 pounds and can be used to power Category 0 and 1 implements including small mowers, sprayers, and tillage implements.

The Mars-45 model weighs 6,000 lb., has a 45 kilowatt-hour battery and is compatible with Category 2 implements.

Superpilot-125 is in an earlier developmental stage, but it weighs 16,000 lb., has a 125 kilowatt-hour battery, and is being designed to compete with tractors in the 150 horsepower range.

“We had one case when it ran only six hours, but it’s an extreme case because it was kind of an abuse test of the tractor and battery, with a large implement larger than it should have had. But eight hours (run time on one charge) I think it’s the right number to give to our customers and it can run longer in many tasks,” Kvezereli said.

He said it takes about three hours to charge the tractors.

A front-end loader or blade is not available on any of the models because they would interfere with the machine’s sensors and safety systems.

Kvezereli said the Ztractors use 67 sensors, including six cameras, GPS RTK, lidar, and the information collected can be used to monitor crop conditions. He said a machine-learning algorithm interprets the data and learns how to safely perform farming operations.

The user interface is tablet or laptop based, where operators design each of the tasks the robots will complete.

“Every time before the tractor starts working, there’s an operator who plans what has to be done in this field and the paths to accomplish this task. If we compare with cars, it’s not the best comparison, but if you could compare with cars it’s an autonomy level 2,” Kvezereli said

Autonomy level 2 achieves partial driving automation, or advanced driver assistance systems (ADAS).

Vehicles with this level of autonomy can control steering and speed, but fall short of self-driving because a human must be at the controls ready to take control.

Ztractors use their own software environment for vehicle automation, however Kvezereli said the company is considering including an application programming interface in the companies system so that it’s compatible with agronomic software.

The Bearcub-24 retails for about US$42,000 and is expected to be available to Canadian farmers in 2022. The other models will start rolling out in 2023 and 2024.