Growers might joke about how much time they’d save if only they could push some buttons and send a vehicle to the orchard and let it perform critical but monotonous chores on autopilot, or at least have the vehicle self-steer while workers on a platform perform tasks such as thinning, tying and picking.

Dr. Marcel Bergerman, Carnegie Mellon University, explains the autonomous prime mover (APM) to growers at a field day. Bergerman is the project manager for the APM and hopes that growers will be able to use the technology to save time and labor.

Thanks to collaboration among fruit growers, extension personnel, researchers and an energetic and creative robotics team from Carnegie Mellon University, that dream is becoming reality. Although the project is still under way, progress is being made with the autonomous prime mover, or APM.

“We hope this machine will be useful to growers to increase production efficiency and decrease labor costs,” said Dr. Marcel Bergerman, systems scientist at the Field Robotics Center at Carnegie Mellon University in Pittsburgh, Pa. Bergerman is the project manager for the Comprehensive Automation for Specialty Crops (CASC) project, funded by the USDA Specialty Crop Research Initiative established by the 2008 Farm Bill. “The machine can be used for many tasks throughout the year,” he said. “There’s no driver, so that’s a cost savings. You can use the machine to go down the row for pruning, thinning, training and even for harvesting. You can attach a mower or a sprayer to the back of the machine and it works for you while you’re taking care of other more strategic aspects of fruit production.”

Right now, Bergerman and his team are in year three of the four-year project. “In year one, we worked on proof of concept,” he said. “We were only worried about having it go down the road and come back. During year two, we concentrated on robustness. We operated on different types of terrain, and it was hand-tuned by our engineers every time we went out. Now we are trying to see if it’s actually useable by growers.”

Bergerman says that during the testing phase, APMs were placed in Washington state and in Pennsylvania for extension educators and growers to use, test and break so that the team can uncover and solve problems. “It’s that cycle of experimentation that will eventually make it commercially available and useful to growers,” said Bergerman.

The APM can be programmed to move at various speeds so that workers on a platform can safely perform tasks.

Brad Hamner, senior research programmer at Carnegie Mellon, developed the programming for the APM. “There’s a laser range finder on the vehicle that sends a laser beam that hits the tree and comes back,” he explained. “By measuring how long that beam is, we can get a distance to the tree. The laser beam sweeps around so the vehicle can ‘see’ all the trees around it. From there it’s a pretty simple matter – we know we’re looking for two parallel lines of trees. The computer finds those two lines, and tells the vehicle to drive.”

The computer associated with the APM runs a Web page that can be accessed by any device that has a Web browser. Hamner mounted an iPad on top of the vehicle, and using the touch pad, the operator can control the APM to drive up to 2 mph. A simple slider control directs the vehicle to drive straight down the middle of the row or to move closer to one row.

Hamner noted that although the technology is fairly simple, the challenge has been in adapting the APM to operate in a variety of canopies, from newly planted trees to mature trees in various planting systems. The vehicle performs best in vertical axis or fruiting wall orchards. In tests at Penn State University’s Fruit Research and Extension Center (FREC) in Biglerville, Pa., the vehicle was operated as a scaffold on which workers could stand to perform tree maintenance tasks such as training, thinning and pruning. The team is hopeful that the APM can be adapted for use during harvest.

The lead institution for the project is Carnegie Mellon University, in collaboration with Oregon State University, Penn State University, Purdue University, Washington State University and the USDA/ARS.

“There are quite a few growers, researchers, extension personnel and commercial partners as well as student interns who have helped with the project,” said Dr. Tara Baugher, extension educator at FREC. Baugher added that the Biglerville unit has been dubbed “Allegheny,” while a sister machine in Washington state, known as “Cascade,” is being introduced to growers by extension educator Karen Lewis.

The author is a new contributor and freelance writer who farms and raises Great Pyrenees in south-central Pennsylvania. Comment or question? Visit and join in the discussions.