Apr 24, 2018Canopy preparation helps robotic apple harvester
Visitors to the trade show floor at the annual meeting of the Washington State Tree Fruit Association in Kennewick saw multiple robotics companies. Robots are often pitched as the wave of the future; however, one of the companies at the meeting in November believes the future is now.
While the implications for the industry may be uncertain, the promise of robotic harvesting is such that growers are looking at what steps they would be needed to use robots on their operations.
Abundant Robotics of Hayward, California, hopes to have a working commercial system in Washington orchards sometime this year.
Company CEO Dan Steere said robotic harvesters can do certain things very well, including identifying fruit and judging whether it’s ripe. They can also harvest the crop quite reliably, given certain conditions. While sophisticated, he said the current generation of robotic pickers does have some limitations compared to a human arm, namely the ability to reach around obstacles to grasp an apple. That means they can’t pick some fruit or select other apples without damaging them.
Branches, wires or large bunches of apples can make it difficult for the robots to grab hold of their targets. In the case of some apple canopies that have small obstructions, picking the apple would be possible, but pulling the apple across the obstruction could damage it. With large bunches, picking one of the bunch could knock off or damage the remainder.
Depending on how robot-ready an orchard is, the percentage of apples picked by the robot can vary by as much as 20 percent.
“The main thing to keep in mind is a robotic harvester is going to start in the row and need to reach directly to grab a piece of fruit, and so it’s (important for growers to look) for ways to migrate pruning and thinning practices in the orchard to be able to simply have direct access fruit in the canopy,” Steere said.
Steere said the Abundant Robotics vacuum apple harvester has shown that it can detect the apples, pick them from the tree and do so without causing significant damage to either. The picking rate has been measured at a rate faster than one apple per second.
With positive test results, researchers are now engineering a machine that will operate effectively in various systems of high-density orchards. Their goal is to have the first machines available for commercial use in 2018.
Researchers at Abundant Robotics, a spinoff of SRI International, have been working on the development of an automated harvester for more than three years. In addition to research conducted in orchards in Washington state, prototypes of the technology have been used during harvest in the Southern Hemisphere.
Abundant Robotics worked with a cross-section of several Washington growers to determine what works best. That group included Scott Jacky with Valley Fruit Orchards near Royal City, Washington.
He described the farm’s formally trained Pacific Gala canopy, with 13-foot by two-foot spacing. In the robotic test area, they picked 82 bins to the acre. An untested block yielded 105 bins per acre. The test area came in at 67 percent robot accessible.
“I think we got a little overzealous with the thinning,” he said, explaining that this year thinning didn’t do much for size. “I think we could have left more fruit on there.”
Steere said there were both angled and vertical trellis systems where harvesting took place. There were mixed results with both systems.
Growers have been able to adapt their existing canopies to a point where they can be successfully harvested by robotic systems, Steere said.
“The biggest difference wasn’t the canopy style but the growers’ ways of how they group and thin and how successful were they in carrying that out,” Steere said.
Above: Abundant Robotics vacuum apple harvester has shown that it can detect the apples, pick them from the tree and do so without causing significant damage to either. Photo: Abundant Robotics