As harvesting is one of the most costly and labor-intensive operations in strawberry production, an UC Merced engineering researcher is looking for ways to make it easier and cheaper. As part of a four-year project, professor Reza Ehsani will explore the possibilities and benefits of people and robots picking the fruit together.
The National Science Foundation’s National Robotics Initiative just awarded Ehsani and two colleagues, at the University of Central Florida and Washington State University, a $1.1 million grant for a study titled “Distributed Co-robots for Strawberry Harvesting.” The project begins this month.
Strawberries are planted on less than 1 percent of California’s farmland, but they are the fourth most valuable crop in the state at $3.1 billion in cash farm receipts, according to the California Strawberry Commission. California and Florida are the leading producers of strawberries in the US
But in recent years, mature strawberries are frequently left unharvested and strawberry production is decreasing due to labor shortages, ever-increasing labor costs, and growing imports from Mexico.
More purpose-built robots
In the same vain, there is Traptic, one of the start-ups that is tackling the issue head on with a purpose-built robot. Comprising an off-the-shelf robotic arm and custom gripper and software, the company’s device is for the function of helping to improve strawberry yields.
The arm is housed inside a space on a cart surround on five of six sides. The vision system utilizes 3D cameras and neural networks to spot strawberries and distinguish ripe from unripe. It’s capable of determining their position within a millimeter and then goes about plucking.
The custom gripper, however, is probably the most unique element on board. Sure, there are plenty of off-the-shelf grippers available to roboticists, but for the aforementioned reasons, Traptic needed one that was rigid enough to pluck the berries, but gentle enough to not smash a ripe one in the process.
What the company ultimately settled on was a gripper that was neither fully rigid, nor soft. The metal base of the claws is augmented by rubberized bands that have enough give to conform to the fruits’ irregular shapes, while holding them snuggly enough to remove them from the plant.