A team of Fresno State engineering students is developing a first-of-its-kind robotic tool that could dramatically change the way citrus fruit is harvested.
In field tests, the machine’s robotic hand has successfully completed several critical benchmarks, including being able to precisely cut the fruit’s stem so as not to leave any sharp edges.
“That part was huge,” said Alaeddin Milhim, assistant professor in the Department of Mechanical Engineering at Fresno State. “The stem has to be as short as possible so as not to damage the other fruit in the bin, but it also has to be intact so the fruit remains protected.”
Milhim has been working on the project since February 2024 and has assembled an eager team of engineering students who have embraced the challenge of creating a potential game-changing method of harvest fruit.
One of the student leaders on the project is Juan Espinoza Jr., a mechanical engineering graduate student who knows first-hand how revolutionary a mechanical harvesting machine could be.
Espinoza spent several summers working in the almond orchards, grape fields and rose nurseries in the Kern County area. Although he has never harvested oranges he knows the work can be back-breaking.
Citrus harvesters carry sacks across their bodies and use them to collect the fruit they pick. When full, the sacks can weight up to 90 pounds.
The workers use 15-foot ladders to reach fruit that is beyond their reach as they maneuver their ladders through the sometimes uneven ground in the groves.
“It is a demanding task that can also be dangerous,” Espinoza said. “And it takes a lot of skill.”
Espinoza admits he had qualms about the project when he first joined the team. He worried about taking jobs away from workers.
But he also realized these labor-intensive jobs are punishing on a workers body.
“My hope is that because most automation efforts don’t happen overnight, it will give people the time to retrain themselves to do other types of work,” he said. “These are the most physically demanding jobs that sometimes come with the least compensation.”
The other factor at play in the development of any robotic harvesting tool is the realization that the supply of farm labor is shrinking, whether through increased federal enforcement of undocumented workers or natural attrition.
“I think something needs to be done to look at the longterm solution for labor issues,” Espinoza said. “And I hope that projects like ours is where things are headed.”
Milhim sees definite signs that he and his students are potentially on to something big, despite being at least two years away from commercial production.
Still, the project, that as yet does not have an official name, has received interest and funding.
The F3 Coalition, a $65 million federal grant initiative aimed at transforming Central Valley agriculture through climate-smart technology, has provided more than $100,000 in funding to the project, Milhim said.
Citrus growers have also taken notice. During a recent field trial at Fresno State’s farm, a representative from the Wonderful Company, a giant in the agriculture industry, visited the campus to get a live look at the device.
The Wonderful Company is the largest grower, shipper, and packer of fresh citrus in California and the United States.
“We are very interested in this technology and what it may be capable of doing,” said Ramesh Muppuru, senior manager business relationships, at the Wonderful Company. “This could be a game changer.”
As Muppuru and others watched, several Fresno State students hovered around a robotic platform that served as the base of the robotic citrus picker.
The device uses a camera to capture an image of the tree that it uses to determine where the fruit is, and the degree of ripeness. More than 2,000 images of ripe citrus fruit were uploaded to the robot’s database to help it figure out what to select.
Once it finds a good piece of fruit, it sends commands to the arm to make precise cuts and then deposits it into a bin.
Each of the students present that day, Andrei Catalan, Nicole Oliva, Alexander Ellis, Daniel Yang and Brendan Chinnock, is responsible for a specific task of the robotic arm.
Chinnock said that while agriculture wasn’t “super big” on his radar for a career, this project may have changed his mind.
“There are a lot more challenges to something like this and a lot more opportunities to figure out new solutions,” he said. “Plus we are getting into some real unchartered territory.”
Within the next two years, Milhim and his team will work on adding more robotic arms to the device, increase its picking speed and making it autonomous.
“It could have maybe five, six, or maybe even eight arms, all working at once harvesting fruit,” he said.
As for a possible name, one of the students joked that it may end up resembling “Doctor Octopus” a supervillain in the Spider Man comic books that had several robotic tenticles.
“We can call it Doc Ochs,” said Yang.
The Fresno Bee
A Valley native, Robert has worked at The Fresno Bee since 1994, covering various topics including education, business, courts and agriculture.