Lettuce is California's biggest vegetable crop, bringing in $US1.6 billion annually. The problem is they require a lot of attention to raise properly. Historically, California has relied of its abundant, affordable work force. But with that labour pool shrinking and foreign competition increasing, lettuce farmers are facing rising labour costs and worker shortages. And that's where the fully automated Lettuce Bot comes in.
The problem is put simply by Stavros G. Vougioukas, professor of biological and agricultural engineering at the University of California, Davis. "We need to increase our efficiency," he told The Economist. "But nobody wants to work in the fields." And since all those acres of lettuce won't thin, weed and harvest themselves, a pair of Stanford engineers, Jorge Heraud and Lee Redden, developed a robot to do the work that humans wouldn't.
The Lettuce Bot is a tractor-towed device that images a row of plants as it rolls past and compares the visual data against a million-point database of other pictures of lettuce (which must have been super exciting to compile) using a custom-designed computer-vision algorithm. It's reportedly 98 per cent accurate, and if it spots a weed or a lettuce plant in need of thinning (lettuce will remain dwarfed if planted too close together), the Lettuce Bot gives it a shot of concentrated fertiliser, killing the offending plant while improving the growth prospects of the rest. Incredibly, even though it dawdles through the fields at just 2km/h, the Lettuce Bot can still thin a field as accurately and as quickly as 20 field hands.
And the Lettuce Bot is only the start. Farmers across the country are finding it harder and more expensive to find enough human workers and are starting to look to robots to augment the labour force. In response, both private and public ventures have started pouring money into agrimech (agricultural mechanisation) technology. As such, research is advancing quickly. Robots are being outfitted with suites of EO sensors, nimble manipulator arms, GPS-guidance and more processing power than the robots in Runaway.
Other harvesting-edge agrimechs include an automated tulip-bulb planter, the seedling transplanter at the Vineland Research and Innovation Centre in Ontario, Canada, as well as an integrated mushroom harvester/trimmer/packager and a potted plant packer; the Harvest Vehicle HV-100 by Harvest Automation that shuttles potted plants around nurseries; and John Deere 7760, king of the mechanised cotton pickers.
Picking fresh fruit designated for consumption rather than processing remains the ultimate goal of the industry given how easily the product bruises. There's also the challenge of teaching the robot to accurately judge a fruit's quality and ripeness as matching the dexterity of their human counterparts.
"The hand-eye coordination workers have is really amazing, and they can pick incredibly fast. To replicate that in a machine, at the speed humans do and in an economical manner, we're still pretty far away," said Daniel L. Schmoldt at the US Agriculture Department's National Institute of Food and Agriculture in a press statement.
One company, Agrobot, is working to overcome those challenges with its 24-armed strawberry picking machine. The device reportedly evaluates each berry for size, colour and quality before plucking and depositing it on a conveyor belt to be packed by a human worker.
Unfortunately, many experts estimate that it will be another decade before a majority of our fresh fruit and vegetables will be picked by the likes of Lettuce Bot toiling in the fields. When we actually get there though, it will be nothing shot of amazing. Just nobody tell Gene Simmons. [Physorg, Economist, Australian News, Blue River]
Pictures: Runaway, Jose Sanchez/AP