Picking robots in England
A lot of money is being invested in farm automation research in England.
An added impetus appears to be fear surrounding Brexit. As in so many places, immigrant labour performs many basic jobs in hospitality and of course, agriculture and horticulture. They fear a post-Brexit reduction in the availability of East European labour.
In the next few years, I believe automation technologies will provide most benefit through making workers more efficient, not replacing them entirely. Some jobs are easy for a robot and hard for a person – think building cars on assembly line. People have been largely replaced by machines that do the same very predictable job over and over very accurately.
Other jobs are easy for a person but very hard for a robot – think picking apples! This highly variable task is easy for a person but extremely tricky for a robot. “Seeing” is hard enough, getting a picking arm to the fruit, holding and disconnecting it from the tree is quite another. Even getting to the tree is a challenge for a robot. One of the world’s largest vegetable crops is broccoli, almost entirely manually harvested. Tom Duckett at the University of Lincoln in England leads a group developing a machine harvester. He says their system is as good as human pickers at detecting broccoli heads of the right size. With identification in hand, development is now on mechanical cutting and collecting. Then you need the robot that carries the picking robot around the field.
Machine detection of broccoli (and practically anything else) is best if the robot can pick at night when controlled lighting makes image analysis much easier. This may be a positive feature: robots readily work in the cool of the night with significant crop quality benefits though reduced field heat. It also separates machines from people, one of the health and safety issues of concern with driverless machines.
The human hand can easily pick up, move and place objects, but for a robot, gripping effectively is a challenge. Andre Rosendo at the University of Cambridge says sometimes it is not the best option to try to build something that is “like a human” – but instead design the best machine for the job.
An early prototype using soft robotics for lettuce harvesting aimed to mimic the action of a human hand grasping the lettuce head, tilting it, and then cutting the stalk. However a real challenge has been the inability of the “hand” to grasp the lettuce with enough strength to subsequently lift it.
US researchers bypassed traditional “hand” designs, and created a versatile gripper using everyday ground coffee and a latex party balloon. The coffee-filled balloon presses down and deforms around the object, then a vacuum sucks the air out of the balloon, solidifying its grip. When the vacuum is released, the balloon becomes soft again, and the gripper lets go.
Harper Adams University in Shropshire is developing a robotic strawberry harvester. They have not designed a simple picker replacement. Development has required integrating genetic development for varieties with long stalks, a growing system that has plants off the ground, and the robotic technologies to identify, locate and assess the ripeness of individual strawberries and then pick them touching only the peduncle (stalk).
Orchard tasks like grass mowing are relatively easy to automate. And various groups have done so. Fruit picking has to be one of the biggest challenges of all. Robotics does have a huge potential but we are not there yet. It’s about rethinking the whole system not just replacing the human picker. But we can use simple mechanical aides to assist workers. Pruning and picking platforms have been available for a long time. As well as getting the picker to the spot, they carry the load and avoid extra handling. And platforms can easily be made much smarter: existing technology could guide them along rows and we could fit sensors to pre-grade and separate fruit immediately.
Simon Pearson at the National Centre for Food Manufacturing says, “It’s a Frankenstein thing, this agrobotics. There are all sorts of great bits available but you have to seek them out and stitch them together yourself to make the creature you want.”