Robot—whether the term conjures up an image of a friendly alphanumerically designated droid with a knack for languages or a merciless killer in an apocalyptic vision of the future, it is hard not to be fascinated by these human-designed machines.

Robots have now established a firm foothold in factories around the world, where they perform highly repetitive or dangerous operations at high speeds more accurately and efficiently than any human could. Robots are now also increasingly found in homes, where they are well suited to such menial tasks as vacuuming and mowing lawns.

Whether you see them in fun and educational showcases such as First Lego League Robotics competitions or in the deadly serious game of explosives disposal, there is no doubt that robots are becoming more and more integrated into human society all the time.

So, what really is a robot? Contrary to the popular image of robots conjured in the minds of science fiction writers and filmmakers, there are actually few practical robots today in humanoid form.

Yes, there are some impressive humanoid robots that can do amazing things—like dance, play the piano or even carry on a passable conversation—but the vast majority of contemporary robots are far less glamorous. After all, there is no need for a welding machine to look like a supermodel!

Definitions of robots vary, but Miriam-Webster provides one that can be usefully applied for the purpose of this discussion: (1) a machine that looks like a human being and performs various complex acts (as walking or talking) of a human being; (2) a device that automatically performs complicated, often repetitive tasks; (3) a mechanism guided by automatic controls.

Agricultural robots, or agribots, have been at work in labs and in field tests for many years now. They have been toiling away—mostly unheralded and unknown to the general public—doing what robots do best; in other words, jobs that are dangerous or boring.

Bots in the Fields

Compared to the manufacturing industries commercial agriculture has been relatively slow to adopt robotics, but not because of a lack of motivation to do so. It's just a lot harder to build safe, reliable robots for agricultural work than it is for manufacturing. There is also still a relatively ready supply of cheap farm labor available in many markets. However, changes are on the horizon and there are many good reasons to consider putting robots into the fields.

With GPS positioning systems, machine vision and other sensors and off-the-shelf control parts, full-sized harvesting, plowing and planting machines are now being successfully tested. To keep costs down, current approaches are mostly centered on adapting existing vehicles to autonomous operation rather than designing custom robotic solutions from the ground up. A production autonomous harvester will cost a bit more up front than a human-driven one, but a large fleet of them could be maintained by a small team of engineers and technicians—or a single driver could watch over and adjust the operation of several semi-autonomous machines while perched on a tower as the machines follow pre-programmed instructions.

When it comes to robots Japan has long been at the development forefront and work on automated tractors began in Japan more than 20 years ago. For the Japanese, agribots aren't just about being on the cutting edge of technology—the median age of Japanese farm workers is increasing and there are not enough young people becoming farmers or interested in being farm workers.

Japan is counting on robots to keep future harvests coming in; among the machines in advanced stages of testing are robots designed for planting and harvesting rice, weeding rice paddies, harvesting tomatoes and strawberries and even performing grafting operations on crop plants.

Researchers at Tokyo University of Agriculture and Technology have tested a human-assistance machine designed to be worn by elderly farmers. Although not an autonomous vehicle, the device provides intelligent support and motion assistance for the user’s legs and arms and the researchers hope to make it available for less than $10,000 within a few years.

Researchers at Carnegie Melon University’s Robotics Institute are working on a project called Comprehensive Automation for Specialty Crops (CASC). The aim of CASC is to improve efficiency and lower costs, especially in the apple and nursery tree industries. The CASC team has developed robotic vehicles for use in orchards, along with systems designed to detect plant stress and disease and take measurements of fruit before harvest. Demonstrations of many CASC projects can be seen on the CASC YouTube channel.

Agribots need not be hulking machines that are simply automatic versions of traditional farming equipment; miniature robots have opened up a whole new spectrum of possibilities for the future farmer.

Small bots are perfectly suited for crawling or rolling along between, under and around plants, where they can monitor soil conditions, photograph and transmit images of plants for monitoring and analysis, do some spot tillage here and there, detect insect infestations and diseases before they become widespread and even dispense precise and controlled amounts of pesticides and fertilizers as needed.

Swarms of such robots will someday act as intelligent agents to provide a level of care, monitoring and data collection that is far beyond what is now economically feasible for any farmer. The cost of such small agribots should be fairly low—once commercial production is in full swing, such machines could be available for around $500 each, or eventually even much less.

Prospero, a five-legged automated seed distributor, is an example of an early prototype of an autonomous micro planter (AMP) designed to be part of a small swarm of bots specially designed for agricultural work. Inventor David Dorhout hopes that people will see Prospero and start to rethink what is possible for the future of farming.

Robots in Nurseries and Greenhouses

If robots can be made to successfully perform in the unpredictable conditions of an outdoor farm field then it should be even easier to get them working in the more controlled environments found in nurseries, greenhouses and indoor gardens—the floors and grounds of these facilities are far easier for robots to negotiate than the more unpredictable and less uniform surfaces found in fields and orchards.

Researchers are making rapid progress in the development of small- to medium-sized robots designed for many of the specialized tasks that need to be performed indoors. Some approaches that have been explored for greenhouse automation so far include installing worker bots that move about on rails or tracks, free-moving machines that operate directly on the floor and bench-mounted systems.

Rail systems have the advantage of keeping the machines on well-defined paths, which makes safety management easier and also simplifies programming and operation. However, being limited to traveling on rails these are not fully autonomous machines and not everyone would consider them to be true robots. Rail-mounted systems for crop spraying are currently in use throughout the world.

Bench-mounted systems are commonly used in commercial operations to perform transplanting and plugging operations. These machines can transplant up to 24,000 seedlings per hour, although the actual speed of the machines depends on many factors and some plants are too delicate to be handled by currently available automated systems. Rolling, walking or crawling machines are in development all over the world and although some bots designed for harvesting tomatoes or cucumbers still have a rather boxy, machine-tool appearance, some recent prototypes are actually quite futuristic!.

One of the most labor-intensive jobs in an ornamental plant nursery—indoors or out—is the movement, collection and placement of plant containers. According to one estimate, up to 40 per cent of this labor can be safely performed by small autonomous vehicles.

A Massachusetts-based start-up company has developed small wheeled robots designed to work in teams alongside humans in plant nursery environments. These machines are entering a final testing phase with the cooperation of a number of greenhouse and nursery operations around the United States, with plans for commercial availability this year.

Swarms of small bots are destined to bustle about in indoor growing facilities as well. These bots will operate in a fairly predictable and stable environment and should be even less expensive than their outdoor cousins, since they won’t have to be as ruggedly built. Small autonomous bots designed for more complex indoor monitoring and plant maintenance operations are still in the development phase, though, and we are probably at least several years away from seeing commercially available machines.

Agribots are beginning to make their presence known in farm fields and greenhouses—just don’t expect them to look like fruit-picking versions of imperial walkers! But the next time you see a tractor with a few unusual gizmos attached to it at work in a field, look closely; there might not be anyone behind the wheel…

Acknowledgement

Thanks to Steve Rainwater of robots.net for information on recent developments in the world of agricultural robotics.

References

Dorhout, D., 2011, Prospero: Robot Farmer, dorhoutrd.com/home/prospero_robot_farmer (accessed December 9, 2011)

Harvest Automation, Agricultural Market Analysis, harvestai.com/agricultural-robots-manual-labor.php (accessed December 5, 2011)

Kusuda, Y. (2010) “The Use of Robots in the Japanese Food Industry”, Industrial Robot, Volume 37, Number 6, pages 503–508

‘Robot’, The Free Miriam-Webster Dictionary, merriam-webster.com/dictionary/robot, (accessed December 3, 2011)

Robot Video: “Dutch Robomatic Using Rhizopon Plant Rooting Hormones”, hortus.com/Video_Robot.htm (accessed December 5, 2011)

Smalley, E., 2011, “These May be the Droids Farmers are Looking For”, Wired, November 11, 2011, wired.com/epicenter/2011/11/mobile-farm-robots/ (accessed December 9, 2011)