Robots take toil from the vineyard

Le Plan Medoc, France--Repetitive and tiring hand-labor tasks are typical of agriculture. But such jobs are ideal for robot applications, with the additional benefits of increasing agricultural, horticultural, and forestry yields.

Coverplant Engineering is working on robotic operations for some of the world's most famous, and demanding, agricultural interests. One is Chateau Mouton-Rothschild in the Bordeaux Medoc wine-growing region of France. Here, vineyard manager Gilles Rey wants to mechanize as much work as possible. For example, he notes, "It is very difficult for a worker driving a tractor to keep an eye on the vehicle and the equipment behind. With a traditional tractor, it is not unusual for vines to be uprooted."

Rey approached nearby Coverplant Engineering to attack that problem. The result now being prototype-tested is a simple but effective tractor-guidance system using some of the basic infrastructure for growing the vines themselves. Engineers decided to take advantage of the wires supporting the vines, which run the length of the vineyard rows. According to Coverplant engineer Pierre Bergerot, a low-voltage, 50-mA ac current is passed thorough the wires. Low-cost, commercially available Coverplant magnetic-field sensors mounted at the front of the tractor detect the wire. Data is fed to a signal-processor board, which then commands the steering to maintain a safe distance from the vines.

"The only significant expense was the connections for the wires at the ends of the rows," says Coverplant Engineering Manager Laurent Cadusseau. The system also reduces tractor driver fatigue. A production decision is expected by the end of the year.

Coverplant engineers have developed a similar system for vegetable-harvesting carts using a wire buried 1m deep in the ground. The technique also guides "walking" irrigation spray lines.

Another interesting Coverplant device is a sensitive electro-pneumatic head that gently uproots flower plants for transfer and replanting into pots (see photo). A four-head unit allows nurseries to transplant up to 5,000 flower plants per hour. The operation involves trays of the young seedlings passing under the heads, which then pick them up and replant them in individual flower pots passing through the machine above.

Similar robotics and transplanting systems are useful in reforestation work around the world, particularly in colder climates. Coverplant has a machine-vision system that classifies rows of greenhouse tree saplings according to their height and diameter. The growth cycle to produce mature pine saplings can be shortened to six months, as opposed to a year, by starting them out in greenhouses. The robotics firm Serrta (Nice, France) has developed a transplanting robot for these saplings that is under demonstration for the forest industry in Quebec, Canada. Once the plants grow to just under 10 inches, the robot machines transplant them into individual pots for sale to reforestation operations. And, according to Serrta head Claude Ferrand, "As with humans, plants are happy with technology when it improves their well-being."