Robot vision to automate tree pruning

Nov. 29, 2012
Purdue University (West Lafayette, IN, USA) researchers have received $6m in grants to automate one of the most laborious and costly jobs in vineyards and apple orchards.

Purdue University (West Lafayette, IN, USA) researchers have received $6m in grants to automate one of the most laborious and costly jobs in vineyards and apple orchards.

Each year, fruit growers spend about 20 percent of their labor costs on pruning vines and trees. Now, Peter Hirst, an associate professor of horticulture, is leading a program to develop and improve machines that use cameras and robotic arms to do the work.

Hirst received a $3m grant from the US Department of Agriculture's Specialty Crops Research Initiative, with another $3m in matching funds from industry partners and institutional funds.

The first part of the project will involve improving the prototype of an automated grapevine pruner developed by Vision Robotics (San Diego, CA, USA) a partner in the program. A tractor pulls the machine over grape vines while cameras capture images of the vines and a computer tells robotic arms where the vines should be pruned.

Presently, the pruner is at the prototype phase, but Hirst said the aim of the program was to move that machine into a commercially available device that would be cost-effective for grape producers.

The group will also start work to model trees, examine how they should be pruned, and to begin the design of a robotic pruner. Building the robotic pruner for apple trees will have to wait until the researchers receive a further grant.

To develop the system, Hirst will work with Johnny Park, a Purdue research assistant professor of electrical and computer engineering, and Avi Kak, a professor of electrical and computer engineering, who will build digital 3-D models of trees and vines and design software.

"The challenge is to accurately construct 3-D models of trees and vines and program that in such a way that the computer can determine the optimal points to prune. Our goal is to make this work at a speed that makes sense financially for growers," Park says.

Related articles on agricultural vision from Vision Systems Design.

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