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Wednesday, April 01, 2009

Robots in Action

Some of you may have noticed (or not) that posting was pretty sparse (non-existent) earlier this year. I was working 'round-the-clock on a robotic grape vine pruner, which we demonstrated in mid-March in vineyards in Lodi, California. The following video shows the pruner and the demo and describes the technology. It's been the most fun and technically interesting project of my career.

Update:A common question seems to be, "So just what is this thing?"

The task at hand is pruning grape vines. After the grapes are harvested and the grape vines drop their leaves, the vines need to be pruned during the winter to ensure the optimal balance between maximizing fruit yield and obtaining optimum fruit quality during the next spring and summer. This is currently done by hand and is by far the most costly part of growing grapes.

The pruning rules vary between growers and varieties, but the general approach is to leave approximately eight Canes (the vertical shoots) on each Cordon (the horizontal portion of the vine). All the other Canes are to be removed as close as possible to the Cordon and the Canes that are kept should be pruned a bit above the 2nd bud.

The operational concept of the pruner is to use multiple sets of stereo cameras to collect images of the vine and then to process those image to create a detailed model of the vine. The pruning rules are applied to that model and a plan is generated to make the cuts with the robot arms. There are also cameras on the arms which enable the arms to be guided in real time to make the necessary intricate cuts.

This one-of-a-kind prototype was deployed in the field for this demo only 4 months after it was built. The production unit will be much faster, gentler (to the vine), and more accurate. But the prototype in the video is a pretty good start and certainly demonstrated the concept to the growers.


erp said...

Bret, Congratulations on a job well done.

It's a fascinating video, but a little commentary would be helpful for us non-technical types.

Hey Skipper said...

That was fascinating.

I particularly liked the part where the robots do image recognition -- of all the problems you had to solve, I would not be surprised if that was the hardest.

Bret said...

Yes, the creating the detailed 3D model from images is a challenging part and we still have a bit more to do before we're ready for production. Fortunately, being "Vision Robotics Corp." we have extensive libraries to collect images and turn them into 3D models.

It was harder than I estimated to get the arms to do what we wanted them to. They kept getting in positions where one or more joint angles were near a limit which then made it difficult to move efficiently to the next cutting location. But we mostly have that under control now too.

Hey Skipper said...


A very good friend of mine has had to deal with the same positioning problems with CAT scan equipment, although he only had one unit to deal with.

Data Spectrum Inc in Manhattan Beach.