Sunday, April 20, 2014

Why robots, revisited

The list of problems is uncomfortably long, and all too familiar...

  • interruption of cycling of biological materials back to land
  • routine tillage accelerating loss of soil carbon
  • soil loss to wind and water
  • reduced ability of remaining soil to absorb and retain water
  • rapid runoff and increased flooding downstream
  • diminished soil fertility and overuse of fertilizers
  • silting and nutrient loading of streams and estuaries
  • overuse of pesticides, herbicides, and fungicides
  • loss of diversity of native flora and fauna
  • loss of diversity in crop species
  • dietary diversity only maintained by long-distance shipping
  • pressure to produce more irrespective of long-term consequences

Most of these problems are addressable by means of better practices...

  • cover crops and mulching
  • crop rotation, polyculture, and perennials
  • recycling of biological materials back to the land
  • maintenance and continual improvement of local crop varieties
  • biological pest controls (free-range chickens, parasitic wasps, etc.)
  • biological and mechanical weed controls
  • minimal cultivation, and that on the contour
  • controlling runoff near the source with terraces and small dams
  • recovering silt from above dams and returning it to the land
  • scaling livestock operations to what available land can provide and absorb
  • hedges, shelter belts, and native-flora waterways
  • providing food and habitat for wildlife

The problem with this set of practices is that, for the most part, they require more attention to detail and don't scale as easily as conventional practice, so they are hard to justify in terms of the farmer's bottom line.

Automation in the form of small robots, operating without constant supervision, and capable of going about farming the right way, could close that gap.

Unfortunately, for most of us, this is a collection of technologies that largely have yet to be created.

On the other hand, the sooner we make it a priority, the sooner it will happen, and the sooner we can get on with the job of healing the planet.

Wednesday, January 22, 2014

stemming the slide of soil degradation

While, in the long run, we should seek to optimize agricultural practice for the improvement of soil health, along with other considerations, in the near term we should be glad for any improvement at all, since the default to be expected from ‘modern’ agriculture is some degree of lost fertility with each passing season.

Traditional practices, like crop rotations including deep-rooted plants like clover, alfalfa, and buckwheat, and like allowing livestock into fields after harvest to browse on the debris left behind, can be enough to tip the scale from degradation to marginal improvement, and can be applied now, without any change in the machinery in use.

We should do what is a matter of differing management choices now, while continuing to work on the technology that will eventually make radically improved techniques possible.

Friday, December 20, 2013

FRE2014 to be held in conjunction with DLG Field Days

Hosted at least in part by the University of Hohenheim, the 2014 Field Robot Event will take place in conjunction with DLG Field Days (brochure, fact sheet), June 17-19, in Strenzfeld, just outside of Bernburg, Germany.

Saturday, November 30, 2013

regarding the transformational application of robotics to agriculture

Robohub's focus series on agricultural robotics either is nearing or has arrived at completion, however the work of applying robotics to agriculture has barely begun. My own contribution to that series turns on the idea that robotics is a fundamental, revolutionary development, with the potential to transform everything it touches, and, by implication, that roboticists should embrace that potential and approach their work as an opportunity to change the world for the better, both generally and in the context of agriculture.

Sunday, November 03, 2013

elaboration of "keeping dust off optics" (2009Mar01)

Realizing that I really should go to the trouble of at least diagraming what I am about to describe, as I have in the past I will wince and proceed, preferring to get the idea out rather than wait on a diagram that I may never get around to creating. As a stop-gap, I will end with links to several relevant Wikipedia articles that do include diagrams and/or images.

In the original post on this topic, I only described the air flow, without going into detail about filtration and drying of the air used. I intend to amend those omissions here.

Since the needed volumetric supply rate of air is fairly small, significant compression (enough to ensure no condensation on the optical elements) should not represent an onerous power requirement. However, even simple impeller turbines can be worn by dust particles, and filters last longer if coarse material is removed before reaching them, so the first stage should be a cyclonic separator.

As the input to the compressor, a slight vacuum will be pulled on the air as it passes through this first stage. If that air is at or very near dew point, condensation may occur inside the separator. (If condensation does occur, most of the heat removed from the condensing water vapor will remain with the air, raising its dew point.) Packing the center of the separator with a downward pointing cone of stainless steel wool will provide that condensation with a surface to adhere to and wick down, collecting in drops at the point of the cone. The moist stainless steel wool will also help remove finer dust particles that would otherwise pass through the cyclonic separator. (The finer the stainless steel wool, the more effective it is likely to be, but also the more likely that it will need an occasional back-flush with steam.)

Next comes the compressor. This should be a very small impeller turning very fast, to achieve significant compression with a low rate of flow. The chamber enclosing the impeller may also act as a second-stage cyclonic separator. Any condensation remaining in the air flowing into the compressor should be flung against the outer wall of that enclosing chamber or reevaporated instantly.

Following the compressor is a HEPA filter, to remove any remaining dust. The clean air from the HEPA filter is then directed into a box containing the optics (lenses and image sensors). That box will need to be strong enough to withstand mild pressurization, and should be sealed except as described below, although the pressurization will help ensure that any imperfections in the seal don't result in dust infiltration.

Rather than exposing the optics directly to the outside air, they should be protected behind a lens cover in the form of a wafer of flat, very clear glass or crystal. That wafer should be etched on its outer edge with widely-spaced grooves, perpendicular to the flat sides, to serve as air channels, and on it its outward-facing side with groves which begin at the groves in the edge, tapering to nothing as they spiral toward the center at a shallow angle. By mounting such a wafer in such a way that air passing out through the groves around the outer edge is forced to turn and flow in an inward spiral across the face of the glass, an air-flow, reminiscent of that in a hurricane, will be set up, with filtered air spiraling inward next to the lens cover, pushing out a bit, and then spiraling back outward a short distance in front of the lens cover, keeping the lens cover itself free of dust and small droplets in the ambient air.

Now for the promised Wikipedia links…

Friday, October 18, 2013

Robohub focus on agricultural robotics

Robohub.org has just opened a new focus on agricultural robotics. Robohub focuses last about a month, so bookmark this page and check back often. There will be a lot more than is there at the moment!

Wednesday, October 02, 2013