wiki:KORUZA/Prototype
Last modified 3 years ago Last modified on 08/27/2014 06:01:23 PM

KORUZA prototypes

The prototype of KORUZA system is under constant development to find the most effective and low-cost design enabling 1 Gbps connectivity of structures up to 100m apart. The current version heavily relies on 3D printing for producing the vast majority of parts possibly suitable for the construction out of plastics and is suitable for the outdoor use.

Theory of operation and the design

Prototype goals

  • 1Gbps connectivity over 100m of clear line-of-sight (achieved with gen 2)
  • Link status monitoring (achieved with gen 3)
  • Outdoor suitable (achieved with gen 3)
  • Auto-alignment and tracking (prototyped with gen 4, under development)
  • Long term stability (prototyped with gen 5, under development)
  • Open-source suitable (prototyped with gen 5, under development)

World Wide Experiment & Release candidate prototype (gen 5)

Generation 5 prototype is a complete redesign of the system in OpenSCAD framework, preparing the system for collaborative open-source development. If features a reduced number of assembly parts and integrating all the components into a single 3D printable unit, that is inserted into an aluminum enclosure and capped with a 3D printed lid.

Currently it is in active development and testing, prior to use in the world wide experiment.

prototype breakout

Improved outdoor prototype (gen 4)

This is a complete redesign of the system optimizing all parts for 3D printing, reducing their number and improving the stability. Some features were removed as they were not necessary, while others more integrated and added. It features an improved sliding setup for more stable focus adjustment, rotational water-resistant joint using industrial rubber as well as overhauled control electronics based on Texas Instuments Launchpad Tiva C, packing much more power and enabling remote debugging and upgrades. It as well packs some sensors, building towards an extensive environment monitoring system to find out all error-sources of the design.

3 sets of these units were assembled and are deployed for long term outdoor testing. Preliminary results show mis-alignment due to thermal expansion, the orror being 30mm beam displacement at a distance of 100m with temperature variation of 20 degrees C.

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Basic outdoor prototype (gen 3)

This design incorporates solutions from gen 2 into an outdoor suitable construction, adding motorized alignment system and completely new control electronics based on Texas Instruments MSP430F5529 Launchpad.

prototype breakout

Performance test of this system have produced the following results:

  • Works well up to over 150m in short-term
  • Easy to align
  • Suffers from thermal deformations and mis-alignment in the daily temperature cycle
  • Control system works well, however more performance could be useful
  • Green laser pointer mounting is far to unstable and insufficiently integrated
  • 3D printed ball causes jitter in aligning
  • Plastic-on-plastic sliding element does not work too well

Fully 3D printed prototype (gen 2)

This design is the first functional construction build with 3D printing, using only a few necessary parts of a different origin, essentially just screws and electronics. While it is not suitable for outdoor deployment or long-term use, it outlines the critical parameters for the construction of a deployable prototype in the next development step.

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  1. Infrared laser source and detector
  2. Kinematic mount for aligning the source to the lens
  3. Plano-convex lens in the linear two axis translational mount for aligning the lens to the detector
  4. Linear translation stage for adjusting focus/collimation (prototype source available)
  5. Indoor desktop mounting system, that is to be upgraded to the outdoor version
  6. Visible laser for alignment purpose
  7. 3D printed kinematic mount for pointing at its pair at a distance (resolution 10urad / 0.6mm at 100m)
  8. High-speed communication extension
  9. 1 Gbps ethernet media converter (TP-Link MC220)

Basic prototype (some 3D printed parts) (gen 1)

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  1. Infrared laser source and detector
  2. Kinematic mount for aligning the source to the lens (3D printed)
  3. Plano-convex lens in the kinematic mount for aligning it to the source
  4. Linear translation stage for adjusting focus/collimation
  5. Mounting bracket (3D printed)
  6. Visible laser for alignment purpose
  7. Rotational mount for aligning the unit to its pair at a distance
  8. High-speed communication extension
  9. 1 Gbps ethernet media converter

SFP digital monitoring mode library

A library for communicating with the SFP module via I2C and extracting diagnostic information has been developed and is available on: https://github.com/SloMusti/sfpddm

Kinematic mount development

3D printing technology has been explored for designing kinematic mounts for the laser source and detector module, eliminating the need for expensive mounting units available on the market. A series of small steps has been taken to develop a suitable construction and test the 3D printer plastic properties.

A video presentation on the development process is available (in Slovenian): http://elektronik.viidea.net/3D_tiskanje/

UNDER CONSTRUCTION.

Indoor testbed

The prototype for mechanical construction testing consists of two identical units displaced by 1.5m on a sturdy aluminum profile. Individual modules are replaced and improved on, the performance is evaluated in this case.

prototype breakout

Thanks

This prototype has been constructed with the support of Dr. Benn Thomsen of Department of Electronic & Electrical Engineering - University College London .

Thanks to Kroko from http://www.planet-cnc.com/ for 3D printing.

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