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This page last changed on Nov 13, 2013 by tm.
Problem Statement for MARS use case
- Wet mate-able connectors are expensive, have limited mating cycles, and have reliability issues.
* Cabled observatories have wet mate-able connectors and would benefit by having an 'easier' connection for maintenance and attach of undersea sensors and platforms by ROV manipulator.
- MARS cabled observatory has connectors that are nearing their mating cycle limit.
Wireless Power and Data Transfer (WPDX) Technology Solution
- Wireless power transfer, also known as inductive power transfer, allows for 'contactless' connection thru electrically insulated plastics that do not corrode in sea water and have nearly unlimited connection mating cycles.
- The MBARI deep ocean Free Ocean CO2 experiment (dpFOCE) system is a MARS cabled observatory connected platform that had the problem of frequent pH sensor maintenance and the need for a medium power solution for motor swap. This project has made the investment and demonstration of the 'easy swap' wireless power and data transfer in sea water for instruments 10 watts or less (low power). A patent has been filed on the MBARI tech.
- This proposal outlines the labor and budget for demonstrating 'medium power' easy swap connector by hardening technology developed for wireless power slip rings.
Project Plan
- Purchase PowerbyProxi 150W wireless power and data devices, no potting, two pairs. Obtain schematics and bill of material
- Evaluate PowerbyProxi on test bench with performance metrics, measure:
- efficiency
- low load
- medium load
- full load
- current limit
- temperature
- temperature rise under load
- environmental temperature 0 (liquid) to 50 (cold performance is more important)
- performance vs coil separation and axial offset
- maximum load, data throughput
- Evaluate PowerbyProxi in test tank sea water (slightly more saline than Monterey Bay) using same performance criteria as bench top (air) evaluation
- Examine the schematic and bill of materials for components that are high pressure sensitive, engineer the replacement components.
- Modify one pair of PowerbyProxi keeping the other pair unmodified for comparison and spare in event of unfixable failure
- Pressure test, in and oil bath (not sea water or air), evaluate PowerbyProxi performance within the constraints of the wires passing into the pressure vessel. Static load, no mating cycle testing.
- 500 psi increments starting at atmospheric. Look for changes in efficiency as a function of pressure. It would be good if the operating frequency of the resonant power transfer could be monitored.
- Address issues with pressure testing
- 'Shoebox' potting. Low effort proof of concept packaging. Allow for mating cycle testing in test tank and ROV. Investigate re-enterable material to allow for failure analysis.
- Duration testing in test tank (several weeks) monitoring deviations in efficiency, noise, etc. Manual mating cycle testing.
Data Communication alternatives
- ProwerbyProxi uses a MicroChip MRF... 802.11 device with claims to 1 to 2 Mbps
- A powerline modem might be a decent option:
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