Chesapeake Open Expedition ILatest update May 7, 2015 Started on December 13, 2014
Much has been learned. Though no shipwrecks were explored this time on this expedition, far more was gained in technical knowledge and improvements for both vehicle, software, and logistics. A more substantial expedition is in the works and we will post plans soon.
We will be posting more on our vehicle modifications, software, and payloads soon! CTD+, water sampler, and more!
Make and make often. Make the world you want, and not the one you were given!
Great results! Much progress has been made and we had a great dive day with both our kits. As a reminder, Eiodothea Mark II was a hybrid standard square frame ROV with the OpenROV control bits. The ROV handled very well, even though looking like some behemoth.
We had some problems which I we contribute to leakage from poor potting of the wires going into the cylinder so we had some water intake and did short the BBB. We haven't checked the BBB out yet (after washing it with fresh water and drying) and we had to rush of to AUVSI, but I suspect that all is well.
In addition, we used a 4350mAh LiPO immersed in mineral oil, which worked perfectly, in a gasketed batter box we built from a simple Radio Shack project case.
Test dives went swimmingly and we learned quite a great deal. We will end this mission blog and start afresh soon.
Thanks for following! We have made good progress on our CTD+ and will have that on a NEW ROV with in the next month for two. More to come!
Eidothea Mark II is 95% complete, and baring any systems check issues tonight and tomorrow we will be diving Sunday afternoon, a happy Easter indeed!
You may ask, why such the delay? Good question. Well, the winter here in Virginia was slightly harsher than I was expected, plus, the same old culprit, time.
Anyway, Eidothea will be diving shortly and video will follow. We will fly the ROV at a collaborator's marina on the beautiful Chesapeake.
Upon completion of our check dive, we will finalize our wreck dive location and polish up the CTD+. We've rebuilt the sinewave generator and amplifier for the salinity probe and feel it is ready to be mounted in the Otterbox containing our Arduino data logger with the temperature, pressure and ambient sensors. We expect this to take an additional week of wrap up and testing prior to mounting the kit onto the ROV. we'll get a full write up soon.
As a reminder, Eidothea Mark II is a cross between an OpenROV and a homebuilt, bilge driven PVC platform. So this should be interesting.
Updates from our last planning meeting:
ROV modifications and redefinition of mission. As we've mentioned before, testing out equipment whilst exploring a region of the Chesapeake has been our two main points of this expedition. Learning from our delay and thinking about the adventure has produced the following modifications and clarifications:
- Vehicle design: As with most planned expedition, there exists a list of important outcomes that best fulfill expectations. we've decided that testing a newly designed CTD and attaching an Oxygen sensor to a new ROV platform would best serve our exploration and scientific expectations. This brings us to the need for a slightly larger ROV, able to hold both the CTD and O2 sensor payloads.
Eidothea Mark II:
It's a simple redesign from the 4 bilge motor Eidothea. However, we've swapped out the top side bits, i.e. topside power and control tether, with the OpenROV controller, motors, and tether. They are just better designs. Coupled with the irrepairable damage for ROV #411, this solution solved two problems with the expedition. Vehicle readiness and payload capacity.
CTD: For some reason, a home grown sine-wave generator with stable signal and reliable operation has proved vary difficult. We are now going to try out an Arduino Due that gives us a DAC or Digital / Analogue Converter. I'll post more on this when we have something more substantial.
Archeological Camera: Finally some movement on this front. We are reviewing the software for Polynomial texture Mapping, plus umbrella design to attach to the Eidothea for trial runs Mid-Feb.
- Vehicle finalization and wet testing - jan 31st
- CTD topside Testing - Jan 23rd
- Location finalization - Feb 7th
- Boat selection and Planning/safety Meeting - Feb 8th
More to come!
Mission Updates: Delayed!
The best laid plans of mice and men...as it were. As can be guessed, we've been delayed due to both logistical and technical issues, forcing us to reschedule. Tentative target is Feb '15.
More to come in regards to equipment updates and build schedule.
Have a great holiday!
Updates: Additional ROVs
As mentioned, two other ROVs will be tested and, hopefully, deployed during the Dec13th expedition. One variant is a simple HomeBuilt ROV design, PVC construction. Eidothea, pictured, utilizes a ttl camera, 4 converted bilge motors, modified high intensity LEDs for illumination, a cat5 tether, and ample room for a CTD and water sampler payload. Power is supplied down the tether, and 100 ft. of cat5 attenuates the voltage supply significantly. That being said, I will hopefully be testing a heavy duty marine battery over the next two weeks to confirm tether applicability. Target max depth ~40 ft. with this platform, so a 60ft. tether may be a better solution.
Preparation: Some past development in regards to setting up the CTD+ and the Nishkin bottle. Coupled with ROV damage from the "oh so careful and professional movers" during my Virginia relocation, the preparation stage for this expedition has taken on an additional level of complexity. ROV 411 has had better days. There were also a number of build issues (long story, had a student group work on it and they skip some steps...added their own interpretation of the instructions, etc), so I've been rebuilding the kit in hopes for a Dec 13th deployment. I also have to additional ROVs that I build prior to the OpenROV kit. I'll post update images next week. As a primer:
Image: CTD+ prototype.
The CTD sinewave generator has been giving me a number of issues. I've gone to using the Arduino as the sine wave generator, while recording data to the SD card from the sensors output. The redesign will be finished this weekend, followed by testing and validation next week. The amplifier and sensor circuit will stay the same as in previous iterations.
The Nishkin bottle is a much simpler device. The open ended tubular design uses a solenoid to release holding bands for the endcaps, triggered from a topside signal.
ROV overviews to follow.
The primary mission is to assess a number of technologies for citizen science ROV platforms. Water sampling will be done with a solenoid actuated water collection tube. The CTD consists of a salinity sensor, temperature sensor, pressure sensor and ambient light sensor. The collected data is collected and stored on board the ROV, correlated post mission and will be posted for the community to access. The archaeological camera consists of a hemisphere LEDs with a single camera in the center top of a shell construction. The LEDs illuminate a selected surface one at a time and offline software stitch the images and allow for surface and reflectance characteristics to be modified, bringing out salient characteristics of a target. This technique has been used to discover worn writing and various other archaeological points on interest for land expedition. This will be the first marine implementation of this system that we are aware of.
A selected wreck will be then explored, testing camera and lighting techniques. The OpenROV kit and an additional home-built ROV will be used.
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