Let's Make Robots!

SEA RENDERING

Measure water depths in lakes
AttachmentSize
Bilde.jpg881.9 KB
MarkII_LOG_microSD.zip2.73 KB
MarkII_NAV_microSD.zip5.11 KB
DELFTship_linesplan.pdf159.55 KB
Mark_II_versjon_1a_mod.zip9.02 KB

This is Mark II of the Whirligig project http://letsmakerobots.com/node/16995 code name SEA RENDERING (it’s not actually a code name, just an anagram for my name :-) )

The purpose of this robot is to have it log water depths along a predefined set of waypoints. It stores its data on memory sticks or on SD cards. The estimated runtime is about 24 hours and with a top speed of 3km/h it will travel roughly 72km. With a log entry for every 10m this would give us over 700 depth measurements   with full GPS reference.

Most of the control system has been moved from the original Whirligig to save cost and time.

The hull was designed in the free version of DELFTship http://www.delftship.net/ and built this winter. With the split mould I can produce a second hull in matter of days.

The original plan was two hulls working in pairs as a catamaran with a solar panel on top. This can still be done but two robots working independently we can cover a larger lake on shorter time.

Some images from the hull build

Adding fiberglass to one half of the mould

Mould completed

The first casting

Here are some pictures from the complete robot

Transducer

Polymorph beddings for the batteries

Control system

Some electronics in the lid

The waypoints are entered using my adaptation of the Ardupilot tool. A great application that lets you interactively add waypoints to your list. This list is then copied onto the SD card and the robot is ready to run.

I run this routing 3 times and this is a GPS visualization of the log. The green markers are the waypoints.
(one of the log files are attached)

My brother (a professor at the University of Oslo) that will be using this robot, then run these 3 logs in something called  "Thin plate spline" http://en.wikipedia.org/wiki/Thin_plate_spline to see if the depths we logged made sense. And this is what he came up with.

All in all this project seems very promising.

Update 28/6-2010

After having had some problems with the VDIP1 USB interface I decided to go for the microSD shield from Sprakfun http://www.sparkfun.com/commerce/product_info.php?products_id=9802 .
Now the whole thing looks much cleaner and is probably more robust.

 

 

Update 11/7-2010

This weekend my brother and I went to the lake ‘Riskedalsvatnet’ to do a full scale test. The full waypoint routing had 337 waypoints and a total length of 18,1km.


The traveling speed of the boat is about 3km/h so the mission should have been completed in about 6 hours. As this was the first full scale test and we had some uncertainties on where the shore line actually where, we decided to split the trip into 3.
This is the first segment of the mission.

This is how the boat run

And this is an Dr.Depth rendering of the depths we got.

After all segments where completed this map was generated in Dr.Depth

A full size map in b/w is attached

 

UPDATE 14/7-2010

Added the Arduino sketch if anyone want to have a look.

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.

There should be no need for an *END* marker in the file as there will always be an EOF marker on the SD card and you can’t (or at least you shouldn’t) read past this marker.

I'm a biologist at the University of Bologna in Italy and are interested in implementing a boat with operational capabilities similar to those of your project. In particular, the ship should be able to load my water samples to determine pH, dissolved oxygen and conductivity as well as other chemical and physical parameters. I have difficulty in finding sonar could tell me the model, the manufacturer and retailers of sonar used by you? I also have difficulty in obtaining a copy of the software Dr. Depth is no longer available on the official website. I am also available to purchase a trial copy of the program: you think it's possible to do so pending the availability and distribution of the new program? If so could you send me a copy of the software? Or could you tell me alternative low-cost software that have features similar to those of Dr. Depth? Thank you in advance for availability and I look forward to your feedback or your email address where you can write directly.

Hi,

An altnerativ solution is reefmaster: http://reefmaster.com.au/

Regards


Carl 

Hi
It turns out that Dr. Depth has sold the software to Lakemaster http://www.johnsonoutdoors.com/uploadedFiles/Media/Press_Releases/LakeMaster/LakeMaster%20AutoChart.pdf
And there is some more information here http://www.lakemap.com/AutoChart/#.UfZXotU4Xct


You can find the transducer online http://www.blueheronmarine.com/Raymarine-DST800-Plastic-Transducer-DST800P-A-6588
But you could probably use any digital transducer that supplies NMEA183 data.


You can send me an email directly via my contact page.


Best of luck.

I'm a biologist at the University of Bologna in Italy and are interested in implementing a boat with operational capabilities similar to those of your project. In particular, the ship should be able to load my water samples to determine pH, dissolved oxygen and conductivity as well as other chemical and physical parameters. I have difficulty in finding sonar could tell me the model, the manufacturer and retailers of sonar used by you? I also have difficulty in obtaining a copy of the software Dr. Depth is no longer available on the official website. I am also available to purchase a trial copy of the program: you think it's possible to do so pending the availability and distribution of the new program? If so could you send me a copy of the software? Or could you tell me alternative low-cost software that have features similar to those of Dr. Depth? Thank you in advance for availability and I look forward to your feedback or your email address where you can write directly.

Hello Geir,

First of all, I must say that it's a great pleasure to read you with the SEA RENDERING project. I am a very beginner with Arduino and electronic as well so what you explain makes me understand lot of things.

Of course I have a little question to ask : I don't really understand how do you connect DST800 transducer to Arduino board ? Don't you need a RS232 / TTL card between both of them ?

Someone say that it could burn the Arduino without RS232 /TTL card. Is it correct that you have tested the transducer before connecting the arduino so you were sure that there was no danger for the Arduino ?

Thank you very much for your answer

CW

Hi
The transducer I used had a 12V input voltage but the communication was at TTL level. The RS232 signal is from +12V to -12V and TTL are 0-5V so I did verify that the communication out of the transducer was in the range 0-5V before I connected up to the Arduino.
So if you hold your transducer in a bucket of water and measure the voltage out on the serial line and it’s in the 5V range your good to go.

 

Hi, I'm from Brazil and I have the sonar depth: Garmin fishfinder 160c ( http://buy.garmin.com/shop/shop.do?pID=292&ra=true ). I would know if could connect Transducer ( https://buy.garmin.com/shop/shop.do?pID=710 ) directly into the Arduino to get the NMEA signal or have to put all equipment?

What Transducer you recommend I buy?

Thank you for your attention and sorry for the poor english, Celso.

 

You need to find a digital transducer that will give you serial information on TTL or RS232 level. From that you can read the NMEA sentences.
I think both of your links are to analog transducers.
I haven’t been working on this for the last 3 years so I won’t be able to give you a good recommendation. Google for transducer and NMEA and you will probably find what you are looking for.
http://www.blueheronmarine.com/NMEA-0183-DST800-Transducer-Plastic-DST800PV-S-6422

Best of luck

Geir, I'm working on a similar project as yours. In some words I want to survey surf spot reefs to understand better the mechanics that make the waves break (and bottom is very important for the shape of the waves). All this using a robot, of course!

You are using the airmar sounder DST 800. Does it give good result, and in particular is it accurate? For the same price Airmar proposes also P79. In the datasheet P79 is more accurate (less wide beam) but does not send temperature and speed. So the choice is not easy more me.

Do you think, after use, that DST800 is accurate enough to clearly detect and map isolated rocks, for example?

Thanks for your thoughts!