I’ve been working on decomposing the different parts of the signal received, trying to figure out what each bit is and how to get rid of it.
The main conclusions of which are that bottom->surface reflections are the most predominant in the signal.
The attached two graphs of experiments where I was comparing the signals in a [...]
Got the first incarnation of the Phased array working now. Had a few hiccups along the way, but managed to get most of them sorted. Main problems included not having enough RAM to store a significant amount of data, so I fixed that using a simple compression technique (I say simple, took me [...]
Not tested yet, but here are some images of the finished PCB!
Image 1 img_0002.JPG Image 3 Image 4
Over the past week I have had enough of the surface tension tests since I was getting nowhere. I redid the low surface tension (Ethylene Oxide) and the high surface tension (salt) tests to get some more resolute data. (I thought I might have just been either putting too much in at a [...]
Just for future reference (because I always forget), using the naff double sided PCB, 3:30 exposure was enough, but by far and away the most important point was to remember to jam the acetate down to the exposure unit, to the point of stressing the joints. Too many times have I relied on the [...]
After lots of testing, here is the brief version. What I have found is that if you lower the surface tension, you increase the longevity and the size of bubbles under, and on top of the water. If you increase the surface tension, the opposite happens. You get lots of tiny bubbles. Neither actually gets [...]
Quick update, I wanted to try the matlab vs c++ routines again, because from what I can remember, matlab was several orders of magnitude quicker than the c++ program. But I recently found a library in Qt called QVector, which claims to be very quick on the
whole memory front. So I went back [...]
Haven’t updated in a while. Cracking on with the PhD doing lots of experimental work. Lots of time has been put into experimenting with the new hardware setup, PC->NI DAQ->Single Hydrophone, playing with all sorts of different concoctions. Results have been adequate, but not astonishing. The expected amount of bubble noise [...]
I have thought of things like this in the past, and it looks like someone has taken the time to actually do it:
http://www.gizmag.com/go/7293/
I think that they have gone down the wrong road for the mouse part though…
[ I chose not to make the reasons why it is not appropriate and what can be done to [...]
After months and days of searching I cant find any websites that are developing a hobby based phased array soultion for robots or whatever, so I am very very tempted to get to work on this straight away when I move in, rather than spending time on my robot like I had planned. Also, another [...]