Underwater Robot (ROV)

[Ridirich]

The way you made it sound was the robot was going to be about 2 feet in length MAYBE. That is why I suggested what I did.

[iatemenchi]

im sorry for using this forum as the support thingy...and im soory for wasting your time...we had a meeting today and the rest of the team decided not to go wireless...and btw...the robot was gonna have its own massive powersupply...so yeah...^_^

[Ridirich]

Why should wireless include only radio waves...?

Because he does not have the currency to pay for anything more advanced. This is for a school project, and I doubt he has the cash to drop on it better technology.

[allentrace]

Certainly a great point. The Navy has been experimenting with frequencies of visible light and sound for communication underwater over short, medium and long distances.

Bioluminecent organisms living under water have been known to use certain frequencies of light to communicate-- frequencies that have been found to be efficient for communicating under water over long distances with less power than other frequencies.

I think they made a movie about that.

[TheCotMan]

Why should wireless include only radio waves...?

Certainly a great point. The Navy has been experimenting with frequencies of visible light and sound for communication underwater over short, medium and long distances.

Bioluminecent organisms living under water have been known to use certain frequencies of light to communicate-- frequencies that have been found to be efficient for communicating under water over long distances with less power than other frequencies.

Rather non-technical pdf on light and sound in water with a table ob depth and absorbtion based on simple wavelength (visible colors)

Also, mammals have been known to use sound to communicate through water. Many times, the sound frequencies they use are efficient for transmitting sound through water. Certain frequencies seem to work well for better resolution over short ditsances (e.g. distance checking) vs longer distance communication.

Non-technical paper article on using sound. Modems for underwater. :-)

An Evaluation of the U.S. Navy's Extremely Low Frequency Submarine Communications Ecological Monitoring Program (1997)

From this we have patent text for digital signal through water and earth as medium.

If wireless is just for remote control, and the remote controlled device is not required to reply, then you can put a lot of power into your "stationary control station" while keeping the receivers low in power.

Most of the above was found with google.

[Voltage Spike]

Water has a way of slowing down radio waves

Why should wireless include only radio waves...?

[Ridirich]

Lucky you, I went to York Vo-tech, then PSU to study robotics. Since I had to choose my own courses relevant to it, I studdied AutoCadd and Machinery, as well as computer science. I will do my best to answer your question. For future notice though, this is not a support forum, it is a security group, and this is the wireless security area. Furthermore, if you want me to do your homework for you, I suggest you pay me.

Wireless is possible underwater, but only to a certain degree. I really would go with fly-by-wire. You will notice that remote-control submarines such as this one don't go below 10 feet. Water has a way of slowing down radio waves..and honestly, unless you have a robot that is huge, it will not be able to house the powerplant needed to supply the larger radio needed for deeper depths. How do we do this? Well, you could do it one of three ways.

1) Attach the wire to a remove control. This is sort of a bad idea. If you tug the remote, you may pull the robot and break it, as this is a class project I doubt that you have a strong structure made for it.

2) Attach a wire to a bouy. You can then "radio control" it from there. It will have wire going into the "ocean" like a real robot does. This is a better option.

3) This is what I would do, and if you want to go all out, you should do it too.
Attach the robot's wire to a boat. Have two remotes. First remote controls the boat. Second remote controls the robot. This is the most realistic of them all, and would make the robot "wireless" for the most part, which is your team's wishes...as well as make it able to move all over your test area with no issue as long as the two remote control users work in tandem.

So, how would it work? Well, make yourself a boat. If you can make a robot, you can make a boat. Make sure it can house two radio-control reception units. Give it two antenas. Now, make sure the boat is able to run on it's own. Then attach the wires to the boat off a rig-system. I would look at various websites that have ships with robot attachments, or look up the old naval rescue divers like in the movie "Men of Honor". a winch system could also be attached to pull the robot back out of the water.

[iatemenchi]

i wasnt sure where else to go...im hoping sombody here can help me out...i was asked to design the control system for my schools rov...my team WANTS to have a wireless control system unless it is absolutly not possible...i have been having trouble finding some transceivers to attach to the control system...the frequency must be low enough to go to about 40 ft underwater and maybe 30 to 40 ft out...can anybody help me??