Interesting project idea, now need help w/ parts
firestorm.v1
Posts: 94
Well, last Friday at work, I managed to save from the landfill a large fibre splice can. For those of you that don't know, here's a reference picture. www.germes-online.com/direct/dbimage/50226937/Fiber_Optic_Splice_Closures.jpg
The left image is a pic of what the thing looks like all closed up. It has several water-tight compression fittings and as soon as it's warm enough, I intend to take this thing (empty) to the local swimming pool to see how watertight it is. I figure it's airtight too as the splice can has a valve stem on it and from what I heard from the guy that gave it to me was that the telco pressurizes them to find where cables are cut. (I don't know exactly HOW, when they could just use a TDR instead.)
My initial reaction was "Great, what am I going to do with a watertight enclosure...." then it hit me. (Maybe due to the fact that "The Abyss" was on TV, too..
I intend to build a ROV robot out of it. It's tube-shaped, and just a bit larger than the size of your average 3L soda bottle. I already sketched out the plans on how to move the thing by using two side thrusters, (one on each side) and one "main" thruster for going forward/back. The side thrusters will have 270 degree rotation capability with the help of a couple of optical encoders to make sure they don't travel out of bounds while the main thruster in the back will be a fixed position with a shroud. I have plans later (way later) after I have built the first version to go wireless with the control (short range) but for now it will be a tethered ROV. I'm going to use an array of LEDs out the front for a camera with an X/Y axis servo set to allow for some looking around.
I'm thinking that I will need two BS2s for this, one to control the three motors and the two side thruster servos and one for the forward looking camera, lights and to monitor the ROV for water seepage. In the event that either one detect water, the ROV will have a failsafe condition where it will point both thrusters up, engage them both and send it back to the surface while sending an error condition to the console. An accelerometer and a tilt sensor may come in handy too as I want to make sure the thing is pointed at whatever it's supposed to be pointed at without needing to constantly adjust. My preliminary research says that the tilt sensor will help with front-to-back and side-to-side detection but will the accelerometer be able to tell if I'm drifting or will I need to go to some gyroscopic setup for that?
Another question is where do I find water-tight motors for such an application? This isn't going to be the next deep-diving submersible, but I'd like it to be able to go to the bottom of an Olympic pool without the motors burning out due to water seepage. Depending on how much the thing floats, I might also have to develop some kind of ballast system (as opposed to strapping a couple of bricks to it. :P) which might further the need for the water fail-safe mentioned earlier. While the tether cable (initially) will provide all the power and communication signals needed for operation, I am putting together the plans to make this a full "remote" controlled vehicle, not just one with a cable coming out of it.
I know that the idea isn't practical, but it should be a ton of fun and I'll learn a lot in the process. After all, isn't that what counts?
The left image is a pic of what the thing looks like all closed up. It has several water-tight compression fittings and as soon as it's warm enough, I intend to take this thing (empty) to the local swimming pool to see how watertight it is. I figure it's airtight too as the splice can has a valve stem on it and from what I heard from the guy that gave it to me was that the telco pressurizes them to find where cables are cut. (I don't know exactly HOW, when they could just use a TDR instead.)
My initial reaction was "Great, what am I going to do with a watertight enclosure...." then it hit me. (Maybe due to the fact that "The Abyss" was on TV, too..
I intend to build a ROV robot out of it. It's tube-shaped, and just a bit larger than the size of your average 3L soda bottle. I already sketched out the plans on how to move the thing by using two side thrusters, (one on each side) and one "main" thruster for going forward/back. The side thrusters will have 270 degree rotation capability with the help of a couple of optical encoders to make sure they don't travel out of bounds while the main thruster in the back will be a fixed position with a shroud. I have plans later (way later) after I have built the first version to go wireless with the control (short range) but for now it will be a tethered ROV. I'm going to use an array of LEDs out the front for a camera with an X/Y axis servo set to allow for some looking around.
I'm thinking that I will need two BS2s for this, one to control the three motors and the two side thruster servos and one for the forward looking camera, lights and to monitor the ROV for water seepage. In the event that either one detect water, the ROV will have a failsafe condition where it will point both thrusters up, engage them both and send it back to the surface while sending an error condition to the console. An accelerometer and a tilt sensor may come in handy too as I want to make sure the thing is pointed at whatever it's supposed to be pointed at without needing to constantly adjust. My preliminary research says that the tilt sensor will help with front-to-back and side-to-side detection but will the accelerometer be able to tell if I'm drifting or will I need to go to some gyroscopic setup for that?
Another question is where do I find water-tight motors for such an application? This isn't going to be the next deep-diving submersible, but I'd like it to be able to go to the bottom of an Olympic pool without the motors burning out due to water seepage. Depending on how much the thing floats, I might also have to develop some kind of ballast system (as opposed to strapping a couple of bricks to it. :P) which might further the need for the water fail-safe mentioned earlier. While the tether cable (initially) will provide all the power and communication signals needed for operation, I am putting together the plans to make this a full "remote" controlled vehicle, not just one with a cable coming out of it.
I know that the idea isn't practical, but it should be a ton of fun and I'll learn a lot in the process. After all, isn't that what counts?
Comments
crustcrawler.com/products/urov/index.php?prod=300
Plus you would need either two of their ESCs or some of your own (600w).
What size are you talking about here? If you are doing something smallish, then you may think about picking up some inexpensive radio-controlled boats or subs and raiding them for motors and props and motor drivers.
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When the going gets weird, the weird turn pro. -- HST
1uffakind.com/robots/povBitMapBuilder.php
1uffakind.com/robots/resistorLadder.php
Last summer I had the privilege of visiting the Marine Advanced Technolgy Education Center's Summer Teacher Institute.··There they were building simple ROVs with PVC frames, and three small bilge pump motors for thrust.··It was tethered for power and control, using two·two BASIC Stamp HomeWork boards.· The topside board was hosting a joystick control and LCD, and the one down below was handling the motors and some other sensors.· There was a camera on its own umbilical.· There are a few pictures on page 53 of the 2009 product catalog.
I know I've seen an ROV project here on the forums...
http://forums.parallax.com/showthread.php?p=714041