I am looking into using a tether for a Seafloor System Hydrone, which is using 2x T200 thrusters. We currently use a Taranis X7 controller paired with the system on the boat. The reason we want to make this modification is that we have a particular need in underground galleries in which we lose line of sight with the boat. Therefore, the tethered controls would be safer in case the wireless communication is lost.
What do you guys think would be the simplest way to make this work:
Keep using the Taranis controller, have a 2.4 GHz receiver at our feet, use a tether between the receiver and an emitter on the boat and communicate with the onboard system that way. (is it possible with a 2 conductors tether?)
Use a fathom interface with some kind of controller and the Blue robotics thruster commander so that we can control both thrusters through a tether.
I need a tether with a neutral buoyancy because there are a lot of obstacles beneath the surface.
Is there bi-directional communication, or does the controller just send information to the boat and the boat follows those directions?
If information is sent back
What kind of information is it?
Does it need to be live, or could it be recorded on the boat and retrieved afterwards?
How far do you need to go?
e.g. how long of a tether would you need?
There’s some discussion of long range thruster commander usage here. You would need at least three conductors in the tether, and 4 if you want to be able to control speed/turning or left/right independently
Buoyancy depends on the density of both the item and the fluid it’s in. Our tethers are designed to be neutrally buoyant in fresh water, and slightly positively buoyant in salt water, but manufacturing tolerances and variable water properties mean the buoyancy may be slightly negative or positive.
Note that additional buoyancy generally comes with extra volume, extra drag, and extra mass in air, so there’s a balance to be struck. If necessary it’s possible to attach some small foam pieces to a tether to increase its buoyancy, but that also increases the risks of snagging and tangling.
Thank you for the prompt answer! Here is some additional info:
How are the thrusters controlled on the boat at the moment? RC receiver (in Hydrone Autonav) → 2 ESCs → 2 Thrusters
Is there bi-directional communication, or does the controller just send information to the boat and the boat follows those directions? No, the boat just needs to follow the directions
Ok, given those responses I’d recommend the thruster commander approach that I linked to, with just the potentiometers at your end of the tether, and the thruster commander, ESCs, and thrusters on the boat - it’s a low cost and simple option that seems to meet your requirements
