Home        Store        Docs        Blog

Research Boat Project


(Yousef Orabi) #1

<div>hi,</div>
<div>I’m making a small boat project that will be used for researching in the water, I’m wondering how to place the 4 thrusters (T200). I noticed that there are some angles that should be considered when placing before fixing the thrusters. So, any idea or recommendation about the fixation angle [formula, title of the search, ideas from your experiences]?</div>
<div></div>
<div>Thank you in advanced,</div>


(Rusty) #2

Thanks for the post. For a boat, we would generally recommend two thrusters mounted side by side and oriented straight forward. That will provide efficient thrust and allow you to steer by changing the thrust from each thruster. This is know as “skid” steering. On ROVs, we use other mounting angles to provide other maneuvering capabilities.

Please let me know if you have any other questions.

-Rusty


(Kevin) #3

I agree with Rusty, two thrusters mounted side by side pointed forward will work just fine. I found that mounting them 2/3rds of the way back from the bow allowed for stable control and the ability to rotate on its middle axis.


(Yousef Orabi) #4

so, what will be the problem using 4 thrusters? just for my knowledge; as I saw most of the people using 4 thrusters when designing such a boat.


(Kevin) #5

Can you show us which boats you are talking about? Unless you need dynamic positioning, then 2 thrusters should be fine. You won’t get any more speed out of using 4.

What control system are you going to use?


(Yousef Orabi) #6

it is a catamaran (2 hulls) boat used for research purposes. Actually, I don’t have a design yet, as a full detailed parameters need to be considered before implementing the design. I’m wondering in placing the thrusters; I read and saw most of the people use the 4 thrusters with certain degrees such as 45’ or 30’ which I don’t know why!. I asked here for the help because I don’t have much experience dealing with marine stuff.


(Kevin) #7

Not a problem, it sounds like you have seen some boats that are capable of dynamic positioning with 4 thrusters. If you have 4 thrusters at 45 degrees you can theoretically move in any direction at the same speed, however, it will be pretty slow an inefficient.

If you need more speed in the forward/back direction, I would have a setup with 30-20 degrees per thruster.

Control wise, I use ArduRover: http://ardupilot.org/rover/index.html However, that does not support dynamic positioning or 4 thrusters at the moment, so you would have to design something yourself.


(Yousef Orabi) #8

I’m concentrating on movements between obstacle avoidance and navigation around points. However, speed is needed in some cases. I understand that 4 vectored thrusters will provide more maneuverability for the vessel. Could you please support me with documents/ links that discuss positioning angles to select the best one.

Also, I’m using Arduino to control the thrusters [Bluerobotics T200 thruster] via the basic ESC 30A.


(Kevin) #9

I don’t have any resources on vessels with 4 vectored thrusters, nobody really uses it. The most common maneuvering setup for tight spaces with speed is two thrusters that area able to rotate. Spally had some on his boat here: https://www.bluerobotics.com/forums/topic/hull-design-ideas/#post-9708

And I looked all through the RoboBoat documents and they all seem to use either skit steer or straight shafts with rudders: http://www.robonation.org/competition/roboboat