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Articulating Thruster ROV

(Terry) #1

My first prototype is a positive buoyant ROV that uses four T100 thrusters to create ballast and directional control. The four thrusters articulate via HiTec servos housed in a watertight NEMA enclosure. I’m using an Arduino MEGA2560 microcontroller, with on board accelerometer, Bar30 pressure sensor, and water sensors. My controller is dual joystick control for forward/reverse, left/right, cw/ccw rotation, and up/down. I also have an lcd screen and multiple pots for feedback and adjustments on the fly.

Most of my testing has been in a trash can, but I’ve finally gotten some pool time (see video link). I’m using the accelerometer to try to maintain level while changing directions. I’m hoping that once I figure out the parameters I need for responsive level and depth correction, I can add more buoyancy, increasing my thruster output and maneuverability.

My tether is a relatively short and heavy 25 wire cable. I found it’s just as easy to tie it to the bottom and let it sink versus trying to make it float. I don’t expect the enclosure to go much deeper that 15ft so I didn’t bother with a longer cable. This is more of a proof of concept but I would appreciate any and all input.



(undersearobotics.com) #2

Interesting build and some very clever ideas. Looking forward to watching this…

(Jacob) #3

Awesome project! I would like to see more about the controller. Why 25 wires? Are you using some wires to carry analog signals from the pots?

(Kevin) #4

This is awesome and one of the first vehicles I’ve seen with this drive mechanism. What is the max speed in the forward direction?

(Terry) #5

The controller has two XY joysticks (fwd/rev, left/right, cw/ccw, up/dn), two rocker switches, 7 potentiometers (ballast, speed angle, joystick zeros, accelerometer gain, etc), and an LCD screen. Since I was only going with a 20ft tether, the 25 wire seemed a simple way to communicate. Once I move to a hull that is capable of more depth and define my running perameters, I will likely move to a lighter tether.

The forward speed is relatively slow at this point because it’s directly related to the ballast thrust required. I need to get a better handle on the stability, then I can add buoyancy foam to increase the required thruster speeds, thus increasing the travel velocity.

(IP68) #6

Cool project I like the idea with vectored thrusters , looks like a quadcopter for underwater ,

How did you fixed thrusters to the shafts , Im building a boat and using same sort of setup for steering, are these the hubs from auctobotics?



(Terry) #7

I attached the thrusters to the shafts using hub horns from ServoCity. I think they are similar to Actobotics. I did run into an issue attaching to the shaft with a single screw at the center (without spline). This is not a very robust design because it is difficult to lock in place and still allow disassembly. Make sure you have some type of positive rotation lock between the hubs and the shaft.

(IP68) #8

ServoCity is like a big daddy to Actobotics so Im glad we talking about the same source, Ive looked in to Actobotics hubs and couplers before but got turned down due to different Mounting Hole Spacing , BR thrusters have 0.750 and Actobotics 0.770 , so slightly different in hole patterns and might not line up properly in addition the screws are not the same, did you do any modifications to thrustrers or hub ?If your hubs have a good match I would use them in conjunction with dual pinch bolt clamping hub for best grip.

Check my video below ( please ignore the issue with dual servo control, its been sorted by now)