How stable the trident is?


I watched many videos and found in all videos the trident, which I believe better than V2.8 2.7 etc, didn’t show very stable performance. The horizontal line is still off by some angle, or the boat is not on the horizontal plane during turning or exploring. Does it mean the 3 thrusters design has an intrinsic shortfall? The feedback control is open loop only? or is passively controlled by buoy / weight?

I watched the gladius mini 4k which shows better. I watched other brands they showed more or less problems similar to openROV’s.



@dumbomb My experience with the Trident and stability has been very positive. I just reviewed a few bits of raw footage and didn’t see any issue. Not sure what you’re talking about. Could you give me an example of a video and exactly what your are talking about, and where I can find an example in the video?



0:22-0:24: from 0 speed to turn left
0:29-0:31: forward, apparently the boat is tilting
or check carefully about turning, forwarding, upward or downward is lacking(I believe worse), during moving, the boat either upward a little or downward a little. it’s hard to keep moving on a horizontal plane.

compare to the motion control of this:


I think there are a couple things at play here.

First is driver experience. The Trident in the video looks like it’s being operated at high thruster speed which results in choppy, lunging performance by an inexperienced operator. High speed is better at covering ground in straight lines than tight manuveuring.

It does appear the Gladius may be more stable in pure up/down movement due to more thrusters, I find the Trident likes to pitch up and down slightly, but the apparent benefit ( I do not have a Gladius to compare) is that it can “fly” at higher speed and descend and ascend quicker, and does seem very stable at those speeds. This “flight” inspired design moves differently through the water than traditional ROV’s so it banks in turns like a plane but almost immediately returns to level when going straight or stopping.

I do find the tether can create a significant amount of drag depending on what depth you are operating at, how much line is in the water and boat movement, currents, etc. This instability will probably be similar in all tethered ROV’s with larger, heavier ROV’s more stable than lighter ones.


I agree with @alaskasurf. I use the high speed for covering ground and not doing sharp maneuvers while trying to accomplish a goal. The high speed would require you to do short thrusts to careful navigate the maneuvers, thus promoting a bit of tilting.

Another thing to consider is that in the video not only is the pilot doing short high speed thrusts, the tether is also dragging on the hoop as its attempting to do a 180. The drag would also cause some issues.

I have not had any issues like this at all. My footage seems very clean and stable so far.