Estimation of position tracking using accelerometers and GPS?

software
#1

Howdy, I am a new Trident owner. I wanted to ask if anyone has tried to use the accelerometer data to integrate and estimate of the relative change in position while underwater, and also used the starting and ending GPS positions to re-map those relative positions to latitude and longitude? Seems like this would be fairly easy to do, but might require deleting or filtering the accelerometer data at the beginning and end of a dive when it is being yanked around by the tether. And adding the depth sensor data to create a 3-D track would be a bonus. My goal is to place tracks into Google Earth and to know what areas the ROV has explored. I appreciate any input.

(sorry if this is discussed in a separate topic, but i first tried searching for something similar).

(i might also start a separate topic to see if there is a control program to automate video transects)

#2

I’m very interested in the prospects of doing what you say! This could be a huge asset to make possible the real location position to whatever sensor data you are collecting at the time! I’m a Trident owner myself and would like to be able to geotag underway to my video stream. When the wifi data portal to Trident is free for the general public…I want to connect other sensors such as SONAR to the outside of the hull and do some detailed underwater mapping.

#3

@james.murray Searching on “acoustic” should show some forum topics. Problem is there’s not much current.
Acoustic Positioning Overview: SBL, LBL, etc
Acoustic Location System
Underwater Acoustic Communication

@bader.matt Would you further explain your comment “When the wifi data portal to Trident is free for the general public…?” It sounds like you’ve heard things OpenROV isn’t making available to all of us.

#4

We have discussed this quite a bit in another forum. The basic consensus is that the consumer grade IMUs are not sensitive enough to be used as an inertial navigation system (INS). They can be use for vehicle orientation, but not for velocity measurements. If not using an acoustic positioning system then, then you will need a sensor capable of measuring velocity against the seabed such as a DVL.

Because DVLs are hideously expensive, I recommend going the acoustic positioning route. Water Linked has a new Locator, the U1 that is entirely batter powered and could be mounted to a Trident. I’m just not sure where as to not throw off the balance. The Explorer Kit with a U1 is the most affordable acoustic positioning system that I am aware of.

https://waterlinked.com/product/locator-u1/