How to create a moving platform that follows a user-defined path

[ekhunter123]

Hi. I'm using Stone Soup on a real dataset and I have a question about the moving platforms. My data is air-to-ground and I would like to use a MovingPlatform class to work with the airborne Sensor. I know the location of the sensor at each time step. Is it possible to feed this data into the platform and make it follow the given path? I've seen the MovementController class but I can't figure out how to incorporate this. Any suggestions? Thanks!

[oharrald-Dstl]

You could use the create_smooth_transition_models (constant accel, constant turn) or ConstantJerkSimulator (constant jerk) simulators to achieve this. You pass them a sequence of timestamped states and they will attempt to generate a sequence of transition models and durations (intended to be passed to the MultiTransitionMovingPlatform) that will allow a platform to achieve the states in the timestamps specified.
See:
https://stonesoup.readthedocs.io/en/latest/auto_examples/Smooth_Platform_Coordinate_Transitions.html#sphx-glr-auto-examples-smooth-platform-coordinate-transitions-py

[ekhunter123]

Thank you! That looks perfect.

[ekhunter123]

That seems to be working pretty well, but I get a problem when the time difference between each platform movement increases. Here is a gist to show what I mean.

I set up three platforms with the same points and same times. I set it so that it takes the platform 1 hour to get between each of the points. If I make the platform move in 100 or 500 second chunks it works fine and it follows the defined path as seen below.

But then if I make it take 600 second steps, it suddenly veers off course about halfway through the simulation. I've tried this with a few other examples and I get the same result as soon as I increase the sim_rate parameter too much. Does anyone know what is causing this?

Thank you :)