Negative velocity for high speeds

[Kerby92]

Thanks for the project and code - very helpful to understand the UKF in detail.

However, it seems that there is something wrong in your application.
I created artificial measurements describing a perfect circle driving round and round infinitely with a radius of 50m.

The UKF is able to stabilize and estimate the state properly (not immediately, took some time, maybe i have to adjust the process noise parameters), but when setting high speeds e.g. 230 km/h, the output velocity "x_(2)" is negative, which doesn't make sense for the amount of speed.

I was investigating your code, but wasn't able to find the root cause for it.
Do you have any idea?

Best regards,
Kerby