BystrickyK / SINDy

Physically-informed model discovery of systems with nonlinear, rational terms using the SINDy-PI method. Contains functionality for spectral filtering/differentiation.
MIT License
8 stars 0 forks source link

Double pendulum cart, but with a good function library #7

Open BystrickyK opened 3 years ago

BystrickyK commented 3 years ago

Trig functions of double angle differences can be decomposed into sine and cosine monomials like this: image

Using completely clean data, acceleration measurements generated using the analytical model (rather than numerical differentiation)

Discovered models, dotx4 = cart acceleration, dotx5 = first pendulum angular acceleration, dotx6 = second pendulum angular acceleration 4 5 6

Prediction results: Figure_4 Figure_5 Figure_6

Prediction is nearly perfect, but simulated trajectories decouple immediately; it might be due to a bug in the code though https://user-images.githubusercontent.com/55796835/117227428-11243b00-ae17-11eb-9df1-95b025d6f23b.mp4