System Identification using ANN

System identification using artificial neural network example

This example file shows system identification using artificial neural network (ANN) of 2DOF system subjected to Gaussian white noise. The neural network consist of the following layers:

-Input layer: 2 nodes for the force at the current step and 2 nodes for the displacement at the previous step using open-loop feedback
-Hidden layer: 2 nodes for two inner states because there are 2 modes for 2DOF system
-Output layer: 2 nodes for the displacement

After training and getting the predicted output, the network was converted to closed-loop network and trained again (closed-loop networks uses predicted feedback from previous step instead of actual feedback). The predicted output from open-loop and closed-loop networks was compared with the actual output in a figure. It shows open-loop network is more accurate than closed-loop network due to the availability of actual output from the previous step.