The Development of Neural Network Based System Identification ...

LIST OF FIGURES
xxiii
5.13 The prediction from HMLP network for pitch dynamics. (a) The one-step
ahead prediction overlaid with the measured helicopter responses. (b)
The error plot between one-step ahead prediction and the measurement
data. The red dashed line indicates estimation from the HMLP neural
network model while solid blue line with ‘x’ marker represents the output
measurement. 136
5.14 The self connection α strength selection results using modified Elman
network with reduced connection.
The Elman network training are
repeated 10 times and validated on a test set. The training is carried out
using 6 hidden neurons. 139
5.15 The validation RMSE comparison for different hidden neuron sizes. The
k-cross validation process was conducted for modified Elman network
with network structure of 4 regressors (n y = 1 and n u = 1). The neural
network training was carried out using the off-line Levenberg-Marquardt
(LM) algorithm. 140
5.16 The prediction from the modified Elman network for roll dynamics. (a)
The one-step ahead prediction overlaid with the measured helicopter
responses. (b) The error plot between one-step ahead prediction and the
measurement data. The red dashed line indicates estimation from the
modified Elman network while solid blue line with ‘x’ marker represents
the output measurement. 141
5.17 The prediction from the modified Elman network for pitch dynamics.
(a) The one-step ahead prediction overlaid with the measured helicopter
responses. (b) The error plot between one-step ahead prediction and the
measurement data. The red dashed line indicates estimation from the
modified Elman network while solid blue line with ‘x’ marker represents
the output measurement. 142
5.18 The percentage of Root Mean Square Error (RMSE) comparison plot for
off-line Levenberg-Marquardt (LM) and recursive Gauss-Newton (rGN)
training methods. 145