Identification of a Duffing Oscillator under Different Types of Excitation

Table 3

Identification results (noise 1%): percentage error $(100·|\text{estimated–actual}|$/actual).

$i$	$m$	$k$	$c$	$k_3$
60	0.13	0.54	0.73	0.73
90	0.13	0.33	0.57	0.49
120	0.08	0.13	0.15	0.21
180	0.07	0.11	0.33	0.18