Identification of a Duffing Oscillator under Different Types of Excitation

Table 4

Identification results (noise 3%): percentage error $(100·|\text{estimated–actual}|$/actual).

$i$	$m$	$k$	$c$	$k_3$
60	0.68	1.87	1.54	2.98
90	0.76	1.37	1.22	2.32
120	0.57	0.74	0.80	1.37
180	0.51	0.66	0.63	1.20