Identification of a Duffing Oscillator under Different Types of Excitation

Table 2

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

	$m$	$k$	$c$	$k_3$
(Case 1-up) Upward sweep	4.63	4.01	4.04	5.86
(Case 1-down) Downward sweep	1.71	1.30	2.64	3.97
(Case 2) Random	0.13	0.54	0.73	0.73