Identification of Engine Inertia Parameters and System Dynamic Stiffness via In Situ Method

Table 4

Sensitivity of the method to system stiffness errors at excitation locations.

	Direction
Estimated stiffness (K/m) with error ±34.8 mm		2688379.0	308.4	537109.7	80584.8	313371.1	−403403.0
		−260.8	272125.0	−652.6	−18363.7	−124.8	−67640.9
		538223.5	53.0	1417243.0	212655.4	138738.3	−80782.5
		80499.8	−18736.8	211808.6	55768.4	20651.1	−18095.9
		314727.8	−155.5	142674.1	21328.5	73933.7	−47109.5
		−403446.0	−66291.1	−80384.6	−17941.4	−46977.6	100948.6
Estimated error (%)		−0.25	—	0.18	0.21	−0.19	−0.22
		—	−1.15	—	0.44	—	−2.11
		0.39	—	0.08	0.11	0.05	0.45
		0.10	2.48	−0.29	0.06	−0.72	−0.64
		0.24	—	2.89	2.54	1.05	0.03
		−0.21	−4.06	−0.04	−1.49	−0.25	−1.36
Estimated stiffness (K/m) with error ±120 mm		2688603.0	274.3	536987.3	80564.2	313366.7	−403420.0
		−269.8	272111.2	−674.7	−18353.5	−128.6	−67632.9
		538230.5	42.9	1417220.0	212642.0	138718.0	−80775.2
		81008.9	−17557.0	212938.1	55060.5	20849.3	−18396.5
		314197.9	1176.8	140636.6	21094.4	73510.2	−47674.7
		−404670.0	−68378.2	−84502.7	−19264.0	−47828.2	102362.8
Estimated error (%)		−0.24	—	0.16	0.18	−0.20	−0.21
		—	−1.16	—	0.39	—	−2.12
		0.39	—	0.08	0.10	0.04	0.44
		0.74	−3.97	0.24	−1.21	0.24	1.01
		0.07	—	1.42	1.41	0.47	1.23
		0.10	−1.04	5.08	5.78	1.55	0.02