A GM (1, 1) Markov Chain-Based Aeroengine Performance Degradation Forecast Approach Using Exhaust Gas Temperature

Table 1

The comparison results of GM (1, 1) model and GM (1, 1) Markov chain model.

Cycle	Forecast model
	Original values	Linear model	Nonlinear model	ARIMA model	RBF model	GM (1, 1) model
4200	86	73.088	74.66925168	76.24820454	83.893778	74.850179
4400	86	71.808	73.63116571	85.04659158	75.345291	73.899849
4600	76	70.528	72.60751169	85.09212012	66.440678	72.961583
4800	72	69.248	71.59808897	79.58775994	77.213138	72.035231
5000	64	67.968	70.60269971	69.85924741	75.907728	71.12064
5200	66	66.688	69.6211488	69.85924741	51.433499	70.217661
5400	72	65.408	68.65324386	70.37022346	77.51105	69.326147
5600	70	64.128	67.69879518	74.57638112	68.512595	68.445951
5800	58	62.848	66.75761567	72.84613016	52.139635	67.576931
6000	62	61.568	65.82952088	62.6255194	75.584126	66.718945
6200	66	60.288	64.91432888	65.48119394	63.496734	65.871852
6400	58	59.008	64.01186029	68.51302315	64.808649	65.035514
6600	60	57.728	63.12193824	61.40259349	54.990815	64.209794
6800	60	56.448	62.24438829	62.78391435	60.518705	63.394558
7000	60	55.168	61.37903843	62.49368451	62.428861	62.589673
7200	64	53.888	60.52571907	62.25825584	61.24122	61.795007
7400	60	52.608	59.68426294	65.60171099	57.527047	61.01043
7600	68	51.328	58.85450511	62.02015608	58.92226	60.235815
7800	62	50.048	58.03628296	68.8277359	53.706033	59.471034
8000	68	48.768	57.22943611	63.72946594	60.035962	58.715964
8200	66.5	47.488	56.4338064	68.75093548	60.237787	57.97048
8400	65	46.208	55.64923791	67.47264457	67.031388	57.234461
8600	55	44.928	54.87557684	66.17459205	53.436919	56.507787
8800	55	43.648	54.11267156	57.5174732	55.602918	55.79034
9000	57	42.368	53.36037254	57.31506291	58.04245	55.082001