[Retracted] Research on Optimal Control Method of Tennis Racket String Diameter Based on Kalman Filter Algorithm

Table 4

Swing vibration frequency of different material groups.

NO	16L polyester thread	16L nylon imitation gut	NO	16L polyester thread	16L nylon imitation gut	NO	16L polyester thread	16L nylon imitation gut
1	4.36	5.88	17	5.76	5.75	33	5.80	4.70
2	5.46	5.56	18	4.62	4.91	34	5.63	6.20
3	5.26	5.24	19	5.56	5.40	35	5.47	5.86
4	5.25	4.92	20	5.62	5.44	36	5.55	5.40
5	5.30	5.84	21	5.77	5.42	37	5.87	6.08
6	5.03	5.86	22	4.92	5.28	38	5.58	4.88
7	4.81	5.63	23	5.56	4.72	39	4.62	5.17
8	4.83	5.97	24	4.41	5.12	40	4.62	6.06
9	4.80	5.67	25	5.06	5.28	41	5.00	4.72
10	5.28	5.25	26	4.75	6.05	42	5.00	6.28
11	4.80	4.92	27	4.53	5.75	43	5.28	5.98
12	4.43	5.08	28	5.85	5.37	44	5.83	4.74
13	5.14	5.15	29	5.49	4.79	45	5.21	5.11
14	5.63	5.16	30	5.49	4.85	46	4.84	4.91
15	4.77	5.08	31	4.55	6.23	47	5.74	5.74
16	4.92	5.32	32	4.86	4.92	48	4.39	5.11