Table 2.

The RMSE (${}^{\circ }$) comparison of three algorithms when IMUs on three subjects were bound in position 1.

	Subject 1			Subject 2			Subject 3
	DWPSO	GWO	GN	DWPSO	GWO	GN	DWPSO	GWO	GN
${\mathrm{H}}_{\mathrm{FE}}$	8.65	9.09	9.36	10.63	10.97	11.05	8.17	9.65	11.90
${\mathrm{H}}_{\mathrm{AA}}$	3.72	6.42	7.90	5.97	7.36	12.53	3.42	7.83	9.61
${\mathrm{H}}_{\mathrm{IE}}$	4.53	5.13	5.26	3.29	4.15	4.69	5.71	6.08	6.86
${\mathrm{K}}_{\mathrm{FE}}$	5.77	6.86	7.45	4.35	5.61	5.99	2.06	3.41	3.76
${\mathrm{K}}_{\mathrm{AA}}$	1.12	3.42	5.02	6.01	7.86	10.34	4.98	6.93	9.28
${\mathrm{K}}_{\mathrm{IE}}$	3.16	5.26	7.02	4.54	6.37	7.63	1.57	4.25	6.97
${\mathrm{A}}_{\mathrm{FE}}$	4.03	5.69	7.36	3.81	4.08	6.62	5.43	8.62	9.45
${\mathrm{A}}_{\mathrm{AA}}$	5.76	6.83	7.71	3.55	5.67	9.71	3.26	4.54	4.86
${\mathrm{A}}_{\mathrm{IE}}$	21.05	23.07	23.45	25.41	26.06	26.83	20.25	21.79	23.67