Re placed inside the second position, the accuracy of your three algorithms were ranked the identical. When the GWO is used for position calibration, the initial population is easy to become unevenly distributed and lacks global communication, resulting within the final answer getting effortless to fall into local optimization. Within the DWPSO algorithm, we introduce dynamic weight to handle the speed with the initial population and increase the accuracy of your algorithm. Consequently, the calibration efficiency of your GWO is reduced than DWPSO. Having said that, the introduction of dynamic weight increases the complexity in the PSO algorithm and reduces the efficiency of DWPSO.Sensors 2021, 21,17 of25The IMUs in positionDWPSO GWO GN25The IMUs in positionDWPSO GWO GNRMSE(15 10 5RMSE(HFE HAA HIE KFE KAA KIE AFE AAA AIE15 ten 5HFEHAAHIEKFEKAAKIEAFEAAAAIEJoint degrees of freedom (DOF)Joint degrees of freedom (DOF)(a)(b)Figure 9. The RMSE comparison of 3 algorithms when IMUs on topic 1 have been bound in two positions. (a) The IMUs in position 1; (b) the IMUs in position two.30The IMUs in positionDWPSO GWO GN25The IMUs in positionDWPSO GWO GNRMSE(RMSE(HFE HAA HIE KFE KAA KIE AFE AAA AIE20 15 10 515 ten 5HFEHAAHIEKFEKAAKIEAFEAAAAIEJoint degrees of freedom (DOF)Joint degrees of freedom (DOF)(a)(b)Figure ten. The RMSE comparison of 3 algorithms when IMUs on topic two have been bound in two positions. (a) The IMUs in position 1; (b) the IMUs in position 2.25The IMUs in positionDWPSO GWO GN25The IMUs in positionDWPSO GWO GNRMSE(15 10 5RMSE(HFE HAA HIE KFE KAA KIE AFE AAA AIE15 ten 5HFEHAAHIEKFEKAAKIEAFEAAAAIEJoint degrees of freedom (DOF)Joint degrees of freedom (DOF)(a)(b)Figure 11. The RMSE comparison of three algorithms when IMUs on subject 3 had been bound in two positions. (a) The IMUs in position 1; (b) the IMUs in position two.Table 1 shows the typical and common deviation (SD) of 15 computation times of three algorithms, and all algorithms are completed on the similar laptop. As shown in Table 1, the GWO utilizes the shortest average computation R428 In Vivo occasions, followed by the DWPSO, along with the GN Ro 67-4853 medchemexpress requires the longest. When a higher calibration accuracy and rapidly algorithm efficiency are essential, the GWO may be utilized for calibration. On the other hand, the SD worth from the GWO could be the highest, indicating that the algorithm is less steady than DWPSO and GN, which might lessen the efficiency. The DWPSO algorithm is relatively steady, along with the optimization efficiency is better than the other two algorithms. When there is certainly no requirement for speed, the DWPSO may be the ideal choice.Table 1. Average and standard deviation (SD) of 15 computation times on the DWPSO, GWO, and GN.Algorithm Form DWPSO GWO GNAverage (s) 1076.1 576.3 1556.SD 2.01 3.76 two.Sensors 2021, 21,18 ofCombined with all the analyses in Table 2 and Figures 91, although the heights and sexes with the subjects are distinctive, the variation range in the outcomes of every single topic is roughly precisely the same, along with the functionality on the calibration algorithm can also be the exact same. This is mainly because the 3 calibration algorithms are carried out beneath precisely the same joint constraints plus the joint constraints of each and every subject will be the exact same, which will not be impacted by the unique gait characteristics of your subjects. Thus, topic 1 is selected because the sample for evaluation. Figure 12 shows the variation on the joint angle of IMUs in position 1 for five s. It shows that the angle variation waveform of each joint is consistent with all the reference value, only the up and down translation is created i.