## 4 Conclusions  
This paper introduces the method and theory of identifying modal parameters of systems based on ambient excitation. It describes the modal test method under ambient excitation and its implementation process. It presents the method of identifying the dynamic parameters of a single person by establishing the coupled human-structure system and the modal tests of the test floor carried out under two conditions: an empty structure  
Figure 16: Identification result of MSD model parameters of the subjects at pacing frequency of 2.1 Hz: (**a**) Group 1; and (**b**) Group 2. Note: \(f_{G1}\) means the mode frequency of the high stature group, \(f_{G2}\) denotes the mode frequency of the short stature group, \(\xi_{G1}\) denotes the damping ratio of the high stature group and \(\xi_{G2}\) denotes the damping ratio of the short stature group. Figure 15: Identification result of MSD model parameters of the subjects at pacing frequency of 1.9 Hz: (**a**) Group 1; and (**b**) Group 2. Note: \(f_{G1}\) means the mode frequency of the subjects in high stature group, \(f_{G2}\) denotes the mode frequency of the subjects in short stature group, \(\xi_{G1}\) denotes the damping ratio of the subjects in high stature group and \(\xi_{G2}\) denotes the damping ratio of the subjects in short stature group. and a pedestrian walking on the floor at different step frequencies. The identification results show that the mean value of the frequency and damping ratio (walking frequency was 1.5 Hz) was 2.1702 Hz and 27.77%. When the walking frequency was 1.7, 1.9 and 2.1 Hz, the mean value of the frequency and damping ratio were 2.1362 Hz and 29.37%, 2.1104 Hz and 30.74% and 2.0894 Hz and 32.24%, respectively. Meanwhile, there exists a significant negative correlation between the mode frequency of the pedestrian and the mass of the body at different walking frequencies. However, the relationship between the damping ratio of the pedestrian and the body mass is unclear. By dividing the test subjects into two groups by height, it was found that, for the high stature group, their body frequency was lower than that of the short stature group, but their body damping ratio was higher. The correlation analysis showed that the correlation between body frequency and body weight remained consistent for different stature groups, that is, a negative correlation was observed. This indicates that pedestrian body weight has a critical effect on body frequency relative to pedestrian height and should be handled with caution when considering pedestrian-structure interactions. Different from the methods commonly adopted in the field of biomechanics to obtain dynamic parameters of the human body using an excitation platform [34; 35], this study is dedicated to the parameters obtained from a full-scale pedestrian-floor coupling system. The full-scale slab platform in this study can eliminate the deficiency of an excitation platform with a high level of excitation intensity, as well as the incapacity to perform pedestrian parameter identification due to the small platform. It is worth noting that, in this study, floor slabs were used as the research object, which is different from the usage of footbridges to study pedestrian-structure interactions in recent years [42; 43; 44]. By substituting the floor slab for the footbridge as the object of this study, it was feasible to explore further the influence of different structural types on the pedestrian-structure interaction and give a reference for the vibration serviceability design involving large span floors. In summary, this study provides human dynamic parameters for the design of light and flexible large-span floor slabs considering pedestrian-structure interactions. However, several limitations of this study merit emphasis. 1. In this study, the walking pedestrian was considered as an unmovable SDOF MSD dynamics model.