# Structure Optimization and Control Design of Electronic Oxygen Regulator
## 4 Experimental Analysis
### Analysis of Experimental Results  
The pressure profiles of the mask chamber at different lung fluxes at an inlet gas pressure of 150 kPa are shown in Figure 11. The positive peak of the waveform indicates the maximum expiratory pressure, and the negative peak indicates the inspiratory pressure [17]. At a lung ventilation volume of 20 L/min, the maximum inspiratory resistance was 0.25 kPa and the maximum expiratory resistance was 0.1 kPa. At a lung ventilation rate of 30 L/min, the maximum inspiratory resistance was 0.27 kPa and the maximum expiratory resistance was 0.13 kPa. At a lung ventilation rate of 44 L/min, the maximum inspiratory resistance was 0.4 kPa and the maximum expiratory resistance was 0.25 kPa. Comparing the appeal data with the ideal boundary values of respiratory resistance in Table 3, the peak resistance was all within the ideal boundary and much smaller than the boundary of respiratory resistance [22].  
Figure 10: Relationship between cockpit height and oxygen supply target pressure curve.  
The experimental data on the respiratory resistance of the indirect electronic oxygen supply anti-charge regulator are shown in Table 4. In comparison with the indirect oxygen regulator, it can be seen that the output of the direct oxygen regulator has less breathing resistance, which greatly enhances the comfort of the pilot when in use.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Lung Ventilation (L/min)** & **Peak Inspiratory Resistance (kPa)** \\ \hline
20 & 0.49 \\
30 & 0.59 \\
44 & 0.88 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Suction resistance of indirect oxygen regulator.  
Figure 11: Mask pressure curves under different lung fluxes.  
When the oxygen supply regulator was used for pressurized breathing, the target pressure values of the pressurization test were 2.0 kPa, 5.0 kPa, 7.5 kPa, and 8.5 kPa, respectively. The pressure curves of the mask cavity are shown in Figure 12a,b.  
During pressurization at 2.0 kPa, the pressure values can reached the target values at 0.4 s. When the pressurization value was at 8.5 kPa, the pressure value reached the stable target value at 0.6 s. The pressurization test process of the electronic oxygen regulator builds pressure quickly at different pressure targets. The speed of pressure building was within 0.8 s for all the different pressure tests. The smaller the target pressure of the pressurization test, the faster the pressure-building speed. For example, during the pressurization process at 2.0 kPa, the pressure value can reach the target value in 0.4 s. After the indirect oxygen regulator reaches the regulated pressure, there is a significant pressure fluctuation. However, indirect oxygen regulators have a longer pressure build-up time and exhibit significant pressure fluctuations.  
The direct oxygen regulator solves the problem of pressure fluctuation of the indirect oxygen regulator, and the single-neuron PID control strategy based on online recognition of the RBF neural network improves the system performance, resulting in less breathing resistance and faster pressure building during pressurized breathing with the direct oxygen regulator.