气动式座舱压力调节系统稳定性的分析与优化

Stability analysis and optimization for pneumatic cabin pressure regulating system

为了解决气动式座舱压力调节系统装配飞机时出现的座舱压力波动现象,分析了座舱压力控制系统的组成,根据余压段实际参与压力调制的组件,对控制系统进行了简化,以此为例分析系统的稳定性。首先对系统中的非线性环节进行了详细分析,得到其描述函数和负导描述函数曲线。比较了小孔-气容结构在常压、小幅充放气条件下的过渡过程,发现在该使用条件下的充放气时间基本相等,据此将小孔-气容结构的传递函数建模为一阶环节,指出了二者的相同及不同之处。使用描述函数的方法对系统的稳定性进行判断,提出了实现稳定的可行性方法。全物理仿真结果表明,使用该方法可使座舱压力调节系统的性能达到规范所要求的指标。

Pressure oscillation arises in cabin of aircraft equipped with the considered pressure regulating system. To solve the problem,the scheme of cabin pressure regulating system was introduced and analyzed.The system in differential pressure flight phase is simplified according to actual components participating in the pressure modulating. The simplified system was taken as an example for stability analysis. The nonlinearity of the system was analyzed in details. The describing function was obtained and the negative inverse describing function curve was plotted. The charging and discharging dynamic of hole-container structure was studied,and it was found that the charging and discharging transient was almost same in the condition. Then the transfer function of hole-container structure was built as first-order element,and the similarities and differences between them were pointed out. Describing function method was employed to analyze stability of the system,and a way of achieving stability was proposed. Full-physical simulation result shows that the required stability is achieved by this way.