Research On Electronic-pneumatic Cabin Pressure Controlling System

Electronic-pneumatic cabin pressure controlling system was introduced and analysis by simulation and experiment in the paper. Based the structure and the principle of the whole system, mathematical models were established which included the aircraft cabin, controller, outflow valve and controlling cavity etc. Outflow valve was the main part of cabin pressure system which structure was presented in the paper. Transfer function was obtained by linearizing mathematical models of the controlling system. The stability and dynamic response of the system were analyzed using MATLAB and the range of PID(Proportional Integral Derivative) parameters were obtained. In the paper the controlling method was put forward: Divide the flight into three states which are climbing, diving and flying at an altitude and three sections which are open ventilation, absolute pressure control and pressure difference control. The system simulation was established using Simulink moduls of MATLAB which would be one of the independent component of the whole ECS(Environmental Control System). Based the control method, the test was done to testify the effectiveness of the control method. Experimental results showed that the method was good enough to satisfy the requirement of the rule of cabin pressure and the pressure difference.The results in this paper would help to provide the basis in theory for Electronic-pneumatic cabin pressure controlling system and Digital Electronic cabin pressure controlling system.