Research On Aircraft Door Open And Closed State Detection System

Most of the cabin doors in civil aircraft are pressurized.The environment control system supercharges the cabin during the flight.As the larger open-able places of the fuselage,the cabin doors must be in a completely closed and locked position,so as to avoid the failure of pressure loss in the cabin caused,which will affect the cabin environment or even flight safety.Therefore,the accurate real-time detection of the open and closed positions of cabin doors is extremely important.The process of the doors’ opening and closing depends on the precise movement of the actuating mechanism of the doors,the correct indication of the doors’ opening and closing state in the door’s signal control system and the accurate detection of position by the proximity sensors.Therefore,the composition and function of the doors’ mechanism and signal control system are analyzed,and the restriction mechanism under the condition of door opening and closing is obtained.After comparing the principle and characteristics of different types of sensors,in consideration of the characteristic of unable to detect the metal objects,a photoelectric proximity sensor is proposed to detect the door position substitute the inductive proximity sensor.And an experimental platform for simulating the position detecting of aircraft cabin doors is designed and manufactured.Based on the analysis of the door actuating mechanism in the boarding door of a certain type of aircraft,the function of the door opening and closing state detection system and the function and overall structure of the experimental platform are determined.The hardware circuit device is designed and made by using STM32 as the processor,and the C language program is completed.The device can simulate the function of the detecting the doors’ position when the aircraft is in flight or ground state.Finally,based on the experimental platform,the function and performance of two types of photoelectric proximity sensors for position detection are verified.The comparison results show that the reflective photoelectric sensor can avoid the limitation of the detection object by the inductive sensor,and the photoelectric proximity sensor can be considered to use for the detection of the doors’ position.