Monitoring system for shock absorbers: application to lightweight aircrafts

During flight, the aircraft mass repartition has a deep impact on its stability together with the landing phase. As far as landing is one of the most critical phase of a flight, before taking off, pilots have to take care of the aircraft's center of gravity, by estimating masses and their repartition. Aircraft owners also would like to be informed of landing gears wear, so predictive maintenance would be an added value for safety. This paper presents the design of an embedded system prototype which continously provides monitoring about the status of the shock absorbers (pressure and accelerations inside them). Our theoritical model shows that, on the first hand, pressure inside shock absorbers is directly linked to the mass estimation; on the other hand, acceleration at landing phase is linked to the effort. The authors propose a mechatronic sytem to measure masses sustained by each landing gear, using low-power electronic boards, MEMS sensors, and a Java Human Machine Interface (HMI) for smartphones.