Adaptive landing gear concept—feedback control validation

Abstract

The objective of this paper is to present an integrated feedback control concept foradaptive landing gears (ALG) and its experimental validation. Aeroplanes aresubjected to high dynamic loads as a result of the impact during each landing.Classical landing gears, which are in common use, are designed in accordancewith official regulations in a way that ensures the optimal energy dissipation forthe critical (maximum) sink speed. The regulations were formulated in order toensure the functional capability of the landing gears during an emergency landing.However, the landing gears, whose characteristics are optimized for these criticalconditions, do not perform well under normal impact conditions. For that situation it isreasonable to introduce a system that would adapt the characteristics of the landinggears according to the sink speed of landing. The considered system assumesadaptation of the damping force generated by the landing gear, which wouldperform optimally in an emergency situation and would adapt itself for regularlandings as well. This research covers the formulation and design of the controlalgorithms for an adaptive landing gear based on MR fluid, implementation of thealgorithms on an FPGA platform and experimental verification on a lab-scalelanding gear device. The main challenge of the research was to develop a controlmethodology that could operate effectively within 50 ms, which is assumed to be the totalduration of the phenomenon. The control algorithm proposed in this researchwas able to control the energy dissipation process on the experimental stand.