Design and Simulation of Aircraft Landing Gear Retraction Hydraulic Servo System

Abstract

Aircraft landing gear retraction and extension are commonly actuated by hydraulic cylinders. Traditionally these hydraulic systems do not include servomechanisms. In this research, a speed controller and a servo valve are attached to the actuator to control the motion. Speed input is composed to generate steady retracting motion. Feedback control with an integrator is adopted. A simulation model containing landing gear mechanism, hydraulic system and the controller is built to investigate the performance of control law. By choosing appropriate gain, landing gear retraction duration and the impacts during retraction are reduced.