Analysis And Design Of Novel Inerter Based Buffer System For Unmanned Aerial Vehicle Landing Gear

ISD structure is the abbreviation of Inerter-Spring-Damper structure,which is a novel inerter based buffer structure.Compared with the original Spring-Damper buffer structure,the dynamic element inerter is innovatively added in ISD structure.The effectiveness of the novel inerter based buffer structure has been verified in many fields.The research of landing gear buffer system based on ISD structure is a frontier subject.The landing gear ISD buffer system can reduce the impact damage of unmanned aerial vehicle(UAV)during taxiing and falling processes,improve the reliability of UAV system,as well as bring into good economic benefits and good military value.In this study,the ISD buffer structure is applied into the UAV landing gear buffer system,which is the novel inerter based buffer system for UAV landing gear,and the theoretical research,simulation analysis and bench experiments are carried out.The purpose of this study is to analyze the response characteristics of the novel inerter based buffer structure used in UAV landing gear buffer system,design a prototype of ball-screw inerter for UAV landing gear buffer system,analyze the response of the prototype,and verify the effectiveness of the novel inerter based buffer system.The main contents and conclusions of the study are as follows:(1)Modeling and verification of ball-screw inerter-the key parts of UAV landing gear ISD buffer system.In this study,considering the mass of each component,the dynamic model of ball-screw inerter is established.This study introduces the principle of inertance testing experiments of ball-screw inerter,and the inertance testing experiments of ball-screw inerter are carried out.The dynamic model of ball-screw inerter is verified by experiments.(2)Modeling and verification of virtual-real mapping model of ball-screw inerter-the key parts of UAV landing gear ISD buffer system.Improper installation pre-tightening force can lead to friction fluctuation of kinematic pairs,nonlinear enhancement of ball-screw inerter and nonlinear fluctuation of measured inertance.In order to judge whether the inerter is installed properly,the virtual-real mapping model of ball-screw inerter is established,and the virtual-real mapping experimental system is constructed,which can provide technical support for the operation and maintenance monitoring of ball-screw inerter.(3)Design and implementation of a new inerter for UAV landing gear ISD buffer system.A ball-screw inerter is designed for the landing gear buffer system of medium and large unmanned aerial vehicles.In order to reduce the impact of traditional inerter with constant inertance caused by switching the moving directions,a ball-screw inerter with double mechanical diodes is designed,and its dynamic model is established.The anti-impact characteristics of the new inerter are verified by experiments.(4)Research and optimization design of dynamic breakdown characteristics of inerter for UAV landing gear ISD buffer system.When dynamic breakdown of inerter occur,the dynamic characteristics of UAV landing gear ISD buffer system will suddenly change,which is not conducive to the exertion of buffer performance.In this study,the definition of dynamic breakdown of inerter is given,the breakdown characteristics of inerter in ISD buffer system are studied,and the optimal designs of two kinds of ball screw inerters with superior anti-breakdown characteristics are given.(5)Modeling and experimental verification of UAV landing gear ISD buffer system.The dynamic model of UAV landing gear ISD buffer system is established,and the response characteristics of ISD buffer system are explored.Based on the designed ball-screw inerter,an experimental platform of UAV landing gear ISD buffer system is built,and frequency sweep experiments are carried out.The model of UAV landing gear ISD buffer system and its effectiveness are verified by experiments.