Research On Gust Load Alleviation Technology Of Civil Aircraft Based On Feedforward Control

When a large passenger aircraft encounters the gust,it will affect the ride quality of the aircraft and the pilot's control to a certain extent,and may even become a critical load on the structure,which adversely affects the weight of the structure.At present,some advanced civilian aircraft use gust load alleviation systems to actively control gust loads.Because gust load alleviation technologies involve aerodynamics,structure,and flight control,the gust load alleviation technology has become a highly dynamic system of aero-servo elasticity.problem.However,at present,domestic and foreign research status mostly adopts feedback closed-loop control strategies,and in actual engineering design,the implementation of the system is still limited by many constraints.Due to the characteristics of negative feedback control,there are often high requirements for system performance.As a result,the weight of the system is excessive.Modern large-scale civil aircraft are based on the concept of "no penalty weight design",and need to implement the gust load alleviation function without increasing the weight of the aircraft.This requires a better feedforward control scheme to reduce the System performance requirements.First,this paper uses the finite element and dipole grid methods to establish the aeroelastic model,and analyzes the typical system performance limitations and their effects in actual engineering,and captures its main system performance requirements,including the rudder deviation authority and speed of the control system.Limits and the maximum delay time allowed by the system.Secondly,based on the gust information detected by the airborne equipment,using wing tip acceleration,wing root bending moment and torque as gust alleviation indexes,a gust prediction and adaptive feedforward control scheme was designed to make up for the deficiencies in traditional feedback control.Finally,considering the typical three types of system performance limitations,the sensitivity of gust alleviation efficiency is compared and analyzed through numerical simulation.The research results show that the limiting factors of system performance requirements have a significant impact on gust alleviation effects.An adaptive feedforward control scheme designed using forward gust detection information has better gust alleviation effects and can effectively reduce the performance index requirements for the operating system.This article analyzes the performance requirements of the typical gust load alleviation system,which can provide a reference for the design of gust load alleviation systems.By studying new gust sensing methods,obtaining gust information,and designing an adaptive feedforward control scheme,it is based on forward It provides guidance for the design of gust load alleviation system based on feedback control,and provides support for the analysis of performance requirements of the gust load alleviation system on the control system.