基于超静定配平的机动载荷控制风洞试验

介绍了俯仰机动载荷减缓(MLA)在某运输类飞机缩比风洞试验模型上的应用,旨在通过风洞试验研究一种基于超静定配平原理的机动载荷控制方法。首先,对模型飞机纵向超静定配平方法进行了研究并从理论上揭示通过其减缓机动载荷的基本原理;然后,依据超静定配平原理设计了MLA控制律,通过反馈模型飞机等效过载驱动副翼偏转减小机翼载荷,同时偏转升降舵来保持飞机的俯仰机动性能;最后,依次实施了超静定配平试验,气动伺服弹性稳定性试验以及机动载荷减缓试验,分别用以确定MLA控制律参数,检查控制系统稳定性以及获取俯仰机动时的系统响应。试验结果表明:在MLA控制律作用下,机翼根部弯矩增量比MLA控制律关闭时减小了10%以上,而模型飞机的俯仰机动性能基本保持不变;MLA控制律的加入使控制增稳系统稳定性略有下降;通过超静定配平试验确定MLA控制参数的方法有效提升了MLA控制律设计可靠性,使翼根弯矩减缓量接近目标值。研究工作为运输类飞机的机动载荷控制设计与试验提供了一种可行途径。

Wind-tunnel test of maneuver load control based overdetermined trim

Pitching maneuver load alleviation (MLA) is demonstrated on the scale-down wind-tunnel test model of a generic transport aircraft.The objective of the research is to develop an approach for maneuver load control based on overdetermined trim theory via wind-tunnel test.The longitudinal overdetermined trim method for the test model is studied and the fundamental of alleviating the maneuver load by this method is revealed theoretically.The MLA control law is then designed based on the overdetermined trim theory,which utilizes equivalent normal acceleration feedback to deflect aileron and elevator to alleviate wing load and maintain pitch maneuver performance of the test model respectively.The overdetermined trim experiment,aeroservoelastic stability experiment as well as the maneuver load alleviation experiment are implemented in sequence to determine the MLA control law parameters,check the stability of the control system and obtain the system response during pitching maneuver,respectively.The experiment results indicate:when MLA control law functions,the incremental wing root bending moment decreases by more than 10％,compared with that without MLA control law;while the pitch maneuver performance remains almost unchanged;introduction of the MLA control law results in slight decrease of stability of the control augmentation system;the approach of determining MLA control parameters by overdetermined trim experiment effectively improves the reliability of MLA control design,making the amount of reduced wing root bending moment close to the target value.This investigation can provide a feasible approach for MLA control design and test of generic transport aircrafts.