【作者】 刘亮；

【导师】 甄子洋；

【作者基本信息】 南京航空航天大学 ， 控制理论与控制工程， 2022， 硕士

【摘要】 本文以具有升力风扇的短距起飞垂直降落(Short Take-off and Vertical Landing,STOVL)飞机为研究对象,围绕该机起降过程中三种非常规飞行模式,开展了动力学与运动学建模、短距起飞控制律设计、减速过渡控制律设计、气动力与直接力复合控制分配、悬停/降落控制律设计、推力矢量动态控制分配等方面的研究,并通过仿真验证了所设计控制系统的有效性。首先,对某型具有升力风扇的STOVL验证机,建立了空中飞行段和地面滑跑段六自由度非线性数学模型,建模过程综合考虑了飞机的非线性气动特性、推力矢量系统布局、滑跑过程中地面力与力矩、飞行环境以及执行机构模型。在Matlab/Simulink环境下搭建了飞行仿真平台,为后文的控制律设计奠定了基础。其次,针对短距起飞段控制目标,分别设计了纵向通道和横侧向通道的控制策略和控制律。对于纵向通道,为了使STOVL飞机在尽可能短的滑跑距离内起飞以及离地后快速稳定爬升,给出了起飞段最优推力矢量预置方案,并设计了俯仰角PID控制律。对于横侧向通道,为了减小滑跑纠偏中的速度损失,采用只纠正航向角偏差的纠偏方案,利用粒子群算法与模糊控制对PID控制律参数离线寻优和在线调整,提高纠偏效果。然后,针对减速过渡段控制目标,采用分层式的控制系统结构,控制律和控制分配设计独立进行:基于非线性动态逆方法和时标分离原理,对飞机的三个子回路分别设计控制律,并通过固定时间干扰观测器对模型不确定项进行估计和补偿,以增强系统鲁棒性;对于气动力和直接力控制分配,将其转化为在非线性目标函数和约束条件下的参数最优化问题,通过自适应引力搜索粒子群算法进行求解,合理地分配各操纵量。最后,针对悬停/降落段控制目标,在沿用了分层式控制系统结构的基础上,根据该阶段飞机特点,对控制律和控制分配进行了调整:控制律基于增量非线性动态逆方法进行设计,削弱了动态逆方法对精确数学模型的依赖,提高了系统的鲁棒性;控制分配模块进一步考虑了操纵面的交叉耦合效应和执行机构的动态特性,并利用序列二次规划算法进行求解,提高了分配精度。更多还原

【Abstract】 In this paper,the research object is a Short take-off and Vertical Landing(STOVL)aircraft with a lift fan,focusing on three unconventional flight modes in the process of take-off and landing.The dynamics and kinematics modeling,control law design for short take-off,deceleration transition control law design,aerodynamic and direct force composite control allocation,hover/translation control law design,thrust vector dynamic control distribution and other aspects are studied.The effectiveness of the designed control system is verified by simulation.Firstly,to a certain type of lift fan STOVL test aircraft,a 6-DOF nonlinear mathematical model is established including the nonlinear aerodynamic characteristics of aircraft,thrust vector system layout,ground force and moment,in the process of flight environment and model of the actuator.The flight simulation platform is built in the Matlab/Simulink platform,which lays a foundation for the control law design in the following paper.Secondly,the control strategies and control laws of longitudinal and lateral channels are designed respectively for the control target of short take-off.For the longitudinal passage,in order to guarantee STOVL aircraft take off within the shortest distance and climb quickly and steadily,the optimal thrust vector preset scheme is given and the pitch PID control law is designed.For lateral and lateral channels,in order to reduce the speed loss during distortion correction,only the yaw angle correction scheme is adopted.In order to improve the correction effect,PSO algorithm and fuzzy control are used to optimize PID parameters.Then,in view of the slow transition section control target,using a cascaded control system structure,control law and control allocation are designed independently: the former is based on the nonlinear dynamic inversion method and the time-scale separation principle.A fixed-time disturbance observer is designed to estimate and compensate of model uncertainties.The allocation of aerodynamics and thrust vector is transformed into parameter optimization problem under nonlinear constraints,and solved by enhanced GSAPSO optimization algorithm.Finally,in terms of the hover/translational period of control target and plane characteristics,the cascaded control system structure is adjusted,including both control law and control allocation:control law is based on incremental nonlinear dynamic inversion,which weaken the dependence on the system model accuracy compared with conventional dynamic inversion method,and improve the robustness of the system;The control allocation module further considers the cross coupling effect of the control variables and the dynamics of actuator.To improves allocation accuracy,the sequential quadratic programming algorithm is used for optimization.更多还原