【作者】 王娜；

【导师】 孙瑞胜；

【作者基本信息】 南京理工大学 ， 兵器发射理论与技术， 2019， 硕士

【摘要】 小型巡飞器以尺寸小、成本低、集侦查与攻击于一体等优点在现代战争中发挥出日益重要的作用。此类飞行器多采用倾斜转弯(Bank-to-turn,BTT)控制方式,以增加机动性能,提高气动效率,充分发挥大展弦比、大升阻比的优势。但是,BTT控制要求巡飞器绕弹轴快速滚转,加剧了通道间的耦合作用,再加上巡飞器受不确定项影响较大,使其控制系统的设计成为一项具有挑战性的研究课题。本文正是围绕这一问题,在巡飞器动力学建模与分析、BTT线性控制参数设计、BTT非线性控制参数设计、基于扰动观测器的控制参数设计及末制导飞行试验研究等几个方面展开了研究工作。首先,针对巡飞器的工作特点,建立了巡飞器空间飞行的运动方程,分析了三通道之间的耦合作用,为本文后续工作的开展奠定基础。其次,针对巡飞器BTT线性控制问题,基于忽略三通道耦合、小扰动、系数冻结等假设将非线性控制问题转化为线性控制问题,给出了三个通道的传递函数,并就弹体对操纵机构的动态响应进行了分析。在此基础上,采用三回路经典频域法设计各个特征点处控制参数,利用增益调度实现整个弹道控制参数自适应调整。六自由度弹道仿真表明耦合影响了控制的性能,但仍能快速准确地跟踪过载指令。第三,针对巡飞器BTT非线性控制系统存在耦合、不确定项的特点,设计了一种鲁棒反演控制律。将巡飞器的数学模型写成适用于反演算法的状态方程的形式,假设其由标称模型与不确定项组成,利用微积分学中的Leibniz法则推导不确定项。采用反演法推导控制律的基本形式,并通过基于改进符号函数的鲁棒函数抵消非匹配不确定项,利用Lyapunov重新设计技术补偿匹配不确定项。仿真结果表明,该系统有效消除耦合对控制性能的影响,能够快速准确地跟踪攻角、侧滑角、滚转角指令,具有强鲁棒性。第四,为了进一步改善线性控制方法的性能,提出基于扰动观测器的控制参数设计方法。给出非线性扰动观测器的改进形式,并将角速度微分方程中的耦合项看成外界干扰,利用非线性扰动观测器估计并补偿由参数摄动与外界干扰组成的复合干扰。仿真结果表明,该方法能够在不参与实际对象控制的情况下,有效抵消复合干扰对控制系统的影响,结构简单,容易实现。第五,为了验证所设计控制参数实际飞行时的正确性及有效性,开展了巡飞器末制导飞行试验研究。设计了盘旋方式进入末制导的飞行方案,并给出具体试验步骤。试验结果表明,即使风干扰、螺旋桨扭矩、耦合等因素影响了控制性能,巡飞器仍能稳定飞向目标。更多还原

【Abstract】 Small-scale loitering vehicles play an important role in modern warfare with its small size,low cost and integration of investigation and attack.This kind of aircraft mostly uses the way of the bank-to-turn(BTT)control mode to increase maneuverability,improve aerodynamic efficiency and make the full use of large aspect ratio and high lift-drag ratio.However,BTT control mode requires the loitering vehicle to roll around the longitudinal axis rapidly,which aggravates the coupling effect between the three channels.In addition,the loitering vehicle is greatly affected by uncertainties,making the design of its control system a challenging research topic.Consequently,this dissertation tries to carry out study on modelling and analysis of flight dynamics,BTT linear control design,BTT non-linear control design,disturbance observer-based control design and terminal guidance flight test for small-scale loitering vehicles.Firstly,in term of the feature of the small-scale loitering vehicle and BTT control,the 6DOF model of the loitering vehicle is established,and the coupling terms are analyzed,which lays the foundation for the subsequent work in this dissertation.Secondly,for sloving the problem of the BTT linear control,small disturbance,coefficient freezing and ignoring the coupling between three channels,etc.are proposed to transform the nonlinear system into a linear one.The transfer functions of three channels are obtained,and the responses to rudder of the loitering vehicle are analyzed.On this basis,three-loop classical frequency domain method is used to design the control parameters for each characteristic point.In addition,gain scheduling is used to realize the adaptive adjustment of the whole trajectory control parameters.Six-degree-of-freedom trajectory simulation shows that the coupling terms affect the control performance,but the controller can track overload instructions quickly and accurately.Thirdly,in view of coupling and uncertain characteristics of nonlinear control system for BTT cruise vehicles,a robust backstepping controller is designed to follow the control command.The mathematical model of cruise vehicles is transformed into a state equation which is suitable for backstepping algorithm.The equation is assumed to be composed of a nominal model and uncertain terms.The uncertain terms are derived and described by using the Leibniz rule in infinitesimal calculus.On this basis,the basic form of the control law is derived by exploiting backstepping algorithm.The modification of robust function i.e.,a new symbolic function,is conducted to compensate the unmatched uncertainties.Simultaneously,the Lyapunov redesign technique is introduced to control the matched uncertainties.The simulation results indicate that the presented control system can avoid the adverse effects of coupling and quickly track the commands of angle of attack,sideslip angle and bank angle,which shows the strong robustness of the system.Fourthly,disturbance observer-based controller design is proposed to improve the performance of linear control.The improved form of the nonlinear disturbance observer is introduced,and the coupling term in the angular velocity differential equation is regarded as external disturbance.The combined disturbance composed of parameter perturbation and external disturbance is estimated and compensated by the nonlinear disturbance observer.The simulation results show that this method can effectively counteract the influence of compound disturbance on the control system without participating in the actual object control.It is simple and easy to implement.Fifthly,in order to further verify the correctness and validity of the designed control parameters in actual flight,the terminal guidance flight test of the loitering vehicle is carried out.The flight scheme of hovering mode entering terminal guidance is designed,and the specific test steps are presented.The test results show that the loitering vehicle can fly steadily to the target even if the wind disturbance,propeller torque,coupling and other factors affect the control performance.更多还原