【作者】 杨旭；

【导师】 姚晓先；

【作者基本信息】 北京理工大学 ， 航空宇航科学与技术， 2016， 博士

【摘要】 动能拦截器利用其高速飞行所产生的巨大动能,通过自主探测、制导与控制采用直接碰撞的方式摧毁来袭目标。拦截器进入末制导阶段时,为了搜索目标其姿态经常需要大角度调整,定位目标后则需根据不同的拦截策略控制拦截器的姿态角跟踪弹目视线角,实现以“零控脱靶量”为目标的精确拦截。故拦截器姿态的精准控制对成功命中目标至关重要。本文以动能拦截器姿态控制系统为研究对象,设计了一种基于附壁射流理论的新型恒定推力固体姿控发动机,并围绕考虑姿控发动机布局形式的拦截器姿态控制方法及拦截器制导方法展开相关研究工作。分析了可实现“三轴稳定”的姿控发动机布局形式,并根据对比分析结论确定了附壁射流式姿控发动机的结构方案。建立了气体附壁流动数学模型,研究了位差、侧壁倾角、控制口宽度等结构参数及控制流量对射流偏角、附壁位置、附壁碰撞角等参数的影响。同时,利用数值计算方法分析射流的动态偏转过程及姿控发动机稳定切换状态。根据压力流量特性,得出了姿控发动机入口及出口面积参数设计范围。最后给出了设计流程图并完成姿控发动机设计。建立了附壁射流式姿控发动机非线性数学模型。研究了线圈电阻、驱动电压、复位弹簧刚度等参数对电磁执行机构动态特性的影响,以及控制口宽度对射流偏转与控制气腔动态特性的影响。利用全桥气路分析方法建立了工作气腔的动态模型,分析了工作气腔结构参数对系统输出的影响,得到延迟时间随换向球质量变化的规律。在此基础上,通过仿真分析得出电磁执行机构触动阶段延迟是降低姿控发动机动态特性的主要因素。由于电磁执行机构动态特性直接影响姿控系统的响应速度及控制精度。以电磁执行机构快速切换为目标,提出了一种基于脉宽调制的驱动控制量优化算法。推导出了占空比及载波周期参数的设计方法,并证明了平衡位置衔铁抖动幅度由控制量的直流分量与基波共同决定。通过仿真及实验,验证了所设计的控制量优化算法对提高姿控发动机动态特性的有效性。最后,搭建了动态推力测试系统,完成了姿控发动机的动态推力测试。结果表明,设计的附壁射流式姿控发动机达到了预期设计要求。针对动能拦截器姿控发动机推力恒定、分散式布局控制力矩的强耦合特性及系统模型存在不确定特点的拦截器姿态稳定跟踪控制问题,提出了一种基于自适应鲁棒反演的新型姿态控制器设计方法。充分考虑姿态控制系统中三通道及姿控推力间的相互耦合关系,建立了姿态控制耦合模型。通过自适应方法对系统内各通道间的耦合及不确定项进行估计及补偿,提高了姿态控制的精度。进一步考虑姿控发动机动态特性,提出基于扩张干扰观测器的姿态控制算法,通过对系统各通道间的扰动进行估计,实现对控制器的动态补偿及干扰抑制。并利用PWPF调制方法将设计的连续控制量解算成可直接用于姿态控制的脉冲控制量,实现了拦截器的数字变推力控制。仿真结果表明,所设计的基于主动干扰补偿思想的动能拦截器姿态控制算法在参数摄动及存在不确定干扰的情况下仍然满足姿态稳定跟踪要求。针对拦截机动目标的动能拦截器制导律设计问题,采用干扰观测器及滑模变结构控制思想设计了一种基于碰撞航线的制导律。通过姿控系统控制拦截器攻角,使拦截器的速度方向始终指向预期碰撞点,并利用干扰观测器对目标加速度进行有效估计及动态补偿,降低了拦截器所需的过载,并提高了命中时的速度。同时,分别从拦截轨迹,可拦截目标区域及拦截目标速度范围对机动目标进行拦截仿真,并与以零化视线角速率为目标设计的有限时间收敛制导律对比,仿真结果表明对于动能拦截器采用基于碰撞航线的滑模制导律具有更好的制导性能。更多还原

【Abstract】 Kinetic kill vehicle(KKV) has the advantage of tremendous momentum generated by its high-speed flight. Through independent detection, guidance and control destroy the incoming target with collision directly. In order to search target, its attitude often need adjust with wide range, when the interceptor goes into the terminal guidance stage.After located the target, attitude angle tracked angle of line of sight(LOS) with different interception strategies to achieve Zero Effort Miss(ZEM) as precise goal.Therefore, the attitude control system is critical to KKV for successful hit. As the research object,for improving performance of attitude control system of KKV, a novel solid attitude control thuster with wall attachment theory is designed. Relative research about attitude control theories and guidance law were done with considering specific issues.For achieving "Three-axis Stabilized", the form of attitude control thrusters(ACT) layout has been analyzed. According to the analysis comparative conclusions, a scheme of attitude control thruster has been determined with wall attachment theory. Its mathematical models were derived. Variation of jet angle, attachment point, collision angle,etc via structural parameters and control flow was discussed. Numerical methods had been used to analyse its dynamic switching process. According to the pressure flow characteristics of ACT, designed range of structural parameters of the actuator was obtained. Finally, the design flow chart and structural of ACT was completed.ACT consisted by electromagnetic actuator, control gas chamber and working gas chamber, its mathematical models were derived. Lots research details of ACT was discussed, Including dynamic characteristics of electromagnetic actuator by coil resistance, driving voltage, reset spring stiffness; Dynamic characteristics of jet deflection by gas flow; Influence of thrust output by the mass of ball. On the basis of research, a conclusion, delay of electromagnetic actuator was the most important factor of ACT’s delay was obtained.Due to the dynamic characteristics of electromagnetic actuator affect the response speed and control precision of attitude control system directly. An optimization algorithm of driving control amount based on the pulse width modulation(PWM) was designed for switching fast. Through the establishment of system transfer function, the influence of armature rotation angle by control input was analyzed. Designed methods of duty ratio and carrier cycle for PWM control scheme was derived, when the structural parameters was determined. Armature vibration amplitude determined by controlled amount of DC component and fundamental wave was proved. Finally, the amount of control optimization algorithm for improving the dynamic characteristics of ACT effectively was verified with the simulation and experiments.Aiming at the problem of exo-atmospheric KKV attitude tracking with the characters of constant thrust, nonlinearity, strong couplings and parameter uncertainties, a novel sliding mode controller is designed which based on adaptive backstepping theory. The attitude coupling mode is established which considers about interaction between three channels and control torque in control loop. The actual control laws and virtual control laws are derived based on the design procedures of sliding mode control and backstepping control, respectively. An adaptive method is introduced to estimate and compensate the model couplings and uncertainties, which improves the accuracy of altitude control. The pulse control laws which could use to attitude control directly, are calculated form the continuous laws with PWPF modulation. For improving accuracy, a novel controller with EDO is designed, which is currently estimating and dynamically compensating to the uncertains.The simulation results show that attitude tracking still satisfies requirements with parameters and disturbance uncertainties.Aiming at the problem of exoatmospheric KKV guidance law design for intercepting targets, a novel missile sliding mode guidance law with disturbance observer was derived base on collision course. According to steering angle of attack of missile, the direction of velocity of missile points at the collision point. KKV can intercept the target with lower overload, faster speed via disturbance observer, which is currently estimating and dynamically compensating to target acceleration. Moreover, comparison to the two interception strategies were obtained with interception trajectories, capture zones and velocity range. Another strategy is the sliding mode guidance law based on finite time convergence which aims to steer the line of sight rate close to zero. The results show that the validities of the proposed sliding mode guidance law based on collision course in application for kinetic kill vehicle.更多还原