【作者】 刘伟星；

【导师】 耿云海；

【作者基本信息】 哈尔滨工业大学 ， 航天工程（专业学位）， 2017， 硕士

【摘要】 本文以升力式再入飞行器为研究对象,主要研究飞行器在再入过程中的制导和姿态控制问题。飞行器的再入过程具有飞行环境恶劣,飞行状态跨度大等特点,这些都给飞行器的制导和姿态控制带来了困难。针对这些问题,本文主要工作如下:首先,针对升力式再入飞行器研究了预测校正制导方法。预测校正制导处理过程约束比较困难。本文通过添加补偿项的方法解决了过程约束问题。该制导律将再入过程分为初始再入段和滑翔段。滑翔段具有明显的横向运动与纵向运动,因此,将制导分为纵向制导和横向制导。纵向制导主要使飞行器满足航程以及过程约束要求,横向制导则主要满足目标点位置的要求。制导过程中,先使飞行器满足终端目标的要求,然后再添加补偿项使飞行器满足过程约束的要求。其次,针对标准轨迹制导法研究了轨迹跟踪方法。基于模型预测控制的思想,引入预测时域,在预测时域内构造最优控制问题,并将最优控制问题转化为两点边值问题,采用高斯伪普法将两点边值问题离散到高斯节点上,得到一系列的线性代数方程组,求解方程组得到最优问题的解析解。该方法可以消除一定范围内的初始误差,且具有较强的抗干扰能力。同时,当飞行器发生故障使飞行器的气动模型变化,标称的参考轨迹和参考制导指令不再适用,需要在线重新规划轨迹时。上述跟踪方法同样适用。最后,针对制导指令跟踪问题研究了一种被动容错控制方法用于控制再入飞行器的姿态控制,使飞行器稳定跟踪制导指令。基于反步法的思想,将姿态控制系统分为两步进行设计。第一步设计期望角速度作为运动学的虚拟控制,第二步设计控制输入跟踪期望角速度。在转动惯量信息未知的情况下,该容错控制方法同样具有较快的收敛速度。更多还原

【Abstract】 In this paper,a high lifting hypersonic gliding reentry vehicle is taken as the research object,and the paper mainly focus on the guidance and the attitude control of the vehicle.There are some difficulties of the guidance and attitude control designing as reentry process faces a complex environment and some hard constraints.In view of these problems,this paper mainly does the following work.First of all,this paper studies the predictor-corrector algorithm guidance method.Predictor-corrector algorithm is not affected by the initial value.However,it is difficult to deal with the hard constraints.According to the three-dimensional equations of motion of the gliding vehicle,this paper divides the reentry movement into the initial re-entry and gliding segments.The initial segment has little effect on the trajectory due to the low atmospheric density.As the atmospheric density rises,the so-called quasi-equilibrium glide condition will be satisfied.In the gliding phase,the predictor-corrector is formed by longitudinal and lateral guidance.Longitudinal guidance law makes the vehicle meet the downrange and the hard path constraints and the lateral guidance determines when to perform bank-angle reversals.Secondly,a trajectory tracking law is studied.Based on the idea of model predictive control,this paper constructs an optimal control problem in the moving horizon window,and alter it into a two-point boundary value problem by using the optimal control principle.Then the Gauss pseudospectral method is implement to the two-point boundary value problem.The proposed method can eliminate the initial error.Furthermore,when failures occur such as the rudder surface stuck,the aircraft’s aerodynamic model will change,and the nominal reference trajectory will no longer be valid.Based on the above trajectory tracking method,this paper changes the trajectory planning problem into an optimization problem.The Gaussian pseudospectral method is used to solve the optimization problem,and the reference trajectory is obtained.Finally,this paper studies a passive fault-tolerant control method for controlling the attitude of reentry vehicles.The method is based on the idea of backstepping-control,and the attitude control system is divided into two steps to design.The first step is to design the desired angular velocity as the virtual control of the kinematics.The next is to tracking the desired angular velocity.The fault-tolerant control method does not need to know the information of the moment of inertia.更多还原