首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到17条相似文献,搜索用时 46 毫秒
1.
2.
张万里  王常虹  夏红伟  解伟男 《控制工程》2012,19(3):467-471,522
气动-引力辅助轨道机动相对于独立的引力辅助轨道机动而言能实现更大更灵活的速度偏转角同时减少燃料消耗。利用拟谱法设计出开环最优轨迹。对于飞行过程中的制导问题,根据拟谱法实现速度快结果精确的优点,将飞行时间按照等距及变间距分段,对每个独立时段采用实时在线轨迹生成的方法得到这一时间范围的最优轨迹,通过不断的轨迹更新实现飞行中对参数扰动等因素的抑制作用,结果显示采用变间距节点对干扰抑制效果有所增强。同时采用预留时间裕度的方式,可以较好地解决制导过程中在线最优化轨迹生成所需少量计算时间导致的制导偏差问题。  相似文献   

3.
讨论了带有分母多项式摄动的参数不确定性系统的鲁棒镇定问题,给出了这类参数不确定性系统存在鲁棒控制器的一个充分条件,并且当这个条件被满足时,得到了部分鲁棒控制器的一个参数化公式.  相似文献   

4.
以导弹逆轨拦截高速运动目标为背景,本文运用间接高斯伪谱法设计带攻击角度约束的最优中制导律.通过零化弹目相对法向速度,将攻击角度约束转化为视线角约束.考虑导弹速度时变的情况,建立带角度约束的制导方程.根据极小值原理推导最优中制导律的解析表达式,运用高斯伪谱法对最优中制导律进行离散化,把微分方程转化为代数方程,避免了求解Riccati方程.该方法不需要预先知道导弹未来的速度信息,计算量小,具有较好的实时性.仿真结果表明该中制导律可以满足逆轨拦截对弹目交会角的约束,且中制导末端的过载较小.  相似文献   

5.
本文给出了不确定性系统族的鲁棒稳定裕度定义以及计算方法。这些结果具有非常一般化的意义。  相似文献   

6.
采用双回路控制方法讨论具有混合不确定性系统的鲁棒镇定及性能设计问题,其内环控制器可改善对象特性,从而使整个双回路闭环系统具有鲁棒稳定性.  相似文献   

7.
采用双回路控制方法讨论具有混合不确定性系统的鲁棒镇定及性能设计问题,其内环控制器可改善对象特性,从而使整个双回路闭环系统具有鲁棒稳定性.  相似文献   

8.
讨论含有参数不确定性系统的鲁棒性能设计问题。首先将该问题转化为一个多项式簇的鲁棒稳定性问题,从而得到鲁棒性能控制器应满足的频域充要条件,然后通过一个双回路控制器的设计将鲁棒镇定和鲁棒性能设计分两步进行,使设计条理化、简单化。  相似文献   

9.
李宁波  雷虎民  周觐  邵雷  王斌 《控制与决策》2017,32(12):2195-2200
为了实现反临拦截弹中制导段的弹道在线优化,基于邻域最优控制(NOC)理论和改进间接高斯伪谱法(GPM)设计一种弹道在线生成算法.根据临近空间拦截作战特点设计弹道优化模型,基于NOC理论推导关于修正状态量和协态量的两点边值问题.对横截条件进行二阶变分,通过逆向递推将终端最优协态修正值表示成跟踪偏差和终端约束修正量的表达式.将拦截弹的当前状态量作为初始约束值,终端最优协态修正值作为干扰量,利用标称弹道数据,基于改进间接GPM求得控制修正量.仿真结果表明,所提出的方法可以快速生成一条修正弹道,且具有较高的终端修正精度.  相似文献   

10.
为了使气动调节阀控制系统满足工业过程对于模型不确定性的鲁棒性要求,设计了1种基于定量反馈理论(QFT)的气动调节阀控制系统。基于QFT的控制器是1种二自由度控制器结构,由前置滤波器和反馈控制器组成。QFT对于控制对象的不确定性具有很强的鲁棒性,能够较好地避免气动调节阀控制系统在工业过程中受到的干扰和模型不确定性影响。通过对气动调节阀控制系统进行仿真分析,验证了基于QFT的控制方法能够较好地避免该系统的不确定性,使得该系统具有较强的鲁棒性,满足相应的性能指标要求。与传统基于常规比例积分微分(PID)控制方法的气动调节阀控制系统相比,基于QFT控制方法的气动调节阀控制系统更加适用于工业过程。  相似文献   

11.
利用高斯伪谱法收敛速率快、精度高的特点,基于通用伪谱优化软件包在线求解非线性系统的最优控制问题.将伪谱反馈控制理论与非线性最优控制理论结合起来,给出了一种自由采样实时最优反馈控制算法,该算法通过连续在线生成开环最优控制的方式提供闭环反馈.考虑计算误差、模型参数不确定性和干扰的作用,假定系统状态方程右侧的非线性向量函数关于状态、控制和系统参数是Lipschitz连续的,利用Bellman最优性原理对闭环控制系统的有界稳定性进行了分析和理论证明.最后,以高超声速再入飞行器为应用对象,研究了其再入制导问题,仿真结果验证了该算法的可行性和有效性.  相似文献   

12.
The on-line optimal autonomous reentry guidance of the hypersonic vehicle is proposed based on the improved Gauss pseudospectral method (IGPM). The autonomous reentry guidance requires the hypersonic vehicle can generate the optimal trajectory for the latest flight mission on line and track the new trajectory well under the uncertainty. These two problems are simplified into a nonlinear optimal control problem with nonlinear constraints. The IGPM is introduced to solve the above two problems. The trajectory has to change according to the flight mission and therefore the new optimal trajectory can be obtained by IGPM within about 10 s. The optimal feedback guidance law is used to track the reference trajectory to handle the uncertainty. In order to deal with the CPU time delay, which comes from optimizing the new trajectory, the new on-line optimal autonomous reentry guidance is depicted. Finally, the numerical simulation shows that the proposed autonomous guidance can generate optimal trajectory for the new flight mission and have a high tracking accuracy  相似文献   

13.
    
To improve the survivability during an emergency situation, an algorithm for aircraft forced landing trajectory planning is proposed. The method integrates damaged aircraft modelling and trajectory planning into an optimal control framework, in order to deal with the complex aircraft flight dynamics, a solving strategy based on Gauss pseudospetral method (GPM) is presented. A 3-DOF nonlinear mass-point model taking into account the wind is developed to approximate the aircraft flight dynamics after loss of thrust. The solution minimizes the forced landing duration, with respect to the constraints that translate the changed dynamics, flight envelope limitation and operational safety requirements. The GPM is used to convert the trajectory planning problem to a nonlinear programming problem (NLP), which is solved by sequential quadratic programming algorithm. Simulation results show that the proposed algorithm can generate the minimum-time forced landing trajectory in event of engine-out with high efficiency and precision.  相似文献   

14.
针对含有复杂约束条件的非线性最优控制问题,提出了一种改进的Gauss伪谱法 (Improved Gauss pseudospectral method, IGPM). 这类问题难以得到解析解,特别是有些问题不存在解析的模型, 一些参数只能通过查表得到,使得传统方法难以求解. 在传统的Gauss伪谱法的基础上,将非线性的终端状态积分约束等价地转化为线性形式,提出了IGPM, 通过协态映射定理可以计算出协态变量,检验最优性,使得IGPM具有间接法一样的精度. 并且给出了初始时刻协态变量和端点时刻控制变量的计算方法. 为了提高解的精度,基于IGPM提出了迭代算法, 最后将该算法应用于求解高超声速飞行器上升段轨迹优化问题,结果表明最优轨迹基本满足路径约束条件和最优性条件.  相似文献   

15.
刘平  胡云卿  廖俊  樊力  黎向宇  刘兴高 《自动化学报》2019,45(12):2344-2354
针对中车株洲电力机车有限公司设计的HXD1-C64电力机车, 提出一种基于两阶段自适应Gauss配点重构的伪谱法, 用于列车优化操纵问题高效快速求解. 首先, 建立了HXD1-C64电力机车优化操纵数学模型; 然后, 在推导Legendre-Gauss配点公式的基础上, 给出控制变量两阶段自适应Gauss配点策略, 第1阶段采用对分配点, 第2阶段引入斜率变化分析对控制变量配点进行自适应细分和合并; 最后, 在运行时间最短目标下对HXD1-C64电力机车优化操纵进行仿真实验. 结果显示, 相较于控制变量参数化方法和传统高斯伪谱方法(Gauss pseudospectral method, GPM), 改进方法获得了更优性能指标和牵引力控制品质, 计算时间分别减少91.93 %和33.88 %, 表明了所提方法的有效性.  相似文献   

16.
    
This article aims at proposing a successive Chebyshev pseudospectral convex optimization method for solving general nonlinear optimal control problems (OCPs). First, Chebyshev pseudospectral discrete scheme is used to discretize a general nonlinear OCP. At the same time, a convex subproblem is formulated by using the first-order Taylor expansion to convexify the discretized nonlinear dynamic constraints. Second, a trust-region penalty term is added to the performance index of the subproblem, and a successive convex optimization algorithm is proposed to solve the subproblem iteratively. Noted that the trust-region penalty parameters can be adjusted according to the linearization error in iterative process, which improves convergence rate. Third, the Karush–Kuhn–Tucker conditions of the subproblem are derived, and furthermore, a proof is given to show that the algorithm will iteratively converge to the subproblem. Additionally, the global convergence of the algorithm is analyzed and proved, which is based on three key lemmas. Finally, the orbit transfer problem of spacecraft is used to test the performance of the proposed method. The simulation results demonstrate the optimal control is bang-bang form, which is consistent with the result of theoretical proof. Also, the algorithm is of efficiency, fast convergence rate, and high accuracy. Therefore, the proposed method provides a new approach for solving nonlinear OCPs online and has great potential in engineering practice.  相似文献   

17.
This paper presents a new approach for the efficient solution of singular optimal control problems (SOCPs). A novel feature of the proposed method is that it does not require a priori knowledge of the structure of solution. At first, the SOCP is converted into a binary optimal control problem. Then, by utilising the pseudospectral method, the resulting problem is transcribed to a mixed-binary non-linear programming problem. This mixed-binary non-linear programming problem, which can be solved by well-known solvers, allows us to detect the structure of the optimal control and to compute the approximating solution. The main advantages of the present method are that: (1) without a priori information, the structure of optimal control is detected; (2) it produces good results even using a small number of collocation points; (3) the switching times can be captured accurately. These advantages are illustrated through a numerical implementation of the method on four examples.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号