制导炮弹解耦控制研究

针对旋转制导炮弹双通道二舵机自动驾驶仪进行解耦控制研究。采用弹体状态方程对旋转制导炮弹进行仿真建模和耦合性分析,推导出了从弹体坐标系到准弹体坐标系弹体运动方程的准确表达式,并采用双通道二舵机方案设计旋转制导炮弹自动驾驶仪,提供了双输入双输出系统解耦控制算法。通过仿真验证了两通道的交连情况和解耦算法的有效性。弹体状态方程适用于双通道旋转弹仿真建模和耦合性分析,为导弹控制系统分析与设计提供了新思路。     

Integrated Game Based Guidance with Nonlinear Autopilot Design for Maneuvering Target Interception

The integrated game theory based guidance law with nonlinear autopilot (GGNA) system is presented in this paper. The guidance law is designed based on linear differential game theory while considering the motion of the target in 3‐D space such that the distance between the missile and the target is minimized faster than before. The autopilot system based on quaternion representation is developed using sliding mode control method to generate the attitude command. The stability of the integrated guidance and nonlinear autopilot system is analyzed with Lyapunov stability theory. In addition, this research assumes wingless missiles in our context in order to reduce the nonlinear effect from the aerodynamics. Furthermore, in order to extend the operation range of missiles from endo‐atmosphere to exo‐atmosphere, the missiles are equipped with Thrust Vector Control (TVC) mechanisms and Divert Control System (DCS). Finally, extensive simulations incorporating aerodynamic models are demonstrated to verify the validity of the proposed integrated guidance/autopilot systems. Moreover, the simulation results reveal that the mission of intercepting a maneuvering target is successfully accomplished.     

Adaptive critic autopilot design of bank-to-turn missiles using fuzzy basis function networks.

A new adaptive critic autopilot design for bank-to-turn missiles is presented. In this paper, the architecture of adaptive critic learning scheme contains a fuzzy-basis-function-network based associative search element (ASE), which is employed to approximate nonlinear and complex functions of bank-to-turn missiles, and an adaptive critic element (ACE) generating the reinforcement signal to tune the associative search element. In the design of the adaptive critic autopilot, the control law receives signals from a fixed gain controller, an ASE and an adaptive robust element, which can eliminate approximation errors and disturbances. Traditional adaptive critic reinforcement learning is the problem faced by an agent that must learn behavior through trial-and-error interactions with a dynamic environment, however, the proposed tuning algorithm can significantly shorten the learning time by online tuning all parameters of fuzzy basis functions and weights of ASE and ACE. Moreover, the weight updating law derived from the Lyapunov stability theory is capable of guaranteeing both tracking performance and stability. Computer simulation results confirm the effectiveness of the proposed adaptive critic autopilot.     

基于直接自适应控制的重构飞控系统研究

通常,飞控系统重构设计需知系统的故障信息,而使用直接自适应控制技术可在不知道系统故障信息的情况下,对飞控系统操纵面损伤进行重构,并且可使故障飞机很好地跟踪参考模型的输出．采用优化算法设计反馈补偿器以保证故障系统的严格正实性,并利用Lyapunov函数证明重构系统的渐近稳定性．将该方法用于某型飞机侧向控制系统的设计,仿真结果表明,在操纵面严重受损的情况下,飞机仍能保持良好的性能．     

离散多步时滞系统的容错控制研究

针对离散多步时滞系统,基于Lyapunov稳定性理论,采用具有状态反馈及时滞状态反馈的控制律,推出了当执行器或传感器发生失效故障时闭环系统仍能保持渐近稳定需满足的充分条件;并利用LMI给出了不依赖时滞的线性离散多步时滞系统的容错控制器的通用求解方法;讨论了该方法对具有不同时滞步数离散多步时滞系统容错的普适性。以执行器失效故障为例,仿真结果证明了该方法的有效性。     

Reliable State Feedback Control Synthesis For Uncertain Linear Systems

This paper is concerned with the problem of designing reliable state‐ feedback control for a class of uncertain linear systems with norm bounded uncertainty. A procedure for designing reliable state‐feedback control is presented for the case of actuator faults that can be modeled by a scaling factor. In the design, the performance of the normal system (without fault) is optimized, as the considered system operates under the normal condition most of the time. In addition, when actuator faults occur, the closed‐loop system retains robust stability and satisfies a known quadratic performance bound. A numerical example is provided to illustrate the effectiveness of the proposed design method.     

Nonlinear sliding sector design for multi‐input systems with application to helicopter control

The ability of helicopters to hover and land vertically has spurred an interesting field of research on the development of autonomous flight for these rotatory wing aircrafts. Linear control theory with gain scheduling, which is based on linearizing the system at the equilibrium points, dominated the helicopter autopilot design. Unlike the linear cascaded autopilot structure used in the existing literature, this paper uses state‐dependent linear like structure, including rate‐limited actuator dynamics, with cascaded autopilot topology. This approach allows nonlinear control laws to be implemented throughout the entire flight envelope, providing satisfactory robustness and stability over the various parameter uncertainties and time delays. The cascaded autopilot topology with nonlinear dynamical equations contains a new sliding sector control (SSC) mechanism which is derived for multi‐input nonlinear dynamical systems. The proposed SSC structure for multi‐input nonlinear systems is used in the inner loop of the cascaded autopilot system where the fastest dynamics are required to be controlled for rapid changes in the helicopter dynamical characteristics which enables one to stabilize the helicopter over a wide range of flight conditions. The proposed cascaded autopilot topology with the new SSC mechanism is tested in simulations to assess its robustness and stability properties. To establish its feasibility, the proposed control method is replaced with a suboptimal control method, namely state‐dependent differential Riccati equation (SDDRE) method, for the inner loop and the results of the proposed control architecture are compared with those of SDDRE method.     

导弹交流电动舵机的非线性解耦控制与仿真

针对交流电动舵机系统非线性,多变量和强耦合的特性,提出了一种基于微分几何方法和变结构控制理论的非线性解耦控制方法。建立了交流电动舵机的非线性模型,利用微分几何理论,通过对系统进行微分同胚变换和反馈变换,实现了非线性系统的精确线性化和输入/输出解耦,并针对电动舵机系统参数摄动和负载扰动的特点,利用指数趋近律设计了电动舵机的变结构控制器。仿真结果表明不仅可以有效地实现交流电动舵机系统的非线性解耦,具有良好的静、动态特性。     

受控旋转弹飞行动力学建模和稳定性分析

选取带有控制系统的旋转弹为研究对象,考虑到控制环节不可避免的时滞及气动非线性效应,从理论上进一步完善了旋转弹动力学模型.从模型的特征方程出发,以时滞、控制增益为分岔参数,对系统的零平衡点稳定性进行了分析,得到平衡点失稳后发生Hopf分岔的临界参数值,并在理论预测的情况下数值模拟了攻角和侧滑角在不同情况下的失稳情况以及Hopf分岔周期解振幅随分岔参数的变化情况.数值结果表明了理论预测的正确性,时滞虽未改变旋转弹锥形运动方式,但是却大幅度的减小了稳定飞行控制增益的取值范围,因此在旋转弹姿态稳定性系统设计过程中时滞的影响不可忽略.     

变采样网络控制系统的鲁棒控制

对于线性时不变控制对象,在控制器和控制对象都采用时间-事件驱动时系统就变成便采样网络控制系统,当网络时延不确定时,在小于或者等于一个变采样周期时,基于动态输出反馈对变采样网络控制系统进行建模,使用李雅普诺夫方法和线性矩阵不等式研究了系统的鲁棒稳定性,并设计了鲁棒控制器,最后给出实例证明在鲁棒控制器的控制下系统稳定。     

状态反馈预测控制干扰解耦的研究

讨论状态反馈预测控制系统设计中的干扰解耦设计问题，给出了状态反馈预测控制系统干扰可解耦设计的充分必要条件。基于状态空间模型，给出了状态反馈预测控制系统设计参数——预测时域按干扰解耦设计的选取方法。它可改善控制系统的性能，提高控制系统的抗干扰能力。仿真结果表明了状态反馈预测控制系统干扰解耦设计的有效性。     

舵机速率饱和时的飞机尾旋改出控制

通过闭环控制进行飞机尾旋自动改出时, 由于控制能量不足舵机速率饱和有可能引起振荡问题. 本文基于反步法设计一种抗舵机速率饱和的尾旋自动改出控制方法. 将飞机模型看做角度、角速度和舵机三层级联结构, 首先利用反步法设计角度和角速度层控制律, 然后在舵机层控制律根据舵机速率饱和限制约束控制量, 同时通过Lyapunov函数保证闭环系统渐近稳定. 对所得控制方法抗舵机速率饱和的效果进行了分析. 以某现代歼击机模型为对象的仿真试验表明, 该方法在舵机存在速率饱和的情况下控制效果明显优于传统动态逆方法与传统反步法.     

Robust wedge-stability analysis and design of continuous constrained systems with stability radii

In this paper, based on stability radii, a sufficient condition is first proposed to ensure the robust wedge stability of continuous-time constrained systems with state feedback. The saturated actuator is reformulated as a conditioned linear actuator subject to structured uncertainties and then an auxiliary matrix is introduced so that the closed-loop system can be characterized into a scheme of stability radius approach. We also investigate the issue of maximizing complex stability radius subject to a wedge region by state feedback. Through iteratively solving a parametrized Riccati equation, a desired maximizing state feedback controller corresponding to the prescribed wedge subregion can be obtained. An example is given to illustrate the design algorithm and to reveal the feasibility of stability radius approach for continuous-time constrained systems.     

Robust Missile Autopilots With Finite‐Time Convergence

This paper presents a new longitudinal autopilot to address the finite‐time tracking problem for uncertain agile missiles. The proposed autopilot is essentially a composite control scheme, which is obtained through the finite‐time control methodology and the nonlinear disturbance observer (NDOB) approach. The key idea in this scheme is that the NDOB is adopted to estimate the aerodynamic uncertainties and external disturbances in an integrated manner. With the aid of the finite‐time bounded function and the Lyapunov function method, the finite‐time stability of the closed‐loop system is established, which shows that the angle‐of‐attack response will converge to the external command signal in finite time. Numerical simulation results are presented to demonstrate the superiority of the proposed scheme.     

多变量时滞过程的解耦控制设计

针对化工生产中常见的多输入多输出时滞过程,基于单位反馈闭环控制结构提出一种新的解析设计解耦控制器矩阵的方法.其突出优点是克服现有的数值化求解方法的局限,能够实现标称系统输出响应之间的显著乃至完全解耦,并且能够在线以单调方式整定解耦控制器矩阵的可调参数来适应被控过程的未建模动态.同时,对于实际中常见的被控过程的加性和乘性不确定性,分析了控制系统保证鲁棒稳定性的充要条件,从而给出在线整定解耦控制器矩阵的可调参数的规则.最后以仿真实例验证了本文方法的优越性.     

含状态时滞及执行器饱和不确定系统反馈镇定及L2增益分析

研究了具有控制饱和状态时滞不确定系统的L2控制问题,提出了状态反馈方法,利用Lyapunov函数可获得时滞相关的线性矩阵不等式.线性矩阵不等式条件可保证闭环系统无干扰时鲁棒内稳定性和在某椭球内预先给定的有干扰时L2性能水平,该不等式通过引入辅助矩阵解除了执行器饱和对系统的影响而更易于实现且减小了保守性.采用线性矩阵不等式技术,将控制器存在的充分条件转化为凸优化问题.在此基础上设计了系统的状态反馈控制器,最后用数值仿真验证了所提出方法的可行性.     

Robust stability analysis and fuzzy-scheduling control for nonlinear systems subject to actuator saturation

Takagi-Sugeno (TS) fuzzy models can provide an effective representation of complex nonlinear systems in terms of fuzzy sets and fuzzy reasoning applied to a set of linear input-output submodels. In this paper, the TS fuzzy modeling approach is utilized to carry out the stability analysis and control design for nonlinear systems with actuator saturation. The TS fuzzy representation of a nonlinear system subject to actuator saturation is presented. In our TS fuzzy representation, the modeling error is also captured by norm-bounded uncertainties. A set invariance condition for the system in the TS fuzzy representation is first established. Based on this set invariance condition, the problem of estimating the domain of attraction of a TS fuzzy system under a constant state feedback law is formulated and solved as a linear matrix inequality (LMI) optimization problem. By viewing the state feedback gain as an extra free parameter in the LMI optimization problem, we arrive at a method for designing state feedback gain that maximizes the domain of attraction. A fuzzy scheduling control design method is also introduced to further enlarge the domain of attraction. An inverted pendulum is used to show the effectiveness of the proposed fuzzy controller.     

一类具有执行器饱和的非线性系统抗饱和方法研究

针对一类具有执行器饱和的非线性控制系统, 提出了一种双环路的动态抗饱和补偿方案, 为执行器输出受限的非线性系统提供了新思路. 与现有结果相比, 所提方案能更好地改善闭环系统控制性能. 考虑执行器饱和约束, 通过优化执行器饱和发生前后控制器的状态误差的积分性能指标, 综合设计一类同时包含传统抗饱和及延迟抗饱和补偿器两个环路的改进抗饱和补偿器, 这类补偿器有效地抑制了饱和现象对控制器的影响, 从而降低了执行器饱和对控制系统性能的影响. 当系统存在高饱和度现象时, 利用该双环路抗饱和补偿器, 可以最大程度弱化饱和对系统性能的影响. 最后, 利用输入状态稳定 (Input state stability, ISS) 定理分析和证明了该闭环系统全局一致有界稳定. 并通过舵机执行器受约束的舵减横摇系统的仿真试验, 验证了该方案的有效性及优越性.     

控制系统输出至x的输出反馈解耦——积分型解耦的对偶性

针对状态反馈加前置比例补偿对系统进行解耦的充分必要条件及积分型解耦方法，提出了采用输出至Ｘ的输出反馈加本文定义的环内后置比例补偿对系统进行解耦的充分必要条件积分型解耦方法。克服了状态反馈在许多时候要设计观测器；避免了对部分系统进行对角优势解耦，具有一定的理论和实用价值。     

一类多执行机构系的滑模控制设计及其应用

针对一类具有多执行机构的非线性系统,利用滑模控制和backstepping技术,研究了输出跟踪问题.针对执行机构的不同特点,利用离散执行机构实现滑模控制中的不连续控制量,利用连续执行机构实现滑模控制中的连续控制量.然后利用backstepping技术实现连续执行机构的输出对滑模控制中的连续控制量的有限时间收敛.将提出的设计方法应用于导弹直接侧向力与气动力复合控制系统设计,并进行了仿真验证.