Analysis and improvement of missile three-loop autopilots

The non-minimum phase feature of tail-controlled missile airframes is analyzed. Three selection strategies for desired performance indexes are presented. An acceleration autopilot design methodology based on output feedback and optimization is proposed. Performance and robustness comparisons between the two-loop and classical three-loop topologies are made. Attempts to improve the classical three-loop topology are discussed. Despite the same open-loop structure, the classical three-loop autopilot shows distinct characteristics from a two-loop autopilot with PI compensator. Both the two-loop and three-loop topologies can stabilize a static unstable missile. However, the finite actuator resource is the crucial factor dominating autopilot function.     

气动人工肌肉的模糊小波神经网络控制

针对一种应用于医疗机器人领域的三自由度人工肌肉的非线性特性，结合模糊理论与小波神经网络，提出一种模糊小波神经网络控制器对人工肌肉驱动器进行控制。利用模糊小波神经网络的学习能力，采用梯度法搜寻控制器的最优参数。将采用模糊小波神经网络控制器与采用小波神经网络控制器及模糊神经网络控制器的控制系统仿真结果进行比较。仿真结果说明模糊小波神经网络控制器有效地改善了驱动器的静动态特性，具有更快的训练速度和更好的控制效果，是一种理想的气动人工肌肉控制方法。     

两回路自动驾驶仪设计与分析

分析了参数变化引起的弹体模型和静稳定性的改变,以及降低静稳定性对导弹机动性能的改善。研究了把工程指标转化为期望的闭环系统极点的方法,以及与全状态反馈等价的从状态反馈到输出反馈的变换技术,给出了基于极点配置和输出反馈的一般性的两回路自动驾驶仪设计方法。结果表明,两回路驾驶仪可以稳定静不稳定的弹体,而执行机构的有限的资源是限制驾驶仪控制作用的关键因素之一,引入加速度计到弹体质心距离这一参数后可以在一定程度上改善系统的稳定性。     

LMI approach to reliable H∞ control of linear systems

The reliable design problem for linear systems is concerned with. A more practical model of actuator faults than outage is considered. An LMI approach of designing reliable controller is presented for the case of actuator faults that can be modeled by a scaling factor. The resulting control systems are reliable in that they provide guaranteed asymptotic stability and H∞ performance when some control component (actuator) faults occur. A numerical example is also given to illustrate the design procedure and their effectiveness. Furthermore, the optimal standard controller and the optimal reliable controller are compared to show the necessity of reliable control.     

满足圆形极点、方差指标与H∞性能约束的满意容错控制

对一类具有范数有界不确定性的线性连续系统,研究了当执行器发生故障时的静态输出反馈满意容错控制问题。在更实际、更一般的执行器连续增益故障模型下,所设计的控制器确保闭环系统同时满足期望的区域极点指标、稳态方差指标和H∞范数指标约束。同时分析了容错控制中三类期望指标的相容性,并给出了静态输出反馈满意容错控制器存在的充分条件和设计方法。仿真算例验证了方法的有效性,并且通过与不考虑故障的系统比较,进一步说明对系统进行满意容错控制的必要性。     

Output feedback based adaptive robust fault-tolerant control for a class of uncertain nonlinear systems

An adaptive robust approach for actuator fault-tolerant control of a class of uncertain nonlinear systems is proposed. The two chief ways in which the system performance can degrade following an actuator-fault are undesirable transients and unacceptably large steady-state tracking errors. Adaptive control based schemes can achieve good final tracking accuracy in spite of change in system parameters following an actuator fault, and robust control based designs can achieve guaranteed transient response. However, neither adaptive control nor robust control based fault-tolerant designs can address both the issues associated with actuator faults. In the present work, an adaptive robust fault-tolerant control scheme is claimed to solve both the problems, as it seamlessly integrates adaptive and robust control design techniques. Comparative simulation studies are performed using a nonlinear hypersonic aircraft model to show the effectiveness of the proposed scheme over a robust adaptive control based faulttolerant scheme.     

LMI approach to reliable H∞ control of linear systems

The reliable design problem for linear systems is concerned with. A more practical model of actuator faults than outage is considered. An LMI approach of designing reliable controller is presented for the case of actuator faults that can be modeled by a scaling factor. The resulting control systems are reliable in that they provide guaranteed asymptotic stability and H_∞, performance when some control component (actuator) faults occur. A numerical example is also given to illustrate the design procedure and their effectiveness. Furthermore, the optimal standard controller and the optimal reliable controller are compared to show the necessity of reliable control     

动量轮控制弹头姿态控制系统设计

提出了一种以动量轮为执行机构的具有中性静稳定气动布局的再入弹头姿态控制新方案。基于动量矩交换原理和中性静稳定概念分析了新方案的可行性,并推导了具有这种新型执行机构的弹头的姿态动力学方程。利用反馈线性化方法,将姿态动力学方程线性化并解耦成俯仰、偏航和滚转三个方向上的单输入单输出系统,然后运用滑模变构控制理论设计各通道的控制器。对姿态控制系统的数值仿真结果表明,所设设计的控制器能实现高精度的姿态机动和姿态稳定,现有动量轮技术指标即可满足滚动通道的姿态稳定。     

不确定时滞系统的指数稳定保代价可靠控制

针对一类含有时变时滞的不确定参数系统,研究了在执行器发生故障情况下系统指数稳定保代价可靠控制器设计问题。系统的性能函数是含有指数项和故障输入项的积分二次型函数。经过适当的状态变换,将原系统的指数稳定保代价可靠控制问题转化为另一个等价系统的保代价可靠控制问题。根据Lyapunov稳定性理论,得到了系统存在指数稳定保代价可靠控制器应满足的一个矩阵不等式,进一步将这个矩阵不等式转化为线性矩阵不等式(LMI),并给出了系统的保代价表达式。利用论文方法设计的控制器能够使得时滞系统对于任意允许的不确定量以及执行器故障都保持鲁棒可靠指数稳定,并且使系统具有保代价的性能指标。仿真结果表明了该控制器设计方法的有效性。     

Robust H∞ guaranteed cost satisfactory fault-tolerant control for discrete-time systems with quadratic D stabilizability

The problem of robust H∞ guaranteed cost satisfactory fault-tolerant control with quadratic D stabilizability against actuator failures is investigated for a class of discrete-time systems with value-bounded uncertainties existing in both the state and control input matrices.Based on a more practical and general model of actuator continuous gain failures,taking the transient property,robust behaviour on H∞ performance and quadratic cost performance requirements into consideration,sufficient conditions for the existence of satisfactory fault-tolerant controller are given and the effective design steps with constraints of multiple performance indices are provided.Meanwhile,the consistency of the regional pole index,H∞ norm-bound constraint and cost performance indices is set up for fault-tolerant control.A simulation example shows the effectiveness of the proposed method.     

Robust H∞ guaranteed cost satisfactory fault-tolerant control for discrete-time systems with quadratic D stabilizability

The problem of robust H∞ guaranteed cost satisfactory fault-tolerant control with quadratic D stabilizability against actuator failures is investigated for a class of discrete-time systems with value-bounded uncertainties existing in both the state and control input matrices. Based on a more practical and general model of actuator continuous gain failures, taking the transient property, robust behaviour on H∞ performance and quadratic cost performance requirements into consideration, sufficient conditions for the existence of satisfactory fault-tolerant controller are given and the effective design steps with constraints of multiple performance indices are provided. Meanwhile, the consistency of the regional pole index, H∞ norm-bound constraint and cost performance indices is set up for fault-tolerant control. A simulation example shows the effectiveness of the proposed method.     

一类不确定线性系统容错保成本控制器设计

考虑了具有参数不确定性的线性定常系统,研究了带有执行器故障和不确定性扰动的保成本容错控制问题。在考虑更一般、更实际的执行器故障模型的基础上,给出了系统鲁棒稳定及容错保成本控制器存在的充分条件。通过求解代数Ricatti方程完成动态反馈控制器的设计。仿真实例验证了所得结果的可行性。比较不考虑故障的控制器与考虑故障的容错控制器的控制效果,进一步说明了对系统进行容错控制的必要性。     

Reference tracking control for flexible air-breathing hypersonic vehicle with actuator delay and uncertainty

This paper considers the problem of reference tracking control for the flexible air-breathing hypersonic flight vehicle with actuator delay and uncertainty.By constructing the Lyapunov functional including the lower and upper bounds of the time-varying delay,the non-fragile controller is designed such that the resulting closed-loop system is asymptotically stable and satisfies a prescribed performance cost index.The simulation results are given to show the effectiveness of the proposed control method,which is validated by excellent output reference altitude and velocity tracking performance.     

考虑执行器故障的无人帆船事件触发控制

针对实际海洋环境下,无人帆船在艏向跟踪控制任务中存在的模型参数未知、控制输入频繁抖振和执行器磨损等问题,提出一种考虑执行器故障的无人帆船事件触发控制算法.首先,采用径向基函数神经网络(radius based function neural networks,RBF-NNs)对系统的未知模型参数进行在线逼近.其次,在无...     

具有对偶极点的不稳定过程的鲁棒控制

为了进一步完善不稳定系统的鲁棒控制器设计方法,将具有对偶极点的不稳定过程分成纯不稳定过程与一般的稳定过程两部分,对于纯不稳定过程采用先成形再镜像映射的方法,而对于一般的稳定过程则基于极点对消原则直接设计控制器,最后用闭环增益成形算法求解鲁棒控制器。将所设计的鲁棒控制器应用于磁浮列车的悬浮控制中,从仿真结果可以看出,控制效果可以达到小超调(<8%)、无静差、调节时间快(<0.1 s)、对模型摄动具有鲁棒稳定性。     

A parameter estimation based adaptive actuator failure compensation control scheme

An adaptive actuator failure compensation control scheme is developed using an indirect adaptive control method,by calculating the controller parameters from adaptive estimates of system parameters and actuator failure parameters.A key technical issue is how to deal with the actuator failure uncertainties such as failure pattern,time and values.A complete parametrization covering all possible failures is used to solve this issue for adaptive parameter estimation.A simultaneous mapping from the estimated system/failure parameters to the controller parameters is employed to make the control system capable of ensuring the desired system performance under failures,which is verified by simulation results.     

非线性系统执行器死区故障的鲁棒自适应控制

针对一类具有不对称执行器死区故障的不确定非线性系统,基于反推滑模控制原理提出了一种神经网络鲁棒自适应控制方案。通过简化死区故障模型,取消了模型倾斜度相等和边界对称条件,结合动态面控制避免了传统反推设计方法存在的计算复杂性问题。所提控制方案取消了控制方向已知的条件,消除了执行器死区故障的影响,使得系统输出趋于给定参考轨迹的一个小领域。仿真结果验证了该方法的有效性。     

基于短期AGC指令的负荷系统预见预测控制

针对目前火力发电单元机组负荷增减频繁、扰动因素较多的情况，在充分利用自动发电挂制(AGC)的负荷指令资源的基础上，提出一种协调控制系统的负荷预见预测控制方案。该方法以多变量预测控制为核心，将预见控制思想融入到预测控制的设计之中，从而构成一种新的负荷协调控制策略。仿真结果表明，该方法集预测控制、预见控制二者的优点，使得机组负荷具有良好的跟踪性能，主蒸汽压力也具有很好的系统动、静态调节品质，而且控制量变化非常平稳，在对象动态特性较大范围内变化的情况下，系统具有较强的鲁棒性。     

具有伪控制补偿的自适应动态逆控制系统设计与仿真

论述了基于伪控制补偿解决自适应控制中作动器饱和问题的方法。基本控制律采用非线性动态逆方法设计，神经网络用于对逆误差进行重构。伪控制补偿消除作动器和自适应单元之间的交互影响。通过在超机动飞行控制的应用仿真表明，该控制方案弥补了动态逆要求精确数学模型的缺点，消除了作动器饱和对自适应单元的影响，提高了整个控制系统的鲁棒性。     

基于模型预测的网络化控制系统补偿控制

针对分时控制模式下存在于网络诱发延迟大于一个采样周期的网络化随机控制系统中的空采样和数据拒绝问题,提出了一种基于模型预测的补偿控制法。该方法通过在执行器设立缓冲区窗口并存放一定数目的历史控制量,利用多个历史控制量对当前采样周期的控制状态进行估计预测,对空采样和数据拒绝情况进行补偿控制,达到改善系统性能的目的。通过仿真实验证明了该补偿控制算法的有效性。