Euler-Bernoulli梁的非线性耗散边界反馈镇定

讨论具有非线性耗散边界反馈的Euler-Bernoulli梁的镇定问题.首先利用非线性半群 理论和能量摄动方法,证明了文中所给出的非线性耗散边界反馈控制可以镇定闭环系统的能量， 并导出了闭环系统的能量衰减速度.然后用例子说明文中所给出的非线性耗散边界反馈控制具 有较强的实用性.     

不确定Euler-Bernoulli梁方程的边界输出跟踪

本文讨论边界带有控制输入非同位的内部不确定和外部扰动的Euler-Bernoulli梁方程输出跟踪问题. 为处理边界干扰, 文章首先设计了一个新的总扰动估计器, 在线估计未知扰动. 其次基于估计出来的总扰动, 设计一个伺服系统跟踪参考信号. 最后根据自抗扰方法获得控制输出跟踪的反馈控制. 闭环系统被证明是适定和有界的, 且受控系统的输出指数跟踪参考信号.     

输入饱和及带宽限制下高超飞行器的闭环稳定边界研究

针对于吸气式高超声速飞行器开环不稳定的动力学特性,研究了控制信号存在饱和约束及带宽限制条件下的闭环稳定边界.首先,简要介绍了吸气式高超声速飞行器的建模方法与动力学特性的主要问题.考虑到飞行器控制信号的幅值限制及带宽约束,综合高超声速飞行器的开环不稳定特性,定量地分析了系统的闭环稳定边界:与系统不稳定极点的位置,其对应的左特征向量及控制信号的幅值约束有关;执行器的带宽限制在此基础上进一步缩小了反馈控制系统的稳定边界.根据高超声速飞行器短周期不稳定特性,解析地给出了闭环稳定边界的计算公式.采用蒙特卡洛分析方法对闭环系统的稳定边界及滑模变结构控制器作用下的稳定区域进行验证.仿真结果与理论分析具有一致性,验证了系统开环特性对于闭环稳定性的限制及控制信号带宽约束对稳定性的影响.     

Euler-Bernoulli梁的反馈镇定

讨论端点带负荷的Bernoulli梁的横向振动的控制问题.分析了系统的谱结构,提出一 种非线性边界反馈来镇定梁的横向振动,并证明了相应的闭环系统的渐近稳定性,最后给出 了一些数值模拟结果.     

具有一般耗散边界反馈的Euler-Bernoulli梁的指数镇定问题

讨论具有一般线性耗散边界反馈的Euler-Bernoulli梁的指数镇定问题.首先将所讨论 的系统化为抽象空间中的发展方程,并利用G0半群理论给出闭环系统解的存在唯一性.其次,对 相应的闭环系统特征方程进行详尽的讨论计算,得到了系统本征值的分布特性,从而利用Lassel 不变原理得到了闭环系统渐近稳定的充分必要条件.最后通过对闭环系统的本征值及其相应的 本征函数进行估计,导出了相应的闭环系统指数稳定的充分必要条件.     

基于反馈控制的开放式实时系统自适应调度算法设计与实现

对于负载不可预测且资源受限的开放式实时系统,传统"开环"调度算法不能根据系统负载情况调整调度策略,影响系统实时性能或造成资源浪费.采用双闭环反馈控制方法,改进目前开放式实时系统常用的时限驱动总带宽利用率服务器.本方法根据负载情况,动态地为不同实时性能需求的任务分配资源,保证硬实时任务满足时限要求并且提高资源利用率.实验表明,系统负载存在突发的情况下,算法既很好地控制了任务的时限错过率,又得到了较高的资源利用率.     

基于保辛算法的绳系卫星系统闭环反馈控制问题求解

应用非线性系统滚动时域控制的保辛算法求解绳系卫星系统子星释放和回收过程的闭环反馈控制问题.通过第二类Lagrange方程推导出二体绳系卫星系统的动力学方程;通过拟线性化方法将绳系卫星系统闭环反馈控制问题转化为线性非齐次Hamilton系统两端边值问题的迭代求解;通过保辛算法将线性非齐次Hamilton两端边值问题转化为线性方程组的求解;通过递进更新时间步的状态变量和控制变量,完成绳系卫星系统的闭环反馈控制.数值仿真表明:相对于Legendre伪谱方法,用保辛算法求解绳系卫星系统的闭环反馈控制问题的计算速度和收敛速度较快.绳系卫星系统的开环控制和闭环反馈控制问题数值仿真结果表明:在绳系卫星的初始状态存在偏差的情况下,使用开环控制会导致系统在终端无法达到稳定状态,而使用闭环反馈控制则能在一段时间内抵消初始状态向量偏差对系统产生的影响,最终达到稳定状态.     

模糊关系系统的反馈控制

以开环系统模糊关系模型为基础,讨论了模糊关系系统反馈控制器的设计.给出了一种 反馈控制律,分析了闭环系统的若干性质.提出的反馈控制律便于实施,且同时适用于跟踪及 调节问题.     

具有耗散边界反馈的Timoshenko梁的镇定

研究了具有线性耗散边界控制的Timoshenko梁的边界反馈镇定问题。首先,在反馈系数矩阵B正定的前提下,我们证明了所论闭环系统是指数稳定的。然后,对于反馈系数矩阵B半正定的情况,得到了闭环系统渐近稳定的几个充要条件。     

航空发电机闭环加载与瞬态参数测试

负载配置和瞬态参数测试是航空发电机性能测试的重要组成部分;传统的负载配置过程较繁锁,效果不佳;瞬态参数测试时间短,参数变化快,要涉及到高速的数据采集、存储和大量的数据处理;针对上述问题,应用虚拟仪器和信号处理技术,设计了一套拥有闭环反馈加载和瞬态参数测试的综合测试系统,对总负载和功率因数进行闭环反馈控制,并在各种负载、转速变化的条件下对航空发电机进行瞬态参数特性测试;该系统已经过计量并投入实际使用,证明其工作性能稳定,界面友好,负载配置操作方便,效果好,瞬态参数测试精度高.     

Boundary feedback exponential stabilization of a Timoshenko beam with both ends free

In the present paper we consider the boundary feedback stabilization of a Timoshenko beam with both ends free. We propose boundary feedback control law that makes the closed loop system dissipative. Using asymptotic analysis techniques, we give explicit asymptotic formula of eigenvalues of the closed loop system, and prove the Riesz basis property of eigenvectors and generalized eigenvectors. By a detailed analysis of spectrum of the closed loop system, we show that the closed system is exponentially stable.     

Feedback stabilization of rotating Timoshenko beam with adaptive gain

The problem of boundary feedback stabilization of rotating Timoshenko beam, arising from control of flexible robot arms, is studied in this paper. First, under gain adaptive direct strain feedback controls, a counterexample is given to show that the corresponding closed loop system is not asymptotically stable, which is contrary to traditional conjecture. The counterexample given in this paper also exemplifies an interesting result: certain two two-order linear partial differential equations with five homogeneous boundary conditions have non-trivial solutions. Then, with an additional boundary feedback control, the related energy of the closed loop system is proved to be strongly stable, or more precisely, the configuration of the beam can be exponentially stabilized with some suitable non-linear boundary feedback controls with adaptive gain.     

Output feedback stabilization for a Kirchhoff‐type nonlinear beam with general corrupted boundary observation

This paper is concerned with the boundary output feedback stabilization for a Kirchhoff‐type nonlinear beam equation with boundary observation subject to a general disturbance. The active disturbance rejection control approach is adopted to design the controller and the disturbance estimator. By this approach, the disturbance is estimated by a relatively independent estimator and then canceled in the feedback loop. The existence and uniqueness of the classical solution to the closed‐loop system are proved. The asymptotical convergence of the closed‐loop system is obtained. Copyright © 2017 John Wiley & Sons, Ltd.     

On boundary feedback stabilization of Timoshenko beam with rotor inertia at the tip

The feedback stabilization problem of a nonuniform Timoshenko beam system with rotor inertia at the tip of the beam is studied. First, as a special kind of linear boundary force feedback and moment control is applied to the beam‘ s tip, the strict mathematical treatment, a suitable state Hilbert space is chosen, and the well-poseness of the corresponding closed loop system is proved by using the semigroup theory of bounded linear operators. Then the energy corresponding to the closed loop system is shown to be exponentially stable. Finally, in the special case of umform beam, some sufficient and necessary conditions for the corresponding closed loop system to be asymptotically stable are derived.     

Euler－Bernoulli梁的反馈镇定

讨论端点带负荷的Ｂｅｒｎｏｕｌｌｉ梁的横向振动的控制问题．分析了系统的谱结构，提出一种非线性边界反馈来镇定梁的横向振动，并证明了相应的闭环系统的渐近稳定性，最后给出了一些数值模拟结果．     

Local stabilization of semilinear parabolic system by boundary control

This paper addresses local stabilization of a semilinear parabolic system by boundary control. Under a certain assumption on the nonlinearity of the parabolic equation, a linear boundary feedback control law is applied to control the semilinear system. Based on the operator theories and relations of different norms, locally exponential stabilization of the closed loop system is established. Simulations support the established stability result.     

Local stabilization of the Burgers–Fisher equation via boundary control

Locally exponential stabilization for the Burgers–Fisher system is addressed by boundary control in this paper. For the nonlinear partial differential equation, a linear boundary feedback control law is applied to control the Burgers–Fisher system. Locally exponential stabilization of the closed loop system is established based on the relationship between operator theories and relations of different norms. Finally, the theory is validated through numerical simulations.     

Boundary stabilization of a cascade of ODE‐wave systems subject to boundary control matched disturbance

In this paper, we are concerned with a cascade of ODE‐wave systems with the control actuator‐matched disturbance at the boundary of the wave equation. We use the sliding mode control (SMC) technique and the active disturbance rejection control method to overcome the disturbance, respectively. By the SMC approach, the disturbance is supposed to be bounded only. The existence and uniqueness of solution for the closed‐loop via SMC are proved, and the monotonicity of the ‘reaching condition’ is presented without the differentiation of the sliding mode function, for which it may not always exist for the weak solution of the closed‐loop system. Considering that the SMC usually requires the large control gain and may exhibit chattering behavior, we then develop an active disturbance rejection control to attenuate the disturbance. The disturbance is canceled in the feedback loop. The closed‐loop systems with constant high gain and time‐varying high gain are shown respectively to be practically stable and asymptotically stable. Then we continue to consider output feedback stabilization for this coupled ODE‐wave system, and we design a variable structure unknown input‐type state observer that is shown to be exponentially convergent. The disturbance is estimated through the extended state observer and then canceled in the feedback loop by its approximated value. These enable us to design an observer‐based output feedback stabilizing control to this uncertain coupled system. Copyright © 2016 John Wiley & Sons, Ltd.     

非均质Euler-bernoulli梁的局部反馈定问题

In this article, we study the locally distributed feedback stabilization problem of a nonuniform Euler-Bernoulli beam. Firstly, using the semi-group theory, we establish the well-posedness of the associated closed loop system. Then by proving the uniqueness of the solution to a related ordinary differential equation, we derive the asymptotic stability of the closed loop system. Finally, by means of the piecewise multiplier method, we prove that, by either one distributed force feedback or a distributed moment feedback control, the closed loop system can be exponentially stabilized.