基于时变内流的柔性立管自适应边界控制

针对具有系统结构参数不确定的海洋柔性立管不确定性系统,为了提高其振动控制效果和品质,通过对立管结构参数进行估计,采用自适应控制技术和Lyapunov综合法,设计了自适应边界控制算法对耦合内流动力学的立管振动进行控制.所设计的自适应控制器能补偿系统参数不确定性,以及避免了控制溢出,并能保证系统的稳定性和一致有界性.仿真结果进一步验证了该控制算法对抑制立管振动的有效性.     

海洋柔性立管输出反馈边界控制

针对耦合内流动力学的海洋柔性立管系统,为了提高其振动控制品质,结合Lyapunov直接法和高增益观测器理论设计了输出反馈边界控制和干扰观测器,用以抑制结构振动偏移量和减弱外部环境干扰载荷的影响.其后,证明了闭环系统解的存在性、唯一性和收敛性及闭环状态的一致有界性.此外,本文的控制设计和稳定性分析是基于立管的原始无穷维动力学进行的,因此关于模型截断法产生的控制溢出问题将不会产生.最后仿真结果验证了本文所提出的输出反馈边界控制器能有效抑制柔性立管的振动.     

针对执行器非光滑反向间隙-饱和的柔性立管边界控制

研究了针对执行器非光滑反向间隙-饱和约束特性的深海柔性立管系统振动控制和全局稳定问题.为了实现控制效果和品质,引入辅助系统和函数设计边界控制策略,以抑制立管系统振动并消除混合的反向间隙-饱和输入非线性影响.采用严格的分析且无需求助于模型降阶,所研发的控制器确保闭环系统在Lyapunov意义下的一致有界稳定性.通过选取恰当的设计参数,仿真结果验证了所设计控制器的控制性能.能.     

基于材料非线性的海洋柔性立管防弯器有限元分析

建立海洋柔性立管防弯器三维有限元模型,研究聚氨酯材料非线性对防弯器弯曲性能的影响．通过算例对比不同材料属性的计算结果,发现不考虑材料非线性的计算结果与理论分析结果吻合较好．试验结果表明考虑防弯器材料非线性的立管最大曲率比不考虑材料非线性的小10％．因此,在防弯器详细分析时很有必要考虑材料非线性．     

柔性机械臂运动轨迹的鲁棒自适应控制

本文针对多连杆柔性机械臂的运动轨迹问题，讨论了动力学建模，控制系统结构设计以及鲁棒自适应控制法，运用假设模记方法得到了柔性机械臂动力学所似方程，通过对柔性机械臂动力学特性分析，建立了等价动力学模型，依此提出了一种鲁棒自适应控制算法，并给出仿真研究结果。     

大加减速轴向移动系统鲁棒边界控制

针对具有大加减速的轴向移动系统,为有效抑制结构振动和避免控制溢出问题,将鲁棒边界控制技术与Lyapunov直接法相结合,基于结构无限维模型设计鲁棒边界控制器对结构振动进行主动控制。使用符号函数处理未知扰动,提高了控制器系统鲁棒性,并对控制系统的稳定性和一致有界性进行了验证。仿真结果表明,所提出的鲁棒边界控制方法能有效抑制结构的振动。     

基于节点状态一致的路网边界控制

针对路网车流分布不均衡的问题,本文提出基于一致性思想的路网边界流量控制策略.首先,基于车辆守恒宏观模型,描述了区域边界车流的动态演化;以区域内路段占有率一致作为控制目标,边界交叉口配时参数为控制输入,进行区域边界反馈控制设计,并推导出边界车流输入与内部路段放行比例的解析关系;最后,通过路网实测数据验证了边界控制策略的适用性.结果表明:边界控制策略不仅能够有效改善路网交通流分布不均衡的状况,还能够有效降低路网的平均延误、排队长度等指标,提高路网运行效率.     

模型不确定系统的鲁棒预测控制

针对一类脉冲传递函数描述的模型不确定系统 ,基于预测控制和鲁棒控制相结合的策略 ,提出一种鲁棒预测控制器的设计方法 ,并讨论了该方法允许的模型摄动鲁棒界 .仿真结果表明文中方法的有效性和理论分析的正确性 .     

末端有未知扰动的分布参数柔性机械臂的鲁棒边界控

本文研究在柔性机械臂的末端具有未知扰动的边界控制,以降低机械臂的振动.柔性机械臂的动态特性由偏微分方程表示的分布参数模型描述.在机械臂的末端边界基于Lyapunov直接法进行控制,以调节机械臂的振动.应用本文所提出的边界控制方法,可达到外界干扰下的指数稳定性.所提出的控制方法与系统参数无关,可确保在参数变化下系统具有鲁棒性.最后对所提控制方法的有效性进行了数值模拟.     

机械臂鲁棒自适应运动控制

针对具有不确定性的机械臂系统,文中阐述了一种基于势函数和Lyapunov稳定性理论的鲁棒自适应控制方法．它是通过合理选择与控制目标相关的势函数,并根据模型中不确定性的实时变化,在控制器中引入可在线可调参数,使得控制器机械臂能够跟踪给定的有界参考信号,跟踪误差收敛到包含零点的很小的邻域内．同时该闭环系统的所有状态半全局最终一致有界（SGUUB）．仿真研究表明该方法的有效性．     

Modeling and boundary control of a flexible marine riser coupled with internal fluid dynamics

In this paper, vibration reduction of a flexible marine riser with time-varying internal fluid is studied by using boundary control method and Lyapunov’s direct method. To achieve more accurate and practical riser’s dynamic behavior, the model of marine riser with time-varying internal fluid is modeled by a distributed parameter system (DPS) with partial differential equations (PDEs) and ordinary differential equations (ODEs) involving functions of space and time. The dynamic responses of riser are completely different if the time-varying internal fluid is considered. Boundary control is designed at the top boundary of the riser based on original infinite dimensionality PDEs model and Lyapunov’s direct method to reduce the riser’s vibrations. The uniform boundedness and closed-loop stability are proved based on the proposed boundary control. Simulation results verify the effectiveness of the proposed boundary control.     

Robust adaptive boundary control of a flexible marine riser with vessel dynamics

In this paper, robust adaptive boundary control for a flexible marine riser with vessel dynamics is developed to suppress the riser’s vibration. To provide an accurate and concise representation of the riser’s dynamic behavior, the flexible marine riser with vessel dynamics is described by a distributed parameter system with a partial differential equation (PDE) and four ordinary differential equations (ODEs). Boundary control is proposed at the top boundary of the riser based on Lyapunov’s direct method to regulate the riser’s vibration. Adaptive control is designed when the system parametric uncertainty exists. With the proposed robust adaptive boundary control, uniform boundedness under the ocean current disturbance can be achieved. The proposed control is implementable with actual instrumentation since all the required signals in the control can be measured by sensors or calculated by a backward difference algorithm. The state of the system is proven to converge to a small neighborhood of zero by appropriately choosing design parameters. Simulations are provided to illustrate the applicability and effectiveness of the proposed control.     

Robust and non‐linear control of marine system

Robust and non‐linear control theories useful for real marine system are developed and applied to a variety of marine vehicles and equipments. In the thesis, the basic principle of marine control system development is described and advanced robust control algorithm and non‐linear control algorithm applicable for real system are shown. It's effectiveness is confirmed by numerical simulations, tank tests, and sea trial tests. Copyright © 2001 John Wiley & Sons, Ltd.     

Robust global stabilisability by means of sampled-data control with positive sampling rate

This work proposes a notion of robust reachability of one set from another set under constant control. This notion is used to construct a control strategy, involving sequential set-to-set reachability, which guarantees robust global stabilisation of non-linear sampled data systems with positive sampling rate. Sufficient conditions for robust reachability of one set from another under constant control are also provided. The proposed method is illustrated through a number of examples, including the study of the sampled-data stabilisation problem of the chemostat.     

Robust adaptive neural network control for environmental boundary tracking by mobile robots

The paper addresses the problem of environmental boundary tracking for the nonholonomic mobile robot with uncertain dynamics and external disturbances. To do environmental boundary tracking, a reference velocity is designed for the nonholonomic mobile robot. In this paper, a radial basis function neural network (NN) is used to approximate a nonlinear function containing the uncertain model terms and the elements of the Hessian matrix of the environmental concentration function. Then, the NN approximator is combined with a robust control to construct a robust adaptive NN control for the mobile robot to track the desired environment boundary. It is proved that the tracking error can be guaranteed to converge to zero in the ultimate. Simulation results are presented to illustrate the stability of the robust adaptive control. Copyright © 2011 John Wiley & Sons, Ltd.     

基于模型参考和内模原理的线性系统鲁棒控制设计

不确定性因素会使系统性能恶化,它包括系统不确定性参数和各种外部干扰等.本文针对这种不确定性线性系统,利用模型参考和内模原理,建立鲁棒控制系统结构,分析了其能控性条件,通过选择参考模型和内模实现系统能控,在此条件下,将鲁棒控制设计转换为控制系统的LQR问题进行研究,并运用最优控制理论,计算其反馈控制律.仿真结果表明该设计方法将"模型参考"与"内模原理"有机结合起来,提高了系统的鲁棒稳定性,有效抑制干扰,并实现系统性能的改善.     

Robust optimal control of time‐delay systems based on Razumikhin theorem

This paper presents an optimal control approach for the general robust control design problem of linear time delay systems, which considers parameter uncertainties as well as state delay. It is shown that the robust control problem can be transformed into an optimal control problem with the amouof plant uncertainties involved in the performance index. A stability criterion has been developed under which the uncertain dynamical system can not only achieve stability, but also acquire the guaranteed level of performance for regulation. A suitable linear state feedback control law is also characterized via Lyapunov stability theory to ensure performance robustness of the closed‐loop system. Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society