Suat Gumussoy, Hitay Ozbay
In this paper, we study the stability of suboptimal H-infinity controllers for time-delay systems. The optimal H-infinity controller may have finitely or infinitely many unstable poles. A stable suboptimal H-infinity controller design procedure is given for each of these cases. The design methods are illustrated with examples.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
继续探索
We report on our experience with fixed-order H-infinity controller design using the HIFOO toolbox. We applied HIFOO to various benchmark fixed (or reduced) order H-infinity controller design problems in the literature, comparing the results with those published for other methods. The results show that HIFOO can be used as an effective alternative to existing methods for fixed-order HIFOO controller design.
We report on our experience with strong stabilization using HIFOO, a toolbox for H-infinity fixed-order controller design. We applied HIFOO to 21 fixed-order stable H-infinity controller design problems in the literature, comparing the results with those published for other methods. The results show that HIFOO often achieves good H-infinity performance with low-order stable controllers, unlike other methods in the literature.
This paper investigates stable suboptimal H-infinity controllers for a class of single-input single-output time-delay systems. For a given plant and weighting functions, the optimal controller minimizing the mixed sensitivity (and the central suboptimal controller) may be unstable with finitely or infinitely many poles in complex right half-plane. For each of these cases search algorithms are proposed to find stable suboptimal H-infinity controllers. These design methods are illustrated with examples.
A state space based design method is given to find strongly stabilizing controllers for multiple-input-multiple-output plants (MIMO). A sufficient condition is derived for the existence of suboptimal stable H-infinity controller in terms of linear matrix inequalities (LMIs) and the controller order is twice that of the plant. A new parameterization of strongly stabilizing controllers is determined using linear fractional transformations (LFTs).
The approach in Foias et al. (1996) is one of the well-developed methods to design H-infinity controllers for general infinite dimensional systems. This approach is applicable if the plant admits a special coprime inner/outer factorization. We give the largest class of single-input-single-output (SISO) time delay systems for which this factorization is possible and factorize the admissible plants. Based on this factorization, we compute the optimal H-infinity performance and eliminate unstable pole-zero cancellations in the optimal H-infinity controller. We extend the results on the finite imp…
We design fixed-order strong H-infinity controllers for general time-delay systems. The designer chooses the controller order and may introduce constant time-delays in the controller. We represent the closed-loop system of the plant and the controller as delay differential algebraic equations (DDAEs). This representation deals with any interconnection of systems with time-delays without any elimination techniques. We present a numerical algorithm to compute the strong H-infinity norm for DDAEs which is robust to arbitrarily small delay perturbations, unlike the standard H-infinity norm. We opt…
This article proposes the design of H-infinity-based robust current controller for single-phase grid-feeding voltage source inverter with an LCL filter. The main objective of the proposed controller is to have good reference tracking, disturbance rejection and sufficient LCL resonance damping under a large range of variations of grid impedance. Based on the aforementioned performance requirements, frequency dependent weighting functions are designed. Subsequently, the sub-optimal control problem is formulated and solved to determine the stabilizing controller. Computational footprint of the co…
The skew Toeplitz approach is one of the well developed methods to design H-infinity controllers for infinite dimensional systems. In order to be able to use this method the plant needs to be factorized in some special manner. This paper investigates the largest class of SISO time delay systems for which the special factorizations required by the skew Toeplitz approach can be done. Reliable implementation of the optimal controller is also discussed. It is shown that the finite impulse response (FIR) block structure appears in these controllers not only for plants with I/O delays, but also for …
Robust Design of H-infinity Controller for a Launch Vehicle Autopilot against Disturbances
本文基于线性时间变化参数模型，利用大气飞行阶段评估H无穷控制器在干扰下的性能，通过鲁棒命令跟踪设计保证稳定操作，实验验证了控制器的高效性和系统抗干扰能力。
An eigenvalue based framework is developed for the H-infinity norm analysis and its norm minimization of coupled systems with time-delays, which are naturally described by delay differential algebraic equations (DDAEs). For these equations H-infinity norms are analyzed and their sensitivity with respect to small delay perturbations is studied. Subsequently, numerical methods for the H-infinity norm computation and for designing controllers minimizing the H-infinity norm with a prescribed structure or order, based on a direct optimization approach, are briefly addressed. The effectiveness of th…
H-infinity controllers are frequently used in control theory due to their robust performance and stabilization. Classical H-infinity controller synthesis methods for finite dimensional LTI MIMO plants result in high-order controllers for high-order plants whereas low-order controllers are desired in practice. We design fixed-order H-infinity controllers for a class of time-delay systems based on a non-smooth, non-convex optimization method and a recently developed numerical method for H-infinity norm computations.
We consider delay differential algebraic equations (DDAEs) to model interconnected systems with time-delays. The DDAE framework does not require any elimination techniques and can directly deal with any interconnection of systems and controllers with time-delays. In this framework, we analyze the properties of the H-infinity norm of systems described by delay differential algebraic equations. We show that the standard H-infinity norm may be sensitive to arbitrarily small delay perturbations. We introduce the strong H-infinity norm which is insensitive to small delay perturbations and describe …
Cloud Control of Connected Vehicle under Bi-directional Time-varying delay: An Application of Predictor-observer Structured Controller
针对网联车辆云控制中的双向时变通信时延，提出Predictor-Observer结构化控制器，同时补偿输出与有界输入时延，并通过仿真和实车横向控制验证其优越性能。
Weighted sensitivity minimization is studied within the framework of strongly stabilizing (stable) H-infinity controller design for a class of infinite dimensional systems. This problem has been solved by Ganesh and Pearson, [11], for finite dimensional plants using Nevanlinna-Pick interpolation. We extend their technique to a class of unstable time delay systems. Moreover, we illustrate suboptimal solutions, and their robust implementation.
In this paper sensitivity minimization problem is considered for a class of unstable time delay systems. Our goal is to find a stable controller stabilizing the feedback system and giving rise to smallest H-infinity norm for the sensitivity function. This problem has been solved by Ganesh and Pearson (1986) for finite dimensional plants using Nevanlinna-Pick interpolation. We extend their technique to include possibly unstable time delay systems. Moreover, we illustrate suboptimal solutions, and their robust implementation.
Reset Controller Synthesis by Reach-avoid Analysis for Delay Hybrid Systems
本文针对时滞混合系统，提出一种将重置控制器综合转化为可达-避让集合生成的方法，利用凸优化求解器高效求解，以确保系统目标实现。
Optimal Distributed Controller Design with Communication Delays: Application to Vehicle Formations
本文提出一种分布式LQG控制问题的控制器合成算法，考虑三个互联线性子系统及延迟信息共享结构，解决输出反馈情况下的最优控制问题。
Handling Packet Dropouts and Random Delays for Unstable Delayed Processes in NCS by Optimal Tuning of PIλDμ Controllers with Evolutionary Algorithms
针对网络控制系统中的随机延迟和丢包问题，提出使用进化算法优化分数阶PIλDμ控制器参数，并在时域中验证其优于整数阶PID控制器。
We present a new fixed-order H-infinity controller design method for potentially large-scale port-Hamiltonian (pH) plants. Our method computes controllers that are also pH (and thus passive) such that the resulting closed-loop systems is again passive, which ensures closed-loop stability simply from the structure of the plant and controller matrices. In this way, we can avoid computationally expensive eigenvalue computations that would otherwise be necessary. In combination with a sample-based objective function which allows us to avoid multiple evaluations of the H-infinity norm (which is typ…
We consider the computation of H-infinity norms for Single-Input-Single-Output (SISO) time-delay systems, which are described by delay differential algebraic equations. Unlike the iterative level set methods in the literature, we present a novel numerical method to compute the H-infinity norm. This method requires solving one eigenvalue problem of at most twice the size of the eigenvalue problem in every iteration of a level set method, but in practice often considerably lower. We first show that the computation of extrema of the transfer function can be turned into the computation of the imag…
An eigenvalue based framework is developed for the stability analysis and stabilization of coupled systems with time-delays, which are naturally described by delay differential algebraic equations. The spectral properties of these equations are analyzed and their stability properties are studied, taking into account the effect of small delay perturbations. Subsequently, numerical methods for stability assessment and for designing stabilizing controllers with a prescribed structure or order, based on a direct optimization approach, are briefly addressed. The effectiveness of the approach is ill…
Delays are ubiquitous in modern hybrid systems, which exhibit both continuous and discrete dynamical behaviors. Induced by signal transmission, conversion, the nature of plants, and so on, delays may appear either in the continuous evolution of a hybrid system such that the evolution depends not only on the present state but also on its execution history, or in the discrete switching between its different control modes. In this paper we come up with a new model of hybrid systems, called \emph{delay hybrid automata}, to capture the dynamics of systems with the aforementioned two kinds of delays…
Estimation of the Plant Controller Communication Time-Delay Considering PMSG-Based Wind Turbines
针对逆变器与电厂控制器间通信时延引发风电场振荡的问题，提出基于永磁同步发电机（PMSG）风力发电机数学模型动态状态估计、利用PMU数据的鲁棒时延估计算法，经外部故障场景验证，可在线识别适合控制器模型的时延。
Safety Controller Synthesis for Stochastic Polynomial Time-Delayed Systems
本文提出了一种基于Krasovsky控制屏障证书的方法，用于具有时间延迟的随机多项式系统的安全控制器综合，通过求和平方优化程序实现概率安全保证。
We analyze and design H-infinity controllers for general time-delay systems with time-delays in systems' state, inputs and outputs. We allow the designer to choose the order of the controller and to introduce constant time-delays in the controller. The closed-loop system of the plant and the controller is modeled by a system of delay differential algebraic equations (DDAEs). The advantage of the DDAE modeling framework is that any interconnection of systems and controllers prone to various types of delays can be dealt with in a systematic way, without using any elimination technique. We presen…
In this paper we consider the computation of H-infinity norm of retarded time-delay systems with discrete pointwise state delays. It is well known that in the finite dimensional case H-infinity norm of a system is computed using the connection between the singular values of the transfer function and the imaginary axis eigenvalues of an Hamiltonian matrix. We show a similar connection between the singular values of a transfer function of a time-delay system and the imaginary axis eigenvalues of an infinite dimensional operator $\mathcal{L}_ξ$. Using spectral methods, this linear operator is app…
Mixed H2/H-infinity Data-Driven Control Design for Hard Disk Drives
本文提出了一种混合H2/H无穷数据驱动控制设计方法，用于多输入单输出系统，通过将混合控制目标转化为凸优化问题，实现闭环稳定性与信号方差最小化。
Increasing Robustness of the Anesthesia Process from Difference Patient's Delay Using a State-Space Model Predictive Controller
本文提出基于状态空间模型预测控制器与扩展卡尔曼滤波器的麻醉控制方法，通过BIS指数和丙泊酚实现麻醉深度控制，实验表明该方法能有效提升对患者延迟偏差的鲁棒性。
Missile Acceleration Controller Design using PI and Time-Delay Adaptive Feedback Linearization Methodology
针对导弹加速度控制中非最小相位特性和模型不确定性问题，提出一种结合时滞自适应补偿和PI控制器的级联反馈线性化方法。
This paper presents an algebraic technique to compute the maximum time-delay that can be accepted in the control loop of a Brushless DC Motor (BLDCM) speed controller before the closed loop response becomes unstable. Using a recently proposed time-delay stability analysis methodology, we derive accurate stability conditions for the BLDCM speed controller. The results of applying the new method show that tuning the PI controller for very fast response in the order of magnitude of the BLDCM mechanical time constant cause the time-delay to significantly affect the system stability.
In this paper we consider a class of linear time invariant systems with infinitely many unstable modes. By using the parameterization of all stabilizing controllers, we show that H-infinity controllers for such systems can be computed using the techniques developed earlier for infinite dimensional plants with finitely many unstable modes. We illustrate connections between the problem solved here and an indirect method for strongly stabilizing H-infinity controller design for systems with time delays.
H-infinity Filtering for Cloud-Aided Semi-active Suspension with Delayed Information
本文提出一种H无穷滤波框架，用于有云协助的半主动悬挂系统，考虑了时间变化延迟。通过结合车载传感器测量和云数据库的延迟道路信息，设计了H无穷滤波器，并通过数值仿真验证了云到车通信中信息融合的有效性。
Electrolysis systems use proportional-integral-derivative (PID) temperature controllers to maintain stack temperatures around set points. However, heat transfer delays in electrolysis systems cause manual tuning of PID temperature controllers to be time-consuming, and temperature oscillations often occur. This paper focuses on the design of the PID temperature controller for an alkaline electrolysis system to achieve fast and stable temperature control. A thermal dynamic model of an electrolysis system is established in the frequency-domain for controller designs. Based on this model, the temp…
In this paper, we deal with the power regulation of tethered-wing systems and demonstrate advantages of variable-pitch control in mitigating the dynamic mechanical loads and power fluctuations. The proposed scheme is based on a strategy that maximizes the energy capture during low-speed wind and prevents overloads during the high-speed wind. To realize this strategy, we use a tether reeling-speed controller to track the optimal generator speed during low-speed wind and a MIMO speed-force controller for power limitation during high-speed wind. The controllers are synthesized using H-infinity me…
A Convex Solution of the $H_\infty$-Optimal Controller Synthesis Problem for Multi-Delay Systems
本文提出通过将问题转化为线性算子不等式，利用半正定规划求解多延迟系统$H_\infty$最优状态反馈控制器综合问题，验证了控制器的最优性。
We address the problem of sparsity-promoting optimal control of cyber-physical systems with feedback delays. The delays are categorized into two classes - namely, intra-layer delay, and inter-layer delay between the cyber and the physical layers. Our objective is to minimize the H2-norm of the closed-loop system by designing an optimal combination of these two delays along with a sparse state-feedback controller, while respecting a given bandwidth constraint. We propose a two-loop optimization algorithm for this. The inner loop, based on alternating directions method of multipliers (ADMM), han…
Direct Adaptive Controller for Uncertain MIMO Dynamic Systems with Time-varying Delay and Dead-zone Inputs
本文提出了一种自适应跟踪控制方法，用于处理具有时间变化延迟和未知非线性死区输入的非线性参数化MIMO动态系统。通过引入新的高维积分Lyapunov-Krasovskii函数，确保系统全局稳定性和跟踪误差收敛到原点。
Centralised Multimode Power Oscillation Damping Controller for Photovoltaic Plants with Communication Delay Compensation
本文针对光伏电站通信延迟影响集中式振荡阻尼控制的问题，提出一种基于开环相移补偿的多模式集中式控制器，并通过实验室实时平台验证了通信通道精确建模对控制器设计的重要性。
In this note, we present an effective solution to the stabilization of linear input delay systems subject to dissipative constraints while all the effect of input delay is compensated by a controller with novel structure. The method is inspired by the recent development in the mathematical treatment of distributed delays and predictor controllers, which are critical for the derivation of the solution. An important conceptual innovation is the use of a parameterized dynamical state feedback controller (DSFC), where the dimension of the controller equals the dimension of the control input. A suf…
This paper studies stochastic aperiodic stabilization of a networked control system (NCS) consisting of a continuous-time plant and a discrete-time controller. The plant and the controller are assumed to be connected by communication channels with i.i.d. time-varying delays. The delays are theoretically not required to be bounded even when the plant is unstable in the deterministic sense. In our NCS, the sampling interval is supposed to be determined directly by such communication delays. A necessary and sufficient inequality condition is presented for designing a state-feedback controller sta…
Distributed Output-Feedback LQG Control with Delayed Information Sharing
针对输出反馈下的分布式LQG控制问题，提出一种控制器综合方法，通过将控制器分解为中心化LQG最优控制器与基于局部信息的校正项之和，推导出最优控制器增益的显式离散时间方程。
Note on the exact delay stability margin computation of hybrid dynamical systems
本文提出了一种新的方法，用于计算混合系统的精确延迟稳定性边界，特别是当离散时间控制器与连续时间系统回路连接时，通过选择适当的离散化技术来最大化延迟边界，并在实施前精确评估延迟边界。
To reduce the chattering and overestimation phenomena existing in classical adaptive sliding mode control, this paper presents a new class K_infinity function-based adaptive sliding mode control scheme. Two controllers are proposed in terms of concave and convex barrier functions to implement this kind of control methodology. To avoid large initial control magnitudes, two modified control schemes are provided, which extend the proposed methodology to different scenarios. It is proven that the proposed controllers yield finite-time convergence to a real sliding mode. Finally, simulations and di…
Practical adaptive control implementations where human pilots coexist in the loop are still uncommon, despite their success in handling uncertain dynamical systems. This is owing to their special nonlinear characteristics which lead to unfavorable interactions between pilots and adaptive controllers. To pave the way for the implementation of adaptive controllers in piloted applications, we propose an adaptive human pilot model that takes into account the time delay in the pilot's response while operating on an adaptive control system. The model can be utilized in the evaluation of adaptive con…
We present a delay-compensating control method that transforms exponentially stabilizing controllers for an undelayed system into a sample-based predictive controller with numerical integration. Our method handles both first-order and transport delays in actuators and trades-off numerical accuracy with computation delay to guaranteed stability under hardware limitations. Through hybrid stability analysis and numerical simulation, we demonstrate the efficacy of our method from both theoretical and simulation perspectives.
Delayed dynamic-feedback controller design for multi-frequency vibration suppression
本文提出一种基于延迟输出反馈的动态控制器设计方法，通过将系统建模为延迟微分代数方程并转化为无约束非凸优化问题，实现多频振动抑制。
Assurance of asymptotic trajectory tracking in robotic manipulators with a smooth control law in the presence of unmodeled dynamics or external disturbance is a challenging problem. Recently, it is asserted that it is achieved via a rigorous proof by designing a traditional model-free controller together with time delay estimation (TDE) such that neither dynamical parameters nor conservative assumptions on external disturbance are required. The purpose of this note is to show that this claim is not true and the stability proof of the method is incorrect. Finally, some modified versions of this…
Comparison of artificial neural network adaptive control techniques for a nonlinear system with delay
针对带延迟的非线性对象，本文比较HDLNNC与AMPC-NPLPT两种神经网络自适应控制器，发现AMPC-NPLPT在控制精度上表现更优。
Toward Neuronal Implementations of Delayed Optimal Control
本研究针对动物神经回路如何实现最优控制行为的问题，探索延迟线性二次调节器的神经元实现方式，发现三种可实现同一二阶控制器的最小神经回路构型，并提出衔接控制器与神经实现的相关概念。
Observer-Based Control of Linear Systems with Mismatched Input and Output Delays
针对控制输入和系统输出向量中存在不匹配时滞的线性系统，提出一种基于线性矩阵不等式和时滞补偿器的观测器控制方法，实现渐近稳定。
This manuscript discusses a scalable controller synthesis method for networked systems with a large number of identical subsystems based on the H-infinity control framework. The dynamics of the individual subsystems are described by identical linear time-invariant delay differential equations and the effect of transport and communication delay is explicitly taken into account. The presented method is based on the result that, under a particular assumption on the graph describing the interconnections between the subsystems, the H-infinity norm of the overall system is upper bounded by the robus…
Optimal Controller Tuning Technique for a First-Order Process with Time Delay
提出一种基于 Padé 近似和 Routh-Hurwitz 稳定性分析的 FOPTD 过程 PID 控制器整定技术，消除时滞影响并实现最小相位系统，仿真证明其跟踪性能优于传统方法。
Stability analysis of semiconductor manufacturing process with EWMA run-to-run controllers
本文基于EWMA算法提出两种控制器，研究了半导体制造中单产品和混合产品过程在不同测量延迟下的稳定性，通过Routh-Hurwitz准则和Lyapunov方法建立了稳定性区域。
This paper examines the robust (strong) H-infinity norm of a linear time-invariant system with discrete delays. The considered system is subject to real-valued, structured, Frobenius norm bounded uncertainties on the coefficient matrices. The robust H-infinity norm is the worst case value of the H-infinity norm over the realisations of the system and hence an important measure of robust performance in control engineering. However this robust H-infinity norm is a fragile measure, as for a particular realization of the uncertainties the H-infinity norm might be sensitive to arbitrarily small per…
Integral Control Barrier Functions with Input Delay: Prediction, Feasibility, and Robustness
本文提出一种用于具有输入延迟非线性系统的安全关键控制框架，通过动态定义的积分控制器补偿延迟并确保可行性，同时利用ICBFs设计二次规划以保证鲁棒性。
Nonzero bound on Fiedler eigenvalue causes exponential growth of H-infinity norm of vehicular platoon
本文研究了由相同车辆组成的分布式控制编队，证明了其图拉普拉斯矩阵的第二小特征值非零下界，并指出该下界导致编队的H-infinity范数随车辆数指数增长。
Optimal Distributed Control for Networked Control Systems with Delays
本文提出了一种基于非合作线性二次博弈的最优分布式控制策略，用于具有时间延迟的网络控制系统，应用于电力系统负荷频率控制。
Dynamic Activation and Assignment of SDN Controllers in LEO Satellite Constellations
本文针对LEO卫星星座中控制器分配需随卫星运动频繁更新的问题，提出动态卫星到控制器分配（DSCA）优化方法，通过最小化传播时延并优化活跃控制器数量，显著优于静态分配方案。
Platooning of Heterogeneous Vehicles with Actuation Delays: Theoretical and Experimental Results
本文提出了一种适用于具有执行延迟的异构车队的基于预测的协作式自适应巡航控制器，通过离散时间稳定性分析指导控制器增益选择，并用全尺寸车辆实验验证了理论结果。
Stochastic Optimal Linear Control of Wireless Networked Control Systems with Delays and Packet Losses
本文研究了具有随机网络诱导延迟和丢包的无线传感器和执行器网络的最优分散状态反馈控制器设计，将系统建模为具有分散控制器的无线网络化控制系统，并将其转化为非合作线性二次博弈问题，通过遗传控制系统和负荷频率控制系统验证了所提算法的性能。
扫码添加微信好友，提出您的宝贵建议 👇
💡 备注请填写：网站反馈
发表机构由 AI 从论文文本抽取，如发现错误，欢迎反馈修正建议。