European Journal of Control最新文献_第5页

Self-learning-based secure control of wind power generation systems under cyber threat: Ensuring prescribed performance 网络威胁下基于自学习的风力发电系统安全控制：确保规定性能

IF 2.5 3区计算机科学 Q2 AUTOMATION & CONTROL SYSTEMS

European Journal of Control

Pub Date : 2024-11-20 DOI: 10.1016/j.ejcon.2024.101152

Mahmood Mazare , Hossein Ramezani , Mostafa Taghizadeh

The increasing prominence of wind energy underscores the need to prioritize cybersecurity measures, with a focus on recognizing vulnerabilities and formulating defensive strategies. Specifically, False Data Injection (FDI) attacks targeted at the communication between rotor speed sensors and wind turbine (WT) controllers can disrupt operations, potentially causing drive-train overload and reduced power generation efficiency. To mitigate these threats, this study introduces an adaptive prescribed performance optimal secure control strategy that employs a reinforcement learning (RL) to compensate the detrimental effects of FDI attack as well as actuator fault. To derive the optimal control policy, the complex Hamilton–Jacobi–Bellman (HJB) equation is solved, facilitated by an actor–critic-based RL approach, where actor and critic neural network (NN) manage control actions and performance assessment. To detect FDI attack, an anomaly detection is developed using a fixed-time disturbance observer. Stability analysis is performed using Lyapunov theory which guarantees semi-global uniformly ultimately bounded (SGUUB) of the error signal. To rigorously validate our approach, we implemented the controller using FAST code for the NREL WindPACT 1.5 MW reference turbine. Simulation results convincingly demonstrate the effectiveness of our proposed control strategy, confirming its potential to enhance both performance and security in real-world WT operations.

风能的重要性日益凸显，因此需要优先采取网络安全措施，重点是识别漏洞和制定防御策略。具体来说，针对转子速度传感器和风力涡轮机（WT）控制器之间通信的虚假数据注入（FDI）攻击会破坏运行，可能导致传动系统过载和发电效率降低。为减轻这些威胁，本研究引入了一种自适应的规定性能最优安全控制策略，该策略采用强化学习（RL）来补偿 FDI 攻击和致动器故障的不利影响。为了推导出最佳控制策略，需要求解复杂的汉密尔顿-雅各比-贝尔曼（HJB）方程，并采用基于行动者-批评者的 RL 方法，其中行动者和批评者神经网络（NN）负责管理控制行动和性能评估。为了检测 FDI 攻击，使用固定时间干扰观测器开发了异常检测。利用保证误差信号半全局均匀终极约束（SGUUB）的 Lyapunov 理论进行稳定性分析。为了严格验证我们的方法，我们使用 FAST 代码为 NREL WindPACT 1.5 MW 参考涡轮机实现了控制器。仿真结果令人信服地证明了我们提出的控制策略的有效性，证实了其在实际风电运行中提高性能和安全性的潜力。

{"title":"Self-learning-based secure control of wind power generation systems under cyber threat: Ensuring prescribed performance","authors":"Mahmood Mazare , Hossein Ramezani , Mostafa Taghizadeh","doi":"10.1016/j.ejcon.2024.101152","DOIUrl":"10.1016/j.ejcon.2024.101152","url":null,"abstract":"<div><div>The increasing prominence of wind energy underscores the need to prioritize cybersecurity measures, with a focus on recognizing vulnerabilities and formulating defensive strategies. Specifically, False Data Injection (FDI) attacks targeted at the communication between rotor speed sensors and wind turbine (WT) controllers can disrupt operations, potentially causing drive-train overload and reduced power generation efficiency. To mitigate these threats, this study introduces an adaptive prescribed performance optimal secure control strategy that employs a reinforcement learning (RL) to compensate the detrimental effects of FDI attack as well as actuator fault. To derive the optimal control policy, the complex Hamilton–Jacobi–Bellman (HJB) equation is solved, facilitated by an actor–critic-based RL approach, where actor and critic neural network (NN) manage control actions and performance assessment. To detect FDI attack, an anomaly detection is developed using a fixed-time disturbance observer. Stability analysis is performed using Lyapunov theory which guarantees semi-global uniformly ultimately bounded (SGUUB) of the error signal. To rigorously validate our approach, we implemented the controller using FAST code for the NREL WindPACT 1.5 MW reference turbine. Simulation results convincingly demonstrate the effectiveness of our proposed control strategy, confirming its potential to enhance both performance and security in real-world WT operations.</div></div>","PeriodicalId":50489,"journal":{"name":"European Journal of Control","volume":"81 ","pages":"Article 101152"},"PeriodicalIF":2.5,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142719688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Gradient-based bilevel optimization for multi-penalty Ridge regression through matrix differential calculus 通过矩阵微分计算实现基于梯度的多惩罚脊回归双级优化

IF 2.5 3区计算机科学 Q2 AUTOMATION & CONTROL SYSTEMS

European Journal of Control

Pub Date : 2024-11-19 DOI: 10.1016/j.ejcon.2024.101150

Gabriele Maroni, Loris Cannelli, Dario Piga

Common regularization algorithms for linear regression, such as LASSO and Ridge regression, rely on a regularization hyperparameter that balances the trade-off between minimizing the fitting error and the norm of the learned model coefficients. As this hyperparameter is scalar, it can be easily selected via random or grid search optimizing a cross-validation criterion. However, using a scalar hyperparameter limits the algorithm’s flexibility and potential for better generalization. In this paper, we address the problem of linear regression with

ℓ_{2}

-regularization, where a different regularization hyperparameter is associated with each input variable. We optimize these hyperparameters using a gradient-based approach, wherein the gradient of a cross-validation criterion with respect to the regularization hyperparameters is computed analytically through matrix differential calculus. Additionally, we introduce two strategies tailored for sparse model learning problems aiming at reducing the risk of overfitting to the validation data. Numerical examples demonstrate that the proposed multi-hyperparameter regularization approach outperforms LASSO, Ridge, and Elastic Net regression in terms of

R^{2}

score both in a static regression and in a system identification problem. Moreover, the analytical computation of the gradient proves to be more efficient in terms of computational time compared to automatic differentiation, especially when handling a large number of input variables, with an improvement of more than an order of magnitude. Application to the identification of over-parameterized Linear Parameter-Varying models is also presented.

常见的线性回归正则化算法，如 LASSO 和 Ridge 回归，都依赖于一个正则化超参数，它能在拟合误差最小化与所学模型系数的规范之间取得平衡。由于该超参数是标量参数，因此可以通过随机或网格搜索优化交叉验证准则来轻松选择。然而，使用标量超参数限制了算法的灵活性和更好的泛化潜力。在本文中，我们用 ℓ2- 规则化来解决线性回归问题，其中每个输入变量都有一个不同的规则化超参数。我们使用基于梯度的方法优化这些超参数，其中交叉验证准则相对于正则化超参数的梯度是通过矩阵微分计算分析得出的。此外，我们还介绍了两种为稀疏模型学习问题量身定制的策略，旨在降低对验证数据过度拟合的风险。数值示例表明，在静态回归和系统识别问题中，所提出的多参数正则化方法在 R2 分数方面优于 LASSO、Ridge 和 Elastic Net 回归。此外，与自动微分相比，梯度的分析计算在计算时间上更有效，尤其是在处理大量输入变量时，其效率提高了一个数量级以上。此外，还介绍了超参数化线性参数变化模型识别的应用。

{"title":"Gradient-based bilevel optimization for multi-penalty Ridge regression through matrix differential calculus","authors":"Gabriele Maroni, Loris Cannelli, Dario Piga","doi":"10.1016/j.ejcon.2024.101150","DOIUrl":"10.1016/j.ejcon.2024.101150","url":null,"abstract":"<div><div>Common regularization algorithms for linear regression, such as LASSO and Ridge regression, rely on a regularization hyperparameter that balances the trade-off between minimizing the fitting error and the norm of the learned model coefficients. As this hyperparameter is scalar, it can be easily selected via random or grid search optimizing a cross-validation criterion. However, using a scalar hyperparameter limits the algorithm’s flexibility and potential for better generalization. In this paper, we address the problem of linear regression with <span><math><msub><mrow><mi>ℓ</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span>-regularization, where a different regularization hyperparameter is associated with each input variable. We optimize these hyperparameters using a gradient-based approach, wherein the gradient of a cross-validation criterion with respect to the regularization hyperparameters is computed analytically through matrix differential calculus. Additionally, we introduce two strategies tailored for sparse model learning problems aiming at reducing the risk of overfitting to the validation data. Numerical examples demonstrate that the proposed multi-hyperparameter regularization approach outperforms LASSO, Ridge, and Elastic Net regression in terms of <span><math><msup><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> score both in a static regression and in a system identification problem. Moreover, the analytical computation of the gradient proves to be more efficient in terms of computational time compared to automatic differentiation, especially when handling a large number of input variables, with an improvement of more than an order of magnitude. Application to the identification of over-parameterized Linear Parameter-Varying models is also presented.</div></div>","PeriodicalId":50489,"journal":{"name":"European Journal of Control","volume":"81 ","pages":"Article 101150"},"PeriodicalIF":2.5,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142719687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Output feedback control of LTI systems using quantized periodic event-triggering and 1-bit data transmission 利用量化周期事件触发和 1 位数据传输实现 LTI 系统的输出反馈控制

IF 2.5 3区计算机科学 Q2 AUTOMATION & CONTROL SYSTEMS

European Journal of Control

Pub Date : 2024-11-19 DOI: 10.1016/j.ejcon.2024.101146

Dhafer Almakhles , Mahmoud Abdelrahim

This paper presents a novel framework for periodic event-triggered control (PETC) coupled with dynamic quantization for linear systems. Unlike traditional time-driven control methods, our approach leverages event-based mechanisms to judiciously update control actions, thus minimizing computational load and network traffic. We introduce a two-level dynamic quantizer for encoding feedback information with a single bit, thereby enhancing resource efficiency. The proposed PETC mechanism decides the transmission instants based on the quantized output samples. The resulting system is modeled as a hybrid dynamical system to capture both continuous and discrete dynamics. Sufficient conditions for ensuring the stability of the closed-loop system are presented in the form of a linear matrix inequality. Through numerical simulations, we demonstrate that our approach captures the initial output within a finite time and significantly reduces data transmissions compared to traditional methods. This paper makes key contributions in the integration of dynamic quantization with PETC, leading to resource-efficient and stable control systems.

本文提出了一种新颖的线性系统周期性事件触发控制（PETC）与动态量化相结合的框架。与传统的时间驱动控制方法不同，我们的方法利用基于事件的机制来明智地更新控制行动，从而最大限度地减少计算负荷和网络流量。我们引入了两级动态量化器，用单个比特对反馈信息进行编码，从而提高了资源效率。提议的 PETC 机制根据量化输出样本决定传输实例。由此产生的系统被建模为混合动态系统，以捕捉连续和离散动态。我们以线性矩阵不等式的形式提出了确保闭环系统稳定性的充分条件。通过数值模拟，我们证明了我们的方法能在有限的时间内捕获初始输出，与传统方法相比大大减少了数据传输。本文在动态量化与 PETC 的整合方面做出了重要贡献，从而实现了资源节约型稳定控制系统。

{"title":"Output feedback control of LTI systems using quantized periodic event-triggering and 1-bit data transmission","authors":"Dhafer Almakhles , Mahmoud Abdelrahim","doi":"10.1016/j.ejcon.2024.101146","DOIUrl":"10.1016/j.ejcon.2024.101146","url":null,"abstract":"<div><div>This paper presents a novel framework for periodic event-triggered control (PETC) coupled with dynamic quantization for linear systems. Unlike traditional time-driven control methods, our approach leverages event-based mechanisms to judiciously update control actions, thus minimizing computational load and network traffic. We introduce a two-level dynamic quantizer for encoding feedback information with a single bit, thereby enhancing resource efficiency. The proposed PETC mechanism decides the transmission instants based on the quantized output samples. The resulting system is modeled as a hybrid dynamical system to capture both continuous and discrete dynamics. Sufficient conditions for ensuring the stability of the closed-loop system are presented in the form of a linear matrix inequality. Through numerical simulations, we demonstrate that our approach captures the initial output within a finite time and significantly reduces data transmissions compared to traditional methods. This paper makes key contributions in the integration of dynamic quantization with PETC, leading to resource-efficient and stable control systems.</div></div>","PeriodicalId":50489,"journal":{"name":"European Journal of Control","volume":"81 ","pages":"Article 101146"},"PeriodicalIF":2.5,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142719686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Boundary exponential stabilization of a time-delay ODE-KdV cascaded system 时延 ODE-KdV 级联系统的边界指数稳定

IF 2.5 3区计算机科学 Q2 AUTOMATION & CONTROL SYSTEMS

European Journal of Control

Pub Date : 2024-11-17 DOI: 10.1016/j.ejcon.2024.101141

Habib Ayadi , Mariem Jlassi

This paper deals with the well-posedness and exponential stabilization problems of a cascaded control system consisting of a linear ordinary differential equation (ODE) and the one-dimensional linear Korteweg–de Vries (KdV) partial differential equation posed on a bounded interval

[0, l]

, where the states are subject to an arbitrary constant delay. The control input for the whole system acts at the left boundary of the KdV domain by Dirichlet condition, whereas the right boundary injects a Dirichlet term in the ODE subsystem. Based on the infinite dimensional backstepping method for the delay-free case, an explicit feedback control law is constructed. Under this feedback, we prove the well-posedness of the considered system in Hilbert space

H = R^{n} \times L^{2} (0, l)

by using semigroup theory and its exponential stability in the topology of

{‖ \cdot ‖}_{H}

-norm by combining Lyapunov method with Halanay’s inequality and linear matrix inequalities (LMIs). A numerical example is provided to illustrate the result.

本文讨论了由线性常微分方程（ODE）和一维线性 Korteweg-de Vries（KdV）偏微分方程组成的级联控制系统在有界区间 [0,l] 上的良好求解和指数稳定问题，其中各状态受任意常数延迟的影响。整个系统的控制输入通过 Dirichlet 条件作用于 KdV 域的左边界，而右边界则在 ODE 子系统中注入 Dirichlet 项。基于无延迟情况下的无限维反步法，我们构建了一个显式反馈控制律。在此反馈条件下，我们利用半群理论证明了所考虑的系统在希尔伯特空间 H=Rn×L2(0,l) 中的良好拟合性，并通过将 Lyapunov 方法与 Halanay 不等式和线性矩阵不等式（LMI）相结合，证明了其在‖⋅‖H-规范拓扑中的指数稳定性。本文提供了一个数值示例来说明这一结果。

{"title":"Boundary exponential stabilization of a time-delay ODE-KdV cascaded system","authors":"Habib Ayadi , Mariem Jlassi","doi":"10.1016/j.ejcon.2024.101141","DOIUrl":"10.1016/j.ejcon.2024.101141","url":null,"abstract":"<div><div>This paper deals with the well-posedness and exponential stabilization problems of a cascaded control system consisting of a linear ordinary differential equation (ODE) and the one-dimensional linear Korteweg–de Vries (KdV) partial differential equation posed on a bounded interval <span><math><mrow><mo>[</mo><mn>0</mn><mo>,</mo><mi>l</mi><mo>]</mo></mrow></math></span>, where the states are subject to an arbitrary constant delay. The control input for the whole system acts at the left boundary of the KdV domain by Dirichlet condition, whereas the right boundary injects a Dirichlet term in the ODE subsystem. Based on the infinite dimensional backstepping method for the delay-free case, an explicit feedback control law is constructed. Under this feedback, we prove the well-posedness of the considered system in Hilbert space <span><math><mrow><mi>H</mi><mo>=</mo><msup><mrow><mi>R</mi></mrow><mrow><mi>n</mi></mrow></msup><mo>×</mo><msup><mrow><mi>L</mi></mrow><mrow><mn>2</mn></mrow></msup><mrow><mo>(</mo><mn>0</mn><mo>,</mo><mi>l</mi><mo>)</mo></mrow></mrow></math></span> by using semigroup theory and its exponential stability in the topology of <span><math><msub><mrow><mo>‖</mo><mi>⋅</mi><mo>‖</mo></mrow><mrow><mi>H</mi></mrow></msub></math></span>-norm by combining Lyapunov method with Halanay’s inequality and linear matrix inequalities (LMIs). A numerical example is provided to illustrate the result.</div></div>","PeriodicalId":50489,"journal":{"name":"European Journal of Control","volume":"81 ","pages":"Article 101141"},"PeriodicalIF":2.5,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142719690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Privacy-preserving anomaly detection in stochastic dynamical systems: Synthesis of optimal Gaussian mechanisms 随机动力系统中的隐私保护异常检测：最优高斯机制的综合

IF 2.5 3区计算机科学 Q2 AUTOMATION & CONTROL SYSTEMS

European Journal of Control

Pub Date : 2024-11-15 DOI: 10.1016/j.ejcon.2024.101142

Haleh Hayati , Carlos Murguia , Nathan van de Wouw

We present a framework for designing distorting mechanisms that allow the remote operation of anomaly detectors while preserving privacy. We consider a problem setting in which a remote station seeks to identify anomalies in dynamical systems using system input–output signals transmitted over communication networks. However, disclosing the true input–output signals of the system is not desired, as it can be used to infer private information. To maintain privacy, we propose a privacy-preserving mechanism that distorts input and measurement data before transmission using additive dependent Gaussian random processes and sends the distorted data to the remote station (which inevitably leads to degraded detection performance). We formulate constructive design conditions for the probability distributions of these additive processes while taking into account the trade-off between privacy, quantified using information-theoretic metrics (mutual information and differential entropy), and anomaly detection performance, characterized by the detector false alarm rate. The design of the privacy mechanisms is formulated as the solution of a convex optimization problem where we maximize privacy over a finite window of realizations while guaranteeing a bound on performance degradation of the anomaly detector.

我们提出了一个框架，用于设计扭曲机制，允许远程操作异常检测器，同时保护隐私。我们考虑一个问题设置，其中一个远程站寻求识别异常动态系统使用系统输入输出信号通过通信网络传输。然而，披露系统的真实输入输出信号是不可取的，因为它可以用来推断私人信息。为了保护隐私，我们提出了一种隐私保护机制，该机制在传输前使用加性相关高斯随机过程扭曲输入和测量数据，并将扭曲的数据发送到远程站点（这不可避免地导致检测性能下降）。我们为这些附加过程的概率分布制定了建设性的设计条件，同时考虑到隐私之间的权衡，使用信息论度量（互信息和微分熵）进行量化，以及异常检测性能，以检测器误报率为特征。隐私机制的设计被表述为一个凸优化问题的解决方案，其中我们在有限的实现窗口上最大化隐私，同时保证异常检测器的性能退化的界限。

{"title":"Privacy-preserving anomaly detection in stochastic dynamical systems: Synthesis of optimal Gaussian mechanisms","authors":"Haleh Hayati , Carlos Murguia , Nathan van de Wouw","doi":"10.1016/j.ejcon.2024.101142","DOIUrl":"10.1016/j.ejcon.2024.101142","url":null,"abstract":"<div><div>We present a framework for designing distorting mechanisms that allow the remote operation of anomaly detectors while preserving privacy. We consider a problem setting in which a remote station seeks to identify anomalies in dynamical systems using system input–output signals transmitted over communication networks. However, disclosing the true input–output signals of the system is not desired, as it can be used to infer private information. To maintain privacy, we propose a privacy-preserving mechanism that distorts input and measurement data before transmission using additive dependent Gaussian random processes and sends the distorted data to the remote station (which inevitably leads to degraded detection performance). We formulate constructive design conditions for the probability distributions of these additive processes while taking into account the trade-off between privacy, quantified using information-theoretic metrics (mutual information and differential entropy), and anomaly detection performance, characterized by the detector false alarm rate. The design of the privacy mechanisms is formulated as the solution of a convex optimization problem where we maximize privacy over a finite window of realizations while guaranteeing a bound on performance degradation of the anomaly detector.</div></div>","PeriodicalId":50489,"journal":{"name":"European Journal of Control","volume":"81 ","pages":"Article 101142"},"PeriodicalIF":2.5,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142746007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Design of planar collision-free trochoidal paths for a multi-robot swarm 为多机器人群设计无碰撞的平面三弦路径

IF 2.5 3区计算机科学 Q2 AUTOMATION & CONTROL SYSTEMS

European Journal of Control

Pub Date : 2024-11-15 DOI: 10.1016/j.ejcon.2024.101143

Adil Shiyas , Sachit Rao

In the literature, a distributed consensus protocol by which a connected swarm of agents can generate artistic patterns in 2-dimensional space is proposed. Motivated by this protocol, in this paper, we design the parameters of this protocol for a 3-agent swarm of non-holonomic robots of finite size that results in the generation of periodic trochoidal trajectories that satisfy a set of geometric and speed constraints; this design also includes selecting the initial positions of the robots. This problem finds applications in persistent surveillance and coverage, guarding a region of interest, and target detection. While the trajectories may be self-intersecting, imposing geometric constraints i. eliminates collisions between robots; ii. ensures minimum and maximum separation distance between any robot and a fixed point, thus ensuring the robots are in communication range. Imposing speed constraints ensure that tracking these trajectories becomes feasible. It is also shown that robots can be injected to these paths at specific locations, in order to increase the refresh rate, without violating any of the geometric constraints. Conditions for the existence of the protocol parameters that satisfy all constraints are identified. The designs are implemented in an indoor mobile robot platform.

文献中提出了一种分布式共识协议，通过该协议，连接的代理群可以在二维空间中生成艺术图案。受这一协议的启发，我们在本文中为一个由有限大小的非自主机器人组成的 3 个代理群设计了这一协议的参数，从而生成满足一系列几何和速度限制的周期性三弦轨迹；这一设计还包括选择机器人的初始位置。这一问题可应用于持久监视和覆盖、保护感兴趣区域以及目标检测。虽然轨迹可能是自交的，但施加几何约束 i. 可消除机器人之间的碰撞； ii. 确保任何机器人与固定点之间的最小和最大分离距离，从而确保机器人处于通信范围内。施加速度限制可确保跟踪这些轨迹变得可行。实验还表明，在不违反任何几何约束的情况下，可以在特定位置向这些路径注入机器人，以提高刷新率。还确定了满足所有约束条件的协议参数的存在条件。这些设计在室内移动机器人平台上得以实现。

{"title":"Design of planar collision-free trochoidal paths for a multi-robot swarm","authors":"Adil Shiyas , Sachit Rao","doi":"10.1016/j.ejcon.2024.101143","DOIUrl":"10.1016/j.ejcon.2024.101143","url":null,"abstract":"<div><div>In the literature, a distributed consensus protocol by which a connected swarm of agents can generate artistic patterns in 2-dimensional space is proposed. Motivated by this protocol, in this paper, we design the parameters of this protocol for a 3-agent swarm of non-holonomic robots of finite size that results in the generation of periodic trochoidal trajectories that satisfy a set of geometric and speed constraints; this design also includes selecting the initial positions of the robots. This problem finds applications in persistent surveillance and coverage, guarding a region of interest, and target detection. While the trajectories may be self-intersecting, imposing geometric constraints <em>i</em>. eliminates collisions between robots; <em>ii</em>. ensures minimum and maximum separation distance between any robot and a fixed point, thus ensuring the robots are in communication range. Imposing speed constraints ensure that tracking these trajectories becomes feasible. It is also shown that robots can be injected to these paths at specific locations, in order to increase the <em>refresh rate</em>, without violating any of the geometric constraints. Conditions for the existence of the protocol parameters that satisfy all constraints are identified. The designs are implemented in an indoor mobile robot platform.</div></div>","PeriodicalId":50489,"journal":{"name":"European Journal of Control","volume":"81 ","pages":"Article 101143"},"PeriodicalIF":2.5,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142719691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A comparative study of sensitivity computations in ESDIRK-based optimal control problems 基于 ESDIRK 的最优控制问题中灵敏度计算的比较研究

IF 2.5 3区计算机科学 Q2 AUTOMATION & CONTROL SYSTEMS

European Journal of Control

Pub Date : 2024-11-01 DOI: 10.1016/j.ejcon.2024.101064

Anders Hilmar Damm Christensen, John Bagterp Jørgensen

This paper compares the impact of iterated and direct approaches to sensitivity computation in fixed step-size explicit singly diagonally implicit Runge–Kutta (ESDIRK) methods when applied to optimal control problems (OCPs). We strictly use the principle of internal numerical differentiation (IND) for the iterated approach, i.e., reusing iteration matrix factorizations, the number of Newton-type iterations, and Newton iterates, to compute the sensitivities. The direct method computes the sensitivities without using the Newton schemes. We compare the impact of these sensitivity computations in OCPs for the quadruple tank system (QTS). We discretize the OCPs using multiple shooting and solve these with a sequential quadratic programming (SQP) solver. We benchmark the iterated and direct approaches against a base case. This base case applies the ESDIRK methods with exact Newton schemes and a direct approach for sensitivity computations. In these OCPs, we vary the number of integration steps between control intervals and evaluate the performance based on the number of SQP and QPs iterations, KKT violations, function evaluations, Jacobian updates, and iteration matrix factorizations. We also provide examples using the continuous-stirred tank reactor (CSTR), and the IPOPT algorithm instead of the SQP. For OCPs solved using SQP, the QTS results show the direct method converges only once, while the iterated approach and base case converges in all situations. Similar results are seen with the CSTR. Using IPOPT, both the iterated approach and base case converge in all cases. In contrast, the direct method only converges in all cases regarding the CSTR.

本文比较了固定步长显式单对角隐式 Runge-Kutta (ESDIRK) 方法应用于最优控制问题 (OCP) 时，迭代法和直接法对灵敏度计算的影响。我们在迭代法中严格使用内部数值微分（IND）原理，即重复使用迭代矩阵因式分解、牛顿型迭代次数和牛顿迭代次数来计算灵敏度。直接法计算敏感度时不使用牛顿方案。我们比较了这些灵敏度计算对四水箱系统（QTS）OCP 的影响。我们使用多重射击对 OCP 进行离散化，并使用顺序二次编程 (SQP) 求解器进行求解。我们将迭代法和直接法与一个基本案例进行比较。该基础案例采用带有精确牛顿方案的 ESDIRK 方法和直接方法进行灵敏度计算。在这些 OCP 中，我们改变了控制区间之间的积分步数，并根据 SQP 和 QPs 的迭代次数、KKT 违反情况、函数评估、雅各布更新和迭代矩阵因式分解来评估性能。我们还提供了使用连续搅拌罐反应器（CSTR）和 IPOPT 算法代替 SQP 的示例。对于使用 SQP 求解的 OCP，QTS 结果显示直接方法只收敛一次，而迭代方法和基本情况在所有情况下都收敛。CSTR 也有类似的结果。使用 IPOPT 时，迭代法和基准法在所有情况下都收敛。相比之下，直接法只在 CSTR 的所有情况下收敛。

{"title":"A comparative study of sensitivity computations in ESDIRK-based optimal control problems","authors":"Anders Hilmar Damm Christensen, John Bagterp Jørgensen","doi":"10.1016/j.ejcon.2024.101064","DOIUrl":"10.1016/j.ejcon.2024.101064","url":null,"abstract":"<div><div>This paper compares the impact of iterated and direct approaches to sensitivity computation in fixed step-size explicit singly diagonally implicit Runge–Kutta (ESDIRK) methods when applied to optimal control problems (OCPs). We strictly use the principle of internal numerical differentiation (IND) for the iterated approach, i.e., reusing iteration matrix factorizations, the number of Newton-type iterations, and Newton iterates, to compute the sensitivities. The direct method computes the sensitivities without using the Newton schemes. We compare the impact of these sensitivity computations in OCPs for the quadruple tank system (QTS). We discretize the OCPs using multiple shooting and solve these with a sequential quadratic programming (SQP) solver. We benchmark the iterated and direct approaches against a base case. This base case applies the ESDIRK methods with exact Newton schemes and a direct approach for sensitivity computations. In these OCPs, we vary the number of integration steps between control intervals and evaluate the performance based on the number of SQP and QPs iterations, KKT violations, function evaluations, Jacobian updates, and iteration matrix factorizations. We also provide examples using the continuous-stirred tank reactor (CSTR), and the IPOPT algorithm instead of the SQP. For OCPs solved using SQP, the QTS results show the direct method converges only once, while the iterated approach and base case converges in all situations. Similar results are seen with the CSTR. Using IPOPT, both the iterated approach and base case converge in all cases. In contrast, the direct method only converges in all cases regarding the CSTR.</div></div>","PeriodicalId":50489,"journal":{"name":"European Journal of Control","volume":"80 ","pages":"Article 101064"},"PeriodicalIF":2.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141510833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Nonlinear model predictive control based on K-step control invariant sets 基于 K 步控制不变集的非线性模型预测控制

IF 2.5 3区计算机科学 Q2 AUTOMATION & CONTROL SYSTEMS

European Journal of Control

Pub Date : 2024-11-01 DOI: 10.1016/j.ejcon.2024.101040

Zhixin Zhao, Antoine Girard, Sorin Olaru

One of the fundamental issues in Nonlinear Model Predictive Control (NMPC) is to be able to guarantee the recursive feasibility of the underlying receding horizon optimization. In other terms, the primary condition for a safe NMPC design is to ensure that the closed-loop solution remains indefinitely within the feasible set of the optimization problem. This issue can be addressed by introducing a terminal constraint described in terms of a control invariant set. However, the control invariant sets of nonlinear systems are often impractical to use or even to construct due to their complexity. The

K

-step control invariant sets are representing generalizations of the classical one-step control invariant sets and prove to retain the useful properties for MPC design, but often with simpler representations, and thus greater applicability. In this paper, a novel NMPC scheme based on

K

-step control invariant sets is proposed. We employ symbolic control techniques to compute a

K

-step control invariant set and build the NMPC framework by integrating this set as a terminal constraint, thereby ensuring recursive feasibility.

非线性模型预测控制（NMPC）的基本问题之一是能够保证基础后退视界优化的递归可行性。换句话说，安全 NMPC 设计的首要条件是确保闭环解决方案无限期地保持在优化问题的可行集内。这个问题可以通过引入以控制不变集描述的终端约束来解决。然而，非线性系统的控制不变集往往由于其复杂性而难以使用，甚至难以构建。K 步控制不变集是对经典的一步控制不变集的概括，并被证明保留了 MPC 设计的有用特性，但通常具有更简单的表示方法，因此具有更大的适用性。本文提出了一种基于 K 步控制不变集的新型 NMPC 方案。我们采用符号控制技术计算 K 步控制不变集，并通过将该不变集整合为终端约束来构建 NMPC 框架，从而确保递归可行性。

{"title":"Nonlinear model predictive control based on K-step control invariant sets","authors":"Zhixin Zhao, Antoine Girard, Sorin Olaru","doi":"10.1016/j.ejcon.2024.101040","DOIUrl":"10.1016/j.ejcon.2024.101040","url":null,"abstract":"<div><div><span><span>One of the fundamental issues in Nonlinear Model Predictive Control (NMPC) is to be able to guarantee the recursive feasibility of the underlying receding horizon optimization. In other terms, the primary condition for a safe NMPC design is to ensure that the closed-loop solution remains indefinitely within the feasible set of the optimization problem. This issue can be addressed by introducing a terminal constraint described in terms of a control invariant set. However, the control invariant sets of </span>nonlinear systems are often impractical to use or even to construct due to their complexity. The </span><span><math><mi>K</mi></math></span>-step control invariant sets are representing generalizations of the classical one-step control invariant sets and prove to retain the useful properties for MPC design, but often with simpler representations, and thus greater applicability. In this paper, a novel NMPC scheme based on <span><math><mi>K</mi></math></span>-step control invariant sets is proposed. We employ symbolic control techniques to compute a <span><math><mi>K</mi></math></span>-step control invariant set and build the NMPC framework by integrating this set as a terminal constraint, thereby ensuring recursive feasibility.</div></div>","PeriodicalId":50489,"journal":{"name":"European Journal of Control","volume":"80 ","pages":"Article 101040"},"PeriodicalIF":2.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141407713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Decoherence time control by interconnection for finite-level quantum memory systems 通过互联控制有限级量子存储器系统的退相干时间

IF 2.5 3区计算机科学 Q2 AUTOMATION & CONTROL SYSTEMS

European Journal of Control

Pub Date : 2024-11-01 DOI: 10.1016/j.ejcon.2024.101054

Igor G. Vladimirov, Ian R. Petersen

This paper is concerned with open quantum systems whose dynamic variables have an algebraic structure, similar to that of the Pauli matrices for finite-level systems. The Hamiltonian and the operators of coupling of the system to the external bosonic fields depend linearly on the system variables. The fields are represented by quantum Wiener processes which drive the system dynamics according to a quasilinear Hudson–Parthasarathy quantum stochastic differential equation whose drift vector and dispersion matrix are affine and linear functions of the system variables. This setting includes the zero-Hamiltonian isolated system dynamics as a particular case, where the system variables are constant in time, which makes them potentially applicable as a quantum memory. In a more realistic case of nonvanishing system-field coupling, we define a memory decoherence time when a mean-square deviation of the system variables from their initial values becomes relatively significant as specified by a weighting matrix and a fidelity parameter. We consider the decoherence time maximization over the energy parameters of the system and obtain a condition under which the zero Hamiltonian provides a suboptimal solution. This optimization problem is also discussed for a direct energy coupling interconnection of such systems.

本文研究的是开放量子系统，其动态变量的代数结构类似于有限级系统的保利矩阵。系统的哈密顿和与外部玻色子场耦合的算子线性依赖于系统变量。这些场由量子维纳过程表示，量子维纳过程根据准线性哈德逊-帕塔萨拉蒂量子随机微分方程驱动系统动力学，该方程的漂移向量和分散矩阵是系统变量的仿射和线性函数。这种设置包括零-哈密尔顿孤立系统动力学，作为一种特殊情况，系统变量在时间上是恒定的，这使得它们有可能被用作量子存储器。在更现实的非消失系统-场耦合情况下，当系统变量与其初始值的均方偏差变得相对显著时，我们定义了记忆退相干时间，该时间由加权矩阵和保真度参数指定。我们考虑了退相干时间在系统能量参数上的最大化问题，并得出了零哈密顿提供次优解的条件。我们还讨论了此类系统直接能量耦合互连的优化问题。

{"title":"Decoherence time control by interconnection for finite-level quantum memory systems","authors":"Igor G. Vladimirov, Ian R. Petersen","doi":"10.1016/j.ejcon.2024.101054","DOIUrl":"10.1016/j.ejcon.2024.101054","url":null,"abstract":"<div><div>This paper is concerned with open quantum systems whose dynamic variables have an algebraic structure, similar to that of the Pauli matrices for finite-level systems. The Hamiltonian and the operators of coupling of the system to the external bosonic fields depend linearly on the system variables. The fields are represented by quantum Wiener processes which drive the system dynamics according to a quasilinear Hudson–Parthasarathy quantum stochastic differential equation whose drift vector and dispersion matrix are affine and linear functions of the system variables. This setting includes the zero-Hamiltonian isolated system dynamics as a particular case, where the system variables are constant in time, which makes them potentially applicable as a quantum memory. In a more realistic case of nonvanishing system-field coupling, we define a memory decoherence time when a mean-square deviation of the system variables from their initial values becomes relatively significant as specified by a weighting matrix and a fidelity parameter. We consider the decoherence time maximization over the energy parameters of the system and obtain a condition under which the zero Hamiltonian provides a suboptimal solution. This optimization problem is also discussed for a direct energy coupling interconnection of such systems.</div></div>","PeriodicalId":50489,"journal":{"name":"European Journal of Control","volume":"80 ","pages":"Article 101054"},"PeriodicalIF":2.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141510838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Observer design for visual-inertial estimation of pose, linear velocity and gravity direction in planar environments 平面环境中姿态、线速度和重力方向视觉惯性估算的观测器设计

IF 2.5 3区计算机科学 Q2 AUTOMATION & CONTROL SYSTEMS

European Journal of Control

Pub Date : 2024-11-01 DOI: 10.1016/j.ejcon.2024.101067

Tarek Bouazza , Tarek Hamel , Claude Samson

Vision-aided inertial navigation systems combine data from a camera and an IMU to estimate the position, orientation, and linear velocity of a moving vehicle. In planar environments, existing methods assume knowledge of the vertical direction and ground plane to exploit accelerometer measurements. This paper presents a new solution that extends the estimation to arbitrary planar environments. A deterministic Riccati observer is designed to estimate the direction of gravity along with the vehicle pose, linear velocity, and the normal direction to the plane by fusing bearing correspondences from an image sequence with angular velocity and linear acceleration data. Comprehensive observability and stability analysis establishes an explicit persistent excitation condition under which local exponential stability of the observer is achieved. Simulation and real-world experimental results illustrate the performance and robustness of the proposed approach.

视觉辅助惯性导航系统结合摄像头和 IMU 的数据来估计移动车辆的位置、方向和线速度。在平面环境中，现有方法假定需要了解垂直方向和地平面，才能利用加速度计测量数据。本文提出了一种新的解决方案，可将估算扩展到任意平面环境。本文设计了一个确定性里卡提观测器，通过将图像序列中的方位对应关系与角速度和线性加速度数据融合，在估算重力方向的同时估算车辆姿态、线速度和平面法线方向。全面的可观测性和稳定性分析确立了一个明确的持续激励条件，在此条件下，观测器可实现局部指数稳定性。仿真和实际实验结果表明了所提方法的性能和稳健性。

引用次数: 0