检索结果-内蒙古大学图书馆

19th IFAC symposium on System Identification (SYSID)

作者： Nechita, Stefan-Cristian Toth, Roland van Berkel, Koos Eindhoven Univ Technol Dept Elect Engn Eindhoven Netherlands Inst Comp Sci & Control Syst & Control Lab Kende U 13-17 H-1111 Budapest Hungary ASML Netherlands BV Res Dept NL-5504 DR Veldhoven Netherlands

The paper addresses the identification of spatial-temporal mirror surface deformations as a result of laser-based heat load within the lithography process of integrated circuit production. The thermal diffusion and surface deformation are modeled by separation of the spatial-temporal effects using data-driven orthogonal decomposition. A novel tree adjoining grammar (TAG) and sparsity enhanced symbolic-regression-based learning methods are deployed to discover temporal dynamics that connect the spatial variation. The resulting datadriven procedure is applied to automatically synthetise a compact model representation of synthetic thermal effects induced mirror surface deformations. Copyright (C) 2021 The Authors.

关键词： Spatial-temporal System Identification Separation of Variables Machine Learning Genetic Programming MIMO System Indentification Tree Adjoining Grammar Equation Discovery Gaussian Proccesses

来源：评论

学校读者我要写书评

暂无评论

An Intelligent and Secure control Approach for Nonlinear systems under Attacks

An Intelligent and Secure Control Approach for Nonlinear Sys...

引用

IEEE symposium Series on Computational Intelligence (SSCI)

作者： Xiangnan Zhong Zhen Ni Florida Atlantic University Boca Raton FL USA

ISBN: (纸本)9781728190495

This paper designs an intelligent and secure control approach based on adaptive dynamic programming for a class of nonlinear systems under the actuator attacks. The designed method can monitor and identify the attacks by an established state estimator based detector. When an attack is triggered, the control process automatically switches to a game-theoretical architecture for attack mitigation. The intelligent learning process is developed for both nominal and attack conditions without the requirement of system dynamics and attack information. Neural network techniques are applied to implement the proposed method with two critic networks and the control signals are calculated accordingly. Therefore, the designed intelligent control method can reduce the computation complexity. Simulation studies and results demonstrate the necessary of attack detection and mitigation during the learning process, and also verify the effectiveness of the developed method.

关键词： System dynamics Neural networks process control Detectors Computer architecture Stability analysis Nonlinear systems

来源：评论

学校读者我要写书评

暂无评论

Model-free PAC Time-Optimal control Synthesis with Reinforcement Learning

Model-free PAC Time-Optimal Control Synthesis with Reinforce...

引用

ACM and IEEE International Conference on Formal Methods and Models for Co-Design (MEMOCODE)

作者： Mengyu Liu Pengyuan Lu Xin Chen Oleg Sokolsky Insup Lee Fanxin Kong Department of Computer Science and Engineering University of Notre Dame Notre Dame IN Department of Computer and Information Science University of Pennsylvania Philadelphia PA Department of Computer Science University of New Mexico Albuquerque NM

ISBN: (数字)9798350378023

ISBN: (纸本)9798350378030

Reaching a target safely and quickly is a control goal pursued by various applications, such as post-disaster rescue robots and industrial shipment. However, it is hard to formally guarantee safety and time-optimality under unknown dynamics via model-free controller synthesis algorithms. As a response, we propose a model-free reinforcement learning (RL) algorithm that synthesize a controller to reach a predefined target set of states with a probabilistic guarantee of time optimality, i.e., the actual reaching time is bounded close to the shortest time possible with high probability, and the bound becomes tighter when more training data is sampled. Our algorithm leverages a reward function that based on signal temporal logic (STL) robustness to reward fast reaching. With this reward function, we prove that Probably Approximately Correct (PAC) optimality in the state-value function implies PAC optimality in reach time. Then, we build our algorithm by extending Deplayed Gaussian process Q learning (DGPQ) algorithm with a safety margin to protect the controlled agent. Consequently, our algorithm guarantees safety and a PAC bound in recovery time. Experiments show our method can achieve $\mathbf{9 7. 7 \%}$ success rate to reach the target with in the maximum time tolerance and outperform baselines.

关键词： Heuristic algorithms Training data Approximation algorithms Probabilistic logic Picture archiving and communication systems Robustness Stability analysis Safety System analysis and design Rescue robots

来源：评论

学校读者我要写书评

暂无评论

Combination of cascade and feed-forward constrained control for stable partial nitritation with biomass retention

引用

JOURNAL OF process control 2020年 95卷 55-66页

作者： Jamilis, Martin Garelli, Fabricio De Battista, Hernan Volcke, Eveline I. P. Univ Nacl La Plata Fac Ingn Grp Control Aplicado GCA Inst LEICI UNLP CONICET La Plata Buenos Aires Argentina Univ Ghent Dept Green Chem & Technol Biosyst Control Grp Ghent Belgium

Ammonium removal is a key step in wastewater treatment which can be accomplished biologically. An interesting process option for this purpose is coupling partial nitritation with the Anammox process. The goal of the partial nitritation process is to convert half of the ammonium in the influent stream into nitrite, so both can be later converted into dinitrogen gas by the Anammox reaction. To obtain a stable partial nitritation, ammonium oxidizing bacteria (AOB) have to prevail over nitrite oxidizing bacteria (NOB) so as to avoid further conversion of nitrite into nitrate. The dissolved oxygen concentration is a key variable for the functional group selection. In this study, a constrained combination of cascade and feedforward control is proposed for reactors with biomass retention, aimed at suppressing unwanted NOB while keeping a nitrite:ammonium ratio suitable for coupling with Anammox. The master controller, aimed to regulate this effluent ratio, generates the set-point for the dissolved oxygen concentration slave controller. In addition to the cascade controller feedback loop, a feed-forward controller calculates the optimal dissolved oxygen concentration based on the current influent stream flow rate and concentrations. The resulting dissolved oxygen concentration set-point is compared to constraints that guarantee the suppression of NOB and survival of AOB. The proposed control strategy is simple to apply in common wastewater treatment plants with biomass retention. A sensitivity analysis is performed to assess the effect of model parameters uncertainty on the controller constraints and to determine which parameters need to be identified with more precision to avoid instability or poor results. The performance and the effect of the uncertainty of the most sensitive parameters on the proposed control algorithm are assessed through simulation using realistic streams as inputs of the process. (C) 2020 Elsevier Ltd. All rights reserved.

关键词： Partial nitritation Aeration Cascade control Feed-forward Constraints

来源：评论

学校读者我要写书评

暂无评论

11th International Munich Chassis symposium, IMCS 2020

11th International Munich Chassis Symposium, IMCS 2020

引用

11th International Munich Chassis symposium, IMCS 2020

ISBN: (纸本)9783662631928

The proceedings contain 39 papers. The special focus in this conference is on Munich Chassis. The topics include: Automated Driving Requires International Regulations;porsche Taycan-recuperative brake system for combined braking;the Integral Bushing Rear Suspension Architecture of the New Lincoln Corsair;An Efficient Evaluation Method for Longitudinal Driver Assistance systems within a Consistent KPI based Development process;the Power of Oil – Influence of Shock Absorber Oil on Vehicle Ride and Handling Performance;how to extract advantage from driving simulator technology in developing brand specific vehicle dynamics;designing and Assessing the Driving Experience of a Tilting Vehicle;basic Study for Materials of Tire and Wheel for Dynamic Wireless Power Transfer System with In-Wheel Coil;analysis of tire wet grip mechanisms and their respective weightings in a wet braking test;tire modeling for extreme handling maneuvers;transient Motion Analysis Based Objective Quantification of Cornering Feedback and Its Application to Vehicle Motion control;enhanced Characterization of Suspension systems for Virtual Chassis Development;the efficient use of HiL simulation and vehicle tests for in-house software development at Porsche;analysis of Suspension Dynamic Characteristics for Ride Comfort Development Using Suspension Rig Test;simulating and optimizing the dynamic chassis forces of the Audi e-tron;lightweight Composite Spring for the new Transit Camper;design of an innovative car wheel suspension concept with a fiber-reinforced plastic spring/control arm;utilizing artificial neural networks and design solution spaces to cope with the complexity in subframe design;virtual operational strength analysis for commercial vehicles;brake-by-Wire Actuator for Electromechanical Disc Brake.

关键词：

来源：评论

学校读者我要写书评

暂无评论

New Class of Attitude controllers Guaranteed to Converge within Specified Finite-Time

引用

JOURNAL OF THE ASTRONAUTICAL SCIENCES 2020年第2期67卷 552-570页

作者： de Almeida, Marcelino M. Akella, Maruthi R. Univ Texas Austin Dept Aerosp Engn & Engn Mech Austin TX 78712 USA

This paper introduces a new class of finite-time feedback controllers for rigid-body attitude dynamics subject to full actuation. The control structure is Lyapunov-based and is designed to regulate the configuration from an arbitrary initial state to any prescribed final state within user-specified finite transfer-time. A salient feature here is that the synthesis of the control structure is explicit, i.e., given the transfer-time time, the feedback-gains are explicitly stated to satisfy the convergence specifications. A major contrast between this work and others in the literature is that instead of resorting to feedback-linearization (to get to the so-called normal form), our approach efficiently marries the process of designing time-varying feedback gains with the logarithmic Lyapunov function for attitude kinematics based on the Modified Rodrigues Parameters representation. Saliently, this finite-time solution extends nicely for accommodating trajectory tracking objectives and possesses robustness with respect to bounded external disturbance torques. Numerical simulations are performed to test and validate the performance and robustness features of the new control designs.

关键词： Attitude tracking Finite-time control Disturbance rejection Modified Rodrigues parameters

来源：评论

学校读者我要写书评

暂无评论

Adaptive Dynamic Surface control for Interconnected Nonlinear Time Delay systems With Unmodeled dynamics and Full State Constraints

Adaptive Dynamic Surface Control for Interconnected Nonlinea...

引用

Fault Detection, Supervision and Safety for Technical processes (SAFEprocess), CAA symposium on

作者： Zhifeng Gao Yabin Liu Donghao Liu Shipeng Hu College of Automation Nanjing University of Posts and Telecommunications Nanjing China Jiangsu Engineering Laboratory for Internet of Things and Intelligent Robotics Nanjing China

ISBN: (纸本)9781665401166

In this study, an adaptive tracking control scheme is developed for interconnected nonlinear time delay systems with asymmetric full state dynamic constraints and unmodeled dynamics by using dynamic surface control(DSC) technique. Firstly, the unstructured uncertainty functions are approximated by using neural network functions(NNS), the unknown output time delay functions are addressed by Lyapunov-Krasovskii functions, the unmodeled dynamic problem is solved by a dynamic signal. Secondly, a state dependent nonlinear functions are constructed to address the asymmetric full state dynamic constraints. To simplify the calculation, an adaptive tracking control strategy is developed base on DSC technique, it could guarantee that the systems states are constrained in the bounds imposed dynamically and the output signal has good tracking effect. Finally, a simulation example is given to show the effectiveness of the developed scheme.

关键词： Adaptation models Adaptive systems Uncertainty Delay effects Fault detection Neural networks process control

来源：评论

学校读者我要写书评

暂无评论

Monitoring Digital Technologies in Hydraulic systems Using CUSUM control Charts

Monitoring Digital Technologies in Hydraulic Systems Using C...

引用

ASME/Bath symposium on Fluid Power and Motion control

作者： Breidi, Farid Chehade, Abdallah Lumkes, John Univ Southern Indiana 8600 Univ Blvd Evansville IN 47712 USA Univ Michigan Dearborn MI 48128 USA Purdue Univ W Lafayette IN 47907 USA

ISBN: (纸本)9780791859339

Digital fluid power is a growing field which utilizes electronics and advanced controls to improve efficiencies, energy savings, and productivity in fluid power systems. Often relying on on/off high-speed switching techniques, digital hydraulics relies heavily on the performance of valves, where an error in the valve performance could lead to a major drop in the efficiency and performance of the entire system Specifically, digital pump/motors are sensitive to valve delay and transition timing which negatively impacts their performance and condition with time. One approach to assessing the performance and efficiency of digital pump/motors is via monitoring its inlet (low) and outlet (high) pressure time-series. Real-time condition monitoring also supports preventive maintenance and provides a better understanding of the dynamics of pump/motors. For condition monitoring, Statistical process control (SPC) charts are often designed to detect shift changes in times series. This paper proposes to construct two cumulative sum (CUSUM) control charts for fast real-time shift detection in the high and low pressure time-series of digital pump/motors. The proposed method will be able to actively detect common misbehaviors in the valves utilized in the digital pump/motor. The model have been successfully tested on a three-piston inline digital pump/motor, but this monitoring technique can be modified and implemented on other digital technology classes where valveperformance is key in the success of the system.

关键词： Time series

来源：评论

学校读者我要写书评

暂无评论

Performance comparison of data-driven reduced models for a single-injector combustion process

Performance comparison of data-driven reduced models for a s...

引用

AIAA Propulsion and Energy Forum / IEEE Electric Aircraft Technologies symposium (EATS)

作者： Jain, Parikshit Kramer, Boris McQuarrie, Shane A. Univ Calif San Diego Dept Mech & Aerosp Engn La Jolla CA 92093 USA Univ Texas Austin Oden Inst Computat Engn & Sci Austin TX 78712 USA

ISBN: (数字)9781624106118

ISBN: (纸本)9781624106118

This paper derives a new data-driven reduced model for a challenging large-scale combustion simulation and offers a detailed performance comparison with two state-of-the-art reduced models that were previously developed for this application. In particular, we learn a physics-based cubic reduced-order model (ROM) via the operator inference framework (OPINF). The key to the efficiency and physics-based nature of the model lies in the use of variable transformations of the original highly nonlinear system that make the governing equations polynomial in the new variables. We compare this approach with a quadratic operator inference ROMand with dynamic mode decomposition with control (DMDc), a modal decomposition method that has been shown to work well in many fluid dynamical applications. An extensive comparison of these approaches yields interesting insights: in particular, we find that the cubic and quadratic models based on operator inference capture more high-frequency content of the system compared to DMDc;we also find that the presence of the cubic term in the operator inference ROM improves stability properties of the system. Each of the reduced models we examine are accurate and provide a significant computational speedup compared to the high-fidelity model.

关键词： Combustion process Nonlinear systems Singular Value Decomposition Combustors Combustion Chambers Specific Volume Computing Eigensystem Realization Algorithm Machine Learning Frequency Domain

来源：评论

学校读者我要写书评

暂无评论

Production dynamics in case of organizational learning

引用

COMPUTERS & INDUSTRIAL ENGINEERING 2021年 157卷 107340-107340页

作者： Voros, Jozsef Univ Pecs Fac Business & Econ Rakoczi 80 Pecs Hungary

Evidences indicate that around 50% of productivity increase originates from organizational learning and learning by doing. The speed of implementing productivity knowledge increase is a key component of competitiveness and for the case when the implementation is instantaneous, an optimal control model is developed. The analysis of this model indicates that, under certain circumstances, the optimal production level does not change over time, and utilizing this property, a closed form solution is provided to determine the optimal production level. When the implementation process happens step by step, a discrete time model is offered, and we found that using the same assumptions, the production dynamics will be decreasing. To determine the optimal production volumes, a backward dynamic programming procedure is presented.

关键词： Production planning Learning Optimal control Dynamic programming

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：