Thèses sur le sujet « Network based control systems »
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1
Xu, Andong. « Flexible adaptive-network-based fuzzy inference system ». Diss., Online access via UMI:, 2006.
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Thesis (M.S.)--State University of New York at Binghamton, Thomas J. Watson School of Engineering and Applied Science, Dept. of Systems Science and Industrial Engineering, 2006.Includes bibliographical references.
2
Zuo, Wei. « Fourier neural network based tracking control for nonlinear systems / ». View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?MECH%202008%20ZUO.
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Ramesh, Chithrupa. « State-based Channel Access for a Network of Control Systems ». Doctoral thesis, KTH, Reglerteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-144057.
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Wireless networked control systems use shared wireless links to communicate between sensors and controllers, and require a channel access policy to arbitrate access to the links. Existing multiple access protocols perform this role in an agnostic manner, by remaining insular to the applications that run over the network. This approach does not give satisfactory control performance guarantees. To enable the use of wireless networks in emerging industrial applications, we must be able to systematically design wireless networked control systems that provide guaranteed performances in resource-constrained networks. In this thesis, we advocate the use of state-based channel access policies. A state-based policy uses the state of the controlled plant to influence access to the network. The state contains information about not only the plant, but also the network, due to the feedback in the system. Thus, by using the state to decide when and how frequently to transmit, a control system can adapt its contribution to the network traffic, and enable the network to adapt access to the plant state. We show that such an approach can provide better performance than existing methods. We examine two different state-based approaches that are distributed and easy to implement on wireless devices: event-based scheduling and adaptive prioritization. Our first approach uses events to reduce the traffic in the network. We use a state-based scheduler in every plant sensor to generate non-coordinated channel access requests by selecting a few critical data packets, or events, for transmission. The network uses a contention resolution mechanism to deal with simultaneous channel access requests. We present three main contributions for this formulation. The first contribution is a structural analysis of stochastic event-based systems, where we identify a dual predictor architecture that results in separation in design of the state-based scheduler, observer and controller. The second contribution is a Markov model that describes the interactions in a network of event-based systems. The third contribution is an analysis of the stability of event-based systems, leading to a stabilizing design of event-based policies. Our second approach uses state-based priorities to determine access to the network. We use a dominance protocol to evaluate priorities in a contention-based setting, and characterize the resulting control performance. An implementation and evaluation of this channel access mechanism on sensor nodes is also presented. The thesis finally examines the general networked control problem of jointly optimizing measurement and control policies, when a nonlinear measurement policy is used to perform quantization, event-triggering or companding. This contribution focuses on some of the fundamental aspects of analyzing and synthesizing control systems with state-based measurement policies in a more generalized setting. We comment on the dual effect, certainty equivalence and separation properties for this problem. In particular, we show that it is optimal to apply separation and certainty equivalence to a design problem that permits a dynamic choice of the measurement and control policies.QC 20140408
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Nardi, Flavio. « Neural network based adaptive alogrithms for nonlinear control ». Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/12012.
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Chan, Yat-fei. « Neurofuzzy network based adaptive nonlinear PID controllers ». Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B43958357.
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Chan, Yat-fei, et 陳一飛. « Neurofuzzy network based adaptive nonlinear PID controllers ». Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B43958357.
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Moles, Joshua Stephen. « Chemical Reaction Network Control Systems for Agent-Based Foraging Tasks ». PDXScholar, 2015. https://pdxscholar.library.pdx.edu/open_access_etds/2203.
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Chemical reaction networks are an unconventional computing medium that could benefit from the ability to form basic control systems. In this work, we demonstrate the functionality of a chemical control system by evaluating classic genetic algorithm problems: Koza's Santa Fe trail, Jefferson's John Muir trail, and three Santa Fe trail segments. Both Jefferson and Koza found that memory, such as a recurrent neural network or memories in a genetic program, are required to solve the task. Our approach presents the first instance of a chemical system acting as a control system. We propose a delay line connected with an artificial neural network in a chemical reaction network to determine the artificial ant's moves.
We first search for the minimal required delay line size connected to a feed forward neural network in a chemical system. Our experiments show a delay line of length four is sufficient. Next, we used these findings to implement a chemical reaction network with a length four delay line and an artificial neural network. We use genetic algorithms to find an optimal set of weights for the artificial neural network. This chemical system is capable of consuming 100% of the food on a subset and greater than 44% of the food on Koza's Santa Fe trail.
We also show the first implementation of a simulated chemical memory in two different models that can reliably capture and store information over time. The ability to store data over time gives rise to basic control systems that can perform more complex tasks. The integration of a memory storage unit and a control system in a chemistry has applications in biomedicine, like smart drug delivery. We show that we can successfully store the information over time and use it to act as a memory for a control system navigating an agent through a maze.
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Kutay, Ali Turker. « Neural Network Based Adaptive Output Feedback Control : Applications and Improvements ». Diss., Available online, Georgia Institute of Technology, 2005, 2005. http://etd.gatech.edu/theses/available/etd-11282005-122234/.
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Thesis (Ph. D.)--Aerospace Engineering, Georgia Institute of Technology, 2006.J. Eric Corban, Committee Member ; Panagiotis Tsiotras, Committee Member ; Eric N. Johnson, Committee Member ; Nader Sadegh, Committee Member ; Anthony J. Calise, Committee Chair.
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Lee, Seungjae. « Neural network based adaptive control and its applications to aerial vehicles ». Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/11957.
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Zhao, Yun-Bo. « Packet-Based Control for Networked Control Systems ». Thesis, University of South Wales, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.490204.
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Networked control systems (NCSs) are such control systems where the control loop is closed via some form of communication networks. These control systems are widely applicable in remote and distributed control applications. The inserted network however presents great challenges to conventional control theory as far as the design and analysis of NCSs are concerned. These challenges are caused primarily by the communication constraints in NCSs, e.g., network-induced delay, data packet dropout, data packet disorder, network access constraint, etc., which significantly degrade the system performance or even destabilize the system. When applying conventional control approaches to NCSs, considerable conservativeness is inevitable due to the failure to exploit network characteristics. Therefore, the co-design approach to NCSs in which control approaches and characteristics of NCSs are both fully considered, is believed to be the best way forward for the design of NCSs. In this thesis, we investigate the packet-based transmission of the network being used in NCSs, and propose a packet-based control (PB-control) approach to NCSs. In this approach, the 'packet' structure of data transmission in NCSs which is distinct from conventional control systems, is taken advantage of where, the control signals are first 'packed' and then sent as a sequence instead of one at a time as done in conventional control systems. \Vith the efficient use of the 'packet' structure, we can then actively compensate for the communication constraints in NCSs including the network-induced delay, data packet dropout and data packet disorder simultaneously. After determining the PB-control structure, we then extend its application to several categories of problems as follows. j • The first application is to two types of special nonlinear systems described by a Hammerstein model and a Wiener model respectively. A 'two-step' approach is adopted in this situation to separate the nonlinear process from the whole system which then enables the PB-control approach to be implemented. • It is observed that the communication constraints in NeSs are stochastic in nature, and thus a stochastic analysis of the PB-control approach is presented -----'''-'--'--~-• .:.o'... '-~.::C''c:....'..:..'..;...';';;;'~~.~'----' ......;.''''- ---'- ..-..;.;.~~ / iii under the Markov jump system framework, by modeling the network-induced delay and data packet dropout as a homogeneous ergodic Markov chain. The sufficient and necessary conditions for stochastic stability and stabilization in this situation are also obtained. • Continuous-time plant and continuous network-induced delay are observed to be more difficult to handle when implementing the PB-control approach. For this challenge, a discretization technique is introduced for the continuous network-induced delay and as a result, a novel model for NCSs is derived which is different to that obtained by conventional analysis from time delay system theory. A stabilized controller is also obtained in this situation by using delay-dependent analysis. • The last application is to deal with the situation where a set of NeSs share the network and thus the network access constraint has to be considered. For this situation, a PB-control and scheduling co-design approach is proposed where, PB-control is still applied to each subsystem while scheduling algorithms are applied to schedule the network resources among the subsystems to guarantee the stability of the whole system. We also point out in the thesis that further research on the PB-control approach is still needed as far as nonlinear, continuous-time systems and stochastic analysis are concerned.
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Iwaki, Takuya. « Wireless Sensor Network Scheduling and Event-based Control for Industrial Processes ». Licentiate thesis, KTH, Reglerteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-237527.
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Control over wireless sensor and actuator networks is of growing interest in process industry since it enables flexible design, deployment, operation, and maintenance. An important problem in industrial wireless control is how to limit the amount of information that needs to be exchanged over the network. In this thesis, network scheduling and remote control co-design is considered to address this problem. In the first part, we propose a design of an optimal network schedule for state estimation over a multi-hop wireless sensor network. We formulate an optimization problem, minimizing a linear combination of the averaged estimation error and transmission energy. A periodic network schedule is obtained, which specifies when and through which routes each sensor in the network should transmit its measurement, so that an optimal remote estimate under sensor energy consideration is achieved. We also propose some suboptimal schedules to reduce the computational load. The effectiveness of the suboptimal schedules is evaluated in numerical examples. In the second part, we propose a co-design framework for sensor scheduling, routing, and control over a multi-hop wireless sensor and actuator network. For a decoupled plant and LQG control performance, we formulate an optimization problem and show that the optimal schedule, routing, and control can be obtained locally for each control loop. In this part, we also introduce algorithms to reconfigure the schedules and routes when a link in the network is disconnected. The results are illustrated in a numerical example. In the third part, we consider event-based feedforward control from a wireless disturbance sensor. We derive stability conditions when the closed-loop system is subject to actuator saturation. Feedforward control with anti-windup compensation is introduced to reduce the effect of actuator saturation. The effectiveness of the approach is illustrated in some numerical examples.QC 20181029
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Cheung, Wan Sup. « Identification, stabilisation and control of nonlinear systems using neural network-based parametric nonlinear modelling ». Thesis, University of Southampton, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333732.
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Ji, Meng. « Graph-Based Control of Networked Systems ». Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/16313.
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Networked systems have attracted great interests from the control society during the last decade. Several issues rising from the recent research are addressed in this dissertation. Connectedness is one of the important conditions that enable distributed coordination in a networked system. Nonetheless, it has been assumed in most implementations, especially in continuous-time applications, until recently. A nonlinear weighting strategy is proposed in this dissertation to solve the connectedness preserving problem. Both rendezvous and formation problem are addressed in the context of homogeneous network. Controllability of heterogeneous networks is another issue which has been long omitted. This dissertation contributes a graph theoretical interpretation of controllability. Distributed sensor networks make up another important class of networked systems. A novel estimation strategy is proposed in this dissertation. The observability problem is raised in the context of our proposed distributed estimation strategy, and a graph theoretical interpretation is derived as well.
The contributions of this dissertation are as follows:
It solves the connectedness preserving problem for networked systems. Based on that, a formation process is proposed.
For heterogeneous networks, the leader-follower structure is studied and sufficient and necessary conditions are presented for the system to be controllable.
A novel estimation strategy is proposed for distributed sensor networks, which could improve the performance. The observability problem is studied for this estimation strategy and a necessary condition is obtained.
This work is among the first ones that provide graph theoretical interpretations of the controllability and observability issues.
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Hong, Xia. « Non-linear time series modelling and prediction with radial basis function network based algorithms ». Thesis, University of Sheffield, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.286888.
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Samal, Mahendra Engineering & Information Technology Australian Defence Force Academy UNSW. « Neural network based identification and control of an unmanned helicopter ». Awarded by:University of New South Wales - Australian Defence Force Academy. Engineering & ; Information Technology, 2009. http://handle.unsw.edu.au/1959.4/43917.
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This research work provides the development of an Adaptive Flight Control System (AFCS) for autonomous hover of a Rotary-wing Unmanned Aerial Vehicle (RUAV). Due to the complex, nonlinear and time-varying dynamics of the RUAV, indirect adaptive control using the Model Predictive Control (MPC) is utilised. The performance of the MPC mainly depends on the model of the RUAV used for predicting the future behaviour. Due to the complexities associated with the RUAV dynamics, a neural network based black box identification technique is used for modelling the behaviour of the RUAV. Auto-regressive neural network architecture is developed for offline and online modelling purposes. A hybrid modelling technique that exploits the advantages of both the offline and the online models is proposed. In the hybrid modelling technique, the predictions from the offline trained model are corrected by using the error predictions from the online model at every sample time. To reduce the computational time for training the neural networks, a principal component analysis based algorithm that reduces the dimension of the input training data is also proposed. This approach is shown to reduce the computational time significantly. These identification techniques are validated in numerical simulations before flight testing in the Eagle and RMAX helicopter platforms. Using the successfully validated models of the RUAVs, Neural Network based Model Predictive Controller (NN-MPC) is developed taking into account the non-linearity of the RUAVs and constraints into consideration. The parameters of the MPC are chosen to satisfy the performance requirements imposed on the flight controller. The optimisation problem is solved numerically using nonlinear optimisation techniques. The performance of the controller is extensively validated using numerical simulation models before flight testing. The effects of actuator and sensor delays and noises along with the wind gusts are taken into account during these numerical simulations. In addition, the robustness of the controller is validated numerically for possible parameter variations. The numerical simulation results are compared with a base-line PID controller. Finally, the NN-MPCs are flight tested for height control and autonomous hover. For these, SISO as well as multiple SISO controllers are used. The flight tests are conducted in varying weather conditions to validate the utility of the control technique. The NN-MPC in conjunction with the proposed hybrid modelling technique is shown to handle additional disturbances successfully. Extensive flight test results provide justification for the use of the NN-MPC technique as a reliable technique for control of non-linear complex dynamic systems such as RUAVs.
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Gil, Alvaro E. « Stability analysis of network-based cooperative resource allocation strategies ». Columbus, OH : Ohio State University, 2003. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1067538505.
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Thesis (Ph. D.)--Ohio State University, 2003.Title from first page of PDF file. Document formatted into pages; contains xiii, 97 p.: ill. (some col.). Includes abstract and vita. Advisor: Kevin M. Passino, Dept. of Electrical Engineering. Includes bibliographical references (p. 94-97).
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Hu, Wenshan. « Design of networked control systems and global Web-based control laboratory ». Thesis, University of South Wales, 2008. https://pure.southwales.ac.uk/en/studentthesis/design-of-networked-control-systems-and-global-webbased-control-laboratory(0c8a2649-120a-494f-a887-defcaceed570).html.
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This thesis mainly focuses on two Internet based control applications. One is a networked control system (NCS) where the control loop is closed through the network. The other is the Networked Control System Laboratory (NCSLab) which is a global web based remote experimentation platform. The contribution in the first part of the thesis relates to the networked predictive control (NPC) which was first introduced by Liu et al. (2004). In this method, the controller uses the model predictive approach to predict a future control sequence and send it to the plant in a network packet. The plant side receives this packet and then determine the appropriate control signal to apply to the actuator according to the time delay measurement. This method is innovative and works well in theory, but it has two deficiencies in practical applications. The first deficiency is that it needs synchronization between the controller and plant side to measure the individual forward and feedback channel time delays and this is very hard to achieve on the Internet. In this thesis, a round-trip NPC is proposed in which the predictive calculations and signal selections are based on the round-trip delay. The measurement of the round-tip delay is achieved using the plant side clock only, so that the need for synchronization is avoided. The second deficiency is that the mathematical model has to be accurately known. Otherwise the accuracy of the predictive calculation is affected, which may result in a degraded control performance. An event-driven NPC scheme is introduced to solve this problem. In this scheme, the selection of the appropriate control signal is not based on the time delay measurement but on the previous system output. This method can compensate for the effect of model uncertainty, which has been verified by both simulations and real-time experiments. Some experiments carried out on other NPC schemes are also reported on in this thesis. They are the NPC in state-space form and nonlinear NPC. These methods expand the use of NPC methodology. The second part of the thesis describes the design and implementation of the Networked Control System Laboratory. The NCSLab is based in the University of Glamorgan but its test rigs are diversely located in four Institutions from both the UK and China. In order to manage these test rigs from different places, a four layer structure (Central Server/Regional Server/Sub-Server/Test Rig) is adopted. The four layers are integrated into one system via the Internet. In order to deliver the remote experimentation to the users, a web-based user interface is designed. It provides great flexibility to the users such as remote monitoring, remote tuning and remote control algorithms. The implementation of the user interface (UI) heavily adopts the AJAX technology, so the remote experiments can be conducted inside the web browsers without installing special plug-ins. In order to show how the NCSLab works, two examples are given in the thesis.
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Horan, Stephen, Ryan Aaronscooke et Daniel Jaramillo. « IP-Based Networking as Part of the Design of a Payload Control System ». International Foundation for Telemetering, 2008. http://hdl.handle.net/10150/606180.
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ITC/USA 2008 Conference Proceedings / The Forty-Fourth Annual International Telemetering Conference and Technical Exhibition / October 27-30, 2008 / Town and Country Resort & Convention Center, San Diego, CaliforniaAs part of a project to develop small satellites, we have developed a combined ground station and flight computer that use IP-based networking for the command and telemetry data communications. The network uses a private IP network between the payload and the ground-station. Commands are sent to the payload as UDP short message packets. Status and real-time telemetry are sent as UDP text strings. Production data are sent as files using a ftp-type of data exchange. Production data types include numeric data (sensor data) and JPEG-formatted picture data (full pictures and thumbnails). Details of the software used, challenges of making the system work over a low-quality radio link, and integration with the operating system will be discussed.
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Wu, Victor Kai Yuen. « OFDM-based cooperative communications in a single path relay network and a multiple path relay network ». Thesis, Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-11092006-152421/.
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Puttige, Vishwas Ramadas Engineering & Information Technology Australian Defence Force Academy UNSW. « Neural network based adaptive control for autonomous flight of fixed wing unmanned aerial vehicles ». Awarded by:University of New South Wales - Australian Defence Force Academy. Engineering & ; Information Technology, 2009. http://handle.unsw.edu.au/1959.4/43736.
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This thesis presents the development of small, inexpensive unmanned aerial vehicles (UAVs) to achieve autonomous fight. Fixed wing hobby model planes are modified and instrumented to form experimental platforms. Different sensors employed to collect the flight data are discussed along with their calibrations. The time constant and delay for the servo-actuators for the platform are estimated. Two different data collection and processing units based on micro-controller and PC104 architectures are developed and discussed. These units are also used to program the identification and control algorithms. Flight control of fixed wing UAVs is a challenging task due to the coupled, time-varying, nonlinear dynamic behaviour. One of the possible alternatives for the flight control system is to use the intelligent adaptive control techniques that provide online learning capability to cope with varying dynamics and disturbances. Neural network based indirect adaptive control strategy is applied for the current work. The two main components of the adaptive control technique are the identification block and the control block. Identification provides a mathematical model for the controller to adapt to varying dynamics. Neural network based identification provides a black-box identification technique wherein a suitable network provides prediction capability based upon the past inputs and outputs. Auto-regressive neural networks are employed for this to ensure good retention capabilities for the model that uses the past outputs and inputs along with the present inputs. Online and offline identification of UAV platforms are discussed based upon the flight data. Suitable modifications to the Levenberg-Marquardt training algorithm for online training are proposed. The effect of varying the different network parameters on the performance of the network are numerically tested out. A new performance index is proposed that is shown to improve the accuracy of prediction and also reduces the training time for these networks. The identification algorithms are validated both numerically and flight tested. A hardware-in-loop simulation system has been developed to test the identification and control algorithms before flight testing to identify the problems in real time implementation on the UAVs. This is developed to keep the validation process simple and a graphical user interface is provided to visualise the UAV flight during simulations. A dual neural network controller is proposed as the adaptive controller based upon the identification models. This has two neural networks collated together. One of the neural networks is trained online to adapt to changes in the dynamics. Two feedback loops are provided as part of the overall structure that is seen to improve the accuracy. Proofs for stability analysis in the form of convergence of the identifier and controller networks based on Lyapunov's technique are presented. In this analysis suitable bounds on the rate of learning for the networks are imposed. Numerical results are presented to validate the adaptive controller for single-input single-output as well as multi-input multi-output subsystems of the UAV. Real time validation results and various flight test results confirm the feasibility of the proposed adaptive technique as a reliable tool to achieve autonomous flight. The comparison of the proposed technique with a baseline gain scheduled controller both in numerical simulations as well as test flights bring out the salient adaptive feature of the proposed technique to the time-varying, nonlinear dynamics of the UAV platforms under different flying conditions.
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Darr, Matthew John. « DEVELOPMENT AND EVALUATION OF A CONTROLLER AREA NETWORK BASED AUTONOMOUS VEHICLE ». UKnowledge, 2004. http://uknowledge.uky.edu/gradschool_theses/192.
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Through the work of researchers and the development of commercially availableproducts, automated guidance has become a viable option for agricultural producers.Some of the limitations of commercially available technologies are that they onlyautomate one function of the agricultural vehicle and that the systems are proprietary toa single machine model.The objective of this project was to evaluate a controller area network (CAN bus)as the basis of an automated guidance system. The prototype system utilized severalmicrocontroller-driven nodes to act as control points along a system wide CAN bus.Messages were transferred to the steering, transmission, and hitch control nodes from atask computer. The task computer utilized global positioning system data to determinethe appropriate control commands.Infield testing demonstrated that each of the control nodes could be controlledsimultaneously over the CAN bus. Results showed that the task computer adequatelyapplied a feedback control model to the system and achieved guidance accuracy levelswell within the range sought. Testing also demonstrated the system's ability tocomplete normal field operations such as headland turning and implement control.
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Shin, Yoonghyun. « Neural Network Based Adaptive Control for Nonlinear Dynamic Regimes ». Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7577.
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Adaptive control designs using neural networks (NNs) based on dynamic inversion are
investigated for aerospace vehicles which are operated at highly nonlinear dynamic regimes. NNs play a key role as the principal element of adaptation to approximately cancel the effect of inversion error, which subsequently improves robustness to parametric uncertainty and unmodeled dynamics in nonlinear regimes.
An adaptive control scheme previously named composite model reference adaptive control is further developed so that it can be applied to multi-input multi-output output feedback dynamic inversion. It can have adaptive elements in both the dynamic compensator (linear controller) part and/or in the conventional adaptive controller part, also utilizing state estimation information for NN adaptation. This methodology has more flexibility and thus hopefully greater potential than conventional adaptive designs for adaptive flight control in highly nonlinear flight regimes. The stability of the control system is proved through Lyapunov theorems, and validated with simulations.
The control designs in this thesis also include the use of pseudo-control hedging techniques which are introduced to prevent the NNs from attempting to adapt to various actuation nonlinearities such as actuator position and rate saturations. Control allocation is introduced for the case of redundant control effectors including thrust vectoring nozzles. A thorough comparison study of conventional and NN-based adaptive designs for a system under a limit cycle, wing-rock, is included in this research, and the NN-based adaptive control designs demonstrate their performances for two highly maneuverable aerial vehicles, NASA F-15 ACTIVE and FQM-117B unmanned aerial vehicle (UAV), operated under various nonlinearities and uncertainties.
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Salami, Ibrahim al. « Observer based fault detection in networked control systems ». Düsseldorf VDI-Verl, 2008. http://d-nb.info/990321029/04.
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Bensing, Richard G. « An assessment of vulnerabilities for ship-based control systems ». Thesis, Monterey, California : Naval Postgraduate School, 2009. http://edocs.nps.edu/npspubs/scholarly/theses/2009/Sep/09Sep%5FBensing.pdf.
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Thesis (M.S. in Computer Science)--Naval Postgraduate School, September 2009.Thesis Advisor(s): Burke, Karen ; Dinolt, George. "September 2009." Description based on title screen as viewed on November 04, 2009. Author(s) subject terms: Vulnerability Assessment, Supervisory Control and Data Acquisition, SCADA, Critical Infrastructure, Information Assurance, control system Includes bibliographical references (p. 161-170). Also available in print.
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Wilcox, Russ Mark 1957. « An interactive PC-based network management and control package using a database management system ». Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276805.
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The growing widespread use of data communication networks has led to increased reliance on the availability of network resources. The network itself is a critical resource which must be managed in a timely and effective manner. In order to manage the network effectively, the network manager must have powerful tools that present network information in a fast and logical way. The work presented here is the design and development of a network management tool for Sytek broadband networks. The Sytek Network Management Package (SNMP) incorporates a commercial database management system, Rbase System V, and menu oriented management functions for the University of Arizona Sytek broadband networks. The SNMP is written in C and executes on a PC connected to the Sytek network. The SNMP allows a network manager to manage both the Sytek LocalNet 20 and System 2000 networks.
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Droge, Greg Nathanael. « Behavior-based model predictive control for networked multi-agent systems ». Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/51864.
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We present a motion control framework which allows a group of robots to work together to decide upon their motions by minimizing a collective cost without any central computing component or any one agent performing a large portion of the computation. When developing distributed control algorithms, care must be taken to respect the limited computational capacity of each agent as well as respect the information and communication constraints of the network. To address these issues, we develop a distributed, behavior-based model predictive control (MPC) framework which alleviates the computational difficulties present in many distributed MPC frameworks, while respecting the communication and information constraints of the network. In developing the multi-agent control framework, we make three contributions. First, we develop a distributed optimization technique which respects the dynamic communication restraints of the network, converges to a collective minimum of the cost, and has transients suitable for robot motion control. Second, we develop a behavior-based MPC framework to control the motion of a single-agent and apply the framework to robot navigation. The third contribution is to combine the concepts of distributed optimization and behavior-based MPC to develop the mentioned multi-agent behavior-based MPC algorithm suitable for multi-robot motion control.
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Khumalo, Simphiwe. « A CAN based distributed telemetry and telecommand network for a nanosatellite ». Thesis, Link to the online version, 2008. http://hdl.handle.net/10019/858.
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Gürbüz, Özgür. « Power control based QoS provisioning for wireless multimedia networks ». Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/14888.
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Singh, Mukhtiar. « Adaptive network-based fuzzy inference systems for sensorless control of PMSG based wind turbine with power quality improvement features ». Mémoire, École de technologie supérieure, 2010. http://espace.etsmtl.ca/314/1/SINGH_Mukhtiar.pdf.
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Le coût de la generation d’énergie éolienne devient concurrentiel à celui de la génération
d’énergie électrique des sources d’énergies fossiles dites conventionnelles. Il est
d’ailleurs à parité avec le coût de génération des centrales au charbon et au gaz. Les
générateurs éoliens sont de tailles plus imposantes et leur conception a évolué d’un
contrôle vitesse avec entraînement à boîte de vitesse à un contrôle d’hélice de vitesse
variable avec ou sans boîte de vitesse. Les progrès réalisés en électronique de puissance
stimulent cette tendance vers les éoliennes à vitesse variable. Aujourd’hui, les turbines
éoliennes sur le marché comportent de nombreux concepts innovateurs avec une
techonologie de pointe autant en génération qu’en interface de puissance. Toutefois, la
forte pénétration de larges centrales éoliennes dans les réseaux électriques actuels pose
d’autres problèmes à cause de leur nature intermittente. Cela motive les concepteurs de
systèmes éoliens à développer des contrôleurs sophistiqués de génératrices et des
systèmes de puissance.
Récemment, les machines éoliennes à aimant permanent de vitesse variable deviennent
plus attrayantes que les machines à vitesse fixe pour les systèmes de generation
éolienne. Dans le cas des systèmes de génération à vitesse variable, les aéromoteurs
peuvent opérer au point de puissance maximum sur une large gamme de vitesse en
ajustant la vitesse de l’arbre de manière optimale. Plus encore, l’utilisation de machines
à aimant permanent réduit la taille du système de génération éolien puisque ni les
enroulements d’aimantation et leur système d’excitation ne sont requis. Cc type de
configuration s’applique aussi de manière préférentielle en off-shore que la machine
éolienne asynchrone à double alimentation qui requiert une maintenance régulière à
cause de l’usure des broches et de la boîte de vitesse.
Pour réaliser la poursuite de puissance maximum à diverses vitesses de vent, il est
nécessaire d’opérer la machine à aimant permanent à vitesse variable. Pour ce faire, la
commande vectorielle est habituellement favorisée car elle permet le contrôle
indépendant du couple et du champ comme dans le cas du contrôle des moteurs
continus. La commande vectorielle de la machine à aimant permanent requiert
essentiellement la position du rotor et la vitesse. A cet effet, un tachomètre et un capteur
de position montés sur l’arbre de la machine sont utilisés. Ces capteurs augmentent le
coût et la complexité du système. Afin d’éliminer les capteurs de position et de vitesse
ainsi que les problèmes qui leur sont associés, une novelle architecture de système
d’inférence flou avec réseaux de neurones (ANFIS) est proposé en vue d’estimer la
vitesse et la position du rotor sur une large gamme de vitesses d’opération.
L’architecture ANFIS a comme avantage de modéliser un système hautement non
linéaire puisqu’il combine les aptitudes de la logique floue par rapport à la prise en
charge d’incertitudes paramétriques et les aptitudes d’apprentissage des réseaux de
neurones. Alors l’ANFIS est utilisé pour développer un modèle adaptatif de la machine à
aimant permanent à vitesse variable sous des conditions d’opération incertaines et
compense aussi l’effet de la variation des paramètres tels que l’inductance er la
résistance etc.
Dans ces travaux, un système de génération éolienne à aimant permanent est modélisé
autant en application autonome qu’en interconnection au réseau. En mode autonome, un
système hybride batterie et éolienne est présenté. Le système de stockage à batterie
permet d’amortir les fluctuations de l’énergie éolienne et de la demande à la charge.
Pour le système éolien connecté au réseau, la capacité d’élimination de défaut est
démontrée sous des conditions de sauts et des creux de tension.
Un autre objectif du travail est de développer un contrôleur avancé de l’onduleur situé
du côté réseau. Comme l’onduleur fonctionne dans des conditions d’opération variables,
il n’est pas possible de fixer les gains des régulateurs PI de manière optimale sans
entraver le fonctionnement de l’onduleur. Pour résoudre ce problème, un contrôleur
neuronal flou adaptatif est développé. Ce contrôleur présente l’avantage de modéliser et
de contrôler des systèmes hautement non linéaires. L’objectif principal de ce contrôleur
est d’assurer une operation régulière de l’onduleur côté réseau lors des changements
brusques de la dynamique du système contrairement aux PI conventionnels.
De plus, dans ces travaux, la puissance nominale de l’onduleur du côté réseau est
optimisée de manière optimale. Normalement, la puissance de l’onduleur situé du côté
réseau a un faible facteur d’utilisation de 20-30% avec un pic 60% de puissance
nominale à cause de l’intermittence du vent. Par conséquent si le même onduleur est
utilisé pour résoudre les problèmes de qualité de l’onde au point de raccordement
commun en plus de ses fonctions normales, alors le coût additionnel d’achat
d’équipements de puissance tels que le filtre actif, le STATCOM ou le compensateur de
puissance réactive est épargné. Alors l’auteur propose une solution simple de coût
competitive consistant à utiliser l’onduleur du côté réseau comme compensateur
d’harmoniques de courant, de puissance réactive à la charge et de déséquilibre d’une
charge triphasé à quatre fils non linéaire et déséquilibrée située au point de raccordement
commun au réseau de distribution en plus d’injecter de la puissance active. Egalement,
nous montrons que le convertisseur côté réseau peut servir à maintenir la tension
constante malgré des sauts ou des creux de tension.
30
Bayou, Lyes. « Assessment and enforcement of wireless sensor network-based SCADA systems security ». Thesis, Ecole nationale supérieure Mines-Télécom Atlantique Bretagne Pays de la Loire, 2018. http://www.theses.fr/2018IMTA0083/document.
Texte intégralRésumé :
La sécurité des systèmes de contrôle industriel est une préoccupation majeure. En effet, ces systèmes gèrent des installations qui jouent un rôle économique important. En outre, attaquer ces systèmes peut non seulement entraîner des pertes économiques, mais aussi menacer des vies humaines. Par conséquent, et comme ces systèmes dépendent des données collectées, il devient évident qu’en plus des exigences de temps réel, il est important de sécuriser les canaux de communication entre ces capteurs et les contrôleurs principaux. Ces problèmes sont plus difficiles à résoudre dans les réseaux de capteurs sans fil (WSN). Cette thèse a pour but d’aborder les questions de sécurité des WSN. Tout d’abord, nous effectuons une étude de sécurité approfondie du protocole WirelessHART. Ce dernier est le protocole leader pour les réseaux de capteurs sans fil industriels (WISN). Nous évaluons ses forces et soulignons ses faiblesses et ses limites. En particulier, nous décrivons deux vulnérabilités de sécurité dangereuses dans son schéma de communication et proposons des améliorations afin d’y remédier. Ensuite, nous présentons wIDS, un système de détection d’intrusion (IDS) multicouches qui se base sur les spécifications, spécialement développé pour les réseaux de capteurs sans fil industriels. L’IDS proposé vérifie la conformité de chaque action effectuée par un noeud sans fil sur la base d’un modèle formel du comportement normal attenduThe security in Industrial Control Systems is a major concern. Indeed, these systems manage installations that play an important economical role. Furthermore, targeting these systems can lead not only to economical losses but can also threaten human lives. Therefore, and as these systems depend on sensing data, it becomes obvious that additionally to real-time requirement, it is important to secure communication channels between these sensors and the main controllers. These issues are more challenging inWireless Sensor Networks (WSN) as the use of wireless communications brings its own security weaknesses. This thesis aims to address WSN-based security issues. Firstly, we conduct an in-deep security study of the WirelessHART protocol. This latter is the leading protocol for Wireless Industrial Sensor Networks (WISN) and is the first international approved standard. We assess its strengths and emphasize its weaknesses and limitations. In particular, we describe two harmful security vulnerabilities in the communication scheme of WirelessHART and propose improvement in order to mitigate them. Secondly, we present wIDS, a multilayer specification based Intrusion Detection System (IDS) specially tailored for Wireless Industrial Sensor Networks. The proposed IDS checks the compliance of each action performed by a wireless node based on a formal model of the expected normal behavior
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Ramesh, Chithrupa. « Contention-based Multiple Access Architectures for Networked Control Systems ». Licentiate thesis, KTH, Reglerteknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-29781.
Texte intégralRésumé :
Networked Control Systems (NCSs) use a wireless network for communication between sensors and controllers, and require a Medium Access Controller (MAC) to arbitrate access to the shared medium. Traditionally, a MAC for control systems is chosen primarily based on the delay it introduces in the closed loop. This thesis focuses on the design of a contention-based MAC, in a time-varying, resource-constrained network for closed loop systems. In this thesis, we advocate the use of a state-aware MAC, as opposed to an agnostic MAC, for NCSs. A state-aware MAC uses the state of the plant to influence access to the network. The state-aware policy is realized using two different approaches in the MAC: a regulatory formulation and an adaptive prioritization. Our first approach is a regulatory MAC, which serves to reduce the traffic in the network. We use a local state-based scheduler to select a few critical data packets to send to the MAC. We analyze the impact of such a scheduler on the closed loop system, and show that there is a dual effect for the control signal, which makes determining the optimal controller difficult. We also identify restrictions on the scheduling criterion that result in a separation of the scheduler, observer and controller designs. Our second approach is a prioritized MAC that uses state-based priorities called Attentions, to determine access to the network. We use a dominance protocol called tournaments, to evaluate priorities in a contention-based setting, and analyze the resulting performance of the MAC. We also consider a NCS that uses a wireless multihop mesh network for communication between the controller and actuator. We design an optimal controller, which uses packet delivery predictions from a recursive Bayesian network estimator.QC 20110216
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楊偉強 et Wai-keung Yeung. « Self-tuning control of nonlinear systems based on neurofuzzy networks ». Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B42576866.
Texte intégral
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Yeung, Wai-keung. « Self-tuning control of nonlinear systems based on neurofuzzy networks ». Click to view the E-thesis via HKUTO, 2002. http://sunzi.lib.hku.hk/hkuto/record/B42576866.
Texte intégral
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Ferreira, Luis Antonio Fialho. « A network-based approach to power system security assessment and control ». Diss., Georgia Institute of Technology, 1986. http://hdl.handle.net/1853/15721.
Texte intégral
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Arghandeh, Jouneghani Reza. « Distributed Energy Storage Systems : Microgrid Application, Market-Based Optimal Operation and Harmonic Analysis ». Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/50603.
Texte intégralRésumé :
The need for modern electricity infrastructures and more capable grid components brings attention to distributed energy storage systems because of their bidirectional power flow capability. This dissertation focuses on three different aspects of distributed energy storage system applications in distribution networks. It starts with flywheel energy storage system modeling and analysis for application in microgrid facilities. Then, a market-based optimal controller is proposed to enhance the operational profit of distributed energy storage devices in distribution networks. Finally, impact of multiple distributed energy storage devices on harmonic propagation in distribution networks is investigated.This dissertation provides a comparison between batteries and flywheels for the ride-through application in critical microgrid facilities like data centers. In comparison with batteries, the application of FES for power security is new. This limits the availability of experimental data. The software tool developed in this dissertation enables analysis of short-term, ride-through applications of FES during an islanded operation of a facility microgrid. As a result, it can provide a guideline for facility engineers in data centers or other types of facility microgrids to design backup power systems based on FES technology.
This dissertation also presents a real-time control scheme that maximizes the revenue attainable by distributed energy storage systems without sacrificing the benefits related to improvements in reliability and reduction in peak feeder loading. This optimal control algorithm provides a means for realizing additional benefits by utilities by taking advantage of the fluctuating cost of energy in competitive energy markets. The key drivers of the economic optimization problem for distributed energy storage systems are discussed.
In this dissertation, the impact of distribution network topology on harmonic propagation due to the interaction of multiple harmonic sources is investigated. Understanding how multiple harmonic sources interact to increase or decrease the harmonic distortion is crucial in distribution networks with a large number of Distributed Energy Resources. A new index, Index of Phasor Harmonics (IPH), is proposed for harmonic quantization in multiple harmonic source cases. The proposed IPH index presents more information than commonly used indices. With the help of the detailed distribution network model, topological impacts of harmonic propagation are investigated. In particular, effects of mutual coupling, phase balance, three phase harmonic sources, and single phase harmonic sources are considered.
Ph. D.
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Svensson, August. « Range-based Wireless Sensor Network Localization for Planetary Rovers ». Thesis, Luleå tekniska universitet, Rymdteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-83213.
Texte intégralRésumé :
Obstacles faced in planetary surface exploration require innovation in many areas, primarily that of robotics. To be able to study interesting areas that are by current means hard to reach, such as steep slopes, ravines, caves andlava tubes, the surface vehicles of today need to be modified or augmented. Oneaugmentation with such a goal is PHALANX (Projectile Hordes for AdvancedLong-term and Networked eXploration), a prototype system being developed atthe NASA Ames Research Center. PHALANX uses remote deployment of expendablesensor nodes from a lander or rover vehicle. This enables in-situ measurementsin hard-to-reach areas with reduced risk to the rover. The deployed sensornodes are equipped with capabilities to transmit data wirelessly back to therover and to form a network with the rover and other nodes. Knowledge of the location of deployed sensor nodes and the momentary locationof the rover is greatly desired. PHALANX can be of aid in this aspect as well.With the addition of inter-node and rover-to-node range measurements, arange-based network SLAM (Simultaneous Localization and Mapping) system can beimplemented for the rover to use while it is driving within the network. Theresulting SLAM system in PHALANX shares characteristics with others in the SLAM literature, but with some additions that make it unique. One crucial additionis that the rover itself deploys the nodes. Another is the ability for therover to more accurately localize deployed nodes by external sensing, such asby utilizing the rover cameras. In this thesis, the SLAM of PHALANX is studied by means of computer simulation.The simulation software is created using real mission values and valuesresulting from testing of the PHALANX prototype hardware. An overview of issuesthat a SLAM solution has to face as present in the literature is given in thecontext of the PHALANX SLAM system, such as poor connectivity, and highlycollinear placements of nodes. The system performance and sensitivities arethen investigated for the described issues, using predicted typical PHALANXapplication scenarios. The results are presented as errors in estimated positions of the sensor nodesand in the estimated position of the rover. I find that there are relativesensitivities to the investigated parameters, but that in general SLAM inPHALANX is fairly insensitive. This gives mission planners and operatorsgreater flexibility to prioritize other aspects important to the mission athand. The simulation software developed in this thesis work also has thepotential to be expanded on as a tool for mission planners to prepare forspecific mission scenarios using PHALANX.
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Ainsworth, Nathan Grey. « Towards a distributed control regime for robust synchronization and power sharing of inverter-based ac power networks ». Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/53985.
Texte intégralRésumé :
The objective of the proposed research is 1) to develop a general dynamic condition sufficient to ensure frequency synchronization of inverter-based AC power networks, and 2) to develop a distributed control regime that is capable of guaranteeing that the above condition holds for a scalable class of such networks. I will first develop a structure-preserving model of an arbitrary network whose sources are all inverters operating frequency-droop control. By applying graph theoretic methods to the model, I will show that there exists a “safe operating region” of the state space such that if the network angle trajectory stays in this region, then frequency synchronization is shown by Lyapunov-like methods. By analogy to similar problems solved in other applications, I will develop a new distributed control regime to constrain a network of the target class to the safe operating region, thus guaranteeing frequency synchronization. These techniques may form the basis for future development of ultra-reliable, scalable inverter-based networks.
38
Fischer, Jörg [Verfasser]. « Optimal Sequence-Based Control of Networked Linear Systems / Jörg Fischer ». Karlsruhe : KIT Scientific Publishing, 2015. http://www.ksp.kit.edu.
Texte intégral
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Sullivan, Anthony John. « Distributed control applications using local area networks : a LAN based power control system at Rhodes University ». Thesis, Rhodes University, 2002. http://hdl.handle.net/10962/d1005246.
Texte intégralRésumé :
This thesis describes the design and development of both the hardware and software of an embedded, distributed control system using a LAN infrastructure for communication between nodes. The primary application of this system is for power monitoring and control at Rhodes University. Both the hardware and software have been developed to provide a modular and scalable system capable of growing and adapting to meet the changing demands placed on it. The software includes a custom written Internet Protocol stack for use in the embedded environment, with a small code footprint and low processing overheads. There is also Linux-based control software, which includes a web-based device management interface and graphical output. Problems specific to the application are discussed as well as their solutions, with particular attention to the constraints of an embedded system.
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Varutti, Paolo [Verfasser]. « Model Predictive Control for Nonlinear Networked Control Systems : A Model-based Compensation Approach for Nondeterministic Communication Networks / Paolo Varutti ». Aachen : Shaker, 2014. http://d-nb.info/1053361688/34.
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Nawaz, Shah. « Performance Study of ZigBee-based Green House Monitoring System ». Thesis, Mittuniversitetet, Avdelningen för informations- och kommunikationssystem, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-24963.
Texte intégralRésumé :
Wireless Sensor Network (WSN) is an emerging multi-hop wireless network technology, and the greenhouse network monitoring system is one of the key applications of WSNs in which various parameters such as temperature, humidity, pressure and power can be monitored. Here, we aim to study the performance of a simulation-based greenhouse monitoring system. To design the greenhouse monitoring system based on WSN, we have used ZigBee-based devices (end devices, routers, coordinators, and actuators. Our proposed greenhouse monitoring network has been designed and simulated using the network simulator OPNET Modeller.The investigation is split into two; first, the aim is to find the optimal Transmit (Tx) power set out at sensor nodes and second, the focus is on studying how increasing the number of sensor nodes in the same greenhouse network will affect the overall network performance. ZigBee-based greenhouses corresponded to 4 network scenarios and are simulated using OPNET Modeller in which 22 different transmit (Tx) power (22 cases) in Scenario 1 is simulated, scenario 2, 3 and 4 estimated to 63, 126, 189 number of sensor nodes respectively. Investigating the performance of the greenhouse monitoring network performance metrics such as network load, throughput, packets sent/received and packets loss are considered to be evaluated under varied transmit (Tx) power and increasing number of sensor nodes. Out of the comprehensive studies concerning simulation results for 22 different transmit (Tx) power cases underlying the greenhouse monitoring network (Scenario1), it is found that packets sent/received and packets loss perform the best with the transmitted (Tx) power falling in a range of 0.9 mWatt to 1.0 mWatt while packet sent/received and packet loss are found to perform moderately with the transmitted (Tx) power values that lie in a range of 0.05 mWatt to 0.8 mWatt. Less than 0.05 mWatt and greater than 0.01 microWatt Tx power experience, the worst performance in terms of particularly packet dropped case. For instance, in the case of the packet dropped (not joined packet, i.e., generated at the application layer but not able to join the network due to lack of Tx power), with a Tx power of 0.01 mWatt, 384 packets dropped with a Tx power of 0.02 and 0.03 mWatt, 366 packets dropped, and with a Tx power of 0.04 and 0.05, 336 packet dropped.While increasing the number of sensor nodes, as in scenario 2, 3 and 4, dealing with sensor nodes 63, 126 and 189 correspondingly, the MAC load, MAC throughput, packet sent/received in scenario 2 are found to perform better than that of scenario 3 and scenario 4, while packet loss in scenarios 2, 3 and 4 appeared to be 15%, 12% and 83% correspondingly.
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George, David K. « Stochastic Modeling and Decentralized Control Policies for Large-Scale Vehicle Sharing Systems via Closed Queueing Networks ». The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1338387102.
Texte intégral
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Ekman, Rasmus. « Automobile Control Systems : Transition from Controller Area Networks to Ethernets ». Thesis, KTH, Radio Systems Laboratory (RS Lab), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-148052.
Texte intégralRésumé :
Due to concerns about the negative impacts of powering vehicles using fossil fuel and the future availability of fossil fuel, there has been an increased focus on electric vehicles. However, current electric vehicle energy efficiency is a key problem as these vehicles are not as efficient as fossil-fueled vehicles. One way of decreasing a vehicle’s energy consumption is to reduce the weight of the vehicle, while still ensuring the safety and reliability of the vehicle. Controller Area Network (CAN) systems have been used in vehicles to realize real-time applications, however the low peak data rates of CAN have begun to limit the applications that can be realized. This bachelor’s thesis project focuses on secure communication within a vehicle using Ethernet. Additionally, the use of Power over Ethernet can be used for powering some of the network attached devices within the vehicle. The goal is to reduce the number of components and the weight of the vehicle while continuing to ensure the security and reliability of the communication – even when the network grows in size (either in physical size or in number of connected devices). This thesis shows that an Ethernet based system can serve as a possible replacement candidate for the CAN system due to its low latencies and high bandwidth. Ethernet is also a very scalable system with none of the limitations that a CAN system have.Den negativa påverkan av fossila bränslen har de senaste årtionden haft en negativ på planeten, mängden fossila bränslen över världen konsumeras även i en högre takt än vad som produceras. Därför har fokusen för att finna förnybara energi källor som både är effektiva och inte påverkar miljön på ett negativt sätt ökat. Därför är elbilar en viktig del i konverteringen av enheter som drivs av fossila bränslen till förnybara energikällor. Ett av problemen i en elbil är att energi konsumptionen är inte lika effektiv som fossila bränslen inom bil industrin. Ett sätt att sänka energi konsumptionen är att minska mängden komponenter inom en bil för att minska på vikten, utan att påverka säkerheten och tillförlitligheten. Tidigare har man använt sig av ett CAN system för att försäkra sig om systemet fungerar felfritt i realtid, problematiken med detta system är att när nätverket ökar i storlek så sätter de fysiska begränsningarna av detta system stop för den garanterade säkerheten. Detta kandidatexamensarbete kommer att fokusera på den interna kommunikationen i en elbil med hjälp av ett ethernet baserat kommunkations system över CAN systemet. Power over Ethernet tekinken kommer att tillämpas för de systemen som kan drivas av detta system. Målet är att reducera antalet komponenter som behövs och att garantera säkerheten och tillförlitligheten av den interna kommunikationen när nätverket av komponenter ökar i storlek. Det här kandidatarbetet visar att Ethernet kan ersätta det nuvarande CAN systemet ef-tersom att Ethernet erbjuder låga latenser och hög bandbredd. Detta arbete visar även att Et-hernet är väldigt skalbart och har inte begränsingarna som ett CAN system har.
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« Neural network based control for nonlinear systems ». 2001. http://library.cuhk.edu.hk/record=b6073339.
Texte intégralRésumé :
Wang Dan.Thesis (Ph.D.)--Chinese University of Hong Kong, 2001.
Includes bibliographical references (p. 128-138).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Mode of access: World Wide Web.
Abstracts in English and Chinese.
45
(9847832), Dawei Zhang. « Network-based output tracking control for continuous-time systems ». Thesis, 2012. https://figshare.com/articles/thesis/Network-based_output_tracking_control_for_continuous-time_systems/13463123.
Texte intégral
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(6469685), Y. Lin. « Event-triggered control and filtering for networked systems based on network dynamics ». Thesis, 2014. https://figshare.com/articles/thesis/Event-triggered_control_and_filtering_for_networked_systems_based_on_network_dynamics/13387244.
Texte intégralRésumé :
With the development of computing and communication technology, networked systems
in which information is exchanged through communication networks have become
prevalent in a variety of practical applications. A considerable number of these
systems have scarcely adequate computation and communication network resources.
Notice that, network dynamics usually affect the quality of the performance of networked
systems; network-based control or filtering design generally interferes with
the quality of service of communication networks. Therefore, successful implementation
of networked systems over communication networks requires the adequate
integration of control or filtering with intelligent computation and communication
networks. This research establishes an information scheduling middleware to effi-
ciently utilise the limited communication resources and the computation capacity
while preserving the desired performance of networked systems. In this proposed
middleware, an event-triggered scheme is given to provide a tradeoff between the
performance of networked systems and the utilisation of communication network
resources. A scheduling mechanism is derived to avoid traffic congestion in the
communication network by introducing a fluid-flow model. By using this information
scheduling middleware, the issues of network-based control and filtering are
investigated. First, a fluid-flow model of the communication network and an eventtriggered
scheme are integrated to develop a new framework, in which the criteria
of stability and stabilisation are derived for networked systems under simultaneous
consideration of control system performance and network dynamics. Second, based
on network dynamics, an online scheduling strategy is proposed to design the H∞
filter for networked systems in the framework with the information scheduling middleware,
the Information Dispatching Middleware (IDM). Third, the IDM is applied
to distributed control for large-scale networked systems and a codesign method is
obtained to determine the parameters of the IDM. Fourth, the mechanism of the
IDM is analysed to investigate the cooperation between the Information Selection
Module and the Congestion Avoidance Module in the IDM. Based on the IDM, distributed
filters are designed considering the dynamics of communication networks.
Finally, numerical and practical examples are given to demonstrate the effectiveness
and advantages of the proposed information scheduling middleware.
47
ORNATELLI, ANTONIO. « Network control systems for 5G multi-connectivity ». Doctoral thesis, 2021. http://hdl.handle.net/11573/1562255.
Texte intégralRésumé :
This thesis aims to develop a network control framework when considering heterogeneous access network technologies. The scenario of interest is when several services are using a common shared and large-scale communication network and the users who are benefiting from these services have different connection requirements. The reason behind the need for a common network satisfying several service requirements at the same time, is the continuous transformation of physical infrastructures such as energy distribution, entertainment, communication, transportation, and many others, in Cyber-Physical Systems interacting with each other. This transformation increases the need of the different industries in the deployment of large-scale communication networks, to connect the high number of sensors and actuators integrated into the physical infrastructure, introducing the so-called Networked Control System. In this framework, when sensors and actuators are used to perform and act decision-making on large-scale systems, several problems introduced by the networking arises. In particular, when unpredictable and uncontrollable packet drop, latency, or data corruption occur, either between sensors or actuators and the autonomous decision-maker, the resulting control actions may perform undesired effects on the controlled physical system introducing instability. These problems can be considered during the autonomous decision-maker design, implying higher design and implementation complexity, that can degrade the performances concerning the controlled physical systems. Another solution is the development of an underlying network control able to provide the needed networking performances to the decision-maker as a service. This solution allows the decision-maker to see the network as a black box that meets its requirements. This network control problem can be faced considering different aspects because of the high number of problems that can be addressed to have an efficient and reliable network, one of the main problems to be addressed is resource allocation. This work deal with the resource allocation considering multi-connectivity, defined as the management of the network resources when the users can connect simultaneously to different access points, even belonging to different radio technologies, to satisfy users’ requirements, and considering network constraints and efficiency. Furthermore, in this work the reference network is the fifth-generation technology standard for broadband cellular networks, known as 5G Network, standardized by the 3GPP association. The 5G Network is designed to provide a general-purpose connectivity platform, considered as the key enabling technology to support markets such as automotive, energy, food and agriculture, city management, government, healthcare, manufacturing, and public transportation, through the digital transformation of their infrastructure and business processes, providing a large scale, efficient and reliable communication platform, able to satisfy several users’ requirements such as high reliability, ultra-low latency, high bandwidth, and mobility. The thesis presents the definition of network architecture, compliant with the 3GPP standards and able to accommodate multi-connectivity algorithms, and control algorithms able to manage the multi-connectivity considering both users’ requirements and network conditions, using either model-based and data-driven techniques, using centralized, distributed and hierarchical solutions, allowing the deployment of the control algorithms either in the cloud or at the edge of the network, on the basis of the resources and performances needed in each particular scenario.
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Ning, Min. « Neural network based optimal control of HVAC&R systems ». Thesis, 2008. http://spectrum.library.concordia.ca/975809/1/NR37738.pdf.
Texte intégralRésumé :
Heating, Ventilation, Air-Conditioning and Refrigeration (HVAC&R) systems have wide applications in providing a desired indoor environment for different types of buildings. It is well acknowledged that 30%-40% of the total energy generated is consumed by buildings and HVAC&R systems alone account for more than 50% of the building energy consumption. Low operational efficiency especially under partial load conditions and poor control are part of reasons for such high energy consumption. To improve energy efficiency, HVAC&R systems should be properly operated to maintain a comfortable and healthy indoor environment under dynamic ambient and indoor conditions with the least energy consumption. This research focuses on the optimal operation of HVAC&R systems. The optimization problem is formulated and solved to find the optimal set points for the chilled water supply temperature, discharge air temperature and AHU (air handling unit) fan static pressure such that the indoor environment is maintained with the least chiller and fan energy consumption. To achieve this objective, a dynamic system model is developed first to simulate the system behavior under different control schemes and operating conditions. The system model is modular in structure, which includes a water-cooled vapor compression chiller model and a two-zone VAV system model. A fuzzy-set based extended transformation approach is then applied to investigate the uncertainties of this model caused by uncertain parameters and the sensitivities of the control inputs with respect to the interested model outputs. A multi-layer feed forward neural network is constructed and trained in unsupervised mode to minimize the cost function which is comprised of overall energy cost and penalty cost when one or more constraints are violated. After training, the network is implemented as a supervisory controller to compute the optimal settings for the system. In order to implement the optimal set points predicted by the supervisory controller, a set of five adaptive PI (proportional-integral) controllers are designed for each of the five local control loops of the HVAC&R system. The five controllers are used to track optimal set points and zone air temperature set points. Parameters of these PI controllers are tuned online to reduce tracking errors. The updating rules are derived from Lyapunov stability analysis. Simulation results show that compared to the conventional night reset operation scheme, the optimal operation scheme saves around 10% energy under full load condition and 19% energy under partial load conditions.
49
Huang, Chu-Hsiang, et 黃楚翔. « Information Fusion, Decision and Control ofSensor Network Based Intelligent Systems ». Thesis, 2009. http://ndltd.ncl.edu.tw/handle/14897655385374004733.
Texte intégralRésumé :
碩士國立臺灣大學
電信工程學研究所
97
Sensor networks to collect various information from environments enable deployment and application of many intelligent devices and systems, such as robots, intelligent vehicles, and even biomedical instruments. Observing traditional approach separately executing information fusion from sensor networks, decision, and later control functions, we propose a novel intelligent decision framework to allow thorough system modeling of such devices, and thus further enhancement beyond traditional approach. Intelligent decision framework improves traditional estimation theory by separating the mapping from event to observation into two mappings, the mapping from observed physical quantity to sensor observation and the mapping from target event to physical quantity. The mathematical formulation is constructed and applied in the firefighting robot navigation scenario to illustrate its effectiveness. We further shows that the intelligent decision framework can be degenerated to traditional decision schemes under special conditions. More importantly, we can extend the framework to fuse observations from multiple kinds of physical quantities and derive the optimal decision, beyond traditional statistical decision mechanisms. For the decision with limited knowledge of the correlations among physical quantities, we propose Observation Selection and derive the equality condition with optimal decision. While fuzzy logic of less strict-sense mathematic structure is commonly employed to resolve this application scenario, we can demonstrate that Observation Selection derived from well-defined decision theory can be degenerated to fuzzy logic of multiple kinds of observations. Finally, simulation results show that the proposed intelligent decision framework indeed improves the accuracy of the decision and enhances system performance. In addition to sensor network, this framework can also be applied in various intelligent system or cognitive systems. We propose a novel cognitive radio spectrum sensing scheme, Dual-way Time-Division Spectrum Sensing, derived under intelligent decision framework to demonstrate the application of this general framework other than sensor network. This scheme mitigates the hidden terminal problem by only one node taking multiple observations from independent sensing channel, while cooperative spectrum sensing needs multiple nodes to perform multiple observation. Moreover, this scheme takes the path-loss due to geographical separation into consideration to improve the sensing performance. Analytical and simulation result shows that the proposed spectrum sensing scheme significantly improves the performance of traditional spectrum sensing. Keywords: Sensor network, information
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Lin, Jiin-Long, et 林錦龍. « Neural Network Based Control System Design ». Thesis, 1999. http://ndltd.ncl.edu.tw/handle/99491058769906289364.
Texte intégralRésumé :
碩士國立臺灣科技大學
機械工程系
87
Because of the traditional design methods could not solve the problems of the uncertainty of systems and the advantage of neural network is that the mathematical model is not needed，neural network is chosen to realize the controller in many research fields recently. Many research results are distributed over many references. There are several approaches to construct a neural network. So it''s rare for a book in which the theoretical structure of neural networks embedded in control systems is discussed and analyzed. This thesis tries to conclude several neural network control structures which are often used in literature. Then the steps of neural network based controller realization are listed and are proved with simulations. A novel identifier realization strategy is proposed so that the system Jacobian can be calculated easily. At last, this thesis applies the parallel neuro-control scheme on the simulation of a two-link robot which gradually achived the requirement with repeatedly learning under the situation without knowing the mathematical model of the robot and the environment in advance.