A wind turbine can experience yawed inflow with large yaw misalignment angle during faulty cases, such as faults in the yaw controller/drives, or during extreme atmospheric cases, such as thunderstorm downbursts. In s...
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ISBN:
(纸本)9780791846193
A wind turbine can experience yawed inflow with large yaw misalignment angle during faulty cases, such as faults in the yaw controller/drives, or during extreme atmospheric cases, such as thunderstorm downbursts. In such cases, it is risky for the turbine to continue operation because it is being exposed to large loads. Instead, it is recommended for the turbine to be transited to parking conditions. Currently, most turbine pitch controllers are designed without considering the yaw misalignment angle, correction of which is normally assigned to the yaw controller this paper investigates the contribution of both a baseline and a proposed collective pitch controllers under yawed inflow conditions. the baseline controller tries to maintain the rated operating condition at an expense of large blade loads. On the contrary, simulation results show that the proposed controller slows down the turbine under the presence of yawed inflow, which helps to park the turbine and reduces the average blade root bending moments.
Prior work has documented that Support Vector Machine (SVM) classifiers can be powerful tools in predicting clinical outcomes of complex diseases such as Periventricular Leukomalacia (PVL). A preceding study indicated...
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ISBN:
(纸本)9780791846193
Prior work has documented that Support Vector Machine (SVM) classifiers can be powerful tools in predicting clinical outcomes of complex diseases such as Periventricular Leukomalacia (PVL). A preceding study indicated that SVM performance can be improved significantly by optimizing the supervised training set used during the learning stage of the overall SVM algorithm. this preliminary work, as well as the complex nature of the PVL data suggested integration of the active learning algorithm into the overall SVM framework. the present study supports this initial hypothesis and shows that active learning SVM type classifier performs considerably well and outperforms normal SVM type classifiers when dealing with clinical data of high dimensionality.
Commercial demand response (DR) has traditionally relied on HVAC and lighting systems as load-shed resources in buildings. However, improvements in technologies such as Energy Information Gateways and smart power stri...
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ISBN:
(纸本)9780791846186
Commercial demand response (DR) has traditionally relied on HVAC and lighting systems as load-shed resources in buildings. However, improvements in technologies such as Energy Information Gateways and smart power strips are making it possible to incorporate distributed plug-loads as an actionable resource. In this paper we explore the addition of a battery storage system (BSS) as a load-shed resource to supplement plug-loads in an office setting. Furthermore we investigate the value of control of BSS battery charging. We develop a model predictive control (MPC) framework for office plug-loads and a BSS. An experimentally derived model of a BSS is presented along with numerical methods for solving the MPC optimization program. Simulations demonstrate the efficacy of a BSS as a load-shed resource. Simulation results also quantify the benefit of BSS controllable charging for DR and load-following scenarios.
the synchronization problem for a class of delayed complex dynamical networks via employing variable structure control has been explored and a solution proposed. the synchronization controller guarantees the state of ...
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ISBN:
(纸本)9780791846209
the synchronization problem for a class of delayed complex dynamical networks via employing variable structure control has been explored and a solution proposed. the synchronization controller guarantees the state of the dynamical network is globally asymptotically synchronized to arbitrary state. the switching surface has been designed via the left eigenvector function of the system, and assures the synchronization sliding mode possesses stability. the hitting condition and the adaptive law for estimating the unknown network parameters have been used for designing the controller hence the network state hits the switching manifold in finite time. Two illustrative examples along withthe respective simulation results are given, which employ the designed variable structure controllers.
Cybersecurity for networked industrial controlsystems presents challenges not faced in information technology systems. the use of heritage protocols, such as Modbus, on unrouted serial buses makes it difficult to aut...
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ISBN:
(纸本)9780791846193
Cybersecurity for networked industrial controlsystems presents challenges not faced in information technology systems. the use of heritage protocols, such as Modbus, on unrouted serial buses makes it difficult to authenticate actuator commands and sensor data. Furthermore, rigid master/slave architectures such as Modbus are especially vulnerable to compromise of the master unit. We describe a logic program called the Qualitative Behavioral Analyzer (QBA) for monitoring a controlled physical process on an unrouted Modbus network. the proposed approach uses knowledge of process physics to identify a possible component fault or cyberattack. To avoid relying on the integrity of the master unit, the QBA directly analyzes Modbus network traffic. the first stage of the QBA is called the Network Analyzer, which evaluates each Modbus packet and extract qualitative information. the second stage is called the Physics Analyzer, which evaluates a qualitative physics model based on qualitative information from Network Analyzer. the QBA is demonstrated on simulations of a water treatment process.
In this paper, we develop a framework for evolution of a multi agent systems (MAS) under local perception. the idea of this paper comes from natural biological swarms where agents adjust their behavior based on indivi...
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ISBN:
(纸本)9780791846186
In this paper, we develop a framework for evolution of a multi agent systems (MAS) under local perception. the idea of this paper comes from natural biological swarms where agents adjust their behavior based on individual perception of the behavior of its neighbors. Most available engineered swarms rely on local communication where an individual agent needs exact state information of its adjacent agents to evolve. We consider agents of a MAS to be particles of a continuum (deformable Body) transforming under a homogenous mapping. Homogenous transformations have the property that two crossing straight lines in an initial configuration translate as two different crossing straight lines. We will consider this feature of homogenous mappings to show how certain desired objectives can be achieved by agents of a swarm by preserving alignment among nearby agents. We show that evolution of a MAS under this alignment strategy can be achieved where agents don't need to know the exact positions of the adjacent agents nor do they need peer to peer communication.
this paper presents an alternative approach to design PID controllers based on frequency response measurements. the proposed method does not require any mathematical model of the system and can handle the design proce...
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ISBN:
(纸本)9780791846209
this paper presents an alternative approach to design PID controllers based on frequency response measurements. the proposed method does not require any mathematical model of the system and can handle the design process directly from a small set of frequency domain data. It is shown that for the class of Linear Time-Invariant (LTI) controlsystems, there exists a rational multilinear function for the frequency response between any two arbitrary breaking points in terms of the design controller this function can be determined by conducting a small set of frequency response measurements and then will be used to synthesize a controller that guarantee a set of desired frequency-domain specifications. In this paper we use this result to design a PID controller for a servomechanism control system. In particular, we show that such desirable PID controller can be calculated by solving an optimization problem.
A flag is modeled as a membrane to investigate the two-dimensional characteristics of the vibration response to an uniform wind flow. Boththe affecting tension and pressure functions for the wind flow with constant v...
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ISBN:
(纸本)9780791846209
A flag is modeled as a membrane to investigate the two-dimensional characteristics of the vibration response to an uniform wind flow. Boththe affecting tension and pressure functions for the wind flow with constant velocity are introduced and utilized in the modeling. In this case, the tension is caused by the weight of the flag. the pressure function is a function describing the pressure variations caused on the flag when in uniform flow. the pressure function is found by assuming that the air flow is relatively slow and that the flag is wide enough to minimize cross flow at the boundaries. An analysis of the downstream motion of the flag is necessary as well. Hamilton's principle is employed to derive the partial differential equation of motion. the flag is oriented in the vertical direction to neglect the effect of the flag's weight on the system's response. Galerkin's method is used to solve for the first four mode shapes of the system, and the system response is numerically solved. Simulations reveal a very reasonable model when the flag is modeled as a membrane.
control of print quality (registration) in roll-to-roll (R2R) printing is challenging because of the presence of transport delays involved in the printing process. In this work we present a delay-independent state fee...
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ISBN:
(纸本)9780791846209
control of print quality (registration) in roll-to-roll (R2R) printing is challenging because of the presence of transport delays involved in the printing process. In this work we present a delay-independent state feedback control design to stabilize a R2R printing press by considering all the significant dynamics involved in the printing process. State feedback control design using past state measurements (controllers with memory) are discussed first. Since controllers with memory are less desirable in industrial applications, we investigate and discuss the feasibility of designing a simple, memoryless, delay-independent state feedback controller for printing applications. the feasibility is shown by the use of a control design procedure that exploits the structure information in the system matrix to find a stabilizing controller. the design procedure is also extended to other common industrial R2R control strategies, such as decentralized control and state feedback with integral action for R2R printing applications.
this paper presents a robust control design for a low-cost mobile robot under modeling uncertainties and external disturbances. We use a radial basis function neural network (RBFNN) to estimate and compensate for the ...
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ISBN:
(纸本)9780791846186
this paper presents a robust control design for a low-cost mobile robot under modeling uncertainties and external disturbances. We use a radial basis function neural network (RBFNN) to estimate and compensate for the model uncertainties and external disturbances. the proposed control design is model-free with guaranteed stability and good path-following performance. the RBFNN weight regulation and adaptive gains are designed based on the Lypanov method. Simulation and experimental results illustrate the design and demonstrate the strength of the proposed control applied to a nonholonomic wheeled mobile robot driven by low-cost permanent magnet dc motors without shaft encoders. the comparison results between proposed control and feedback linearization control confirm the effective role of the compensator in terms of precision, simplicity of design and computations.
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