In this paper, first we survey Fault Detection and Isolation (FDI) for nonlinear systems. A necessary condition for the problem to be solvable is derived in terms of an unobservability distribution, which is computabl...
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A sliding mode controller is employed to improve the robust performance of the position control of an induction motor in response to mechanical parameter uncertainty or load torque variations. In this paper a discrete...
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The main contribution of the paper is an output-feedback application in the inertia wheel pendulum (IWP). Due to the absence of a separation principle, it is necessary to design control laws that guarantee robustness ...
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The main contribution of the paper is an output-feedback application in the inertia wheel pendulum (IWP). Due to the absence of a separation principle, it is necessary to design control laws that guarantee robustness against the observer error. We present a design, which renders the system iISS with respect to the observer error and, hence, ensures robustness when the error is exponentially decaying. The advantage of our design over the observer-based backstepping scheme is that we employ nonlinear damping terms, which grow slower than those in (A toolkit for nonlinear feedback design, 1989), (Singular perturbations and input-to-state stability, 1996), and result in a "softer" control law.
Iterative median filtering for restoration of images corrupted by impulsive noise is considered. A modified version of median filtering that can be also applied iteratively is also proposed. The methods are compared w...
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Iterative median filtering for restoration of images corrupted by impulsive noise is considered. A modified version of median filtering that can be also applied iteratively is also proposed. The methods are compared with an iterative method suggested by Marvasti for images with high pixel loss. The results show that applying the median filter iteratively results in well sighted resulting images. Moreover, despite the implementation simplicity, the proposed modified median filtering scheme provides a considerably higher convergence speed which intends a lower numerical complexity.
The paper presents the design of fuzzy sliding mode control based on genetic algorithms. An optimal design criterion is not required in the design of a fuzzy sliding mode control. Therefore, we design a fuzzy sliding ...
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The paper presents the design of fuzzy sliding mode control based on genetic algorithms. An optimal design criterion is not required in the design of a fuzzy sliding mode control. Therefore, we design a fuzzy sliding mode controller for the general nonlinear control systems as an optimization problem and apply the optimal searching algorithms and genetic algorithms to find the optimal rules and membership functions of the controller. The proposed approach has the merit to determine the optimal structure and the inference rules of fuzzy siding mode controller simultaneously. Using the proposed approach, the tracking problem of two-degree-of-freedom rigid robot manipulator is studied. Simulation results of the close-loop system with the proposed controller based on genetic algorithms show the effectiveness of the approach.
In process control the main goal is not only the output tracking, but also the design of a suitable control signal because it is dealt with the actuators directly. This means that the undesired oscillations should be ...
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In process control the main goal is not only the output tracking, but also the design of a suitable control signal because it is dealt with the actuators directly. This means that the undesired oscillations should be removed to alleviate the malfunction of actuators. In this paper, a nonlinear saturating element is designed with the help of an adaptive neural network. This element would chop the undesired oscillations of the control signal. The performance of the system is guaranteed by the use of a central controller such as PID and implementation of a performance measurement index to reduce the error between the output and desired input signal. The multilayer perceptron network, with its adaptive activation function is used and trained with Error Back Propagation algorithm. The simulations applied to a Heating, Ventilating and Air Conditioning (HVAC) system, demonstrates the good performance of the new design method.
In this paper a backstepping controller for a nonlinear, MIMO HVAC system is introduced. Feedback linearization method with introduction of a feedback of states and disturbances is used for the purposes of disturbance...
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In this paper a backstepping controller for a nonlinear, MIMO HVAC system is introduced. Feedback linearization method with introduction of a feedback of states and disturbances is used for the purposes of disturbance decoupling and nonlinear model linearization. The backstepping controller is applied to the linearized model of the system. It is shown that by this method, heat and moisture loads can be compensated, considering them as measurable disturbances. In this way the system can adapt itself to load variations fast and without any offset. Finally the simulation results are brought to show the ability of the method to present a controller with high disturbance decoupling and good tracking properties.
This paper introduces robust control architecture for nonholonomic mobile robots. The proposed technique linearizes and decouples the nonlinear and coupled dynamic equations of the robot by computed torque approach. S...
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This paper introduces robust control architecture for nonholonomic mobile robots. The proposed technique linearizes and decouples the nonlinear and coupled dynamic equations of the robot by computed torque approach. Since the computed torque technique requires the exact knowledge of the corresponding nonlinear dynamics, therefore, any mismatch in this regard may leave some nonlinear and also uncertain parts in the resulting system. The effect of mentioned parts may be compensated via a robust controller. As a result, in the present work, the remaining uncertainty is compensated by the H/sub /spl infin// technique, which requires the boundedness of the uncertain part. It is shown that the elements of the said uncertainty are L/sub 2/ -bounded. Numerical simulations demonstrate the effectiveness of the proposed H/sub /spl infin// based robust control scheme.
This paper, presents a traction control algorithm for an electric vehicle (EV) with four separate wheel drives. This algorithm is necessary to improve the handling and stability of EV during cornering or under slipper...
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This paper, presents a traction control algorithm for an electric vehicle (EV) with four separate wheel drives. This algorithm is necessary to improve the handling and stability of EV during cornering or under slippery road condition. It distributes the traction power among four drives and especially an independent torque reference on each wheel. The proposed algorithm is implemented in terms of a hierarchical architecture, which incorporates all new known vehicle systems ABS (anti-lock brake system), ASR (anti slip regulation), ESP (electronic stability program). To achieve good performances, a robust sliding mode control strategy is implemented. Several simulation results, which show the potential of such an algorithm, are presented.
In this paper, a method to design a nonlinear optimal controller using approximate solution of the HJB equation is presented. Using this method, the power system stabilizer is designed. In order to regulate generator ...
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ISBN:
(纸本)0780379241
In this paper, a method to design a nonlinear optimal controller using approximate solution of the HJB equation is presented. Using this method, the power system stabilizer is designed. In order to regulate generator terminal voltage to its nominal value, we use a simple neuro-automatic voltage regulator. The final control action is the sum of nonlinear optimal controller and neuro-voltage regulator. Also, the advantages of the controller with nonlinear feedback in some grounds like increasing domain of validity of the system are shown. Simulation results show that the nonlinear control action exhibits a better performance compared to that of corresponding linear counter part. As a result, the fault tolerance of the system using the nonlinear control law is increased. Also, the proposed voltage regulator, which can be trained on-line, shows satisfactory performance.
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