This paper addresses the trajectory tracking control of a nonholonomic wheeled mobile manipulator with parameter uncertainties and disturbances. The proposed algorithm adopts a robust adaptive control strategy where p...
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This paper addresses the trajectory tracking control of a nonholonomic wheeled mobile manipulator with parameter uncertainties and disturbances. The proposed algorithm adopts a robust adaptive control strategy where parametric uncertainties are compensated by adaptive update techniques and the disturbances are suppressed. A kinematic controller is first designed to make the robot follow a desired end-effector and platform trajectories in task space coordinates simultaneously. Then, an adaptive control scheme is proposed, which ensures that the trajectories are accurately tracked even in the presence of external disturbances and uncertainties. The system stability and the convergence of tracking errors to zero are rigorously proven using Lyapunov theory. Simulations results are given to illustrate the effectiveness of the proposed robust adaptive control law in comparison with a sliding mode controller.
Face recognition is becoming a difficult process because of the generally similar shapes of faces and because of the numerous variations between images of the same face. A face recognition system aims at recognizing a...
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Face recognition is becoming a difficult process because of the generally similar shapes of faces and because of the numerous variations between images of the same face. A face recognition system aims at recognizing a face in a manner that is as independent as possible of these image variations. Such variations make face recognition, on the basis of appearance, a difficult task. This paper attempts to overcome the variations of facial expression and proposes a biological vision-based facial description, namely Perceived Facial Images (PFIs), applied to facial images for 2D face recognition. Based on the intermediate facial description, SIFT-based feature matching is then carried out to calculate similarity measures between a given probe face and the gallery ones. Because the proposed biological vision-based facial description generates a PFI for each quantized gradient orientation of facial images, we further propose a weighted sum rule based fusion scheme. The proposed approach was tested on three facial expression databases: the Cohn and Kanade Facial Expression Database, the Japanese Female Facial Expression (JAFFE) Database and the FEEDTUM Database. The experimental results demonstrate the effectiveness of the proposed method.
This work is aimed at looking into the flatness control of the crane detailing adopted mechanisms and approaches in order to be able to control this system and to solve problems encountered during its functioning. The...
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This work is aimed at looking into the flatness control of the crane detailing adopted mechanisms and approaches in order to be able to control this system and to solve problems encountered during its functioning. The control objective is the sway free transportation of the crane s load taking the commands of the crane operator into account. Based on the mathematical model linearizing and stabilizing control laws for the slewing and luffing motion are derived using the input/output linearization approach. The method allows for transportation of the payload to a selected point and ensures minimisation of its swings when the motion is finished. To achieve this goal a mathematical model of the control system of the displacement of the payload has been constructed. A theory of control which ensures swing free stop of the payload is presented. Selected results of numerical simulations are shown. At the end of this work, a comparative study between the real moving and the desired one has been presented.
This paper describes an Adaptive Backstepping Neural Network (ABNN) method used for a ship course tracking control. The ship model is described by a third order nonlinear model whose parameters are unknown. The contro...
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In this paper we present a design of a minimum phase noise current controlled oscillator in CMOS technology. Owing to their high degree of controllability, the second generation current conveyer is used as a basic blo...
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In this paper we present a design of a minimum phase noise current controlled oscillator in CMOS technology. Owing to their high degree of controllability, the second generation current conveyer is used as a basic block for our oscillator. Thus, the first step in our design was to improve static and dynamic behaviour of second generation current conveyers. We present therefore a design of CMOS class AB second generation current conveyors. The translinear implementation in CMOS technology was first studied and then a considerable improvement of the parasitic series resistance on port X is done by presenting a structure of CCII. With a control current of 300 mu;A, a reduction of RX by a factor of 10 is observed leading to a notable improvement of the frequency behaviour. This improved CCII version was used as a basic building block in the design of a new current controlled oscillator covering [100MHz-600MHz] frequency is presented. Phase noise characteristics of the presented oscillator are investigated. We present then a new methodology of modelling and optimisation of phase noise of current controlled oscillators for CMOS process. This optimization strategy leads to a minimum phase noise acting on device geometries and design sources. PSpice simulation results are performed using CMOS 0.35 mu;m process of AMS.
This paper describes an Adaptive Backstepping Neural Network (ABNN) method used for a ship course tracking control. The ship model is described by a third order nonlinear model whose parameters are unknown. The contro...
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This paper describes an Adaptive Backstepping Neural Network (ABNN) method used for a ship course tracking control. The ship model is described by a third order nonlinear model whose parameters are unknown. The controldesign uses estimate values of unknown parameters of the system. Then, adaptive laws of the estimation of these values have been proposed. The stability of the controlled system has been ensured by the use of a Lyapunov function. Simulation results show the effectiveness of the proposed approach and the designed controller can be applied to the ship course tracking with good performances.
In this paper, we have developed a feedforward neural networks to detect and to diagnosis rotor fault on induction motors using stator currents. In the first step, causes and effects of rotor fault have been studied, ...
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In this paper, we have developed a feedforward neural networks to detect and to diagnosis rotor fault on induction motors using stator currents. In the first step, causes and effects of rotor fault have been studied, particularly, the number of broken bars has been considered. Then, in the second step, the number of broken rotor bars has been localized by Artificial Neural Networks (ANN), using the Fast Fourier Transform. Simulation results show that the Neural Network proposed approach presents a good tools for the diagnostic of induction machines.
A new approach to path tracking based on fractional prefilter was developed in this *** previous works,this approach based on a Frequency Band Limited Fractional Differentiator(FBLFD)prefilter,with the position contro...
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A new approach to path tracking based on fractional prefilter was developed in this *** previous works,this approach based on a Frequency Band Limited Fractional Differentiator(FBLFD)prefilter,with the position control,has been *** permits the generation of optimal movement reference input leading to aminimum path completion
To govern perfectly the MIMO(Multi-Input Multi-Output) processes,a fully populated matrix controller has been proposed due to its *** non diagonal quantitative feedback theory approach is used with CRONE control struc...
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To govern perfectly the MIMO(Multi-Input Multi-Output) processes,a fully populated matrix controller has been proposed due to its *** non diagonal quantitative feedback theory approach is used with CRONE control structure taking into account the plant *** to the fractional derivation order,the control loop frequency
In this paper we investigate the leader follower motton coordination of multiple nonholonomic mobile robots. A combination of the virtual vehicle and trajectory tracking approach is used to derive the formation archit...
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