Most of iterative learning control (ILC) methods requires that the relative degree of the plant is less than 2 for a linear system or the plant is passive for a non-linear system. A new modelreference parametric adap...
详细信息
Most of iterative learning control (ILC) methods requires that the relative degree of the plant is less than 2 for a linear system or the plant is passive for a non-linear system. A new modelreference parametric adaptive iterative learning control using the command generator tracker (CGT) theory is proposed in this paper. The method can be applied to control a plant with a higher relative degree and it only requires to iteratively adjust n m + 2 parameters for an SISO plant. Therefore, the ILC control system is very simple. The proposed method is in the spirit of simple adaptive control which has received intensive researches during past two decades. Simulation results show the effectiveness and usefulness of the proposed method.
A modelreference adaptive controller for nonlinear systems is implemented using rectangular local linear model (RLLM) network approach. An RLLM network is used to identify the plant as NARX model. Another network of ...
详细信息
ISBN:
(纸本)0780355199;0780355202
A modelreference adaptive controller for nonlinear systems is implemented using rectangular local linear model (RLLM) network approach. An RLLM network is used to identify the plant as NARX model. Another network of the same kind consisting of linear controllers is tuned to achieve the closed-loop behaviour of a linear referencemodel. A master slave configuration is realised to decide about the activation of candidate linear controllers in the controller network The implemented control scheme is tested in simulations and real-time control on a hydraulic positioning system.
The permanent magnet AC motor drive (PMAC) is a multivariable, nonlinear, closely coupled system subject to saturation due to finite dc supply voltage and hard current limits for protection of the drive hardware. Mode...
详细信息
The permanent magnet AC motor drive (PMAC) is a multivariable, nonlinear, closely coupled system subject to saturation due to finite dc supply voltage and hard current limits for protection of the drive hardware. model following controls can be applied to this class of motor with PI current controllers enabling tracking of quadrature current command values. The presence of a finite supply voltage constraint results in reduced system performance when the current regulators saturate. A dynamic model reference controller is presented which includes the currents and voltage limits, constraining the magnitudes of the command signals, operating the system to just within the bound of saturations, allowing the PI controllers to accurately track the command signals and retains control of the current vector. This regime ensures maximum possible dynamic performance of the system. The system and controller is simulated and experimentally verified, controller gains are found by Monte Carlo simulation.
The design of a control system, that provides a modelreference performance specification for the command response and, at the same time, achieves some prespecified feedback properties, is discussed. The use of a part...
详细信息
The design of a control system, that provides a modelreference performance specification for the command response and, at the same time, achieves some prespecified feedback properties, is discussed. The use of a particular configuration of a two degree-of freedom controller will allow the feedback and performance specifications to be tackled independently through the design of a feedback controller for the nominal plant and the modelreference part by means of model matching in a min-max sense. A closed-form solution is provided for the optimal min-max controller. This closed-form solution will be very useful when using this controller in an adaptive way. The resulting adaptive controller will consist of a fixed feedback part and an adaptive open-loop part. Only one degree-of-freedom is adapted. An example will show that it is possible to match the modelreference performance specification, even near the stability limit.
This paper investigates the effectiveness of velocity-scheduled Driver Assisted control (DAC) to control the yaw rate of a front wheel drive, four-wheel steer passenger vehicle. The goal of this research is to be able...
详细信息
This paper investigates the effectiveness of velocity-scheduled Driver Assisted control (DAC) to control the yaw rate of a front wheel drive, four-wheel steer passenger vehicle. The goal of this research is to be able to impart new handling characteristics to a vehicle through the entire range of operational longitudinal velocities. The DAC uses vehicle yaw rate as input and the rear steering angle as output, thus allowing the driver to maintain a direct line of vehicle control via the front wheels for safety reasons. Multiple DAC controllers are designed for discrete longitudinal velocities within the vehicle's operating range. A transition methodology was then implemented to switch between DAC controllers as the longitudinal velocity changes. Finally, the controller was tested experimentally on a scaled vehicle testbed.
In this paper we consider the use of linear time-varying controllers for simultaneous stabilization and performance. We prove that for every finite set of plants, we can design a linear time-varying controller which p...
详细信息
In this paper we consider the use of linear time-varying controllers for simultaneous stabilization and performance. We prove that for every finite set of plants, we can design a linear time-varying controller which provides not only closed-loop stability, but also near-optimal modelreference tracking. (C) 2002 Elsevier Science B.V. All rights reserved.
The purpose of this paper is to provide a quick overview of neural networks and to explain how they can be used in control systems. We introduce the multilayer perceptron neural network and describe how it can be used...
详细信息
The purpose of this paper is to provide a quick overview of neural networks and to explain how they can be used in control systems. We introduce the multilayer perceptron neural network and describe how it can be used for function approximation. The backpropagation algorithm (including its variations) is the principal procedure for training multilayer perceptrons;it is briefly described here. Care must be taken, when training perceptron networks, to ensure that they do not overfit the training data and then fail to generalize well in new situations. Several techniques for improving generalization are discussed. The paper also presents three control architectures: modelreference adaptive control, model predictive control, and feedback linearization control. These controllers demonstrate the variety of ways in which multilayer perceptron neural networks can be used as basic building blocks. We demonstrate the practical implementation of these controllers on three applications: a continuous stirred tank reactor, a robot arm, and a magnetic levitation system. (C) Copyright 2002 John Wiley Sons, Ltd.
This paper proposes a novel modelreference robu st speed control with load torque estimator and feedforward compensation based on neural network (NN) for induction motor drives with time delay. First, a two-layer neu...
详细信息
This paper proposes a novel modelreference robu st speed control with load torque estimator and feedforward compensation based on neural network (NN) for induction motor drives with time delay. First, a two-layer neural network torque estimator (NNTE) is used to provide a real-time identification for unknown load torque disturbance. The back-propagation algorithm was used as the learning algorithm. In order to guarantee the system's convergence and to obtain faster NN's learning ability, a Lyapunov function is also employed to find the bounds of the learning rate. Since the performance of the closed-loop controlled induction motor drive is influenced greatly by the presence of the inherent system dead time during wide-range operations, a dead time compensator (DTC) and the modelreference following controller (MRFC) using a neural network proportional controller (NNPC) are proposed to enhance the robustness of the PI controller. The theoretical analysis, simulation, and experimental results demonstrate that the proposed modelreference robust control scheme can improve the performance of induction motor drive with time delay and reduce its sensitivity to system parameter variations and load torque disturbances.
The paper presents a model for motion generation of differential-drive mobile robots. The parameters of the dynamic model allow adjusting the robot translational and rotational behaviours separately. The model takes i...
详细信息
The paper presents a model for motion generation of differential-drive mobile robots. The parameters of the dynamic model allow adjusting the robot translational and rotational behaviours separately. The model takes into account the robot kinematic and dynamic constraints, making the velocities and accelerations bounded and compatible with those the robot can perform. The main contribution of the paper is to use the model itself as a motion controller: under soft hypothesis on the velocities and accelerations, this approach allows an easy tuning of the controller parameters. A system stability and parameters sensitivity analysis is developed, in order to get guidelines for controller tuning. The clear physical sense of the parameters make this tuning easy and intuitive. Experimental results involving a real mobile robot show the performance of this approach.
In this paper, we present a decentralized modelreference adaptive control for interconnected subsystems in the sense that no information exchange occurs between the subsystems. The approach is based on the interconne...
详细信息
In this paper, we present a decentralized modelreference adaptive control for interconnected subsystems in the sense that no information exchange occurs between the subsystems. The approach is based on the interconnection output estimation using the polynomial series which offers a general solution for interconnected subsystems. The parameter estimation scheme is a combined adaptive data filtering with a recursive least-squares algorithm with parameter projection and normalization. The problem of minimum phased subsystems is handled by an adaptive input-output data filtering. Hence the zeros of each subsystem estimated model are relocated inside the unit circle. This estimated model which is minimum phased is then used for the control synthesis. It is shown that the stability conditions based on weak interconnections are relaxed. Also the robustness of the proposed adaptive control against unmodeled dynamics is stated. Finally, the results are illustrated by numerical examples. (C) 1999 Elsevier Science Ltd. All rights reserved.
暂无评论