Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
3,477
result(s) for
"Continuous time systems"
Sort by:
Kanban change leadership : creating a culture of continuous improvement
\"This book provides an understanding of what is necessary to properly understand change management with Kanban as well as how to apply it optimally in the workplace\"-- Provided by publisher.
Book
Residue Matching: A Method to Determine Intersample Vibrations in Systems With State Feedback
In this paper, we present a new method to determine the continuous‐time response of sampled‐data systems with uniform sampling, zero‐order hold, and full‐state feedback. In such systems, a continuous‐time plant is controlled using a discrete‐time control law. Traditionally, sampled‐data systems are designed in discrete time, resulting in, given by the nature of this kind of modelling, unmodelled intersample behaviour. We show that the Laplace transform of the otherwise piecewise‐continuous state response can be expressed in closed form that fully represents the intersample dynamics. A practical technique is also provided to decouple individual vibration components and reconstruct response functions in the time domain. The proposed approach is also able to capture intersample vibrations compared to common methods, which may lead to inaccurate results in specific cases. The presented new formulae are derived analytically and verified by simulations through numerical examples and experiments on a DC motor drive. This paper presents a new method for analysing the continuous‐time response of sampled‐data systems, addressing the intersample dynamics often overlooked in traditional discretized approaches. The method includes a closed‐form expression for the Laplace transform of the state response and offers techniques for decoupling vibration components and reconstructing time‐domain response functions. The presented new formulae are derived analytically and verified by simulations and experiments.
Journal Article
Nonlinear Continuous-Time System H∞ Control Based on Dynamic Quantization and Event-triggered Mechanism
The
H
∞
state feedback control problem of Takagi–Sugneo (T–S) fuzzy system with dynamic quantization and event-triggered mechanism is studied in this paper. Based on T–S fuzzy model, a new quantization scheme is proposed to solve the problem of synchronous quantization and event-triggered mechanism in continuous-time system. A new event-triggered communication scheme is proposed to improve the utilization rate of network resources. The sufficient conditions for the stability of
H
∞
state feedback control are given by means of linear matrix inequalities. Finally, the effectiveness of the proposed method is verified by a simulation of the spring-mass-damping system.
Journal Article
Neural-network-based online optimal control for uncertain non-linear continuous-time systems with control constraints
In this study, an online adaptive optimal control scheme is developed for solving the infinite-horizon optimal control problem of uncertain non-linear continuous-time systems with the control policy having saturation constraints. A novel identifier-critic architecture is presented to approximate the Hamilton–Jacobi–Bellman equation using two neural networks (NNs): an identifier NN is used to estimate the uncertain system dynamics and a critic NN is utilised to derive the optimal control instead of typical action–critic dual networks employed in reinforcement learning. Based on the developed architecture, the identifier NN and the critic NN are tuned simultaneously. Meanwhile, unlike initial stabilising control indispensable in policy iteration, there is no special requirement imposed on the initial control. Moreover, by using Lyapunov's direct method, the weights of the identifier NN and the critic NN are guaranteed to be uniformly ultimately bounded, while keeping the closed-loop system stable. Finally, an example is provided to demonstrate the effectiveness of the present approach.
Journal Article
Transformations of Linear Standard Systems to Positive Asymptotically Stable Linear Ones
New approaches to transformations of linear continuous-time systems to their positive asymptotically stable canonical controllable (observable) forms are proposed. It is shown that, if the system matrix is nonsingular, then the desired transformation matrix can be chosen in block diagonal form. Procedures for the computation of the transformation matrices are proposed and illustrated with simple numerical examples.
Journal Article
Online identification of non-homogeneous fractional order Hammerstein continuous systems based on the principle of multi-innovation
In the process of online identification of non-homogeneous fractional order Hammerstein systems in continuous time, traditional identification algorithms have slow convergence speed and low precision, and it is difficult to simultaneously identify multiple non-homogeneous fractional orders and system parameters. This paper proposes an identification method based on the principle of multi-innovation identification. Firstly, the Hammerstein non-homogeneous fractional order continuous-time system is given, and the parameters to be identified are clarified. Secondly, based on the Riemann–Liouville differential operator, the partial derivative equation of the objective function to non-homogeneous fractional orders in the identification process is given, which ensures that the coefficients of the system and non-homogeneous fractional orders can be identified at the same time. Then, within the given value range of the fractional vector, the partial derivative equation is progressively simplified to make it convenient for online calculation. And the principle of multi-innovation is introduced into the traditional Levenberg–Marquardt algorithm, which improves the convergence speed and convergence precision of the algorithm. Finally, we illustrate the validity of the theory through two experiments, including a numerical simulation example of a fractional-order system and a numerical example of a flexible manipulator system. Experiments prove that the algorithm proposed in this paper has good performance in both simulation examples and actual systems.
Journal Article
Online approximate optimal control for affine non-linear systems with unknown internal dynamics using adaptive dynamic programming
In this study, a novel online adaptive dynamic programming (ADP)-based algorithm is developed for solving the optimal control problem of affine non-linear continuous-time systems with unknown internal dynamics. The present algorithm employs an observer–critic architecture to approximate the Hamilton–Jacobi–Bellman equation. Two neural networks (NNs) are used in this architecture: an NN state observer is constructed to estimate the unknown system dynamics and a critic NN is designed to derive the optimal control instead of typical action–critic dual networks employed in traditional ADP algorithms. Based on the developed architecture, the observer NN and the critic NN are tuned simultaneously. Meanwhile, unlike existing tuning laws for the critic, the newly developed critic update rule not only ensures convergence of the critic to the optimal control but also guarantees stability of the closed-loop system. No initial stabilising control is required, and by using recorded and instantaneous data simultaneously for the adaptation of the critic, the restrictive persistence of excitation condition is relaxed. In addition, Lyapunov direct method is utilised to demonstrate the uniform ultimate boundedness of the weights of the observer NN and the critic NN. Finally, an example is provided to verify the effectiveness of the present approach.
Journal Article
Slime Mould Optimization-Based Approximants of Large-Scale Linear-Time-Invariant Continuous-Time Systems with Assured Stability
In this paper, a novel hybrid model reduction method is presented to simplify a complex, large-scale continuous-time system using the slime mould optimization algorithm (SMOA). The proposed method ensures the stability of reduced-order approximants as stability equations are incorporated along with the SMOA. It is also demonstrated that the stability claim of some of the existing model reduction methods is incorrect. An extensive comparative analysis of the dynamic responses and performance indices is also shown by using two case studies, confirming the supremacy of the presented method over the existing methods.
Journal Article
Robust Fault Estimation Based on a Learning Observer for Linear Continuous-Time Systems with State Time-Varying Delay
This study addresses the problem of robust actuator fault estimation for a class of critical linear continuous-time systems subject to state time-varying delays, external disturbances, and actuator faults. A learning observer is proposed to achieve the challenging task of simultaneously estimating both the system states and actuator faults, irrespective of whether the faults are constant or time-varying. A key theoretical contribution is the derivation of a less conservative delay-dependent condition for the existence of the proposed learning observer, which is expressed in terms of linear matrix inequalities (LMIs). The H∞ performance index is employed to attenuate the effects of disturbances to a prescribed level. The efficacy of the proposed strategy is rigorously validated through three illustrative examples, including quantitative performance metrics and a comparative analysis with existing methods.
Journal Article
Applications of fuzzy Laplace transforms
A natural way to model dynamic systems under uncertainty is to use fuzzy initial value problems (FIVPs) and related uncertain systems. In this paper, we express the fuzzy Laplace transform and then some of its well-known properties are investigated. In addition, an existence theorem is given for fuzzy-valued function which possess the fuzzy Laplace transform. Consequently, we investigate the solutions of FIVPs and the solutions in state-space description of fuzzy linear continuous-time systems under generalized H-differentiability as two new applications of fuzzy Laplace transforms. Finally, some examples are given to show the efficiency of the proposed method.
Journal Article