Search results for "backstepping"
showing 10 items of 30 documents
Direct adaptive tracking control for a class of pure-feedback stochastic nonlinear systems based on fuzzy-approximation
2014
Published version of an article in the journal: Abstract and Applied Analysis. Also available from the publisher at: http://dx.doi.org/10.1155/2014/462468 Open Access The problem of fuzzy-based direct adaptive tracking control is considered for a class of pure-feedback stochastic nonlinear systems. During the controller design, fuzzy logic systems are used to approximate the packaged unknown nonlinearities, and then a novel direct adaptive controller is constructed via backstepping technique. It is shown that the proposed controller guarantees that all the signals in the closed-loop system are bounded in probability and the tracking error eventually converges to a small neighborhood around …
Robust adaptive neural backstepping control for a class of nonlinear systems with dynamic uncertainties
2014
Published version of an article in the journal: Abstract and Applied Analysis. Also available from the publisher at: http://dx.doi.org/10.1155/2014/658671 Open Access This paper is concerned with adaptive neural control of nonlinear strict-feedback systems with nonlinear uncertainties, unmodeled dynamics, and dynamic disturbances. To overcome the difficulty from the unmodeled dynamics, a dynamic signal is introduced. Radical basis function (RBF) neural networks are employed to model the packaged unknown nonlinearities, and then an adaptive neural control approach is developed by using backstepping technique. The proposed controller guarantees semiglobal boundedness of all the signals in the…
Semiactive Control Methodologies for Suspension Control With Magnetorheological Dampers
2012
Authors version of an article published in the journal: IEEE/ASME Transactions on Mechatronics. Also available from the publisher at: http://dx.doi.org/10.1109/TMECH.2011.2107331 Suspension systems are one of the most critical components of transportation vehicles. They are designed to provide comfort to the passengers to protect the chassis and the freight. Suspension systems are normally provided with dampers that mitigate these harmful and uncomfortable vibrations. In this paper, we explore two control methodologies (in time and frequency domain) used to design semiactive controllers for suspension systems that make use of magnetorheological dampers. These dampers are known because of th…
Heuristic and Backstepping Control Strategies for Semiactive Suspension in Automotive Systems Equipped with MR Dampers
2010
Abstract This paper deals with the problem of semiactive vibration reduction in a class of automotive systems. Most conventional suspensions use passive devices to absorb impacts and vibrations, which is generally difficult to adapt to the uncertain circumstances. Semiactive suspension techniques promise a solution to the above problem with some comparatively better features than active and passive suspension devices. In this work, the semiactive suspension with magnetorheological (MR) dampers is applied for the vibration attenuation. Both backstepping and heuristic control strategies are proposed. In the design of backstepping controller, the Dahl model of the MR damper is used to estimate…
Robust adaptive backstepping control design for a Nonlinear Hydraulic-Mechanical System
2009
The complex dynamics that characterize hydraulic systems make it difficult for the control design to achieve prescribed goals in an efficient manner. In this paper, we present the design and analysis of a robust nonlinear controller for a Nonlinear Hydraulic-Mechanical (NHM) System. The system consists of an electrohydraulic servo valve and two hydraulic cylinders. Specifically, by considering a part of the dynamics of the NHM system as a norm-bounded uncertainty, two adaptive controllers are developed based on the backstepping technique that ensure the tracking error signals asymptotically converge to zero despite the uncertainties in the system according to the Barbalat lemma. The resulti…
Nonlinear Control of a Pneumatic Muscle Actuator System
2001
Abstract The performance of a Pneumatic Muscle Actuator under three tracking control strategies is compared: robust backstepping, sliding-mode and gain scheduling. Robustness is assured for the three controllers in the presence of model uncertainties and external perturbations. Exponential stability is proved for the sliding-mode tracking controller, ultimate boundedness for the backstepping tracking controller and exponential stability for constant or slowly-varying reference signals for the gain scheduling controller. Computer simulations show a good performance for the tracking of a sine wave by the first two controllers, although the sliding-mode strategy yields a high-frequency switchi…
Landing gear suspension control through adaptive backstepping techniques with H∞ performance
2011
Author's version of a chapter published in the book: Proceedings of the 18th IFAC World Congress 2011. Also available from the publisher at: http://dx.doi.org/10.3182/20110828-6-IT-1002.00589
Semiactive Backstepping Control for Vibration Reduction in a Structure with Magnetorheological Damper Subject to Seismic Motions
2009
The use of magnetorheological (MR) dampers for mitigating vibrations caused by seismic motions in civil engineering structures has attracted much interest in the scientific community because of the advantages of this class of device. It is known that MR dampers can generate high damping forces with low energy requirements and low cost of production. However, the complex dynamics that characterize MR dampers make difficult the control design for achieving the vibration reduction goals in an efficient manner. In this article, a semiactive controller based on the backstepping technique is proposed. The controller was applied to a three-story building with an MR damper at its first floor subje…
Semiactive vibration control of nonlinear structures through adaptive backstepping techniques withH∞performance
2011
This article presents a new approach to the vibration mitigation problem in structures subject to seismic motions. These kinds of structures are characterised by the uncertainties of the parameters that describe their dynamics, such as stiffness and damping coefficients. Moreover, the dampers used to mitigate the vibrations caused by earthquakes are usually nonlinear devices with frictional or hysteretic dynamics. We propose an adaptive backstepping controller to account for the uncertainties and the nonlinearities. The controller is formulated in such a way that it satisfies an H∞ performance. It is designed for a 10-storey building whose base is isolated with a frictional damper (passive …
daptive Backstepping Control of Nonlinear Hydraulic-Mechanical System Including Valve Dynamics
2010
Published version of an article from the journal: Modeling Identification and Control. Also available from publisher: http://dx.doi.org/10.4173/mic.2010.1.3 The main contribution of the paper is the development of an adaptive backstepping controller for a nonlinear hydraulic-mechanical system considering valve dynamics. The paper also compares the performance of two variants of an adaptive backstepping tracking controller with a simple PI controller. The results show that the backstepping controller considering valve dynamics achieves significantly better tracking performance than the PI controller, while handling uncertain parameters related to internal leakage, friction, the orifice equat…