Showing papers by "Yan Lin published in 2013"

High-gain observer based decentralised output feedback control for interconnected nonlinear systems with unknown hysteresis input

Abstract: In this paper, an adaptive dynamic surface control is proposed for a class of interconnected nonlinear systems with inputs preceded by unknown saturated PI hysteresis. By using the proposed dynamic surface control scheme, the explosion of complexity problem when the hysteresis is fused with backstepping design can be eliminated which, together with the estimation of vector norm of the unknown parameters, greatly simplifies the control law and reduces the computational burden. Moreover, by introducing an initialisation technique, the tracking performance of each subsystem can be guaranteed, which, for the first time, establishes the relationship between tracking performance and design parameters in the interconnected system.

An adaptive output feedback dynamic surface control for a class of nonlinear systems with unknown backlash-like hysteresis

Abstract: This paper is devoted to the output feedback control for a class of nonlinear systems with unknown backlash-like hysteresis at the input. Based on a high-gain observer, an adaptive dynamic surface control scheme is proposed which is able to mitigate the effect of the hysteresis, to eliminate the explosion of terms inherent in backstepping control, and in particular, by introducing an initialization technique, to guarantee the ∞ performance of the system's tracking error. Another advantage of the proposed scheme is that the adaptive law is needed only at the first design step, which greatly simplifies the design procedure and makes our control easy to implement. Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society

Adaptive control for a class of nonlinear time-delay systems preceded by unknown hysteresis

Abstract: In this article, a robust adaptive neural dynamic surface control is proposed for a class of time-delay nonlinear systems preceded by saturated hystereses. Compared with the present schemes of dealing with time delay and hystereses input, the main advantages of the proposed scheme are that the prespecified transient and steady-state performance of tracking error can be guaranteed, the computational burden can be greatly reduced and the explosion of complexity problem inherent in backstepping control can be eliminated. Moreover, the utilisation of saturated-type Prandtl–Ishlinskii model makes our scheme more applicable. It is proved that the new scheme can guarantee all the closed-loop signals semiglobally uniformly ultimate bounded. Simulation results are presented to demonstrate the validity of the proposed scheme.

Robust output tracking control for a velocity‐sensorless vertical take‐off and landing aircraft with input disturbances and unmatched uncertainties

Abstract: SUMMARY In this paper, we develop a nonlinear controller to achieve output tracking for a nonminimum phase vertical take-off and landing aircraft without velocity measurements. To attenuate the effects of input disturbances and unmatched uncertainties, auxiliary control inputs are introduced in the state observer. Then by taking the aircraft lateral movement into consideration, a control law is proposed to force the vertical take-off and landing aircraft to asymptotically track the desired trajectories even in the presence of unexpected changes of the trajectories, while driving the unstable internal dynamics to follow the bounded and causal ideal internal dynamics via the stable system center method. Numerical simulation results illustrate the effectiveness and robustness of the proposed controller. Copyright © 2012 John Wiley & Sons, Ltd.

A linear algebraic criterion for controllability of both continuous-time and discrete-time symmetric bilinear systems

Abstract: This paper presents a necessary and sufficient condition for controllability of two-dimensional continuous-time and discrete-time symmetric bilinear systems The presented condition is a linear algebraic version which is easy to apply and verify In particular, for the continuous-time case, the necessary and sufficient condition can replace the classical Lie-algebraic one For the discrete-time case, the necessary and sufficient condition is new

Adaptive nonlinear output-feedback dynamic surface control with unknown high-frequency gain sign

Abstract: In this paper, an adaptive dynamic surface control (DSC) for a class of nonlinear systems with unknown high-frequency gain (HFG) sign is proposed. The novelty of our scheme is that we separate the first virtual control signal from the HFG, which enables us to estimate the HFG directly. As a result, the traditional Nussbaum function (NF) approach is abandoned. By using the proposed DSC, the adaptive laws are needed only at the first design step and the explosion of terms in backstepping control can be eliminated, which greatly reduces the computational burden. In particular, based on an initialisation technique, we prove that the performance of the system tracking error can be guaranteed even when the HFG sign is unknown. It is shown that all signals of the closed-loop system are semi-globally uniformly bounded. Simulation results illustrate that the proposed scheme is more applicable than that of the NF-based backstepping control.

Output‐feedback robust adaptive backstepping control for a class of multivariable nonlinear systems with guaranteed L∞ tracking performance

Abstract: SUMMARY This paper is devoted to output-feedback adaptive control for a class of multivariable nonlinear systems with both unknown parameters and unknown nonlinear functions. Under the Hurwitz condition for the high-frequency gain matrix, a robust adaptive backstepping control scheme is proposed, which is able to guarantee the tracking performance and needs only one parameter to be updated online regardless of the system order and input–output dimension. To cope with the unknown nonlinear functions and improve the tracking performance, a kind of high-gain K-filters is introduced. It is proved that all signals of the closed-loop system are globally uniformly bounded. Simulation results on coupled inverted double pendulums are presented to illustrate the effectiveness of the proposed scheme. Copyright © 2012 John Wiley & Sons, Ltd.

A robust output-feedback adaptive dynamic surface control for linear systems with input disturbance

Abstract: In this paper, a robust output-feedback adaptive control is proposed for linear time-invariant (LTI) singleinput single-output (SISO) plants with unmeasurable input disturbance. Using dynamic surface control (DSC) technique, it is shown that the explosion of complexity problem in backstepping control can be eliminated. Furthermore, the proposed adaptive DSC scheme has the following merits: 1) by introducing an initialization technique, the L∞ performance of system tracking error can be guaranteed even if the plant high-frequency gain is unknown and the input disturbance exists, and 2) the adaptive law is necessary only at the first design step, which significantly reduces the design procedure. It is proved that with the proposed scheme, all the closed-loop signals are semiglobally uniformly ultimately bounded. Simulation results are presented to demonstrate the effectiveness of the proposed scheme.