Observer-based Controller Design Method Research Articles

A3C-Based Intelligent Event-Triggering Control of Networked Nonlinear Unmanned Marine Vehicles Subject to Hybrid Attacks

This paper is concerned with the intelligent event-triggering-based positioning control of networked unmanned marine vehicle (UMV) systems with hybrid attacks, where the UMV and control station is connected by a communication network and the DoS attack and Deception attack are studied. Firstly, a stochastic switched Takagi-Sugeno (T-S) fuzzy system model is proposed for the networked nonlinear UMV systems subject to aperiodic DoS attack and random Deception attack. Then, a novel asynchronous advantage actor-critic (A3C) learning-based event-triggering approach is introduced to alleviate the communication load. By using the Lyapunov stability theory and switched system analysis method, the mean-square exponential stability condition of the closed-loop system and the design method of observer-based controller are devised. Finally, an example of a networked UMV system is given to verify the effectiveness of the proposed resilient control strategy.

Observer-based controller design for linear time-varying delay systems using a new Lyapunov-Krasovskii functional

This paper presents an observer-based controller design method for linear systems with interval time-varying state-delay. In this work, using a new Lyapunov-Krasovskii (LK) functional, a less conservative stabilisation criterion is derived. The Wirtinger's inequality and reciprocally convex combination lemma are exploited to develop a computationally tractable method by representing the design constraints in linear matrix inequality (LMI) framework. Numerical examples are given to demonstrate the superiority of the proposed results over the existing method.

Observer-based H∞ control for second-order neutral systems with actuator saturation and the application to mechanical system

The observer-based H∞ control problem for second-order neutral systems with actuator saturation is considered. First, a sufficient delay-dependent condition is proposed using Wirtinger-based integral inequality, under which such type neutral system with time-delay and actuator saturation is stable and satisfies H∞ performance. Then, based on the derived condition, the design method of observer-based controller is developed using linear matrix inequalities (LMIs) optimization problem. Finally, a numerical example is provided to illustrate the application of the second-order mechanical systems and the effectiveness of the theoretical results.

Simultaneous Robust Control and Sensor Fault Detection for a Ducted Coaxial-Rotor UAV

This paper addresses the aerodynamic modeling, observer-based state-feedback robust control and sensor fault detection for a laboratory ducted coaxial-rotor UAV (DCUAV). First, by introducing the main model elements of this novel unmanned vehicle, the detailed nonlinear mathematical model of the hovering flight UAV is presented. Second, through introducing a weighting matrix and a new form of change-of-variables, a new method is proposed by designing two different systems simultaneously as detector and controller. An observer-based controller is proposed to achieve the control objective and finite-frequency sensor fault detection objective simultaneously. The observer-based controller design method is derived from a new formulation of linear matrix inequality (LMI), which can achieve the prescribed H ∞ performance, H - performance and the stability of the closed-loop system. By constructing a new matrix decomposition form, the simultaneous design of detector parameters and controller parameters is solved. Finally, simulations are conducted for the hover flight with disturbances and sensor faults, the results show the satisfactory control performance and fault detection performance.

Relaxed observer-based controller design method of discrete-time multiplicative noised LPV systems via an extended projective lemma

ABSTRACTThe aim of this paper is to discuss a relaxed observer-based control problem of multiplicative noised Linear Parameter Varying (LPV) systems with unmeasurable states. For discussing the problem, positive definite matrices without neglecting any element are employed to construct a novel parameter-dependent Lyapunov function. Based on the Lyapunov function, some relaxed sufficient conditions are derived to hold the freedom in searching feasible solutions. Furthermore, an extended projective lemma is developed to convert those conditions into Linear Matrix Inequality (LMI) form. Solving these LMI conditions, controller gain and observer gain can be simultaneously obtained in one-step procedure via using convex optimization algorithm. Therefore, an observer-based controller can be established to guarantee the asymptotical stability of the multiplicative noised LPV systems in the sense of mean square. At last, two numerical examples are used to show effectiveness and applicability of the proposed design method.

Robust observer-based control for uncertain discrete-time piecewise affine systems

The main contribution of this paper is to present a novel robust observer-based controller design method for discrete-time piecewise affine systems with norm-bounded uncertainties. The key ideas are to construct a piecewise-quadratic Lyapunov function to guarantee the stability of the closed-loop systems, approximate polytopic operating regions by ellipsoids, and use the singular value decomposition technique to treat the constraint of matrix equality. It is shown that the suggested control method can be formulated as linear matrix inequalities that are numerically feasible with commercially available software. A numerical example is also given to verify the proposed approach.

Observer-based controller design of discrete-time piecewise affine systems

This paper presents a novel observer-based controller design method for discrete-time piecewise affine (PWA) systems. The basic idea is as follows: at first, a piecewise linear (without affine terms) state feedback controller and a PWA observer are designed separately, and then it is proved that the output feedback controller constructed by the resulting observer and state feedback controller gains can guarantee the stability of the closed-loop system. During the controller design, the piecewise-quadratic Lyapunov function technique is used. Moreover, the region information is taken into account to treat the affine terms, so the controller gains can be obtained by solving a set of linear matrix inequalities, which are numerically feasible with commercially available software. Three simulation examples are given finally to verify the proposed theoretical results. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society

Observer-based robust control giving consideration to transient behaviour for linear systems with

In this paper, we present an observer-based controller design method which achieves performance robustness together with robust stability for linear multivariable systems with structured uncertainties. The performance robustness means that the deterioration of control performance is suppressed when we compare the transient behaviour for the uncertain system with a desired one generated by using the nominal system directly and at the same time excessive control input is avoided. In this approach, we adopt a similar way to the model-following technique and assume that the control law consists of a state feedback law for the nominal system and a compensation input for the purpose of preventing the error between the transient behaviour for the uncertain system and the desired one. The compensation input is additional modification term given by feedback form of an estimated error signal and is determined so that an upper bound of a quadratic cost function for the error system between the real trajectory for the plant and the desired one is minimized. We show that a condition for the existence of the compensation input which minimizes an upper bound of the quadratic cost function for the error system is given in terms of linear matrix inequalities (LMIs). Finally, numerical examples are presented.

An observer-based controller design method for improving air/fuel characteristics of spark ignition engines

The wide operating range, the inherent nonlinearities of the induction process and the large modeling uncertainties make the design of the fuel-injection controller very difficult. Even though a sliding mode fuel-injection control method is in good agreement with the characteristics of the system, the unavoidable large time-delay between control action and measurement causes the problem of chattering. In this paper, an observer-based fuel-injection control algorithm is suggested for fast response and small amplitude chattering of the air-to-fuel ratio. The characteristics of the proposed controller are compared with those of other controllers. The proposed controller is simple enough for online computation and is implemented on an automotive engine using a PC-386. The simulation and the experimental results show that this algorithm reduces the chattering magnitude considerably while speeding up the transient response and is robust to modeling errors.