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For a class of chaotic systems with uncertain nonlinear time-delay functions and exogenous disturbance, the problem of observer-based adaptive synchronization is investigated. Based on Lyapunov-Krasovskii fucntional method, a delay-free observer is presented by using sliding mode control and adaptive control techniques. Two numerical simulations are given to show the effectiveness of the proposed...
This paper investigates the periodic disturbance rejection control of time-delay process by integrating a modified disturbance observer (MDOB) and internal model control (IMC) structure. A modified disturbance observer design method based on zero-pole placement is proposed. By the MDOB, periodic disturbance can be accurately estimated and the estimation is used as compensation to suppress disturbance...
Feedback linearization control based on nonlinear disturbance observer is investigated for an electro-hydraulic servo system with external disturbances and system uncertainties. Firstly, a mathematical model of electro-hydraulic servo system is developed and a single input-output affine system form is obtained. Then the technique, based on the feedback linearization, is employed to transform the nonlinear...
In this paper, precise tracking control of a class of high-order hydraulic servo systems is studied, where the dynamics of the electrohydraulic actuator are considered. Different to available results, a new control method is proposed without using the backstepping scheme and any function approximators. The model of the hydraulic servo system is transformed into a Brunovsky form, so that the tracking...
This paper proposes a robust adaptive backstepping sliding mode control (ABSMC) algorithm for the speed regulation of a six-phase permanent magnet synchronous motor (PMSM). In the proposed technique, ABSMC is used to guarantee the speed tracking and parameter perturbation suppression, meanwhile, nonlinear H∞ is utilized to minimize the influence of fast-varying load disturbances on its tracking output...
The design of a disturbance observer (DOB) for a nonlinear half-car hydraulic active suspension system is presented. The system is controlled by the flatness-based controller (FBC) which is capable to provide efficient control under deterministic road disturbances and model uncertainties. The main objective is to design the mutually coupled general-proportional-integral (GPI) disturbance observers...
The recent paper [9] studied the cooperative robust output regulation of linear multi-agent systems with arbitrary parametric uncertainty via the distributed output feedback control, where the network is assumed to be fixed. In this paper, we further show that the same controller is also efficient for the more general uniformly connected switching network. In contrast to the traditional quadratic...
In this work, we consider a testbed for a robotic astronomical 0.5-m. telescope mount. We focus on the problem of identification uncertainty that cannot be obtained from analytical consideration (i.e. friction phenomena). Thus, we use a recursive least-squares algorithm for identification values of friction terms. Since the required signals cannot be obtained directly from the object (or they are...
A continuous stirred tank reactor (CSTR) is typical of equipment found in the process control industry. The dynamics represent a wide class of second order nonlinear systems and thus as well as having specific industrial application, control of the CSTR is frequently used as a benchmark problem for application and testing of new control algorithms. Due to the high complexity of the CSTR system, the...
A disturbance estimation approach is presented for a class of nonlinear systems by incorporating two-layer structure. The multiple-disturbances concerned are supposed to include two parts. One is generated by an exogenous system, which can represent the single-sinusoidal signal with unknown frequency. The other part is norm bounded uncertain disturbance. The special auxiliary observer represent the...
This paper investigates the tracking control problems of a voice coil motor (VCM) actuated servo gantry system. A novel sliding mode disturbance observer based control algorithm is proposed to accommodate both model uncertainties and various disturbances. In the proposed control architecture, the sliding mode observer is introduced to estimate the total disturbances such that the observer error can...
This paper is concerned with the state estimation problem of a class of uncertain Markovian jump neutral-type stochastic systems. This kind of systems involves parameter uncertainties, noise disturbances and time-delay. Based on Lyapunov-Krasovskii functional approach, a delay-dependent condition is derived for the existence of state observer. The desired gain matrix and state-feedback controller...
In this paper, a novel output feedback tracking control scheme based on neural sliding mode without joint velocity measurement and the high order sliding mode observer for the uncertainty of robot manipulators are presented. Two second-order sliding mode observers are designed to estimate joint velocities and dynamic uncertainties of the robot manipulator, respectively. The first-second order sliding...
In this paper a discrete-time static H∞ loop shaping control method for linear parameter-varying (LPV) systems is presented. The formulation aims to find a static parameter dependent stabilizing controller which yields guaranteed performance. Using quadratic H∞ performance, a set of sufficient conditions is provided in a two-step LMI (Linear Matrix Inequality) approach. The first step consists in...
This paper proposes a method for the design of a robust functional H∞ observer for a class of time delay bilinear systems. The considered system is affected by norm-bounded uncertainties in the system matrices and an unmeasured perturbations which are of finite energy. The unbiasedness conditions on the nominal part of the error dynamics of the proposed reduced order observer were given by calling...
Event-triggered output robust control algorithm is proposed in the paper. Controller synthesis is based on the consecutive compensator method. Event-trigger mechanism is based on the high-gain state observer. Developed controller provide input-to-state practical stability of unstable linear plants under conditions of parametric uncertainties and bounded external disturbances. Computer simulation confirm...
This paper presents a design of a robust tracking controller for a quadrotor UAV. A sliding mode controller (SMC) is employed in which the unmatched perturbations and uncertainties are estimated by a nonlinear disturbance observer (NDO). The NDO is employed to estimate the effect of wind perturbations and unknown aerodynamical forces. Several sliding surfaces are designed to explicitly depend on the...
The paper describes the robust algorithm for linear time-invariant plants under parametric uncertainties, external disturbances and high-frequency noises in measurements. The proposed algorithm allows one to reduce the noise impact on the output variable of the plant and to compensate parametric uncertainties and external disturbances independently. The modeling results illustrate the effectiveness...
This paper deals with the problem of robust state estimation for switched LPV continuous-time systems with measurable and unmeasurable scheduling parameters. The switching law is assumed to be uncontrollable but online available, while the unmeasurable varying parameters are assumed to be bounded with a priori known bounds. The proposed approach is based on switched interval observers which provide...
Active disturbance rejection control (ADRC) as a standalone motion solution has been made available in recent years on various industrial platforms. The idea of ADRC, however, can be integrated with the existing control technologies seamlessly, as shown in this paper. A modularized ADRC design is proposed in this particular work for set-point tracking task in motion control, such that better uncertainty...
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