Héctor Ríos

Robust regulation for a 3-DOF helicopter via sliding-mode observation and identification

Abstract This paper tackles the problem of robust output regulation for a 3-DOF helicopter. The considered system is subjected to model uncertainties and external perturbations. A sliding mode observer is used to estimate the state vector in finite time and identify the uncertainties and perturbations using the information of the equivalent output injection. Based on these estimations a robust regulation controller is designed. Experimental results show the feasibility of this approach.

High-order sliding mode observers for nonlinear autonomous switched systems with unknown inputs

The unknown input identification and state observation problems are studied for a class of linear autonomous switched systems. The necessary conditions for the reconstructability of the unknown inputs and states are given. Under structural conditions, it is proposed a robust estimator capable to reconstruct the continuous state, the discrete state and the unknown inputs.

Fault tolerant control allocation via continuous integral sliding-modes

In this paper a continuous fault tolerant control allocation is proposed. This approach is based on a uniform High-Order Sliding-Mode Observer where only measurable outputs are used. The fault tolerant control scheme is developed using, for the first time, a continuous integral sliding-mode and a fixed control allocation technique which provides an approximate estimation of matched faults. The conditions for stability are found by ensuring the stability of the closed loop system in the presence of possible faults in the components, and actuator faults or failures. The effectiveness of the proposed approach is verified through simulation of a linear version of the benchmark B 747 -100/200 civil aircraft model.

Robust regulation for a 3-DOF Helicopter via sliding-modes control and observation techniques

In this paper, two robust control strategies for a 3-DOF Helicopter via sliding-modes techniques are presented. First, quasi-continuous controllers along with a sliding mode differentiator are designed and then the design of classical PID controllers in combination with a second-order sliding mode observer is presented. Both strategies preserve high position regulation accuracy and robustness to model uncertainties and external disturbances. Simulations and experimental results on a 3-DOF Helicopter by Quanser are shown.

Global non-homogeneous Quasi-continuous controller for a 3-DOF helicopter

This paper presents a practical design approach to the stabilization of a three degrees of freedom helicopter. In this paper the global non homogeneous Quasi-continuous controller is presented in order to preserve high position regulation accuracy and robustness to model uncertainties and external disturbances. The non-homogeneous differentiator is also implemented to obtain exact differentiation in the control strategy. Simulations and the obtained results on a 3DOF helicopter by Quanser are shown.

Fault detection and isolation for nonlinear non-affine uncertain systems via sliding-mode techniques

ABSTRACTThis paper considers the fault detection and isolation problem for nonlinear uncertain non-affine systems. The proposed approach is based on an output-feedback stabilisation strategy, which exploits a Luenberger-like nonlinear observer. As a main result, a residual-based fault detection and isolation approach is developed, which relies on the measurable output, some of its derivatives, which are provided exactly by a uniform high-order sliding-mode differentiator, and the observer’s state. The proposed methodology is able to detect some possible components and actuators faults, and to isolate, under some mild conditions, the actuator faults from those ones in components. Simulation results illustrate the feasibility of the proposed approach.

Homogeneity Based Uniform Stability Analysis for Time-Varying Systems

The uniform stability notion for a class of nonlinear time-varying systems is studied using the homogeneity framework. It is assumed that the system is weighted homogeneous considering the time variable as a constant parameter, then several conditions of uniform stability for such a class of systems are formulated. The results are applied to the problem of adaptive estimation for a linear system.

Fault Detection and Isolation for Nonlinear Systems via HOSM Multiple-Observer

Abstract The fault detection and isolation problem is studied for a class of nonlinear systems. Under structural conditions, a bank of High-Order Sliding-Mode observers is proposed. The value of the equivalent output injection is used for detecting and isolating particular faults in the system. The proposed method provides finite-time isolation of actuator and plant faults. Simulation results support the proposed approach.

Robust tracking output-control for a quad-rotor: A continuous sliding-mode approach

Abstract This paper deals with the problem of robust tracking output-control design for a Quad-Rotor. The proposed approach is based on continuous sliding-modes control (SMC) techniques and it is able to robustly track a desired trajectory for the Quad-Rotor despite some class of disturbances acting on the system. Such a robust tracking control is composed of a finite-time sliding-mode observer (SMO) and cascaded continuous SMCs providing uniform finite-time stability and uniform exponential stability, for the vertical and yaw tracking error, and for the horizontal tracking error, respectively; despite the disturbances on the system, and only using the measurable positions and angles. Simulation results illustrate the feasibility of the proposed tracking strategy.

Robust synchronization of master-slave chaotic systems using approximate model: An experimental study

Robust synchronization of master slave chaotic systems are considered in this work. First an approximate model of the error system is obtained using the ultra-local model concept. Then a Continuous Singular Terminal Sliding-Mode (CSTSM) Controller is designed for the purpose of synchronization. The proposed approach is output feedback-based and uses fixed-time higher order sliding-mode (HOSM) differentiator for state estimation. Numerical simulation and experimental results are given to show the effectiveness of the proposed technique.