The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The problem of the global asymptotic stabilization by dynamic output feedback of systems belonging to a particular family of feedforward systems is solved. The equations considered depend nonlinearly on the unmeasured part of the state and are nonminimum phase. Feedback laws arbitrarily small in norm are constructed. The result can be applied repeatedly. It is illustrated by the cart-pendulum system...
In this paper, a sensor fault diagnosis and accommodation method is developed in nonlinear case. This method makes possible the sensor faults compensation. Its principle is based on the on-line detection, localization and estimation of a faulty element when a fault occurs on a nonlinear system. Then, a new control law is computed in order to compensate the fault effect on the system. The performances...
In this article we present, in a tutorial fashion, an introduction to the links between flatness, generalized PID control and sliding mode control of linear systems. Several simple illustrative examples are presented including computer simulations and experimental results.
The problem of observer design for robust residual generation in nonlinear discrete-time systems is considered. The method is proposed to solve this problem involving nonlinear time-dependent transformation of state-space system model into strict feedback form. To make this transformation practicable, algebra of time-dependent functions is developed.
The paper considers an example of mechanical system with high relative degree: a fully actuated robot with elastic joints and the related control problem. The considered system is characterized by a uniform relative degree five, assuming as available output only the joints' angles. Two different strategies can be exploited to address this control problem. A first possibility is to use a full order...
In recent papers, the authors proposed a novel control approach based on the use of a Switching Linear Internal Model (SLIM) to cope with asymptotic tracking of a significant class of periodic references for “real world” applications, while guaranteeing good robustness properties with respect to disturbances. In the path toward a final assessment of this methodology, the problem of observing the state...
The present work deals with the classical problem of speed estimation for a small 4 rotors helicopter drone based on acceleration, rotation angles and angular speed measurements only. This problem concerns indoors applications as well as outdoors applications close-by large structures. Small Unmanned Air Vehicles (UAV) are commonly used for inspection applications such as beneath bridges, water dams,...
High performance operation of speed controlled AC drives without mechanical speed/position sensors rely on the dynamic models for estimation of flux and speed. Using backstepping, which is a recursive nonlinear design method, a new approach for the design of observers for speed sensorless control is developed. The resulting scheme leads to a nonlinear full order observer for the rotor field. The rotor...
In this paper, we develop a discrete-time time-invariant tracking controller for dynamic systems affected by hysteresis. This controller utilizes an approximate model for the inverse hysteresis dynamics, a non-linear discrete-time observer and two linear tracking controllers. The control system is tested on a simulation model of a mechanical translation stage.
The fact that the feedback interconnection of strictly positive real (spr) systems leads to an asymptotically stable closed loop can be used for the synthesis of robust observer-based state-space controllers. Since most control plants originally are not spr structural modifications must be done to establish this property even under parameter variations. Going that way one gets a modified spr plant...
We face the problem of stabilizing Linear Parameter Varying systems by means of Gain Scheduling Control. This technique consists on designing a controller which is able to update its parameters on-line according to the variations of the plant parameters. We first consider the state feedback case and we show a design procedure based on the construction of a Lyapunov function for discrete-time LPV systems...
This report presents a study on the problem of residual evaluation and threshold computation for detection of faults in continuous time nonlinear systems. A generalized framework for designing norm-based residual evaluation scheme is proposed. The problem of threshold computation is formulated as an optimization problem and its solution is developed using the well known LMI technique. Three commonly...
This paper presents a method to identify the parameters of continuous and discrete MIMO Takagi-Sugeno (TS) fuzzy models. The proposed method combines the Levenberg/Marquadt (LM) optimisation algorithm and least squares (LS) method. The LM algorithm is used to estimate the Gaussian membership function parameters whereas the parameters of linear local models is determined using a LS algorithm. To illustrate...
It is shown that by means of an appropriate choice of the coefficients of the regulator of the order smaller by one from that of the plant, it is possible to obtain the freely prescribed poles of the discrete-time (DT), closed loop (CL) system. The algorithm of design of the regulator-observer for the DT CL system with output feedback is described. The resulting CL system retains all the poles of...
In the present article we propose a nonlinear observer that merges the behaviors 1) of an extended Kalman filter, mainly designed to smooth off noise, and 2) of high-gain observers devoted to handle large perturbations in the state estimation. We specifically aim at continuous-discrete systems.
Fault Detection and Isolation is one of the necessary requirements to guarantee the stability and performance of a control system under fault conditions. This paper will focus on observer based detection and isolation of actuator and sensor faults for a segmented primary dish telescope testbed using a relationship between sensors. This testbed is located at the Structures Pointing And Control Engineering...
Considering the rotating engine speed control problem, speed sensors of measurement output are replaced by an event-detection scheme or simply an imprecise and low-resolution encoder. This results in considerable measurement simplification and cost reductions. Modeling the integrated plant-detector system will result in a nonlinear discrete-time model with a sample time dependent on state vector....
The paper deals with the comparison of different mathematical models with regard to their usage in the model-based leak-monitoring scheme. The pipeline is represented as a two-port system. Three models are compared: a nonlinear distributed parameters model, a linearised model whose transcendent transfer function is obtained by a Laplace transformation and corresponding initial and boundary conditions...
This paper considers the use of sliding mode observers for fault detection/disturbance estimation. A new observer design method is considered which is based on Linear Matrix Inequality (LMI) optimisation. Sliding mode observers have previously been used for fault detection and disturbance estimation; however the systems for which they have been designed were of low dynamical order. The LMI approach...
Using the results of the linear sub-state estimation and of the linear matrix inequality (LMI), we develop a Luenberger low — order unknown input observer/controller, which gives full unbiased state estimation and H∞ disturbance attenuation. This method is designed in a nonstandard case: an output-disturbance free system, it's based on the bounded real lemma, and the resultant design algorithms are...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.