scispace - formally typeset
Search or ask a question
Author

Rogelio Lozano

Bio: Rogelio Lozano is an academic researcher from University of Technology of Compiègne. The author has contributed to research in topics: Control theory & Adaptive control. The author has an hindex of 58, co-authored 496 publications receiving 14570 citations. Previous affiliations of Rogelio Lozano include University of Illinois at Urbana–Champaign & Instituto Politécnico Nacional.


Papers
More filters
Proceedings ArticleDOI
07 Dec 1999
TL;DR: In this article, a smooth control Lyapunov function for the ball and beam system is proposed, which relies on extensions of nonlinear control design techniques called backstepping and forwarding.
Abstract: A smooth control Lyapunov function for the ball and beam system is proposed. Its construction relies on extensions of nonlinear control design techniques called backstepping and forwarding. The smooth state feedbacks resulting from this approach yield closed-loop systems with strong robustness properties.

16 citations

Journal ArticleDOI
TL;DR: A dynamic model is derived employing the Newton–Euler approach and a nonlinear controller to stabilize, in closed-loop system, and to validate the theoretical results, a real-time embedded control system has been developed.
Abstract: In this paper, a vision based line tracking control strategy for mini-rotorcraft is presented. In order to estimate the 3-D position of the mini-rotorcraft over the trajectory a vanishing points technique is used. A dynamic model is derived employing the Newton---Euler approach and a nonlinear controller to stabilize, in closed-loop system, this mathematical model is proposed. To validate the theoretical results, a real-time embedded control system has been developed. The performance of the vision and control algorithms has been tested when the helicopter has tracked a line painted in a wall. The experimental results have shown the good behavior of the control laws.

16 citations

Journal ArticleDOI
TL;DR: In this paper, a straight-line following controller for a small and light airplane flying in windy conditions is proposed, where the lateral dynamics of the plane are derived and the error deviation velocity with respect to the desired trajectory is computed.
Abstract: A straight-line following controller for a small and light airplane flying in windy conditions is proposed. In a first time, the lateral dynamics of the plane are derived and the error deviation velocity with respect to the desired trajectory is computed. A simple nonlinear control law is developed in order to impose a linear behavior for the airplane position and to track the desired trajectory. Several simulations, taking into account quasi-constant wind disturbances, are performed to analyze the performance of the closed-loop system. Improved results are obtained including the airplane orientation to counter the wind as an input for the flight planning. In order to validate the proposed control scheme an airplane has been developed based on the classic aerodynamic layout. Future work will introduce the experimental results when applying in real-time the proposed control algorithm.

16 citations

Journal ArticleDOI
TL;DR: The designs, simulations and real-time experimental results of two energy-based control strategies to stabilize an Unmanned Aerial Vehicles (UAV) using a quaternion representation of the attitude using a logarithmic mapping in the quaternions space are presented.
Abstract: This article presents the designs, simulations and real-time experimental results of two energy-based control strategies to stabilize an Unmanned Aerial Vehicles (UAV) using a quaternion representation of the attitude. The mathematical model is based on Euler-Lagrange formulation using a logarithmic mapping in the quaternion space. The proposed solutions introduce a new approach: a quaternion-energy-based control, which use an energy-based expression defined as a Lyapunov function. The control laws are described with unit quaternions and their axis-angle representation. The proposed algorithms allow the stabilization of the quadrotor in all its states. The strategies ensure the stability of the closed loop system. Simulation results and experimental validations are developed to verify the effectiveness of the proposed controllers.

15 citations


Cited by
More filters
Journal ArticleDOI

[...]

08 Dec 2001-BMJ
TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

33,785 citations

Journal ArticleDOI
TL;DR: Some open problems are discussed: the constructive use of the delayed inputs, the digital implementation of distributed delays, the control via the delay, and the handling of information related to the delay value.

3,206 citations

Journal ArticleDOI
Arie Levant1
TL;DR: In this article, the authors proposed arbitrary-order robust exact differentiators with finite-time convergence, which can be used to keep accurate a given constraint and feature theoretically-infinite-frequency switching.
Abstract: Being a motion on a discontinuity set of a dynamic system, sliding mode is used to keep accurately a given constraint and features theoretically-infinite-frequency switching. Standard sliding modes provide for finite-time convergence, precise keeping of the constraint and robustness with respect to internal and external disturbances. Yet the relative degree of the constraint has to be 1 and a dangerous chattering effect is possible. Higher-order sliding modes preserve or generalize the main properties of the standard sliding mode and remove the above restrictions. r-Sliding mode realization provides for up to the rth order of sliding precision with respect to the sampling interval compared with the first order of the standard sliding mode. Such controllers require higher-order real-time derivatives of the outputs to be available. The lacking information is achieved by means of proposed arbitrary-order robust exact differentiators with finite-time convergence. These differentiators feature optimal asymptot...

2,954 citations

01 Nov 1981
TL;DR: In this paper, the authors studied the effect of local derivatives on the detection of intensity edges in images, where the local difference of intensities is computed for each pixel in the image.
Abstract: Most of the signal processing that we will study in this course involves local operations on a signal, namely transforming the signal by applying linear combinations of values in the neighborhood of each sample point. You are familiar with such operations from Calculus, namely, taking derivatives and you are also familiar with this from optics namely blurring a signal. We will be looking at sampled signals only. Let's start with a few basic examples. Local difference Suppose we have a 1D image and we take the local difference of intensities, DI(x) = 1 2 (I(x + 1) − I(x − 1)) which give a discrete approximation to a partial derivative. (We compute this for each x in the image.) What is the effect of such a transformation? One key idea is that such a derivative would be useful for marking positions where the intensity changes. Such a change is called an edge. It is important to detect edges in images because they often mark locations at which object properties change. These can include changes in illumination along a surface due to a shadow boundary, or a material (pigment) change, or a change in depth as when one object ends and another begins. The computational problem of finding intensity edges in images is called edge detection. We could look for positions at which DI(x) has a large negative or positive value. Large positive values indicate an edge that goes from low to high intensity, and large negative values indicate an edge that goes from high to low intensity. Example Suppose the image consists of a single (slightly sloped) edge:

1,829 citations