Generalized immersion and nonlinear robust output regulation problem

summary:The problem of output regulation of the system affected by unknown constant parameters is considered here. Under certain assumptions, such a problem is known to be solvable using error feedback via the so-called immersion to an observable linear system with outputs. Nevertheless, for many interesting cases this kind of finite dimensional immersion is difficult or even impossible to find. In order to achieve constructive procedures for wider classes, this paper investigates a more general type of immersion. Such a generalized immersion enables to solve robust output regulation problem via dynamic feedback compensator using error and exosystem state measurement. When the exosystem states are not completely measurable, a modified observed-based generalized immersion is then presented. The main result obtained here is that under reasonable assumptions both the full and partial exosystem measurement problems are equivalently solvable. Examples together with computer simulation are included to clarify the suggested approach

Dynamic Control Applied to a Laboratory Antilock Braking System

The control of an antilock braking system is a difficult problem due to the existence of nonlinear dynamics and uncertainties of its characteristics. To overcome these issues, in this work, a dynamic nonlinear controller is proposed, based on a nonlinear observer. To evaluate its performance, this controller has been implemented on an ABS Laboratory setup, representing a quarter car model. The nonlinear observer reconstructs some of the state variables of the setup, assumed not measurable, to establish a fair benchmark for an ABS system of a real automobile. The dynamic controller ensures exponential convergence of the state estimation, as well as robustness with respect to parameter variations

Power Line Inspection Via an Unmanned Aerial System Based on the Quadrotor Helicopter

The inspection of high voltage power transmission lines is mainly carried out by manned aerial vehicles or foot patrol. However, these maintenance methodologies for inspection are somehow inefficient and expensive. Moreover, helicopter assisted inspection endangers the human life. Recently, unmanned aerial vehicles have been under development in several research centers all over the world due to its potential applications. In this paper, we present an unmanned aerial system based on the quadrotor helicopter for high voltage power line inspection. Our interest is to equip the quadrotor helicopter with the necessary payload in order to be able to carry out a qualitative inspection, therefore the hardware architecture of the aerial robotic system is presented. Finally, some experimental results are shown to demonstrate the feasibility of the proposed system.ITESO, A.C

Robust Tracking of Bio-Inspired References for a Biped Robot Using Geometric Algebra and Sliding Mode Control

Controlling walking biped robots is a challenging problem due to its complex and uncertain dynamics. In order to tackle this, we propose a sliding mode controller based on a dynamic model which was obtained using the conformal geometric algebra approach (CGA). The CGA framework permits us to use lines, points, and other geometric entities, to obtain the Lagrange equations of the system. The references for the joints of the robot were bio-inspired in the kinematics of a walking human body. The first and second derivatives of the reference signal were obtained through an exact robust differentiator based on high order sliding mode. The performance of the proposed control schemes are illustrated through simulation.ITESO, A.C

Robust Tracking of Bio-Inspired References for a Biped Robot Using Geometric Algebra and Sliding Modes

Controlling walking biped robots is a challenging problem due to its complex and uncertain dynamics. In order to tackle this, we propose a sliding mode controller based on a dynamic model which was obtained using the conformal geometric algebra approach (CGA). The CGA framework permits us to use lines, points, and other geometric entities, to obtain the Lagrange equations of the system. The references for the joints of the robot were bio-inspired in the kinematics of a walking human body. The first and second derivatives of the reference signal were obtained through an exact robust differentiator based on high order sliding modes. The performance of the proposed control scheme is illustrated through simulation.CINVESTA

Multi-mode Flight Sliding Mode Control System for a Quadrotor

There is a wide range of applications for unmanned aerial vehicles that requires the capability of having several and robust flight controllers available. This paper presents the main framework of a multimode flight control system for a quadrotor based on the super twisting control algorithm. The design stages for the four flight control modes encompassing manual, altitude, GPS fixed and autonomous mode are presented. The stability proof for each flight mode is carried out by means of Lyapunov functions while the stability analysis for the complete system, when a transition from one mode to another occurs, is demonstrated using the switching nonlinear systems theory. The performance of the proposed framework is demonstrated in a simulation study taking into account external disturbances.ITESO, A.C.CINVESTAV-IP

Los robots ¿para qué sirven?

Bernardino Castillo-Toledo es doctor en ciencias por la Universidad de Roma “La Sapienza”, e Investigador nivel II del Sistema Nacional de Investigadores.Sus líneas de investigación principales son el análisis y síntesis de estructuras de control para sistemas no lineales, y la aplicación de esos esquemas al control de procesos químicos y control de robots. En esta charla aborda las definiciones de robótica y las funciones de los robots, en orden de sustituir tareas repetitivas que realizan los humanos. Duración de la grabación: 1:05:28

Café Scientifique

Bernardino Castillo-Toledo es doctor en ciencias por la Universidad de Roma “La Sapienza”, e Investigador nivel II del Sistema Nacional de Investigadores.Sus líneas de investigación principales son el análisis y síntesis de estructuras de control para sistemas no lineales, y la aplicación de esos esquemas al control de procesos químicos y control de robots. En esta charla aborda las definiciones de robótica y las funciones de los robots, en orden de sustituir tareas repetitivas que realizan los humanos. Duración de la grabación: 1:05:28.ITESO, A.C

Tracking through singularities using sliding mode differentiators

summary:In this work, an alternative solution to the tracking problem for a SISO nonlinear dynamical system exhibiting points of singularity is given. An inversion-based controller is synthesized using the Fliess generalized observability canonical form associated to the system. This form depends on the input and its derivatives. For this purpose, a robust exact differentiator is used for estimating the control derivatives signals with the aim of defining a control law depending on such control derivative estimates and on the system state variables. This control law is such that, when applied to the system, bounded tracking error near the singularities is guaranteed

On the regulator problem for a class of LTI systems with delays

summary:This paper deals with the problem of tracking a reference signal while maintaining the stability of the closed loop system for linear time invariant systems with delays in the states. We show that conditions for the existence of a solution to this problem (the so-called regulation problem), similar to those known for the case of delay-free linear systems, may be given. We propose a solution for both the state and error feedback regulation