Abstract

Abstract

Abstract
Sliding mode controllers are derived for the control of the average output voltage in DC/DC power converters. The controller design is carried out on the basis of well-known bilinear models of such circuits. A cascaded control structure is chosen for ease of control realization and to exploit the motion separation property of this power converter. The performance of the proposed sliding mode controllers is tested for the buck and boost converter type. The numerical simulations will demonstrate the efficiency of sliding mode techniques in this field as a powerful alternative to other existing methods. © 2003 IFAC.

Abstract
This paper describes a surveillance system for forest environments and protected natural areas. The surveillance system has a capacity for detecting fires and other ecological crimes. The system uses a digital camera that is controlled remotely by a system operator. Using the software the operator may choose to zoom a special spot or even take measures to strategically fight the fire right before it becomes uncontrollable. Since this system is operated in the middle of forests, aspects like effectiveness, robustness and reliability are crucial. In positioning the camera, the system uses a stepper motor for the vertical movement of the camera and a DC motor for the horizontal movement. The system also captures information about the temperature, humidity, wind speed and direction. All the processing is realized by a PIC16f877 microcontroller. © 2003 IEEE.

Abstract
A new online identification methodology for estimation of the rotor flux components and the main electrical parameters of vector controlled induction motors is presented in this paper. The induction motor model is referred to the rotor reference frame for estimation of rotor flux and rotor parameters, and referred to the stator reference frame to estimate stator parameters. The stator parameters estimation is achieved by a prediction error method based on a model structure described by a linear regression that is independent of rotor speed and rotor parameters. The rotor flux components and rotor parameters are estimated by a reduced order extended Kalman filter, using a 4th-order state-space model structure where the state equation is described by matrices that are diagonal and independent of rotor speed as well as stator parameters. Both methods work in a boot-strap manner. © 2003 IEEE.

Abstract
In this article, we propose a linear parameterization (LP) for representing the friction in the tire-road interface, suitable for on-line Identification. This model was obtained by employing function approximation techniques, which results in an optimization problem to minimize the fitting error between the LP and the nonlinear Burckhardt model. Compared with others LPs proposed in the literature, the optimal LP features a reduced number of parameters and good approximation capabilities. Moreover, the proposed model can be identified though linear Identification techniques, simplifying the on-line peak friction estimation. Simulation results obtained with a vehicle simulator demonstrates the effectiveness of the proposed parameterization. © 2011 IFAC.