P. Ruipérez

Virtual and remote control labs using Java: a qualitative approach

This article describes a new way of teaching adopted at the Universidad Nacional de Educacion a Distancia (UNED) that uses dynamic and interactive simulations in a stand-alone or Web-based environment to permit control engineering students to do practical work at a distance. The article focuses on how this new stand-alone experimentation environment maintains a clear separation between the graphical experimentation interface, developed in Java, and the math and simulation engine. By constructing the environment in this fashion, the math engine can be replaced with a different one or with a real plant, or can even be ported to a remote server. A Web-based, multiuser virtual lab is also possible without the necessity of reprogramming the experimentation interface code. Other differences with respect to tools are the dynamic simulations, the user interactivity, the generation of new experiments as goals change, and the opportunity to practice with classical or advanced control strategies in different plants: a heat exchanger, a tank, a distillation column, or an inverted pendulum.

Identification of the Vertical Plane Motion Model of a High Speed Craft by Model Testing in Irregular Waves

Abstract Experiments in towing tanks are concerned with the determination of the motion transfer functions, which are obtained by testing in irregular waves. For this purpose a model of pitch and heave motions has been developed, and the identified models of the vertical plane motions of a high-speed craft are showed. Linear models are obtained for different sea states and ship speeds. A general low order model is obtained by pole-zero cancellation. So, a full model may be considered for simulation and verification, and a low order model for design. From the lowest order models, a state space model is obtained.

An Asynchronous, Robust, and Distributed Multisensor Fusion System for Mobile Robots

In this paper, a multisensor fusion system that is used for calculating the position and orientation of an autonomous mobile robot is presented. The developed fusion system is distributed, robust, and asynchronous. It is distributed to permit the parallel function of all the sensors. It is robust because, being distributed, the system has been designed to keep working properly in spite of the failure, removal, or change of any sensor. It is asynchronous to take advantage of the different features and rates of each sensor. The implementation of the system is based on the distributed Kalman filter developed by Durrant-Whyte and Rao. In that distributed filter, all the sensors work in parallel to obtain their own estimate based on their own observations and on the observations coming from other sensors. Changes have been made to simplify and speed up the computation of the external validation equations and to allow the use of any sensor model. The equations have also been adapted to deal with asynchronously operating sensors and with the existence of communication delays. The fusion system is used to estimate the position and orientation of a mobile robot. The performance of the fusion system is shown both under simulation and in a real test with a mobile robot.

Decreasing of the Motion Sickness Incidence by a Multivariable Classic Control for a High Speed Ferry

Abstract The decreasing of the motion sickness in a high speed ferry produces a greater passengers comfort and safety of the vehicle. The paper presents a comparative study of the decreasing of the motion sickness incidence in a high speed ferry using different multivariable classic controllers (PD, first order filter and second order filter). The tuning of the controllers is made solving a non-linear optimization problem. The tuning method uses first a genetic algorithm and then a classic non-linear optimization algorithm.

Modelling of a High Speed Craft by a Non-Linear Least Squares Method with Constraints

Abstract A non linear least squares method with constraints have been tried. However, the extra complexity associated with non-linear systems, with constrains and no initial information of model structure, means that exhaustive search is not always feasible. In these cases genetic identification strategy can be used to obtain initial values. On the other hand, a trend in the area of system identification is to try to model the system uncertainties to fit the available analysis and design tools of robust control. The method described is applied to obtain the interval model of the vertical dynamic of a high speed craft for different speed, and comparative results obtained with the mathematical model and with a scaled model in a towing tank are showed.

Conceptual Learning of Control by Java-Based Simulations

Abstract The combination of Java applications as graphical user interfaces and the Matlab-Simulink environment as the simulation engine seems to be a good solution for taking a particular control lab to distant students. In this paper, it is presented a new kind of simulation environment for qualitative teaching on concepts of Control Engineering by means of a suitable configuration of experiments by the tutor or teacher.

REDUCED-ORDER KALMAN FILTER FOR ALIGNMENT

The use of a full-order Kalman filter for the alignment process of an inertial navigation system (INS) imposes an unacceptable burden on computers. In this paper we intend to design and analyze a low-order Kalman filter for the initial alignment of a ring laser gyro strapdown inertial system that results in a substantially lighter computer burden with a little significant reduction in system accuracy.

Experimental and robustness analysis of a multivariable control for vertical dynamic of a high speed craft

This paper deals with post design robustness analysis of fast ferries vertical dynamic controllers, and experimental study of a PD multivariable control. First a PD multivariable control is designed, then we consider the discrepancy between the real system and the nominal design model. This discrepancy can be expressed as structured uncertainties by linear fractional transformations. These uncertainties include linearization errors and unmodeled dynamics. Finally we validate the design control by an experimental study.

Computer aided development and simulation of a remote control VTOL tiltwing model aircraft

This paper describes the computer aided development of a remote control tiltwing scale aircraft. Tiltwings --even scale models-- are difficult to fly by human pilots due to their instability and the different flying modes they exhibit. For this reason a complex flight simulation and training environment and an onboard control system (fly-by-wire) that increases stability have been developed. Modular design, both for hardware and software, has been kept in mind in order to modify the prototypes easily and use them as test-beds for new concepts and configurations.