José Ignacio Suárez

Fractional PID Controllers for Industry Application. A Brief Introduction

In recent years the increasing amount of work related to the application of Fractional Calculus (FC) is remarkable in many areas of science and engineering. In relation to automatic control, the use of Fractional Order Control (FOC) needs, for real applications, to develop methods for controller design and parameter tuning, and efficient strategies for controller implementation. On the other hand, the Proportional Integral Derivative (PID) controller is currently by far the most widely used form of feedback controller in industrial applications. This paper, after an introduction to FC and FOC, briefly presents methods for fractional PID controller tuning, including auto-tuning, and some software and hardware strategies for efficient implementations of controllers in industrial applications.

A Fractional Adaptation Scheme for Lateral Control of an AGV

Lateral control of an autonomous guided vehicle is influenced strongly by both the longitudinal speed and the position input command (magnitude of the reference signal) of the vehicle. For that reason some suitable strategies for governing the vehicle are adaptive and robust controllers. In this article, an adaptive scheme which combines a model reference approach with a fractional order adjustment rule for a feedforward gain adjustment is proposed. Two parameters can be tuned to obtain robustness with respect to variations in speed and magnitude of the reference signal: Adaptation gain, and derivative order of the adjustment rule. A model is developed for the vehicle, the design procedure is discussed, and simulation results are obtained to show the advantages the proposed fractional adaptation scheme.

Electronic Nose Based on Independent Component Analysis Combined with Partial Least Squares and Artificial Neural Networks for Wine Prediction

The aim of this work is to propose an alternative way for wine classification and prediction based on an electronic nose (e-nose) combined with Independent Component Analysis (ICA) as a dimensionality reduction technique, Partial Least Squares (PLS) to predict sensorial descriptors and Artificial Neural Networks (ANNs) for classification purpose. A total of 26 wines from different regions, varieties and elaboration processes have been analyzed with an e-nose and tasted by a sensory panel. Successful results have been obtained in most cases for prediction and classification.

A FRACTIONAL ADAPTATION SCHEME FOR LATERAL CONTROL OF AN AGV

Abstract The lateral control of an autonomous guided vehicle (AGV) is highly in‡uenced both for the longitudinal speed and the position input command (magnitude of the reference signal) of the vehicle. For that reason, a suitable strategy to govern the vehicle would be to use an adaptive and robust controller. In this paper an adaptive scheme is proposed which combines a model reference approach and a fractional order adjustment rule for a feedforward gain adjustment. Two parameters can be tuned to obtain robustness against speed and magnitude of the reference signal variations: adaptation gain, and derivative order of the adjustment rule. A model is developed for the vehicle, the design procedure is exposed, and simulation results are obtained to show the advantages of using the proposed fractional adaptation scheme.

Using Fractional Calculus for Lateral and Longitudinal Control of Autonomous Vehicles

Here it is presented the use of Fractional Order Controllers (FOC) applied to the path-tracking problem in an autonomous electric vehicle. A lateral dynamic model of a industrial vehicle has been taken into account to implement conventional and Fractional Order Controllers. Several control schemes with these controllers have been simulated and compared . First, different controllers with similar parameters have been implemented and then they have been improved by using optimization methods. The preliminary results are presented here.

Acoustic local positioning system using an iOS device

This work benefits from the capability of the iPhones or iPads microphone to acquire high-frequency sound for accurate acoustic code identification. Although the maximum theoretical value for the frequency response of the built-in iOS device microphone is 20 kHz, emissions with frequencies close to 22 kHz have been experimentally detected. The frequencies used in this work are in the range from 18 to 22 kHz, which are high enough to be inaudible for almost every people but low enough to be generated by standard sound hardware. The aim of this work is to develop an inexpensive indoor positioning system where the user gets its location by using an iOS devices microphone. For this purpose a third-generation iPad is used for high-frequency sound data acquisition and neither external acquisition system nor ultrasonic microphone are required. The capability of iOS devices to acquire acoustic signals in the vicinity of 20 kHz has been successfully demonstrated. This fact allows the use of this kind of device for acoustic code detection and accurate positioning by means of multilateration.

GPC strategies for the lateral control of a networked AGV

The performance of a Networked Control System (NCS) is affected directly and indirectly by transmission time delays and data losses in the communications network. Based on the communications network model, this paper presents the validity of two different predictive control strategies and the study of the network effects on the lateral (guidance) control of an Autonomous Guided Vehicle (AGV) in the presence of sensor noise. Simulation results are presented to validate the proposed strategies.

On-line classification of pollutants in water using wireless portable electronic noses.

A portable electronic nose with database connection for on-line classification of pollutants in water is presented in this paper. It is a hand-held, lightweight and powered instrument with wireless communications capable of standalone operation. A network of similar devices can be configured for distributed measurements. It uses four resistive microsensors and headspace as sampling method for extracting the volatile compounds from glass vials. The measurement and control program has been developed in LabVIEW using the database connection toolkit to send the sensors data to a server for training and classification with Artificial Neural Networks (ANNs). The use of a server instead of the microprocessor of the e-nose increases the capacity of memory and the computing power of the classifier and allows external users to perform data classification. To address this challenge, this paper also proposes a web-based framework (based on RESTFul web services, Asynchronous JavaScript and XML and JavaScript Object Notation) that allows remote users to train ANNs and request classification values regardless users location and the type of device used. Results show that the proposed prototype can discriminate the samples measured (Blank water, acetone, toluene, ammonia, formaldehyde, hydrogen peroxide, ethanol, benzene, dichloromethane, acetic acid, xylene and dimethylacetamide) with a 94% classification success rate.

Cooperative maneuver study between autonomous cars: overtaking

This research studies the overtaking maneuver in some representative situations. A simulator using Matlab Simulink connecting its outputs to a Virtual Reality module to show the complete overtaking performance from all points of view has been made. With this useful tool the parameters of the car controllers and decision making systems can be set up, and unforeseen new features of the overtaking maneuver can also be taken into account.

Effects of a communication network on the longitudinal and lateral control of an AGV

The performance of an networked control system (NCS) is affected directly and indirectly by transmission time delays and data losses in the communications network. This paper presents the modelling of main problems of a communications network in an NCS, and the study of their effects on the longitudinal (velocity) and lateral (guidance) control of an autonomous guide vehicle (AGV). The results are compared to the embedded control system (ECS) case considered as reference for performances.