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- Localization system for pedestrians based on sensor and information fusionPublication . Anacleto, Ricardo; Figueiredo, Lino; Almeida, Ana; Novais, PauloNowadays there is an increase of location-aware mobile applications. However, these applications only retrieve location with a mobile device's GPS chip. This means that in indoor or in more dense environments these applications don't work properly. To provide location information everywhere a pedestrian Inertial Navigation System (INS) is typically used, but these systems can have a large estimation error since, in order to turn the system wearable, they use low-cost and low-power sensors. In this work a pedestrian INS is proposed, where force sensors were included to combine with the accelerometer data in order to have a better detection of the stance phase of the human gait cycle, which leads to improvements in location estimation. Besides sensor fusion an information fusion architecture is proposed, based on the information from GPS and several inertial units placed on the pedestrian body, that will be used to learn the pedestrian gait behavior to correct, in real-time, the inertial sensors errors, thus improving location estimation.
- Step count algorithm adapted to indoor localizationPublication . Terra, Rui; Figueiredo, Lino; Barbosa, Ramiro; Anacleto, RicardoThis paper presents a step count algorithm designed to work in real-time using low computational power. This proposal is our first step for the development of an indoor navigation system, based on Pedestrian Dead Reckoning (PDR). We present two approaches to solve this problem and compare them based in their error on step counting, as well as, the capability of their use in a real time system.
- Shopping center tracking and recommendation systemsPublication . Anacleto, Ricardo; Luz, Nuno; Almeida, Ana; Figueiredo, Lino; Novais, PauloShopping centers present a rich and heterogeneous environment, where IT systems can be implemented in order to support the needs of its actors. However, due to the environment complexity, several feasibility issues emerge when designing both the logical and physical architecture of such systems. Additionally, the system must be able to cope with the individual needs of each actor, and provide services that are easily adopted by them, taking into account several sociological and economical aspects. In this sense, we present an overview of current support systems for shopping center environments. From this overview, a high-level model of the domain (involving actors and services) is described along with challenges and possible features in the context of current Semantic Web, mobile device and sensor technologies.
- Providing location everywherePublication . Anacleto, Ricardo; Figueiredo, Lino; Novais, Paulo; Almeida, AnaThe ability to locate an individual is an essential part of many applications, specially the mobile ones. Obtaining this location in an open environment is relatively simple through GPS (Global Positioning System), but indoors or even in dense environments this type of location system doesn't provide a good accuracy. There are already systems that try to suppress these limitations, but most of them need the existence of a structured environment to work. Since Inertial Navigation Systems (INS) try to suppress the need of a structured environment we propose an INS based on Micro Electrical Mechanical Systems (MEMS) that is capable of, in real time, compute the position of an individual everywhere.
- Person Localization Using Sensor Information FusionPublication . Anacleto, Ricardo; Figueiredo, Lino; Almeida, Ana; Novais, PauloNowadays the incredible grow of mobile devices market led to the need for location-aware applications. However, sometimes person location is difficult to obtain, since most of these devices only have a GPS (Global Positioning System) chip to retrieve location. In order to suppress this limitation and to provide location everywhere (even where a structured environment doesn’t exist) a wearable inertial navigation system is proposed, which is a convenient way to track people in situations where other localization systems fail. The system combines pedestrian dead reckoning with GPS, using widely available, low-cost and low-power hardware components. The system innovation is the information fusion and the use of probabilistic methods to learn persons gait behavior to correct, in real-time, the drift errors given by the sensors.
- Orientation system for people with cognitive disabilitiesPublication . Ramos, João; Anacleto, Ricardo; Costa, Ângelo; Novais, Paulo; Figueiredo, Lino; Almeida, AnaIn health care there has been a growing interest and investment in new tools to have a constant monitoring of patients. The increasing of average life ex-pectation and, consequently, the costs in health care due to elderly population are the motivation for this investment. However, healthmonitoring is not only important to elderly people, it can be also applied to people with cognitive disabilities. In this article we present some systems, which try to support these persons on doing their day-to-day activities and how it can improve their life quality. Also, we present an idea to a project that tries to help the persons with cognitive disabilities by providing assistance in geo-guidance and keep their caregivers aware of their location.
- Traveled Distance Estimation Algorithm for Indoor LocalizationPublication . Terra, Rui; Figueiredo, Lino; Barbosa, Ramiro S.; Anacleto, RicardoThis paper presents an ankle mounted Inertial Navigation System (INS) used to estimate the distance traveled by a pedestrian. This distance is estimated by the number of steps given by the user. The proposed method is based on force sensors to enhance the results obtained from an INS. Experimental results have shown that, depending on the step frequency, the traveled distance error varies between 2.7% and 5.6%.
- PSiS MobilePublication . Anacleto, Ricardo; Luz, Nuno; Figueiredo, LinoIn this paper, we present a state of the art on applications of mobile devices to support decision of a tourist running on a trip. We focus on two types of applications, tourism recommendation and tourism guide, making a brief description of the main characteristics of each one of them. We also refer the main problems encountered on the development of applications for mobile devices, and present PSiS (Personalized Sightseeing Tours Recommendation System) Mobile, our proposal to a mobile recommendation and planning support system, which is designed to provide an effective support during the tourist visit, providing contextaware information and recommendations about places of interest (POI) to visit, based on tourist preferences and his current context.
- Simulation and dynamics of freeway trafficPublication . Figueiredo, Lino; Machado, J. A. TenreiroThis paper presents the new package entitled Simulator of Intelligent Transportation Systems (SITS) and a computational oriented analysis of traffic dynamics. The SITS adopts a microscopic simulation approach to reproduce real traffic conditions considering different types of vehicles, drivers and roads. A set of experiments with the SITS reveal the dynamic phenomena exhibited by this kind of system. For this purpose a modelling formalism is developed that embeds the statistics and the Laplace transform. The results make possible the adoption of classical system theory tools and point out that it is possible to study traffic systems taking advantage of the knowledge gathered with automatic control algorithms. A complementary perspective for the analysis of the traffic flow is also quantified through the entropy measure.
- Application of Fractional Calculus in Control and ElectromagnetismPublication . Tenreiro Machado, J. A.; Barbosa, Ramiro; Jesus, Isabel S.; Silva, Manuel; Reis, Cecília; Figueiredo, LinoThis article illustrates two applications of fractional calculus (FC) in engineering. It has been recognized the advantageous use of this mathematical tool in the modeling and control of many dynamical systems. In this perspective, this paper investigates the use of FC in PID tuning and electrical potential.