3) Affinity Propagation Clustering: In our system, we adopt Affinity Propagation Clustering (APC)  to improve the performance of fingerprinting method. The APC algorithm divides roughly the database (and so the localization area) into several parts (called clusters). It is a process done in the off-line phase, right after the database recording. Since we collect and build 4 RSSI databases for 4 directions (i.e. north, east, south and west), we apply APC to these databases individually to generate clusters for different directions. A cluster regroups several reference points. An exemplar is the most representative RP in the cluster. At beginning of this algorithm, we need to initiate a set of exemplars which are randomly chosen and refine this set to achieve a minimal sum of squared errors. Because the initial set of exemplars is randomly generated. It will take several trials to get a good clustering unless the initial set is very close to the optimal set. On the contrary, the APC algorithm views every RP as a node in a network and considers all RPs as potential exemplars. In the APC algorithm, clusters and exemplars are generated by passing real-valued messages between each RP in the database. More details can be found in .
28 1. State-of-the-art Characteristics of IndoorLocalizationSystems This problem is overcomed with UWB pulses because they allow to filter the reflected signals from the original one. In this way, the system can offer higher accuracy compared to traditional wireless technologies such as RFID and WLAN . This is clearly reflected in the Ubisense system, which achieves an accuracy of about 15 cm in 3D, considered very high compared to other RF positioning systems. The delay time of the position estimates is short and the sensing rate can reach 20 times per second. Unlike conventional RFID systems, which operate on a single band of the radio spectrum, UWB transmits a signal over several frequency bands simultaneously, from 3 .1 to 10.6 GHz. UWB signals are also transmitted for a much shorter time (less than 1 ns) than those used in conventional RFID . In addition, UWB tags consume less energy than conventional RF tags and can operate over a wide range of frequencies. UWB can be used in the immediate vicinity of other RF signals without causing or experiencing interference due to differences in signal types and the radio spectrum used. So using UWB technology in positioning systems has been a popular way to improve positioning accuracy. Therefore, UWB technology can be applied to fixed or moving indoor objects and people tracking and navigation, and can provide very high positioning accuracy.
National CIMS Engineering Research Centre, Tsinghua University, Beijing, China firstname.lastname@example.org, [henry.xue; weiming.shen; qi.hao]@nrc.gc.ca
Abstract—This paper proposes an architecture for integration
of indoorlocalizationsystems and decision support systems and/or manufacturing executive systems. In this paper, an indoorlocalization integration architecture is introduced under the scenario of an intelligent building localization system to uncover the relations among the necessary components and functions. Implementation details are also thoroughly explored, including class diagrams, work flows and the interface of the key component. The proposed architecture has the advantages of scalability and reconfigurability. In this architecture, different types of wireless sensors technologies including WiFi, ZigBee and RFID can be integrated simultaneously to support “smart environments”. Information from different data sources is transparent to information consumers (application systems), which means they can track “real” time position information of the interested assets in spite of the data sources. An application has been designed and implemented with the proposed architecture.
Continuous Movement Detection
4.1 Device-Free Movement Detection
As discussed in Chapter 3, we correlate the walking periods extracted from the ac- celerometer sensor with the motion from the device-free localization system. WiID takes as input a person’s location data over time. Then, we identify periods when the person was moving. We cannot simply take the velocity of the person, because the RF-based sensor registers any motion as movement. For example, a person waving his hands while sitting on the couch can be registered as a high speed motion. We use the diameter computation algorithm described in  to compute a metric indicative of the actual movement of the person. This provides a more robust metric of moving which does not suffer from the described problems.
indeﬁnite potentials in the continuum and on the lattice, without any regularity assump- tion on P. To the best of our knowledge, these would be the ﬁrst results with such generality, and they would imply new localization results; see , , , . For example, if P = ⊗ µ, then our estimates would allow to extend [70, Theorem 0.4] to dis- tributions µ which are merely log-Hölder continuous with a large exponent. The weakest regularity assumption so far is for lattice models in the large disorder limit, see , where the authors prove localization if µ is Hölder continuous. For continuous models, the only available results assume that µ admits a density µ = ρ(λ)dλ, with ρ of bounded variation. Note that a Wegner bound for sign-indeﬁnite potentials is also mentioned in , but since it relies on the method of , it has the same restrictions on c β and P.
While a complete classification of non-ergodic systems remains an open problem, it has recently been estab- lished that many-body localization [ 6 – 17 ] provides a ro- bust mechanism of ergodicity breaking in systems with quenched disorder. Many-body localized (MBL) systems are characterized by an extensive number of quasi-local conservation laws [ 13 , 14 ], which strongly restrict quan- tum dynamics and prevent energy transport and thermal- ization. MBL systems have universal dynamical prop- erties, such as the logarithmic-in-time growth of entan- glement entropy for initial product states [ 9 , 11 – 15 ], in contrast to ergodic and Bethe-ansatz-integrable systems where entanglement spreads linearly in time [ 18 – 20 ].
Fig. 1. Simplified multipath indoor 2D scenario
IV. P ROPOSED A LGORITHMS
In the following two algorithms will be described and then compared by simulations, namely the MAL and a modified version called extended MAL (eMAL). Both algorithms rely on an estimation tree and use a path-by-path approach, which seems a natural choice given the intrinsic separability of IR- UWB received signal. As a common prior stage, a database containing the expected received paths in the time domain is synthesized once and for all, according to the deterministic model described in . Indeed, the AoI domain [0, π 2 ] is considered as made up of N θ clusters indexing the waveforms
I. C ONTEXT
For the Agence Nationale de la Recherche (ANR)- Diréction Générale de l’Armement (DGA)-ASTRID project, several selected companies and laboratories compete each year during one week to test various solutions allowing fast deployment for indoor positioning: inertial systems, camera detection systems, and wireless measurement of distance. Three French laboratories (Femto-ST-Bsançon, IRIT-UT2J Toulouse, and LCIS-Valence) and two companies joined their efforts to design a new radio-based solution for an Indoor Positioning System (IPS). They combined IEEE 802.15.4 Impulse Radio Ultra-Wide Band (IR-UWB 6 to 6.5 GHz) with LoRa (868 MHz and 2.4 GHz) technology to cover various building topologies. For firefighter application, we propose to integrate radio modules in autonomous light sources elements deposited on the ground firefighters to indicate the path during the interventions. To obtain accurate information position, we propose to add localized beacon radio modules outside the building. Thus, firefighters will obtain orientation information from different beacons to find their way to the building exit in the absence of visibility . With a dedicated user interface supported by an industrial partner, we can collect wireless data to provide information to the operation task force leader which shows the position on a map for each firefighter in operation.
Abstract— This paper presents a use case for SLAM tech- niques applied to real time localization and detailed map- ping for emergency response personnel in non cooperative environments. Such environments tend to defeat conventional localization approaches, therefore we must ensure continuous operation of our localization and mapping regardless of the difficulties encountered (lack of GPS signals, lighting conditions, smoke, etc.). The proposed system fuses two SLAM algorithms, a LiDAR-based and a camera-based. Since LiDAR-based SLAM uses dense 3D measurements, it is well suited to the construction of a detailed map, while the visual SLAM allows to quickly recognize already visited places in order to apply loop closure corrections, by using a key frames graph. The currently proposed system allows collaboration between these two SLAMs through pose sharing and relocalization.
5 Locating in Crowdsourcing-based DataSpace As an effective measurement, RSS is easily available from various wireless signals which are from most off- the-shelf wireless equipment such as WiFi- or Bluetooth- compatible devices. And a large number of RSS-based indoorlocalization algorithms are proposed. However, considering RSS as a database to support indoor local- ization (e.g., RSS fingerprint space), it is time-consuming and labor-intensive. Especially, from extensive experi- ments, we observe that the RSS is vulnerable due to en- vironmental dynamism (an example is shown in Fig. 4(a)). How to avoid these weaknesses to improve the perfor- mance of RSS-based indoorlocalization? It is worth noting that the trend of RSS change is obvious between different locations (Figure 4(b)).
it possible to “lift” phase transitions from the ground state to the full spectrum . This obser- vation is at the heart of very recent investigations of new phases of matter inside the many-body localized phase .
Hence, in view of the increasing role played by localized Floquet systems in modern condensed matter physics, it appeared useful to bring some firm mathematical foundations to the theory of Anderson localization in periodically driven systems, even though the need for mathematical rigor forces us to restrict the setup to non-interacting particles. Results in this direction already appeared in , where the localization for some random unitary operators is established; this question is directly related to ours since the long time evolution of a periodically system is governed by the spectral properties of the unitary U (T ), where U (t) solves idU (t)/dt = H(t)U (t). However, for a Hamiltonian as in (1), we do not recover the particular form for U studied in . Before stating our results, we now introduce two more specific aspects that deserved clarifi- cation and motivated the present article.
Keywords-prototype; demonstrator; localization; positioning; time of flight; wireless sensor network; 802.15.4
In every layer of the OSI model, there are protocols and services which could benefit from knowing the current geographical position of the node in a network. Geographical routing in layer 3, content-display application in layer 7 are examples of such possibilities. Their existence has encouraged the scientific community to develop localization solutions which are precise even in areas where the GPS cannot be used, such as an indoor environment. These propositions are often studied through simulations and sometimes using a prototype. In this article, we introduce the results obtained first from a prototype, then from a homemade simulator. We will thus begin with a presentation of the existing testbeds and simulators. We will then discuss the tools used in this study. Finally, we will present and analyze the results obtained from both platforms.
composed of eight antenna elements. Data collection occurs in three scenarios: a static environment (SE), a dynamic en- vironment (DE) and a static environment where the target de- vice moves slightly and arbitrarily around its location (SA). A first finding is that the SA scenario performs as well as the SE one. This is promising for future deployment of CSI- based fingerprinting solutions. A second finding is that the localization accuracy improves as the number of antenna el- ements increases at the gateway in the SA scenario. We ex- tend the preliminary analyses to the study of unsupervised data complexity reduction (UDCR) methods. In doing so we introduce the principal component analysis (PCA), the factor analysis (FA), the independent component analysis (ICA), the kernel PCA (KPCA) and the kernel entropy component analysis (KECA) methods. We find that PCA and KCPA methods have low accuracy in the SE training scenario while the FA method provide good performances, whatever the data collection scenario. We then assess how difficult it is to improve the localization in the SA scenario with UDCR methods. Another outcome is that the FA and ICA meth- ods enhance the accuracy in direct relation with the number of antenna elements at the gateway. The KPCA and KECA methods show stable performances whatever the SIMO con- figurations. We also show how difficult it is to determine the best method, and hence define five heuristic scores to assess the accuracy and robustness of solutions in multiple exper- imental setups. The first score indicates the improvement of a method compared to a UDCR-free method. The sec- ond and third scores provide information about the stability of performances in all SIMO configurations. The fourth and five scores give the average performances for all the possible cases. Based on this multi-score evaluation, the implemen- tation of KECA method outperform the other approaches. Finally, the procedure is repeated in several training mesh grids (TMG). The last analysis proves that a UDCR-based solution with the KECA method delivers the best localiza- tion, regardless of the training mesh grid.
glare may result in the reduction of daylight and solar heat gains, which may therefore result in increasing seasonal building energy use. Previous studies for artificial lighting (13,15) showed that the discomfort glare rating is proportional to the luminance (or intensity) and size of the light sources, the light source position with respect to the line of sight, and the background indoor luminance. Glare from windows would depend, among other factors as above, on the luminance and size of the window and/or the outdoor light sources (7,16) . For clear window products, where the light direction of the source is not altered after transmission, the luminance (or intensity) and size of the outdoor sources become the driving factors for discomfort glare. In this case, the window product contributes to reduce the source luminance, and the window size may become irrelevant for light sources of smaller apparent size than the window. However, for fully diffuse window products where the light direction of the source is altered after transmission, the source size and its luminance are irrelevant as the window luminance becomes only dependent on the amount of lighting energy falling on it. In this case, the window may increase or reduce the luminance along the line of view to the outdoor source. The size of the window thus becomes an important
Physics Department, Queen’s University, Kingston, Ontario, Canada K7L 3N6
~Received 13 July 1999!
We demonstrate control of quantum dynamics in a finite model system described by a tight-binding Hamil- tonian, through interaction with a multifrequency external field. Effective defects can be introduced into the lattice by a two-frequency field, and the character of the defects can be controlled by the relative phase between the two field components. These field-induced defects imply robust localization of dressed ~Floquet! states on lattice sites. Implications for a spin system in crossed magnetic fields are discussed. @S1050-2947~99!51211-0# PACS number~s!: 42.50.Hz
vol. 52, p. 229-246, 2005.
uncertainty propagation process may produce oversized zones on the image plane. Since uncertainty grows as the distance browsed between two image acquisitions increases, this approach necessitates a high sampling rate. Moreover, it must be recalled that not every image acquisition provides sufficient information to accurately update the robot pose. An alternative approach has been adopted by Talluri and Aggarwal 1996. In this work, the localization problem is handled by introducing the notion of Edge Visibility Regions, which are equivalent to aspect graphs within the object-recognition domain. These regions are used to restrict the matching process to a small subset of features in the global model; an interpretation tree search method is then applied. For the global localization problem, a generalized Hough transform is implemented to select a small set of candidate regions. The investigation is unfortunately restricted to horizontal features representing rooftop edges. Conversely, Munoz and Gonzalez 1998 used only vertical-line correspondences and an interpretation tree search in order to determine the interpretation that maximizes the number of correspondence pairs. A restriction is introduced on the global model edges thanks to dead- reckoning pose estimation. The geometric constraint added to eliminate false correspondences is based on the order of model vertices stored in a circular list and involves identifying the order of appearance of corresponding segments on the image. Confining the search to a particular category of segments constitutes a real shortcoming in the indoor application. One disadvantage of model-based localization is in fact the required minimum number of distinguishable features eligible to be used for matching. Eliminating some of the environmental features would not seem to be a wise strategy, especially when the reliability of a matching result is correlated with the number of correspondence pairs.
geolocalized by divers. The sonar images provided by the robot are distorted and strongly noised. The reader will be convinced that the image processing step, required to detect the point of interest for localization, is a highly complicated task: see Figure 5.2b. Considering the problem from a temporal point of view would allow a simpler resolution and guaranteed results. It is indeed easier to segment the wreck image from the seabed and thus to obtain a reliable envelope of the wreck. This way, we ensure to enclose the point of interest within a measurement box [t] × [ρ], where [t] is the time interval during which the robot has seen the wreck. This example shows how a classic robotic application can be related to strong time uncertainties. The current chapter is a first step towards new state estimation approaches that will focus on both the time and the state spaces. It proposes a theoretical basis to deal with the former in the most generic way and is illustrated by reproducible examples in order to highlight the interest and simplicity of the method and encourage further comparisons. Finally, the developed tools will be used in Chapter 7 for a new reliable SLAM method.
The need for localization is not just confined to people or vehicles in outdoor environments, where Global Navigation Satellite System (GNSS) plays an impor- tant role for this purpose and is recognized to be the legacy solution. However, accurately estimating loca- tion indoors relying only on GNSS signals remains a difficult problem, mainly because of signal blockage or severe attenuations. Because of the advent of location- based services (LBS) and the multiple technologies available for indoor solutions, there exists an actual
Concerning RCS, since project partners (AL, UU, CCS, CEA) are also members to the ISO committees, they will push forward for that Hyindoor recommandations will be implemented in the new international norms.
Concerning the scientific perspectives, the consortium has identified some remaining research gaps that still have to be filled. These gaps are the comprehensive design of forced ventilation systems, the structural response of structures (containers for example) to internal explosions, the prediction of the consequences for vented explosion in realistic conditions (vent panel deployment, non homogenous hydrogen distribution, initial turbulence...) and the reliable use of CFD in risk assessment. The consortium partners have already submitted and will submit some project proposals to European and national funding institutions to perform the pre-normative research on these still open research gaps.