This
paper is all about a system of indoor navigation on the basis of Wi-Fi
fingerprint localization and multi-destination path planning.
In
the start, it has been described that the demand of navigation systems has been
increasing due to the broad use of mobile communication and mobile devices
technology. In navigation systems, the crucial tasks are route planning and
positioning. In terms of outdoor environments, GPS or Global Positioning System
has been actually used widely as it can offer reliable positions. Its service,
however, is limited greatly in environments which are indoor. In recent years,
IPS or Indoor Positioning System has taken a challenging form. On several
technologies like Wi-Fi, Zig bee, Bluetooth, and RFID, the present indoor
positioning systems are based. Among the technologies which are mentioned,
Wi-Fi IPS is considered one of the greatest studies because of the presence of
several access points of Wi-Fi, specifically in environments of indoor and the
ease of a receiving module of Wi-Fi which is developed in all devices of mobile
(Kannan, Meneguzzi, Dias, & Sycara, 2013).
Piggybacking
information is used in the system in addition to the present system with almost
no additional modification to the environment of indoor. The Wi-Fi fingerprint
that includes the signal features or characteristics is usually used,
specifically on the basis of fingerprint on RSS or Received Signal Strength. Although
the strength of signal can be impacted by shadowing and multi-path influenced
by diffraction, scattering, and reflection, for each position, the fingerprint
is different it can be no doubt a good source for positions. Performed phases
are two: localization and training. In the phase of training, a map of
fingerprint is designed by collecting the vector of RSS achieved from the APs
which are nearby at each and every point of reference in the selected sector. In
the phase of positioning, it is more or less a task for identifying the
position which is targeted. The issue can be considered a classification of
multi-class. For identifying the needed positioning, many methods can be used
like the KNN or k-nearest neighbor, SVM or Support mixture model, Naïve Bayes
Classifier, statistical Gaussian mixture model, and WKNN or weighted KNN (Fallah, Apostolopoulos, Bekris, & Folmer, 2013).
The
theme of KNN is to select fingerprints with k shortest distance in the database
in comparison with the measured fingerprint. Moving on, the position result is
the k-nearest location’s average coordinate. But if the APs which are k-nearest
are scattered, large errors will be caused by it in the result of positioning.
By using the calculated weights from the RSSI distance inverse can minimize the
error. But limited reference points with WKNN cannot always obtain the accuracy
which is required for the reason similar as the easy and simple KNN. For
estimating the positioning, SVM was presented by finding the most suitable
hyperplane that seems to separate fingerprints of one from the other class. The
method of bilinear median interpolation was actually applied for reducing the
calibration on the designing of fingerprint map. On the basis of fingerprint
classification, Naïve Bayes has the nature of probabilistic which has actually
been proven for being effective to handle RSS’s time variation. The new data
point is associated to the class with probability that is highest.
Moving
further, it has been explained that in the paper, the presented indoor system
of navigation is described by the authors which actually permits navigation of
multi-destination with the path using A* algorithms and 2-opt that is
automatically updated with the fingerprint positioning of Wi-Fi. Localization
and path planning have been integrated for providing find navigation solution
with precise prediction. The user can detour any time and is permitted to
specify various destinations. A position coordinate is provided by the Wi-Fi
IPS which determines the position of user. It can be said that path finding is
presented for organizing almost all destinations for forming the path route
which is the shortest. Whenever the position of user is out of the route which
is predefined, it will be activated again for navigation refinement and route
updating.
In
the second section of the paper, proposed algorithms have been described. 3
main and important components are included in the system architecture: Route
Updating, Multi-destination Path Planning, and IPS or Indoor Positioning
Service. At the beginning, an outline is offered by the user including
destinations in a good number to the server. Moving on, Multidestination path
planning is performed by the server that finds the route consisting of
destination as per the requirements of the user and offers the outcome to the
portable device of the user. In the process of tour, the Wi-Fi signal is
continuously sensed by the portable device while retrieving the position of the
user from the IPS. Whenever it is detected by the system that the user is
detouring from the predetermined route, the report is automatically sent to the
server by the portable device for a brand new route.
Moving
on in the third section of the paper, the indoor positioning service using the
localization of Wi-Fi fingerprint is explained. The service of indoor
positioning is more or less a module for estimating the current position of
user on the basis of RSS fingerprint of Wi-Fi where the connection between the
given location’s radio signature and its corresponding is also analyzed. In
every fingerprint, each AP’s RSS information is contained and fingerprints from
the given location has a combination that is unique in comparison with map
fingerprints. Again, the issue can be considered as a classification of
multi-class. The presented methods of classification can be classified into two
classes or groups: Probabilistic and deterministic algorithms. In the algorithm
which is deterministic, the measured point’s RSS fingerprint in the database
with the minimal signal of statistical distance between the detected vector of
location and itself is usually regarded as the location estimation that is
best. The methods of nearest neighbor are recognized as examples of the
algorithms which are deterministic on the basis of Manhattan distances’
statistical distance computation. In the algorithm that is probabilistic,
probability inferences are utilized for determining the possibility of the
given location’s occurrence on the basis of conditional probability
distribution in the database of reference.
Further,
it has been explained that the classifier of Naïve Bayes is selected as the
classification of probabilistic based fingerprint. More or less it is the
simplest form of network classifier of Bayes that is a learning algorithm which
is supervised on the basis of stochastic model with the independent features
assumption. Regardless of its simple nature, it is less responsive or sensitive
to RSS time variation, no estimation of iterative parameter with easy building
which is quite useful for the dataset which is large and frequently exceeds in
terms of performance compared to sophisticated classifiers.
In
the end, it has been concluded that the system of indoor navigation has been
presented on the basis of fingerprint positioning of Wi-Fi RSS and a mix of A*
and 2-opt algorithms for path finding of multi-destination. Localization and
path planning are integrated by it for flexibly navigating users to their
several destinations even when a user takes another route. It has been
determined that the demand of users on the indoor navigation service can be met
by the presented service while improving the experiences of indoor, therefore
decreasing time of search for the position that is required.
References of Multi destination Indoor Navigation Critical Analysis
Fallah, N.,
Apostolopoulos, I., Bekris, K., & Folmer, E. (2013). Indoor human
navigation systems: A survey. Interacting with Computers, 25(1), 21-33.
Kannan, B., Meneguzzi,
F., Dias, M. B., & Sycara, K. (2013). Predictive indoor navigation using
commercial smart-phones. Proceedings of the 28th Annual ACM Symposium on
Applied Computing, 519-525.