Spatial navigation includes organization, acquirement, utilization and reconsideration of knowledge about various spatial environments. The main concern regarding spatial navigation lays stress on finding and modelling natural navigation systems utilized in presenting and Processing spatial information and on the concerned navigation problems. There are several research projects like:
1. Practical investigations on human spatial navigation capabilities.
2. Theoretical investigations on limitations to various approaches in order to represent and process spatial knowledge.
3. Implementing and presenting various different schemes and considering them with regards to their biological perspective.
4. Thoroughly investigating the possibilities of applying the concept of spatial navigation to a network of various computer systems.
All the above mentioned approaches/ investigations carry some relation to each other directly or indirectly.
One can easily identify various types and representations of spatial data in systems navigating in complex environment around us. Spatial navigation is nothing but a pathway or route and hence one of the most vital distinction and a research level concern is the landmark and survey information about a particular environment. Landmarks are nothing but distinct objects placed at fixed routes and locations. The survey data helps to integrate information available from different sources to form a single model.
According to a workshop organized in 1997, known as Gottingen workshop, all these concepts of landmark, pathways, routes and survey knowledge were utilized to fetch the underlined concepts
In robot navigation and theories and concepts related to human navigation
In order to liquefy communication between all these concepts, a common term known as a hierarchical taxonomy was designed, developed on the concept of navigational behaviours for higher level concepts. The model is basically a network/framework of results and investigations with respect to navigational performance. Initially, two distinct settings need to be notified:
1. Open or closed space.
2. A network of passages.
Spatial navigation exhibits different characteristics with respect to designated passages such as junctions as well as for flowing passages. A junction is basically one point of decision making. Several characteristics views depend on one’s decision of choosing a particular passage. Such views are made on the basis of visible localized landmarks such as objects, smells, noises etc.
Let us quote an example to understand this better. In a model based on spatial navigation proposed by Poucet, in1993, he sets up a hierarchy of three distinct stages in order to represent an environment. Initially, several place representations are formed, each with a different reference name. Moving ahead, several place representations are connected together with their initial reference frames. It’s only later that different place representations are replaced by a common system of reference. Needless to say, all these different stages imply different forms of behaviours.
INITIAL SOLUTION 1:
The use of internet is accompanied with World Wide Web (www) which is experiencing a rapid growth these days. Keeping in mind the user goals and limitations, we will talk about an easy way to help users to navigate through the World Wide Web spatially with the help of a spatial user interface in a virtual environment. This method is dedicated to assist users to arrange themselves in the huge chunk of available information. The concept of spatial navigation lays stress on the fact that structure of the available space is made unique in this type of navigation.
. Spatial grouping in this system
was done by the users and often signified topical closeness.
According to this procedure, we analyze common spatial navigation techniques on the world wide web and figure out how these techniques utilize the defined structure of information space. When hypertexts are used, they tend to hide their unique structures whereas we define navigational differences between physical environments and hypertexts and thus devise a strategy to combine the benefits of both.
As a live example, we have taken data from the current implementation of such a technique at the Georgia Institute of Technology, where an environment in the form of texts and visuals is added to the world wide web in order to create a mirror like space. Such a system compliments interaction between different users and hence enables collaborative spatial navigation. This also allows room for organizing tours and guiding paths to available data similar to a real environment.
We often use web pages in the form of user interfaces to access the available data. Such interfaces have to be created keeping in mind the navigational needs in order to provide essential pathways carrying information. This adds a real life touch to the web pages and the planner has to keep in mind the user navigational needs in order to provide functional routes.
In order to support such a navigation technique, it is important not only to define a visible structure but it is equally important to mention additional data about landmarks and destinations. Most web browsers indicate if a particular user has been to a link already. The additional data to be quoted includes object size, network connection speed which is directly related to the geographical location of the object etc. Another example of a world wide web (www) browser is the audible web system and its role is to transfer additional information with the help of sound cues.
INITIAL SOLUTION: 2
The second proposed solution to the problem of spatial navigation is the concept of navigating wheelchair. An electric wheelchair is laid with a personal computer and sensors to support the platform. The 3-D structure of the images is pasteurised through a camera that is laid with a technique known as “structure from motion”. The 3D information is utilized to extract out features such as edges and corners. A mingle of these features is used in the form of paths and landmarks. Currently, we utilize only the artificial 2D marks well recognized by image processing algorithms.
A multi layer design structure for controlling the wheelchair system has been chosen. Such architecture is strongly supported by models through several discussions carried out within the DFG vital program. There are three levels in it namely:
1. Survey Knowledge
2. Basic behaviours and
3. Path Knowledge
Various forms of basic behaviours like following the wall and turn in door form the foundations of the navigation techniques. This makes possible the wheel chair to move freely across the corridors and to enter or leave any existing rooms. Such basic behaviours are extremely flexible against environmental changes. Once a route is indicated from the starting position, a route guides a static path for the wheelchair to drive at the amalgamation point of all the basic behaviours. Routes also perform the task of initiating the start and modification of such behaviours. Hence, routes are referred to as a list of behaviours and route marks as initiators of such behaviours. Now, there comes a stage where representation of data becomes complex. It is when the route marks are not seen and are accompanied with a level of uncertainty. As a solution to this issue, the more expected routes can be pointed out with a greater possibility than less expected ones and since marks are assigned in a particular series, it becomes easy to record them and support one other in the recognition procedure.
The third step of the procedure constitutes survey knowledge where the spatial navigation between routes is presented. With the help of this knowledge, new routes and shortcuts can be devised from the multiple ones. It is easily recognizable by the wheelchair routes are inter-related and that same sequence of routes can exists in multiple routes. Such cluster of routes can be combined together to get a graphical structure to be used as shortcuts and bypassing elements moving around hindrances. However, if there is no information available, one can propose to integrate dead reckoning to the strategy in order to explore new shortcuts and bypasses.
ASSET DESIGN AND PLAN:
Shopping Mall metaphor
Through this section, we make use of a shopping mall metaphor to implement the proposed system. The task of the mall is to spatially navigate a hotlist topic wise. The respective arrangement is as per the subject and to the detailed level mentioned in each subject. The mall makes use of a spatial metaphor but the sub sections make use of more physical space in the form of tabs like “next” and “previous”. Several levels of the mall are connected via an elevator. Each level has specified departments and there are a couple of rooms at each level for the user to be able to navigate for more information. Let us analyze a short description of a room here with the help of a web page.
Look
This signifies the entrance point of the URL mall. There are several different levels in the mall with each level consisting of multiple departments. There are pointers to point to a specific topic at each level. When you walk through the departments, the system will navigate you through the connected web pages. There are more specific web pointers, as you move deeper in a department.
There are four departments in particular:
Hypertextdisplays general data related to hypertext
HTMLcarries information on HTML and the World Wide Web (WWW)
()> hyper
The Hypertext 1
With this, you enter the hypertext department. There is this link [mall] that leads you back to
the entrance of the mall, and the links [next] and [prev] lead you to the
previous or next room in the same sequence in order. [first] guides you to
the first (this) room in the series which signifies the URL of the "World Wide Web FAQ". This FAQ is dedicated to answer most typical beginner questions.
> next
The Hypertext 2
()
This room helps you to link to the introductory information regarding how to launch
One’s own Web pages. Further these department rooms provide links to tools in order to make this task easier.
> first
The Hypertext 1
Now, you are in the hypertext department. The link [mall] takes you back to
the entrance of the mall.
