FIELD OF INVENTION:
This invention generally relates to a navigation system and method that can be tailored to a user's particular wishes.
PRIOR ART:
Due to ever increasing traffic volume, traffic control and due to quality vehicles, there is an ever increasing practice of driving for long distances. It is not possible for drivers to know all the geographical particulars and information acquisition of travel routes, at all times. So, Navigation System is essential for planning the route and also for planning the strategy of the route which may suffer from traffic, diversions, constructions etc.
A typical navigation system, as shown in Fig 1, consists of a central microcontroller or a microprocessor, memory - RAM, ROM, Hard disk, memory card, a liquid crystal display, which may support displaying of a map, a CD/DVD drive/SD card slot to access the road/map database, an RDS decoder to receive the traffic messages, GPS receiver to receive the GPS data for position information, a set of keys for the user to operate the system. The system is capable of accepting the destination in the form of address (country, city, street etc.) or destination point directly from the map. The starting point for route calculation is normally the current position of the vehicle, which is computed by the system based on GPS data. Based on the present position and destination desired, the navigation system reads the road/map data base, computes the


flighted on the map, for the driver. Turn-by-turn instructions and/or a iscription of the route may be given visually and/or orally.
Various techniques have been developed for recommending a route, with user selectable options, typically referred as route options. In the present day navigation systems, the route options typically comprise of the shortest route, fastest route, optimized route (combination of short and fast route) etc.
In addition, selections have been provided for avoiding highways, avoiding toll ways, avoiding tunnels, for example. These are typically referred as route avoidances.
With the help of the route options and route avoidances, the user can inform the navigation system, about his preferences for the route calculation from start point to the destination. The navigation system will access the database of road segments, and computes the best possible route, provides route recommendations for the user, from the start point to the destination, taking into account the route options and route avoidances.
But the disadvantage of the present navigation systems is: the route avoidance is applied for every subsequent route calculation.
Some drivers may prefer to avoid certain roads, Ex. Highways, Toll roads, Roads with tunnels etc., at certain times, due to personal preferences, construction delays, traffic congestion, personal safety etc. But present systems do not provide the user this choice.

So there is a need for a navigational route planning device which provides the user with more dynamic route calculation capabilities.
OBJECT OF THE INVENTION:
The present day navigation system does not permit an user to designate the route avoidance to be considered only for a particular duration of time. Thus, it is desirable to provide a method and a system that permits an user to input and store route avoidances, to be avoided from recommended route determinations, only during specified time duration.
The above mentioned method with navigational devices, as well as other advantages, are addressed by the present invention and will be understood by reading and studying the following specification. Systems and methods are provided for a navigational route planning device which is more user friendly for route avoidances. The systems and methods of the present invention offer an improved navigational route planning device, which provides an user with more desirable route calculation capabilities.
The present invention relates to the field of vehicle route recommendation systems, and in particular to such systems which utilize fixed route avoidances to calculate a desired route.

DESCRIPTION OF DRAWINGS:
Figure 1: illustrates navigation system as known in prior art.
Figure 2: illustrates flowchart of sequence of entering the avoidances as per the
invention.
Figure 3: illustrates the menu for inputting the avoidances wherein the black
circle indicates option of active and wherein the white circle indicates option of
inactive.
DESCRIPTION OF INVENTION:
As much as traffic management system has helped the driver free from route planning in many situations, it can be further improved by integrating the dynamic traffic data or dynamic road conditions known to the driver, which too shall be employed in route planning. The aim of this invention is to achieve a navigation system with an open architecture, with dynamic end for recording driver's choices.
These and other features and advantages of this invention will become more apparent to those skilled in the art from the following detailed description of the presently preferred embodiment.
In one embodiment, the present invention provides a device which permits the user to designate certain routes to be avoided during certain time period, when recommending a route. The route avoidances normally available are Highways, Toll roads, roads with ferries and roads with tunnels. The present invention comprises of providing user a menu with choices displayed for route avoidances.

The invention also provides the user the options to input to the navigation system, a time duration during which the route avoidances are to be avoided for route calculation.
We now describe the working of the invention with reference to Figure 2 and Figure 3. Whenever user wants to input route avoidances to the system, the user enters into a menu called "Avoid routes". The system will display the choices available for avoidances. Presently the available choices are Highways, Toll roads, Tunnels and Ferries. It also provides the user, options to enter the time duration within which the route avoidances will be active. Once the user enters the required route avoidances and the time associated with the avoidances, the system saves the data. If the user sets only the dates and not the time fields, then the options are always considered within the start and end date, irrespective of time. When the user has set dates for enabling the options, when the current date becomes greater than end date, the system cancels the setting and informs the user that the option is being cancelled. If the user sets only the time and not date fields, then the options are always considered irrespective of dates. Subsequently any route calculation will check for this route avoidance data, along with associated time and plan the route according to the saved data.
After the expiry of the time duration, the system automatically removes the route avoidance data and will include them for subsequent route calculations, or if the travel time is outside the time window set by the user, the system will include the routes that were previously avoided, for subsequent route calculations.

The present invention relates generally to navigational system and in particular to navigational system with different route calculation capabilities as described. Route planning/recommendation devices are well known in the field of navigational instruments.
The method and system herein provides for storing and retrieving route avoidances, which will potentially affect the driver's particular commute, at some particular time, using simple steps. The navigation system or a personal computer is started. The user enters into a menu where, route avoidances are displayed for the user to select. Also options to enter the time duration associated with each route avoidance are displayed. Then the user selects the route avoidances and assigns time duration for each route avoidance. The route avoidances and the associated time durations are stored in the system. In these simple steps, the navigation system is fed with the route avoidances in planning a route thereafter.
The present invention relates in general to route generation in vehicle navigation systems, and, more specifically, to route calculation criteria based on the route options and route avoidances specified by the user, also taking into account the time duration for excluding the route avoidances.
The system in general avoids the route avoidance for the specified time duration, for route calculation. On expiry of the duration set for the route avoidance, the system includes them for subsequent route calculation. These and other embodiments, asoects. advantaaes. and features of the oresent invention will be

et forth in part in the description, and in part will become apparent to those skilled in the art by reference to the following description of the invention and referenced drawings or by practice of the invention. The aspects, advantages, and features of the invention are realized and attained by means of the instrumentalities, procedures, and combinations particularly pointed out in the appended claims.
The invention is applicable to any type of navigation system or route planning device which may be running on PC, or a vehicle fitted device or a mobile device. There may be multiple lists of route avoidances, ex: user specific, trip specific etc. The options in the route avoidances may be expanded to cover other possibilities like: Exclude bicycle routes, exclude pedestrian paths and any other segment which can be avoided provided the road/map data base contains the same.

WE CLAIM
1. A navigation system comprising:
- a map memory means for storing map information;
- an output means displays a route recommendation to a user of the navigation system, based on a destination input by the user and the map information; and
- a route avoidance memory means for storing time information and/or date information associated with routes that are to be avoided in the route recommendation.

2. A navigation system according to claiml, wherein the route avoidance memory means is adapted to receive the user preferences of routes to be avoided at selected duration for compiling outputting of route recommendation, along with information on date and/or time for each avoided route.
3. A navigation system according to claim 1 and 2, wherein the route avoidance memory means is further adapted such that when the date and/or time input by the user expires, then the output means displays a route recommendation without considering the route avoidance information stored in the memory.
4. A method for a navigation system comprising:
storing map information in a map memory;
displaying a route recommendation to a user of the navigation system, based on a destination input by the user and the map information;

storing time information and/or date information associated with routes that are to be avoided in the route recommendation.
5. A method for a navigation system according to claim 4, wherein the user enters his preference of routes to be avoided during outputting of route recommendation, along with information on date and/or time for each avoided route.