Abstract:
A method of displaying navigation information and A navigation device comprising a receiver to receive traffic information, whereas the device is programmed with a map database and software that enables to display a current position of the device on a road navigation map, the device is further programmed to be able to display a status bar providing information about a planned route, whereas
       the user can plan a first route by inputting a first position and inputting a second position and store said first position and said second position,   the user can initiate a displaying of received traffic information assigned to said first route between said stored first position and said stored second position independent from the current position, and   after displaying of received traffic information assigned to said first route between said stored first position and said stored second position a second route is calculated between the current position and a destination.

Description:
PRIORITY STATEMENT 
       [0001]    The present application hereby claims priority under 35 U.S.C. § 119(e) on each of U.S. Provisional Patent Application Nos. 60/879,523 filed Jan. 10, 2007, 60/879, 549 filed Jan. 10, 2007, 60/879,553 filed Jan. 10, 2007, 60/879, 577 filed Jan. 10, 2007, 60/879,599 filed Jan. 10, 2007, 60/879, 529 filed Jan. 10, 2007, 60/879,601 filed Jan. 10, 2007, the entire contents of each of which is hereby incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to a navigation device that can display traffic information. The device find particular application as an in-car navigation system. 
       BACKGROUND 
       [0003]    Prior art navigation devices based on GPS (Global Positioning System) are well known and are widely employed as in-car navigation systems. Such a GPS based navigation device relates to a computing device which in a functional connection to an external (or internal) GPS receiver is capable of determining its global position. 
         [0004]    Moreover, the computing device is capable of determining a route between start and destination addresses, which can be input by a user of the computing device. Typically, the computing device is enabled by software for computing a “best” or “optimum” route between the start and destination address locations from a map database. A “best” or “optimum” route is determined on the basis of predetermined criteria and need not necessarily be the fastest or shortest route. The selection of the route along which to guide the driver can be very sophisticated, and the selected route may take into account existing and predicted traffic and road conditions, historical information about road speeds, and the driver&#39;s own preferences for the factors determining road choice. In addition, the device may continually monitor road and traffic conditions, and offer to or choose to change the route over which the remainder of the journey is to be made due to changed conditions. Real time traffic monitoring systems, based on various technologies (e.g. mobile phone calls, fixed cameras, GPS fleet tracking) are being used to identify traffic delays and to feed the information into notification systems. 
         [0005]    The navigation device may typically be mounted on the dashboard of a vehicle, but may also be formed as part of an on-board computer of the vehicle or car radio. The navigation device may also be (part of) a hand-held system, such as a PDA (Personal Navigation Device) a media player, a mobile phone or the like. The user interacts with the navigation device to tell it the journey they wish to make. The device selects a route for the journey. The user may intervene in, or guide the route selection process. The device provides visual and audible instructions to show the user the vehicle&#39;s current position and to guide the user along a chosen route. User interaction with the device may be by a touch screen, by steering column mounted remote control, by voice activation or by any other suitable method. 
         [0006]    By using positional information derived from the GPS receiver, the computing device can determine at regular intervals its position and can display the current position of the vehicle to the user. The navigation device may also comprise memory devices for storing map data and a display for displaying a selected portion of the map data. 
         [0007]    Also, it can provide instructions how to navigate the determined route by appropriate navigation directions displayed on the display and/or generated as audible signals from a speaker (e.g. ‘turn left in 100 m’). Graphics depicting the actions to be accomplished (e.g. a left arrow indicating a left turn ahead) can be displayed in a status bar and also be superimposed upon the applicable junctions/turnings etc. in the map itself. It is known to enable in-car navigation systems to allow the driver, whilst driving in a car along a route calculated by the navigation system, to initiate a route recalculation. This is useful where the vehicle is faced with construction work or heavy congestion. It is also known to enable a user to choose the kind of route calculation algorithm deployed by the navigation device, selecting for example from a ‘Normal’ mode and a ‘Fast’ mode (which calculates the route in the shortest time, but does not explore as many alternative routes as the Normal mode). 
         [0008]    It is also known to allow a route to be calculated with user defined criteria; for example, the user may prefer a scenic route to be calculated by the device. The device software would then calculate various routes and weigh more favourably those that include along their route the highest number of points of interest (known as POIs) tagged as being for example of scenic beauty. 
         [0009]    In order to determine a route between start and destination addresses, the navigation device uses map data. Depending on stored or input preferences (shortest route, fastest route, scenic route, . . . ), the navigation device computes an “optimum” route using the stored map data. However, the “optimum” route may differ from time to time, depending on the current situation on the road. It may for instance depend on the amount of vehicles on certain segments of the road, possible traffic jams, congestion, diversions etc. 
         [0010]    US 2002/0128770 A1 describes a system to provide a driver with real-time information about the situation on the road. The system uses cameras to make pictures of the earth&#39;s surface. The cameras may be cameras positioned on the ground or may be cameras positioned on a satellite. The server transmits (part of) a picture to a navigation device mounted on a client&#39;s vehicle. The navigation device is arranged to display the received picture to allow the client to assess the situation on the road. 
         [0011]    Known navigation devices are arranged to take into account changing road situations and conditions. Such navigation devices are arranged to receive information on traffic jams from a server. This information is used by the navigation device when planning a route or may be used to re-route an already planned route. The information about traffic jams is for instance collected using detection systems embedded in the road surface measuring the speed of the passing vehicles. 
         [0012]    EP 1 611 416 A1 describes a navigation device. The user can, by touching the screen, task away completely form a 2D or 3D navigation map to a menu screen which displays one or more options that, if selected through a further touch action, initiate a re-calculation to find a detour away from the planned route. 
       SUMMARY 
       [0013]    It is an object of the invention to provide a navigation device and a method that provide a more comfortable access to traffic information. 
         [0014]    This need may be met by a navigation device and a method according to the independent claims. 
         [0015]    In a first aspect, there is a navigation device comprising a receiver to receive traffic information. Examples of the receiver are a bluetooth receiver connectable with a mobile phone or the like wirelessly, an interface connectable with a mobile phone or the like via a cable, or a integrated RDS-TMC receiver. The device is programmed with a map database and software that enables to display a current position of the device on a road navigation map. The current position of the device is preferable derived from a measured actual geographic position. E.g. a GPS-Signal could be estimated to derive the current position from it. 
         [0016]    The device is further programmed to be able to display a status bar providing information about a planned route. The status bar contains text and/or symbols describing the information. 
         [0017]    The user can plan a first route by inputting a first position and inputting a second position. E.g. the user can use a geocoding functionality of the navigation device, inputting a postal address (land additionally city additionally street additionally house number) and geocoding it into a geo coordinate. Alternatively the user can input geo coordinates directly. Afterwards the user can store said first position and said second position. The stored first and second position can be loaded from the memory independently from the current position. 
         [0018]    The user can initiate a displaying of received traffic information assigned to said first route between said stored first position and said stored second position with the first position and the second position being independent from the current position. E.g. the traffic information is a roadblock or congestion or a delay assigned to a specific incident or a total delay assigned to several incidences concerning the whole first route. The traffic information is preferably a textual message and/or a symbol assigned to a position where the incident occurs. Preferably the user is taken to a navigation view in which traffic information can be obtained by looking at the traffic bar. If there is no traffic information on route, the user is informed accordingly. 
         [0019]    After displaying of received traffic information assigned to said first route between said stored first position and said stored second position a second route is calculated between the current position and a destination. 
         [0020]    In one exemplary embodiment the user can input a direction of said first route between said stored first position and said stored second position. E.g. the first position is the users “home” and the second position is at his “work”. The user can choose the direction “home” to “work” or “work” to “home” by touching a button on a displayed menu screen. 
         [0021]    Exemplary the destination could be derived from a previous destination. Alternatively in one preferred embodiment of the invention said stored first position or said stored second position is used as said destination. Further exemplary the destination is derived from the first position or the second position depending on the direction the user has entered before by selecting the first position or the second position to be to be the start and the other to be the destination. 
         [0022]    In one embodiment of the invention, starting to calculate said second route is initiated by the user. Alternatively in a preferred embodiment of the invention, said second route is calculated automatically. In this case a user action is not required. 
         [0023]    In one embodiment of the invention, said second route is calculated, if a speed of said device exceeds a predetermined value. 
         [0024]    In one embodiment of the invention, said second route is calculated if a timer exceeds a predetermined value. 
         [0025]    The condition of said predetermined speed value and said predetermined time value are preferably combined. In a further refinement other conditions, like a geographical distance to the first stored position and/or the second stored position are taken into account as well. 
         [0026]    In one embodiment of the invention, the first route is calculated. Alternatively the first route is input by the user directly, using several geocoordinates. 
         [0027]    In one embodiment of the invention, said initiating of displaying said received traffic information overwrites a previous destination preferably with said stored first position or said stored second position. 
         [0028]    In another embodiment of the invention a previous calculated route is maintained when displaying said received traffic information assigned to said first route. The previous calculated route is the second route afterwards. The previous route could be recalculated if, the current position has changed. If the current position is unchanged the second route is calculated by loading the route data of the previous route. 
         [0029]    In one exemplary embodiment of the invention, on start up of the device or on initiating by the user traffic information assigned to at least on of a first area around said first stored position and a second area around said second stored position are received preferably automatically. 
         [0030]    In a second aspect there is a method of displaying navigation information. The method is deployed in a navigation device programmed with a map database and software that enables to display a current position of the device on a road navigation map. 
         [0031]    In a program routine it is implemented that the user can plan a first route by inputting a first position and inputting a second position and store said first position and said second position. 
         [0032]    It is further implemented that the user can initiate a displaying of received traffic information assigned to said first route between said stored first position and said stored second position independent from the current position. 
         [0033]    It is further implemented that after displaying of received traffic information assigned to said first route between said stored first position and said stored second position a second route is calculated between the current position and a destination. 
     
    
     
       BRIEF SUMMARY OF THE DRAWINGS 
         [0034]    These and other aspects of the present invention will become apparent from and elucidated with reference to the embodiments described hereinafter. The present invention will be described with reference to the accompanying drawings, in which 
           [0035]      FIG. 1  shows a schematic display with a map of a navigation device; 
           [0036]      FIG. 2  shows a schematic flow process chart of a routine running on a navigation device; 
           [0037]      FIGS. 3 to 5  show schematic flow process charts of subroutines. 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0038]    A Navigator software runs for instance on a touch screen (i.e. stylus controlled) Pocket PC powered PDA device. It provides a GPS based navigation system when the PDA is coupled with a GPS receiver. The combined PDA and GPS receiver system is designed to be used as an in-vehicle navigation system. The invention may also be implemented in any other arrangement of navigation device, such as one with an integral GPS receiver/computer/display. The navigation device may implement any kind of position sensing technology and is not limited to GPS; it can hence be implemented using other kinds of GNSS (global navigation satellite system) such as the European Galileo system. Equally, it is not limited to satellite based location/velocity systems but can equally be deployed using ground-based beacons or any other kind of system that enables the device to determine its geographic location. 
         [0039]    The Navigator software, when running on a PDA, results in a navigation device that causes the normal navigation mode screen shown in  FIG. 1  to be displayed. 
         [0040]    This view provides driving instructions using a combination of text, symbols, voice guidance and a moving map. Key user interface elements are the following: 
         [0041]    In  FIG. 1  a 2-D map  1  occupies most of the screen. The map shows the user&#39;s car and its immediate surroundings, rotated in such a way that the direction in which the car is moving is always “up”. Running across the bottom quarter of the screen is the status bar  2 . The current location of the device, as the device itself determines using conventional GPS location finding and its orientation (as inferred from its direction of travel) is depicted by an arrow  3 . The route calculated by the device (using route calculation algorithms stored in device memory as applied to map data stored in a map database in device memory) is shown as darkened path  4  superimposed with arrows giving the travel direction. On the darkened path  4 , all major actions (e.g. turning corners, crossroads, roundabouts etc.) are schematically depicted by arrows  5  overlaying the path  4 . The status bar  2  also includes at its left hand side a schematic  6  depicting the next action (here, a right turn). 
         [0042]    The status bar  2  also shows the distance to the next action (i.e. the right turn—here the distance is 220 meters) as extracted from a database of the entire route calculated by the device (i.e. a list of all roads and related actions defining the route to be taken). Status bar  2  also shows the name of the current road  8 , the estimated time before arrival  9  (here 2 minutes and 40 seconds), the actual estimated arrival time 10 (11.36 am) and the distance to the destination  11  (1.4 Km). The GPS signal strength is shown in a mobile-phone style signal strength indicator  12 . 
         [0043]    The actual physical structure of the device itself may be fundamentally no different from any conventional handheld computer, other than the integral GPS receiver or a GPS data feed from an external GPS receiver. Hence, memory stores the route calculation algorithms, map database and user interface software; a microprocessor interprets and processes user input (e.g. using a device touch screen to input the start and destination addresses and all other control inputs) and deploys the route calculation algorithms to calculate the optimal route. ‘Optimal’ may refer to criteria such as shortest time or shortest distance, or some other user-related factors. 
         [0044]    More specifically, the user inputs his start position and required destination in the normal manner into the Navigator software running on the PDA using a virtual keyboard. The user then selects the manner in which a travel route is calculated: various modes are offered, such as a ‘fast’ mode that calculates the route very rapidly, but the route might not be the shortest; a ‘full’ mode that looks at all possible routes and locates the shortest, but takes longer to calculate etc. Other options are possible, with a user defining a route that is scenic—e.g. passes the most POI (points of interest) marked as views of outstanding beauty, or passes the most POIs of possible interest to children or uses the fewest junctions etc. 
         [0045]    Roads themselves are described in the map database that is part of Navigator (or is otherwise accessed by it) running on the PDA as lines—i.e. vectors (e.g. start point, end point, direction for a road, with an entire road being made up of many hundreds of such sections, each uniquely defined by start point/end point direction parameters). 
         [0046]    A map is then a set of such road vectors, plus points of interest (POIs), plus road names, plus other geographic features like park boundaries, river boundaries etc, all of which are defined in terms of vectors. All map features (e.g. road vectors, POIs etc.) are defined in a co-ordinate system that corresponds or relates to the GPS co-ordinate system, enabling a device&#39;s position as determined through a GPS system to be located onto the relevant road shown in a map. 
         [0047]    Route calculation uses complex algorithms that are part of the Navigator software. The algorithms are applied to score large numbers of potential different routes. The Navigator software then evaluates them against the user defined criteria (or device defaults), such as a full mode scan, with scenic route, past museums, and no speed camera. The route which best meets the defined criteria is then calculated by a processor in the PDA and then stored in a database in RAM as a sequence of vectors, road names and actions to be done at vector end-points (e.g. corresponding to pre-determined distances along each road of the route, such as after 100 meters, turn left into street x). 
         [0048]    Additionally the navigation device receives traffic information  14 ,  15 . They can be received using i.e. TMC (Traffic Message Channel) or TMCpro. The traffic information  14 ,  15  is assigned to the route  4  and displayed on the map  1 . The example of  FIG. 1  shows as traffic incidences a roadblock  14  and congestion  15  shown as symbols and linked to a textual description. 
         [0049]      FIG. 2  shows a schematic diagram of part of a program routine running on the navigation device. With the first step  100  the routine is started, if the user presses a button i.e. “View traffic on preferred route”. In the following second step  101  it is asked whether traffic information (RDS-TMC) is available. If traffic information is not available the routine continues to the subroutine  200 . Otherwise, if traffic information is available the routine continues with step  102 . 
         [0050]    In step  102  it is checked whether a preferred route is planned. In the following description the preferred route is referred to as the first route. E.g. for planning the first route a first position is input and a second position is input and stored by the user. If the route is not planned the routine continues to the subroutine  300  for setting up route planning. Otherwise, if traffic information is available the routine continues with step  103 . 
         [0051]    In step  103  a menu is displayed showing buttons to select the first route including a direction. E.g. the first position is the “home” of the user and the second position is the “work” of the user. In step  103  the user can select the route from “home” to “work” or vice versa. 
         [0052]    After selecting the first route the routine continues to step  104 . In step  104  it is checked whether traffic information is available. E.g. the routine checks whether a connection with a RDS-TMC receiver is available. If no traffic information is available it continues to the subroutine in step  400 , updating traffic information. Otherwise, if traffic information is available, traffic information will be displayed in step  105 . In step  105  route statistics and information about incidents on the route are displayed on a traffic bar. 
         [0053]    This way of accessing the traffic information is specifically advantageous for a regularly traveled route. The traffic information can be retrieved prior to navigating. It is not necessary to estimate a current position before. The traffic situation on this first route can therefore be assessed before driving. The user is able to view a summary of traffic information for his device. The summary is preferably statistic information, containing e.g. driving time, delay time, changes of congestions over time etc. 
         [0054]    The first route between the first position and the second position could be input by the user directly. Alternatively the user just inputs the first position and the second position and the first route between the first position and the second position is calculated. 
         [0055]    In the following step  106  a parameter is estimated. Such parameter could be e.g. a timer value, a speed value, a distance value. E.g. the time since step  105  is measured. E.g. the speed of the device (moving with the vehicle) is measured. E.g. the distance between the current position of the device and the first position and/or the second position is measured. 
         [0056]    In the following step  107  the value of at least one of the parameters is estimated to meet a condition. If the condition is not met the routine turns back to step  106 . Otherwise, if the condition is met the routine continues to step  108 . A possible condition could be that a speed of said device exceeds a predetermined value. Another possible condition could be that a timer exceeds a predetermined value. Again another possible condition could be that the device is located in a predefined area around the first position or the second position. Several conditions are preferably combined. 
         [0057]    E.g. to prevent recalculation if the current position derived from a GPS-Signal is not the same as the first position or the second position (depending on the direction) a system with two timers is used. A first timer counts during a preview, so that recalculation is prevented until a first length of time (e.g. 5 minutes) has passed and unless the user is moving slower than a predetermined speed, e.g. 8 kilometers per hour. A second timer counts during a preview, so that recalculation is prevented until a second length of time (e.g. 30 seconds) has passed and unless the user is moving faster than the predetermined speed, e.g. 8 kilometers per hour. The timers are set the moment the received traffic information along with the first route is displayed. The length of time of each timer is preferably set depending on receiving of a GPS-signal. In case a GPS-signal is received the current position is estimated and compared with the first position or the second position. The length of time of each timer is then set depending on the distance between the current position and the first or second position, e.g. comparing with a distance value, e.g. 2 kilometers. 
         [0058]    In step  108  a second route is calculated. This new route uses the current position of the device as the start and the first position or the second position as a destination, depending on the direction chosen in step  103 . The second route is calculated between the start and the destination. 
         [0059]    Assuming that the second position is the destination, the second route will differ from the first route if, the start is not equal to the first position. Although it might be equal the second route is calculated and the current position is shown on the map in step  9  using normal navigation operation of the device. 
         [0060]      FIG. 3  shows a more detailed diagram on the subroutine  200 . First in step  201  of the subroutine it is checked whether the user has enabled a link to download traffic information from a server wirelessly. If the link is enabled the routine continues to step  102 . If the link is not enabled step  202  follows showing a display with buttons to start a traffic connection wizard. After successfully setting up the link the routine continues in step  102 . 
         [0061]      FIG. 4  shows a more detailed diagram on the subroutine  300 . First in step  301  a message is displayed, that the first position and the second position of the first route—called a “regular route”—will follow. In step  302  a menu is prompted to input the first position. In step  303  a menu is prompted to input the second position. The positions can be selected from predetermined favorites, points of interest, recent destinations or the like. Another possibility is to estimate the first and/or second from an address. Afterwards the routine continues with step  102 . 
         [0062]      FIG. 5  shows a more detailed diagram on the subroutine  400 . If no traffic information is available the subroutine  400  starts with step  401  checking whether a connection with the traffic server is available. In case the connection to the traffic server is available the subroutine continues to step  402  checking whether the traffic information is up to date. For this a time stamp of the last traffic information is compared with the current time. If the time difference between time stamp and current time exceeds a time value, e.g. 5 minutes, the subroutine continues to step  405 . If the traffic information is up to date the routine continues with step  105 . 
         [0063]    If there is no connection to the traffic server in step  401 , the subroutine continues with step  403  setting up an appropriate connection. If the setup of said connection is successful the subroutine continues with step  402 . Otherwise the routine ends with step  404 , displaying to the user an error message that the device is unable to retrieve traffic information. After this a grey traffic ball is displayed in a navigation view in order to indicate that traffic has not been updated. 
         [0064]    In step  405  a message and/or a symbol is displayed that an updating process progresses. Afterwards in step  406  it is checked whether the update process was successful. In case of a successful update the routine continues with step  105 . Otherwise a error message will be displayed in step  404 . 
         [0065]    Various modifications and alterations of this invention will become apparent to those skilled in the art without departing from the scope of this invention, and it should be understood that this invention is not to be unduly limited to the illustrative embodiments.