Patent Application
20090177373
Portable navigation devices (PNDs) including GPS (Global Positioning System) signal reception and processing means are well known and are widely employed as in-car navigation systems. In essence, modern PNDs comprise:
The utility of the PND is manifested primarily in its ability to determine a route between a start or current location and a destination, which can be input by a user of the computing device, by any of a wide variety of different methods, for example by postcode, street name and number, and previously stored well known, favorite or recently visited destinations. Typically, the PND is enabled by software for computing a “best” or “optimum” route between the start and destination address locations from the map data. 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, predicted and dynamically and/or wirelessly received traffic and road information, historical information about road speeds, and the driver'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.
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, and in these cases, the normal functionality of the hand-held system is extended by means of the installation of software on the device to perform both route calculation and navigation along a calculated route. In any event, once a route has been calculated, the user interacts with the navigation device to select the desired calculated route, optionally from a list of proposed routes. Optionally, the user may intervene in, or guide the route selection process, for example by specifying that certain routes, roads, locations or criteria are to be avoided or are mandatory for a particular journey. The route calculation aspect of the PND forms one primary function provided, and the navigation along such a route is another primary function. During navigation along a calculated route, the PND provides visual and/or audible instructions to guide the user along a chosen route to the end of that route, that is the desired destination. It is usual for PNDs to display map information on-screen during the navigation, such information regularly being updated on-screen so that the map information displayed is representative of the current location of the device, and thus of the user or user's vehicle if the device is being used for in-car navigation. An icon displayed on-screen typically denotes the current device location, and is centred with the map information of current and surrounding roads and other map features being also displayed. Additionally, navigation information may be displayed, optionally in a status bar above, below or to one side of the displayed map information, examples of navigation information including the distance to the next deviation from the current road required to be taken by the user, the nature of that deviation possibly being represented by a further icon suggestive of the particular type of deviation, for example a left or right turn. The navigation function also determines the content, duration and timing of audible instructions by means of which the user can be guided along the route. As can be appreciated a simple instruction such as “turn left in 100 m” requires significant processing and analysis. As previously mentioned, user interaction with the device may be by a touch screen, or additionally or alternately by steering column mounted remote control, by voice activation or by any other suitable method.
A further important function provided by the device is automatic route re-calculation in the event that
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, or may wish to avoid any roads on which traffic congestion is likely, expected or currently prevailing. 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, or, using stored information indicative of prevailing traffic conditions on particular roads, order the calculated routes in terms of a level of likely congestion or delay on account thereof. Other POI-based and traffic information-based route calculation and navigation criteria are also possible.
Although the route calculation and navigation functions are fundamental to the overall utility of PNDs, it is possible to use the device purely for information display, or “free-driving”, in which only map information relevant to the current device location is displayed, and in which no route has been calculated and no navigation is currently being performed by the device. Such a mode of operation is often applicable when the user already knows the route along which it is desired to travel and does not require navigation assistance.
Regardless of whether the device is operating in a navigation mode or a free driving mode, if the display of traffic information is enabled on the device, particular segments of the current road, future roads in a planned route, or roads in the vicinity of the current road, represented graphically on the display of the device, may be appropriately graphically emphasized, identified by, or overlaid with one or more icons, linear indicators or other graphics representative of traffic congestion. This allows a user, particularly when the device provides an overview display of a calculated route, to quickly determine the prevailing traffic conditions along his route, and whether these are likely to give rise to significant delays.
Of course, wirelessly received traffic information has been available for many years, for example as part of the RDS-TMC (radio data system—traffic message channel) and more recently over wireless/mobile telecommunications networks. The quality and detail provided of such data has also been increasing in recent years, and it is now possible to receive information describing particular levels of traffic congestion on a particular segment of a road, and to derive from this the absolute and relative speeds of vehicles in the particular road segment concerned.
PNDs and navigation systems of the prior art are known which are capable of receiving such traffic data and graphically presenting such in different forms, for example as different coloured icons with each colour representing traffic congestion of increasing severity on particular road segments. Thus, a plurality of traffic data relating to a plurality of different road segments is received, decoded and stored, together with some location identifier substantially corresponding to the middle of the segment of road defined in the map data to which that data relates. In one prior art traffic information display method, one or more icons are optionally resized and displayed, together with the map information, in the appropriate location identified in the map data so that the icons appear to coincide with the segments of the road on which traffic congestion is prevailing. The colour or appearance of the icons may be different to represent traffic conditions of differing in severity.
An alternative prior art method of representing traffic congestion graphically is to overlay or combine one or more elongate coloured bitmaps or other image types, appropriately sized to match the segments of roads to which they relate, with the map data so that the graphically displayed road has one or more coloured blocks representative of particular road segments on which traffic congestion is prevailing. Again, different colours may be used to convey different levels of severity of the traffic congestion, for example standing traffic, very slow traffic, slow traffic and the like. Of course, no such bitmap is displayed on screen for segments of the road along which there is no congestion. For roads which are busy therefore, the graphical display often appears with a many differently coloured blocks adjacent one another to represent that different segments of the road have different levels of congestion along a particular stretch.
An alternative prior art system combines the above technique with an averaging technique over particular stretches of road along which various levels of congestion have been identified, and uses bitmaps of only a single colour to signify the existence of congestion, but not its severity. For any particular stretch of road, either the calculated average congestion level is below a threshold, in which case no bitmap is displayed, or it is above that threshold, in which case a bitmap is displayed. Consecutive segments of a road in which the traffic congestion is above a predetermined threshold level therefore appeared “filled in” on the display, and other segments appear normally displayed.
While such indications of traffic congestion are useful to a certain degree, the main disadvantage with the various methods is the graphics do not instantly inform the user of the overall severity of, and likely transit time and/or speed through, the various differently congested segments of a stretch of road. In the first case where icons are displayed, and in the second case where differently coloured bitmaps are used, the only information conveyed to the user is that either a stretch of road is only lightly congested or it is more heavily congested in a number of different segments thereof. In the latter case, where only a single colour bitmap or other graphic is used, an aggregate calculation is performed by the PND, and the information conveyed to the user is that one or more consecutive segments of a road are congested to some degree, but there is no indication of the particular level of congestion.
In the real world, traffic congestion is a highly fluid characteristic, and the graphical representation thereof, as achieved by the methods above, is an understandably crude approximation to the actual traffic conditions.
As the reader will be aware, current traffic levels, certainly on Western European roads, are so severe that congestion tends to arise, to varying degrees, along lengthy stretches of roads with a resulting stop-start traffic motion. In these cases, users of navigation devices are more concerned not with whether different segments of the stretch of road are congested to different degrees, or the proportion of particular stretches of roads which are congested to any degree, but more with the likely average speed which might be achieved through, or the likely overall time delay which might be experienced as a result of, the congestion. Additionally, some graphical indication of the severity of the congestion is still of informational value to the user, and therefore it is an object of this invention to provide a method, a PND, and/or a navigation system which is adapted to display enhanced graphical indications representative of traffic congestion in a useful manner and thus overcome the described disadvantages.
According to the present invention there is provided a method of providing a graphical indication of traffic congestion along a stretch of physical road notionally divided by a traffic information provider into one or more road segments,
Characterized in by the steps of
determining that stop-start type traffic congestion exists by analyzing the traffic information received for each of a plurality of adjacent or proximate road segments and identifying that different traffic congestion severities prevail therein, determining an aggregated traffic congestion value for some or all of said plurality of segments and comparing that value to a first threshold value, a positive comparison result therewith being indicative of a level of congestion for said segments which should be identified to a user graphically,
determining a measure of the relative density of segments within said plurality of segments for which the aggregated traffic congestion value does not result in a positive comparison, and displaying one of a plurality of different graphical indicators repeatedly for all said plurality of segments, the particular graphical indicator being dependent on said determination, and thus providing an indication of both the relative overall severity of traffic congestion in said plurality of segments, and that a stop-start type of traffic congestion prevails along the stretch of road comprised of said plurality of segments.
Preferably, the graphical indicator is different from the graphical indicators used to represent different traffic congestion severities, such being derived directly from traffic information received for individual road segments, and preferably such are also capable of being displayed where the method above determines that no stop-start traffic conditions exist.
Most preferably, the graphical indicators are representative of one of average speed or the likely transit or delay time throughout the plurality of segments, the calculation of such standard parameters being based on the traffic information received and the overall physical length of the stretch of road comprised of said plurality of segments.
Most preferably, only a single graphical indicator is used for the stretch of road on which different severities of traffic congestion prevail so that a user can immediately understand that the congestion is of a start-stop nature, and also one of
In further aspects of the invention, a computer program, embodied on computer readable media as required, is provided for implementing the methods described above, as is a PND and/or navigation system adapted to perform the methods described.
The present application will be described in more detail below by using example embodiments, which will be explained with the aid of the drawings, in which:
The GPS system is implemented when a device, specially equipped to receive GPS data, begins scanning radio frequencies for GPS satellite signals. Upon receiving a radio signal from a GPS satellite, the device determines the precise location of that satellite via one of a plurality of different conventional methods. The device will continue scanning, in most instances, for signals until it has acquired at least three different satellite signals (noting that position is not normally, but can be determined, with only two signals using other triangulation techniques). Implementing geometric triangulation, the receiver utilizes the three known positions to determine its own two-dimensional position relative to the satellites. This can be done in a known manner. Additionally, acquiring a fourth satellite signal will allow the receiving device to calculate its three dimensional position by the same geometrical calculation in a known manner. The position and velocity data can be updated in real time on a continuous basis by an unlimited number of users.
As shown in
The spread spectrum signals 160, continuously transmitted from each satellite 120, utilize a highly accurate frequency standard accomplished with an extremely accurate atomic clock. Each satellite 120, as part of its data signal transmission 160, transmits a data stream indicative of that particular satellite 120. It is appreciated by those skilled in the relevant art that the GPS receiver device 140 generally acquires spread spectrum GPS satellite signals 160 from at least three satellites 120 for the GPS receiver device 140 to calculate its two-dimensional position by triangulation. Acquisition of an additional signal, resulting in signals 160 from a total of four satellites 120, permits the GPS receiver device 140 to calculate its three-dimensional position in a known manner.
The navigation device 200 is located within a housing (not shown). The housing includes a processor 210 connected to an input device 220 and a display screen 240. The input device 220 can include a keyboard device, voice input device, touch panel and/or any other known input device utilized to input information; and the display screen 240 can include any type of display screen such as an LCD display, for example. The input device 220 and display screen 240 are integrated into an integrated input and display device, including a touchpad or touchscreen input wherein a user need only touch a portion of the display screen 240 to select one of a plurality of display choices or to activate one of a plurality of virtual buttons.
In addition, other types of output devices 250 can also include, including but not limited to, an audible output device. As output device 241 can produce audible information to a user of the navigation device 200, it is equally understood that input device 240 can also include a microphone and software for receiving input voice commands as well. In the navigation device 200, processor 210 is operatively connected to and set to receive input information from input device 240 via a connection 225, and operatively connected to at least one of display screen 240 and output device 241, via output connections 245, to output information thereto. Further, the processor 210 is operatively connected to memory 230 via connection 235 and is further adapted to receive/send information from/to input/output (I/O) ports 270 via connection 275, wherein the I/O port 270 is connectable to an I/O device 280 external to the navigation device 200. The external I/O device 270 may include, but is not limited to an external listening device such as an earpiece for example. The connection to I/O device 280 can further be a wired or wireless connection to any other external device such as a car stereo unit for hands-free operation and/or for voice activated operation for example, for connection to an ear piece or head phones, and/or for connection to a mobile phone for example, wherein the mobile phone connection may be used to establish a data connection between the navigation device 200 and the internet or any other network for example, and/or to establish a connection to a server via the internet or some other network for example.
The navigation device 200 may establish a “mobile” or telecommunications network connection with the server 302 via a mobile device 400 (such as a mobile phone, PDA, and/or any device with mobile phone technology) establishing a digital connection (such as a digital connection via known Bluetooth technology for example). Thereafter, through its network service provider, the mobile device 400 can establish a network connection (through the internet for example) with a server 302. As such, a “mobile” network connection is established between the navigation device 200 (which can be, and often times is mobile as it travels alone and/or in a vehicle) and the server 302 to provide a “real-time” or at least very “up to date” gateway for information.
The establishing of the network connection between the mobile device 400 (via a service provider) and another device such as the server 302, using the internet 410 for example, can be done in a known manner. This can include use of TCP/IP layered protocol for example. The mobile device 400 can utilize any number of communication standards such as CDMA, GSM, WAN, etc.
As such, an internet connection may be utilized which is achieved via data connection, via a mobile phone or mobile phone technology within the navigation device 200 for example. For this connection, an internet connection between the server 302 and the navigation device 200 is established. This can be done, for example, through a mobile phone or other mobile device and a GPRS (General Packet Radio Service)-connection (GPRS connection is a high-speed data connection for mobile devices provided by telecom operators; GPRS is a method to connect to the internet.
The navigation device 200 can further complete a data connection with the mobile device 400, and eventually with the internet 410 and server 302, via existing Bluetooth technology for example, in a known manner, wherein the data protocol can utilize any number of standards, such as the GSRM, the Data Protocol Standard for the GSM standard, for example.
The navigation device 200 may include its own mobile phone technology within the navigation device 200 itself (including an antenna for example, wherein the internal antenna of the navigation device 200 can further alternatively be used). The mobile phone technology within the navigation device 200 can include internal components as specified above, and/or can include an insertable card (e.g. Subscriber Identity Module or SIM card), complete with necessary mobile phone technology and/or an antenna for example. As such, mobile phone technology within the navigation device 200 can similarly establish a network connection between the navigation device 200 and the server 302, via the internet 410 for example, in a manner similar to that of any mobile device 400.
For GRPS phone settings, the Bluetooth enabled device may be used to correctly work with the ever changing spectrum of mobile phone models, manufacturers, etc., model/manufacturer specific settings may be stored on the navigation device 200 for example. The data stored for this information can be updated.
Further, it will be understood by one of ordinary skill in the art that the electronic components shown in
In addition, the portable or handheld navigation device 200 of
The server 302 includes, in addition to other components which may not be illustrated, a processor 304 operatively connected to a memory 306 and further operatively connected, via a wired or wireless connection 314, to a mass data storage device 312. The processor 304 is further operatively connected to transmitter 308 and receiver 310, to transmit and send information to and from navigation device 200 via communications channel 318. The signals sent and received may include data, communication, and/or other propagated signals. The transmitter 308 and receiver 310 may be selected or designed according to the communications requirement and communication technology used in the communication design for the navigation system 200. Further, it should be noted that the functions of transmitter 308 and receiver 310 may be combined into a signal transceiver. Server 302 is further connected to (or includes) a mass storage device 312, noting that the mass storage device 312 may be coupled to the server 302 via communication link 314. The mass storage device 312 contains a store of navigation data and map information, and can again be a separate device from the server 302 or can be incorporated into the server 302.
The navigation device 200 is adapted to communicate with the server 302 through communications channel 318, and includes processor, memory, etc. as previously described with regard to
Software stored in server memory 306 provides instructions for the processor 304 and allows the server 302 to provide services to the navigation device 200. One service provided by the server 302 involves processing requests from the navigation device 200 and transmitting navigation data from the mass data storage 312 to the navigation device 200. Another service provided by the server 302 includes processing the navigation data using various algorithms for a desired application and sending the results of these calculations to the navigation device 200.
The communication channel 318 generically represents the propagating medium or path that connects the navigation device 200 and the server 302. Both the server 302 and navigation device 200 include a transmitter for transmitting data through the communication channel and a receiver for receiving data that has been transmitted through the communication channel.
The communication channel 318 is not limited to a particular communication technology. Additionally, the communication channel 318 is not limited to a single communication technology; that is, the channel 318 may include several communication links that use a variety of technology. For example, the communication channel 318 can be adapted to provide a path for electrical, optical, and/or electromagnetic communications, etc. As such, the communication channel 318 includes, but is not limited to, one or a combination of the following: electric circuits, electrical conductors such as wires and coaxial cables, fiber optic cables, converters, radio-frequency (rf) waves, the atmosphere, empty space, etc. Furthermore, the communication channel 318 can include intermediate devices such as routers, repeaters, buffers, transmitters, and receivers, for example.
For example, the communication channel 318 includes telephone and computer networks. Furthermore, the communication channel 318 may be capable of accommodating wireless communication such as radio frequency, microwave frequency, infrared communication, etc. Additionally, the communication channel 318 can accommodate satellite communication.
The communication signals transmitted through the communication channel 318 include, but are not limited to, signals as may be required or desired for given communication technology. For example, the signals may be adapted to be used in cellular communication technology such as Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Code Division Multiple Access (CDMA), Global System for Mobile Communications (GSM), etc. Both digital and analogue signals can be transmitted through the communication channel 318. These signals may be modulated, encrypted and/or compressed signals as may be desirable for the communication technology.
The server 302 includes a remote server accessible by the navigation device 200 via a wireless channel. The server 302 may include a network server located on a local area network (LAN), wide area network (WAN), virtual private network (VPN), etc.
The server 302 may include a personal computer such as a desktop or laptop computer, and the communication channel 318 may be a cable connected between the personal computer and the navigation device 200. Alternatively, a personal computer may be connected between the navigation device 200 and the server 302 to establish an internet connection between the server 302 and the navigation device 200. Alternatively, a mobile telephone or other handheld device may establish a wireless connection to the internet, for connecting the navigation device 200 to the server 302 via the internet.
The navigation device 200 may be provided with information from the server 302 via information downloads which may be periodically updated upon a user connecting navigation device 200 to the server 302 and/or may be more dynamic upon a more constant or frequent connection being made between the server 302 and navigation device 200 via a wireless mobile connection device and TCP/IP connection for example. For many dynamic calculations, the processor 304 in the server 302 may be used to handle the bulk of the processing needs, however, processor 210 of navigation device 200 can also handle much processing and calculation, oftentimes independent of a connection to a server 302.
As indicated above in
The navigation device 200 may sit on an arm 292, which itself may be secured to a vehicle dashboard/window/etc. using a large suction cup 294. This arm 292 is one example of a docking station to which the navigation device 200 can be docked. As shown in
Referring now to
As can be seen from the graph, the solid columns represent different traffic congestion levels for different segments of road. The horizontal line represents some predetermined threshold stored in the memory of the device, and the varyingly inclining and declining line represents a moving average of the traffic congestion over the stretch of physical road represented by the 13 segments. Thus, if the nominal length of each road segment is unitary, the average traffic congestion is 3 within the first segment, (3+0)/2, that is 1.5 for segments 1 and 2, (3+0+1)/3=1.333 for segments 1, 2 and 3, and so on.
In the same manner that it can be immediately appreciated from a visual inspection of the graph that the traffic congestion is intermittent and of varying differing levels of severity, the PND or navigation system can also make an assessment that the traffic congestion for the stretch of road is of a stop-start nature.
In one prior art method, an aggregation method is used, such as a rolling average as illustrated, a basic average (e.g. (3+0+1+0+2+0+1+0+2+0+1+2+3)/13=1.154) or any other suitable mathematical function, to derive some measure of the traffic congestion level over the entire stretch of road. In the instance, for any segment, that the averaged value diminishes below the threshold value, e.g. in segment 8, the PND does not display a traffic congestion graphic indicator for this segment of the road as it appears on the display of the device.
Thus, although simplistic, the linear representation 506 is indicative of the manner in which traffic information can be represented graphically on a PND or navigation system display screen. It is of course to be understood that the straight linear format is unlikely as the display of roads on screen typically includes a variety of bends and straight portions. Thus, for each of segments 1-7, and 9-13, the rolling average value of traffic congestion is above the threshold value, and therefore the PND causes the display of a suitably sized graphical indicator, such as a simple block of colour, within the demarcation lines of the road as they appear on the screen of the device. In the prior art method, the colour is uniform for those segments where it is desired to represent the existence of traffic information, and no graphical indicator is used for segment 8, where it is determined that the traffic congestion level is below the threshold for display.
Accordingly, a user of the PND device looking at the display screen showing graphical map data in which a road is represented and additionally marked as described above can appreciate that there is a significant congestion along the length of road represented by segments 1-7, a brief respite from the congestion in segment 8, and more congestion within segments 9-13. However, there is no indication of the nature of the congestion or its severity using this method of traffic information representation.
An alternative method representing traffic information is shown in
Incidentally, it is worth mentioning that, in this case, no traffic congestion is prevailing for segments of road preceding or following segments 1-13 shown in the figures, and either this is as a result of no traffic information having been received for such segments, or that information which has been received indicates that there is no or very little congestion on such segments.
Referring now to
Although only one colour of indicator is represented in
The legend or key may provide an indication of average speed of travel, expected time delay relative to travel along the uncongested road, or the likely time for travel along the stretch of road, and although the specific information relating to speed or time may not be displayed on screen, it is party of the invention that the PND or system is capable of displaying a plurality of different types of graphical indicator representing stop-start traffic congestion of different severities, aggregated or otherwise averaged as the case may be along the particular stretch of road.
