Abstract:
Methods and apparatus are provided for generating turn instructions on a turn-by-turn navigation system. The turn instructions can include a turn icon as well as visual and audio prompts. A countdown bar is typically embedded within the turn icon to provide upcoming turn information in intuitive graphic form, in order to reduce driver distraction. The turn-by-turn navigation system can generally be produced more economically than a typical premium system having a full complement of costly features, such as a color map display. Moreover, the turn-by-turn navigation system can be configured with only those features deemed most useful to a broad-based market segment, in order to further reduce manufacturing costs.

Description:
TECHNICAL FIELD 
     The present invention generally relates to navigation systems for automobiles, and more particularly relates to a turn-by-turn navigation system integrated with an automobile radio. 
     BACKGROUND 
     Recent trends in automobile technology have included the development of navigation systems incorporated within the driver control cluster. These navigation systems are generally designed to help a driver reach a specific destination without using a physical road map. As such, an automobile navigation system can make the driving experience more convenient and enjoyable. 
     In addition to providing basic driving directions, some navigation systems also supply resource locations, such as restaurants, hospitals, points of interest, and so forth. However, as new features and capabilities are added to automobile navigation systems, the interaction between driver and navigation system can become relatively complex. Therefore, it is desirable to have a driver-to-navigation system control interface that is both convenient and intuitive, in order to minimize driver distraction. 
     Another consideration affecting the design of automobile navigation systems is the cost associated with implementing various sophisticated features, such as color map displays, synthesized speech commands, touch screens, and the like. As such, the cost/feature trade-off typically becomes a determining factor regarding the degree of complexity designed into a navigation system for the consumer market. Furthermore, the relatively high cost of current “premium” navigation systems, which typically include a profusion of high-tech features, generally limits their marketability to the luxury, or near-luxury, car market. 
     Accordingly, it is desirable to provide a relatively low cost automobile navigation system that provides route guidance information to a typical consumer/driver. In addition, it is desirable that the low cost automobile navigation system be incorporated into the automobile audio system for convenient and intuitive operation. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background. 
     BRIEF SUMMARY 
     According to various exemplary embodiments, devices and methods are provided for presenting turn instructions on an automobile navigation system display. One method comprises the steps of graphically generating a turn icon on the display and embedding a countdown bar within the displayed turn icon, such that the countdown bar starts out completely filled and becomes increasingly empty as the vehicle approaches a turn point. 
     One device comprises a vehicle navigation system having a control unit with a visual display. The exemplary control unit is typically integrated into the audio system of the vehicle, which can include various types of radio reception, such as AM, FM, SDARS, and RDS, among others. A processor is typically electrically coupled to the control unit, and to a database and a vehicle location apparatus, such as a GPS receiver. The exemplary processor is configured to receive vehicle position data from the vehicle location apparatus, retrieve destination information from the database, calculate a turn-by-turn route to the destination, and generate instructions and graphics, such as a turn icon image on the visual display. The turn icon image is enhanced by the addition of an embedded countdown bar that starts out completely filled and becomes increasingly empty as the vehicle approaches a turn point. 
     The database typically contains road-network/address information, and may also contain Point of Interest (POI) information. In addition, the exemplary navigation system generally includes voice prompts that are synchronized with the visual instructions and graphics, such as the enhanced turn icon, to help the driver navigate accurately, and with minimum visual distraction. The exemplary navigation system typically utilizes turn-by-turn instructions in place of a color map display, and provides those features generally considered to be most useful for a shopping/commuting type of driver. As such, the exemplary system represents an effective and economical alternative to a relatively high cost premium navigation system. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and 
         FIG. 1  is a block diagram of an exemplary automobile navigation system; 
         FIG. 2  is an illustration of an exemplary control panel for an automobile navigation system; 
         FIG. 3  is an illustration of an exemplary control panel display in the “Radio Only” mode; 
         FIG. 4  is an illustration of an exemplary control panel display in the “Navigation Only” mode; 
         FIG. 5  is an illustration of an exemplary control panel display in the “Split Radio/Nav” mode; 
         FIG. 6  is a flow diagram of an exemplary control sequence for an automobile navigation system; 
         FIG. 7  is an illustration of an exemplary Turn List display; 
         FIG. 8  is an illustration of an exemplary turn icon display in a “Navigation Only” mode; 
         FIG. 9  is an illustration of an exemplary turn icon display in a split “Nav/XM” mode; 
         FIG. 10  is an illustration of an exemplary turn icon display in a split “Nav/FM-RDS” mode; 
         FIG. 11  is an illustration of an exemplary turn icon display in a split “Nav/FM” mode; and 
         FIG. 12  is an illustration of an exemplary turn icon display with an embedded disappearing countdown bar in a “Navigation Only” mode. 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description. 
     Various embodiments of the present invention pertain to the area of automobile navigation systems. The exemplary embodiments disclosed herein are particularly configured for the type of user/driver that represents a broad segment of the consumer market. That is, the exemplary navigation system embodiments are especially configured for ease of use, flexibility, and minimal driver distraction. Moreover, the navigation system controls are integrated into the vehicle audio system for added convenience and intuitive operation. The exemplary embodiments provide a wide range of audio and navigation capabilities, while at the same time eliminating certain types of high cost features (e.g., a color map display) having relatively low perceived utility to certain users. As such, the exemplary embodiments represent effective, lower cost alternatives to the premium types of automobile navigation systems. 
     According to an exemplary embodiment of an automobile navigation system  100 , as shown in the simplified block diagram of  FIG. 1 , a control panel  102  provides the interface between the driver and system  100 . Control panel  102  typically includes a visual display  104  and a set of manual controls  106 , such as buttons, knobs, and the like. A processor  108  manages the flow of data between control panel  102  and the various input devices, including a Global Positioning Satellite (GPS) receiver  110 , a radio  112 , a database  114  and/or the like. 
     Processor  108  may be any type of microprocessor, micro-controller, or other computing device capable of executing instructions in any computing language. GPS receiver  110  provides vehicle positioning information to processor  108 , typically via an external GPS antenna (not shown), or any other suitable device. Radio  112  is generally connected to an external AM/FM antenna (not shown), for receiving AM and FM broadcast transmissions, and can also be configured to receive other types of signals, such as satellite digital audio radio service (SDARS) and RDS (Radio Data System) signals. Database  114  is typically configured to provide map data, such as road-network/address data for the U.S. and Canada, to processor  108 . In addition, database  114  can be further configured to provide other types of data, such as Point Of Interest (POI) data. Database  114  can be implemented by a form of disk media, such as CD, DVD, and the like, or can be implemented by any other suitable type of media, such as flash memory cards or the like. Database  114  may also be configured to provide audio playback capabilities, including CD, DVD, MP3, WMA, and so forth. 
     One exemplary physical embodiment of control panel  102  is illustrated in  FIG. 2 . Control panel  102  can be mounted in any suitable location that allows the driver to conveniently read the data on display  104  and to access controls  106 . Display  104  may be sized to be capable of displaying at least 5 lines of 24 characters each, with a minimum character height of approximately 5 mm, although other embodiments may have any dimensions and display resolution. These parameters generally result in a display  104  having dimensions of approximately 125 mm minimum width (a) and approximately 47 mm minimum height (b). In general, LCD technology is used to produce the display characters, although any other suitable display technique (e.g., plasma or the like) may be used. Controls  106  are suitably configured to provide a combination of buttons and knob(s) that enable the driver to conveniently and intuitively access both the radio and navigation features, as will be described in further detail below. 
     According to one exemplary embodiment, control panel  102  can be configured to operate in three distinct display modes, which can be toggled by pressing an appropriate button  106  or other control on display  102 . In the exemplary embodiment, the three display modes are characterized as “Radio Only” mode, “Navigation Only” mode, and “Split Radio/Nav” mode. Exemplary embodiments of the three display modes are illustrated in  FIGS. 3 ,  4  and  5 . 
     The “Radio Only” display mode is typically designated as the default mode, where the driver has not requested navigation information. As shown in  FIG. 3 , the “Radio Only” mode can be configured to display time and date information from processor  108 , as well as radio  112  reception data, on display  104 . In the  FIG. 3  example, radio  112  is shown as receiving satellite (e.g., XM) data. In similar fashion, AM and FM data would typically be displayed if those modes were selected by the driver. Display  104  can also be configured to display additional selection choices (e.g., 95.5, 1017, X104, etc.) using associated controls  106 , as illustrated in  FIG. 3 . 
     An exemplary “Navigation Only” display mode is shown in  FIG. 4 . In this embodiment, the vehicle location is displayed in addition to time and date information. Vehicle location is typically displayed as a default function in a Navigation mode, prior to a driver request for destination routing information. 
     An exemplary “Split Radio/Nav” display mode is illustrated in  FIG. 5 . In this example, the audio data (XM) and navigation data (e.g., vehicle location) are displayed on a split screen portion of display  104 , in addition to the time and date display portion. Other multi-function display mode embodiments could be used as well, such as Picture-within-Picture (PIP) and similar types of graphical combinations. 
     In accordance with one exemplary embodiment of an automobile navigation system, a top-level menu of selections  600  available in system  100  ( FIG. 1 ) is illustrated in  FIG. 6 . For example, a driver can initiate a route guidance mode by activating “Destination” menu  602  and entering an address  604 ,  606  via controls  106 . Once the address has been entered, the system typically calculates a route from the present vehicle position to the destination address. The driver can also be given additional options, such as making an intermediate stop  608 ,  610 , locating a POI  612 , going to a previous destination  616 , or to a “Favorite” destination  618 ,  620 . The driver can typically exit the route guidance mode by depressing a soft key, such as “cancel guidance”  622 . 
     Another exemplary feature available in the activated route guidance mode is a “Turn List”, which the driver can access by pressing an appropriate soft key  624  in the Destination  602  menu. The Turn List typically displays a summary of distance, direction and turn-into street names of upcoming turns or other types of waypoints. As noted previously, the exemplary embodiments disclosed herein do not typically include a color map display, in order to reduce the cost and complexity of the system. Instead, turn-by-turn information is generally supplied to the driver in both visual and audio forms, as will be described below. As such, the exemplary embodiments disclosed herein can be categorized as “Turn-By-Turn” navigation systems. 
     Additional exemplary selective modes may also be made available to the driver, as are illustrated in  FIG. 6 , such as “Configure”  626 , “Repeat”  628 , and “Detour”  630 , among others. The various optional features extending from these additional exemplary modes are generally accessible to the driver through the activation of appropriate sequences of soft keys, as indicated in the respective flow diagrams of  FIG. 6 . 
     In an exemplary embodiment of a “Turn-By-Turn” navigation system, one visual form of turn-by-turn information is typically the Turn List, as previously described. An exemplary Turn List  702  is generally shown in tabular form on display  104 , as illustrated in  FIG. 7 . In this display example, the distance, direction, and turn-into street names of upcoming turns are listed in simple, easy-to-read format. For example, the first line in the displayed listing indicates an upcoming left turn, 0.2 miles ahead, into 13 mile Road. 
     Another exemplary visual form of turn-by-turn information is shown in  FIG. 8 , where a turn icon  802  is presented graphically on display  104  to indicate an upcoming turn. Route data is also shown on display  104 , as would be typically presented in the “Navigation Only” mode. 
     In addition to the types of visual displays described herein, various embodiments of exemplary Turn-By-Turn navigation systems generally incorporate audible voice prompts. Voice prompts are typically synchronized with visual turn instructions in order to help the driver navigate to the desired destination with minimal visual distraction. For example, voice prompts can announce an upcoming turn in three steps, as follows:
         1) A first voice prompt may suggest: “Prepare to turn”.   2) A second voice prompt may announce detailed turn instructions, such as: “Turn right onto  175  north in one half mile”.   3) A final prompt may be played immediately before the turn must be made: “Turn right now”.       

     To further aid the driver in processing turn information, the previously described turn icon ( 802  in  FIG. 8 ) can be graphically enhanced in various ways. For example, when an upcoming turn or other waypoint is still a considerable distance away (e.g. on the order of 0.5 miles or so, although other embodiments may use longer or shorter distances) icon  802  can be displayed as an arrow pointing straight ahead, as illustrated in  FIG. 9 . Also, the exemplary displayed data in  FIG. 9  is representative of the Split Radio/Nav mode, where XM is the selected audio mode. 
     When the vehicle reaches a distance of approximately 500 feet from the upcoming turn, turn icon  802  can be displayed as a bent arrow, as illustrated in  FIG. 10 . Concurrently, a voice prompt can announce: “prepare to turn right”. In this example, the displayed data is representative of the Split Radio/Nav mode, where FM-RDS is the selected audio mode. 
     When the vehicle begins to approach the upcoming turn, e.g., at about 300 feet, turn icon  802  can be displayed as a right-angle arrow, as illustrated in  FIG. 11 . Concurrently, a voice prompt can announce: “turn right in 300 feet”. In this example, the displayed data is representative of the Split Radio/Nav mode, where FM is the selected audio mode. 
     When the vehicle is close to the upcoming turn, e.g., at a distance of about 15 feet, turn icon  802  can revert to a right-angle arrow, as depicted in  FIG. 12 . Concurrently, a voice prompt can announce: “turn right now”. In this example, the displayed data is representative of the Navigation Only mode, with no audio selection. 
     The graphic image of turn icon  802  can be intuitively enhanced by the addition of a ‘countdown’ bar superimposed on turn icon  802  that becomes progressively highlighted as the vehicle approaches a turn or other waypoint. That is, turn icon  802  can integrate an embedded countdown bar, which is typically filled (e.g., black) when a turn is not imminent, as shown in  FIGS. 9 ,  10 ,  11 . As the vehicle approaches a turning point, as shown in  FIG. 12 , the embedded countdown bar can become increasingly blank (e.g., white). Alternate embodiments of an embedded countdown bar integrated with a turn icon can show, for example, a blank bar becoming shaded as the vehicle approaches a turn, or can indicate an upcoming turn by a change in color or intensity of the countdown bar, or through any other manner of highlighting, shading or the like. Various other embodiments of an integrated countdown bar may also be used to allow the changing image (e.g. progressive highlighting) of the embedded countdown bar to indicate the proximity of an upcoming turn. 
     In general, navigation systems use a separate countdown bar and turn icon, or perhaps a numeric distance-to-turn indicator instead of a graphic representation. In the exemplary embodiments disclosed herein, however, the merging of turn icon and countdown bar into a single image can reduce the driver workload to process information, and can thereby help the driver to make the proper turns with fewer errors. 
     Accordingly, the shortcomings of the prior art have been overcome by providing an improved automobile navigation system based on a turn-by-turn display concept. Exemplary embodiments of a versatile and economical navigation system are disclosed, with a graphic turn icon and associated visual and voice prompt instructions used in lieu of a costly color map display. The turn icon is enhanced with an embedded countdown bar that is progressively modified as the vehicle nears an upcoming turn. As such, the driver can intuitively anticipate the approaching turn point with fewer distracting glances at the instructions on the display. 
     While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the exemplary embodiment or exemplary embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the invention as set forth in the appended claims and the legal equivalents thereof.