Vehicle navigation system with off-road navigation

<u>BACKGROUND OF THE INVENTION</u>

0001This invention relates to vehicle navigation systems and, more specifically, to map images appearing on a navigation system video screen of a display device.

0002Vehicle navigation systems typically include a display device with a video display that provides a graphical interface for the user. A main function of the video display is to depict the desired map area and route on which the user's vehicle is travelling. For convenience to the driver, several navigational modes may be provided. For example, an on-highway guidance mode may be provided in which directional arrows, highlighted routes, and/or voice instructions are given to the driver to guide the driver to a preselected destination.

0003An off-highway navigational mode has been provided to drivers when traveling off of the road network provided by the storage device or other media. Once the vehicle is driven to an location without any nearby roads or other reference points it becomes more difficult to convey directions to the driver on how to get to the next destination. To this end, waypoints have been used, which represent a location such as latitude and longitude. The waypoints may be linked together to form a route by which the navigation system may direct the driver to follow. However, even with the use of waypoints and defined routes, providing direction to the driver may result in driver confusion. Therefore, what is needed is a navigation system that clearly conveys directions to a waypoint.

0004Depending upon the route, directing a driver from one waypoint directly to the next may be an inefficient manner in which to travel along a route. For example, a route which has sharp turn from one waypoint to the next will require the driver to arrive at the waypoint and then turn around and travel in a similar direction to reach the next waypoint. Therefore, what is needed is a navigation system that more efficiently guides a driver along a route.

<u>SUMMARY OF THE INVENTION AND ADVANTAGES</u>

0005The present invention provides a method according to claim 1.

0006The present invention also includes an apparatus according to claim 8. Further embodiments are defined by the dependent claims.

0007Accordingly, the above invention provides a navigation system that more efficiently guides a driver along a route.

0008Publication XP00222781 Microsoft FLIGHT SIMULATOR PILOTENHANDBUCH discloses a flight simulator system for airplanes where a path to be followed is determined through waypoints. <patcit id="pcit0001" dnum="US5528248A"><text>US 5528248</text></patcit> shows a personal digital assistant having a GPS system which may be used for aerial navigation with waypoints or for land vehicle navigation with road maps. <patcit id="pcit0002" dnum="EP0763714A"><text>EP 0763714</text></patcit> shows a navigation system for aircrafts. <patcit id="pcit0003" dnum="DE10058492"><text>DE10058492</text></patcit> shows a mobile telephone having the feature of an arrow for indicating a desired direction to be followed. <patcit id="pcit0004" dnum="WO8905019A"><text>WO 89 05019</text></patcit> shows an aerial navigation system using a single mode system with waypoints and a cursor indicating drift of the plane caused by lateral wind.

<u>BRIEF DESCRIPTION OF THE DRAWINGS</u>

0009Other advantages of the present invention can be understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein: <ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001">Figure 1</figref> is a schematic view of the vehicle navigation system of the present invention;</li><li><figref idref="f0001">Figure 2</figref> is a front elevational view of the vehicle navigation system display unit having a video display;</li><li><figref idref="f0002">Figure 3</figref> is a video display of the display unit depicting a configuration options menu;</li><li><figref idref="f0002">Figure 4</figref> is a video display of the display unit depicting an off-road selection menu;</li><li><figref idref="f0002">Figure 5</figref> is a video display of the display unit depicting marking a waypoint by the use of a cursor;</li><li><figref idref="f0003">Figure 6</figref> is a video display of the display unit depicting a waypoint entry screen;</li><li><figref idref="f0003">Figure 7</figref> is a video display of the display unit depicting a map area with waypoints;</li><li><figref idref="f0003">Figure 8</figref> is a video display of the display unit depicting a first directional screen;</li><li><figref idref="f0004">Figure 9</figref> is a video display of the display unit depicting a second directional screen; <figref idref="f0004">Figure 10</figref> is a video display of the display unit depicting a third directional screen similar to the first directional screen;</li><li><figref idref="f0004">Figure 11</figref> is a video display of the display unit depicting another second directional screen;</li><li><figref idref="f0005">Figure 12</figref> is a video display of the display unit depicting a waypoint selection menu;</li><li><figref idref="f0005">Figure 13</figref> is a video display of the display unit depicting an off-road options menu;</li><li><figref idref="f0005">Figure 14</figref> is a video display of the display unit depicting an advanced off-road options menu;</li><li><figref idref="f0006">Figure 15</figref> is a schematic representation of the laterally parallel waypoint proximity option; and</li><li><figref idref="f0006">Figure 16</figref> is a schematic representation of the radial waypoint proximity option.</li></ul>

0010The navigation system 20 of the present invention is shown schematically in <figref idref="f0001">Figure 1</figref>. The navigation system 20 includes a unit 30 having a CPU 22 (Central Processing Unit) connected to a display device 24 and a directional input device 26 attached to the vehicle interior by a bracket 27, or the like. The navigation system 20 further includes a database 28 connected to the CPU 22. The database 28 is a mass media storage device, such as a CD-ROM, hard drive, DVD, RAM, ROM or the like which includes a map of the road system in the area to be traveled by the user. Each road in the database is divided into road segments, each having an associated set of cost values, which indicate the "cost" of traveling that road segment. For example, the cost values may include the length of the road segment, the estimated time to travel the road segment, and the type of road (i.e., highway, secondary road, toll road, one way, etc.). The road segment may be part of the vehicle route or may be a road segment outside the vehicle route.

0011The navigation system 20 can, but need not, be installed in a vehicle 21. The navigation system can be used in conjunction with position determining devices, such as a GPS receiver 38 and a multi-axis accelerometer 40. Navigation system 20 could alternatively or additionally include a gyroscope 42, a compass 44, and a wheel speed sensor 46, all connected to the CPU 32 (connections not shown for simplicity). Preferably, a combination of these position determining devices is utilized to assure accurate location.

0012The display device 22 may include a speaker 26. <figref idref="f0001">Figure 2</figref> is a perspective view of the display device 24 and directional input device 28, preferably designed as an integral unit attached to the CPU by connection 25. The display device 24 includes a video display 50, or screen, such as a high resolution LCD or flat panel display. The directional input device 28 includes a multiple of input buttons 78 including, preferably, an eight-way button shown generally at 80 and a selection key 86 such as an "Enter" key. Although an eight-way button is shown, it will be realized that other input devices, such as a joystick, mouse or roller ball can be employed. The eight-way button 80 and is capable of moving in the direction of any one of the directional arrows 84. Movement of the button 80 in the direction of one of the directional arrows 84 transmits a directional signal.

0013In on-road guidance mode, the vehicle route 52 is highlighted in a bright color, such as magenta, and arrows 54 overlay the route for easy identification by the user. On-road guidance mode is typically used when the user selects a particular destination. The navigation system then selects and highlights the route 52 based upon certain user selected parameters, such as shortest distance or shortest time. In on-road mode, the user has selected no particular destination. In this mode more detail may be desired than in on-road guidance mode because the user has not necessarily decided upon a particular route. In off-road mode, the navigation system has determined that the vehicle is no longer on any known road and that the vehicle is travelling off the road. To navigate, the driver may set waypoints that represent a precise location on a map. Waypoints may be linked to one another to form a complex route by which the driver may navigate from one destination to the next. Furthermore, wave points may be used to represent such locations as telephone polls. This information may be used by utility companies to set a route from a location on-road to the location of the telephone poll off-road. Of course good, wave points may be applied to other such similar applications.

0014<figref idref="f0002">Figure 3</figref> is a video display of the display unit depicting a configuration options menu 64. From this menu, the user may select an "Off-Road Navigation" menu by which the user may manipulate waypoint and route information. <figref idref="f0002">Figure 4</figref> depicts an off-road selection menu 66 having menu selection options "Mark by Position", "Select Route/Waypoint", "Next Waypoint", and "Reverse Route". Using the "Mark by Position" option, a map location may be saved as a waypoint by utilizing a cursor 68, as shown in <figref idref="f0002">Figure 5</figref>. The user may pan, or move, the cursor 68 in a map area 69 to a desired location, which may be other than the present vehicle location (indicated by the vehicle icon 70). The latitude 72 and longitude 73 of the cursor 68 is displayed to the user. The distance of the cursor 68 to the vehicle 70 is indicated above the cursor 68 at 75. The waypoint may be saved be pressing the "Enter" key 86, after which a waypoint entry screen 74, shown in <figref idref="f0003">Figure 6</figref>, will be displayed prompting the user to enter information regarding the waypoint. Regardless of the mode of entry of a new waypoint, the user is prompted to enter descriptive information about the waypoint. As seen in <figref idref="f0003">Figure 6</figref>, the latitude and longitude of the waypoint is displayed. A default label 77 of "Way001" is displayed unless the user enters a new 6-character alphanumeric description of the waypoint in the label field 77. A default label of "Way002", and so on, would be displayed for subsequent waypoints. The waypoint is represented by an icon in the map area once the waypoint has been saved. One default icon that may be used is a flag 90. The default icon may be changed and selected from a group of icons to more meaningfully correspond the waypoint to the user.

0015<figref idref="f0003">Figure 7</figref> depicts a map area with first 92 and second 94 waypoints in a map area 69. The waypoints 92 and 94 define a route depicted by path 96, which is a straight line between the waypoints 92 and 94. The direction and distance from the vehicle 70 to the next waypoint, which is first waypoint 92, is indicated at 97 and 98, respectively. The next waypoint, first waypoint 92, is highlighted to stand out to the user. An option "More" 99 may be temporarily displayed to the user, to enable the user to readily manipulation waypoint and route information. As a simplified alternative to the map area 69 shown in <figref idref="f0003">Figure 7</figref>, a first directional screen 100 may be used, as shown in <figref idref="f0003">Figure 8</figref>. A simple horizon 102 is displayed with a three dimensional directional arrow 104 pointing the direction to next waypoint. The next waypoint, or waypoint to which the vehicle is traveling, is indicated at 103.

0016According to the invention the first directional screen 100 includes a lane indicia 106 to further assist the user in navigating to the next waypoint. A pointer 107 pointing at the center 108 of the lane indicia 106 corresponds to the vehicle following the route path. The ends 109 of the lane indicia 106 correspond to a user selected offset from the path. For example, the ends 109 may correspond to an offset of 500 feet from the path. Total time remaining and total remaining distance of the route may also be displayed. As long as the pointer 107 is on center 108, the user is driving the vehicle along the path. As the vehicle wanders from the path, the pointer 107 will move along the lane indicia 106 to provide the user feed back of the degree to which the vehicle has strayed from the path.

0017A second direction screen 110 is shown in <figref idref="f0004">Figure 9</figref> in off-road guidance mode. A highlighted path 112 from the vehicle 70 to a waypoint (not shown) is displayed in the map area 69. A two dimensional arrow 114 is overlaid on the path 112. When the user selects a third directional screen 116, shown in <figref idref="f0004">Figure 10</figref>, the two dimensional arrow 114 is converted to a three dimensional arrow 118 on the simple horizon similar to the first directional screen 100 shown in <figref idref="f0003">Figure 8</figref>. If the vehicle 70 varies from the path 112 when in off-road mode, a new path 120 will be displayed from the present vehicle location to the next waypoint (not shown). The new path 120 may be a highlighted dashed line.

0018Waypoint and route information may be further manipulated by selecting "Select Route/Waypoints" from the off-road selection menu 66. <figref idref="f0005">Figure 12</figref> depicts a waypoint selection menu 122 having "All Routes", "Waypoints by Name", "Waypoints by Distance", and "Waypoints by Time" options. "All Routes" displays all of the routes alphabetically when selected. Similarly, "Waypoints by Name" displays all of the waypoints alphabetically. "Waypoints by Distance" displays all of the waypoints in order of closest to the present vehicle location to farthest from the present vehicle location. "Waypoints by Time" displays the waypoints in order of time of creation. In this manner, the waypoint and route information may be manipulated quickly in several different ways.

0019More advanced information relating the waypoints and routes may be manipulated using an off-road options menu 124, shown in <figref idref="f0005">Figure 13</figref>. Routes and waypoints may be deleted using the "Clear" option. The offset from a path may be set by the user, as described above, using the "Advanced..." option under the off-road options menu 124, which will display the advanced off-road options menu 126, shown in <figref idref="f0005">Figure 14</figref>. The offset from the path may set by the user by selecting the "XTE Alarm" option. As shown in <figref idref="f0005">Figure 14</figref>, the offset is set at 0.2 miles. The offset sets the ends 109 of the lane indicia 106. An audible alarm through speaker 26 may be used when the vehicle reaches one of the offsets from the path. The lane indicia 106 and how it relates with the waypoints 92, 94 and path 96 is graphically illustrated in <figref idref="f0006">Figure 15</figref>. Each of the ends 109 correspond to an offset 130, which is shown as dashed lines parallel to the path 96. Preferably, the dashed lines are not displayed, but are only used to illustrate the operation of the offset. When the vehicle 70 reaches one of the offsets 130, the arrow 107 will point at one of the ends 109 corresponding to the side of the offset, shown by dashed arrows 132. An audible alarm may sound, or voice instructions may be activated, indicating to the driver that the vehicle has veered off the path by the selected offset distance.

0020An waypoint arrival option may also be set using the "Arrival Alarm" option under the advanced off-road menu 126. <figref idref="f0006">Figure 16</figref> is a schematic representation of a radial waypoint proximity option. The radial waypoint proximity option may be used to simplify navigation along the route by directing the user to travel to the next waypoint once the vehicle is sufficiently proximate to the target waypoint. The route contains a path 96a from a first waypoint (not shown) to a second waypoint 94 and a path 96b from the second waypoint 94 to a third waypoint 134. The arrival alarm may be set to any radial distance, such as 250 feet indicated at 136 and 500 feet indicated at 138. Of course metric distances may be used. The dashed lines corresponding to the radial distance preferably is not displayed. If the radial distance is set to 500 feet, when the vehicle 70 reaches the radius 138, the user will be directed to travel to the third waypoint 134 and a new path 140 will be generated. In this manner, the user may more efficiently travel along the route instead of needlessly traveling directing to each waypoint, which may add a significant distance to the distance traveled. An audible alarm, or voice instructions may be activated when the vehicle reaches the radial distance. For example, the voice instructions may direct the vehicle operator to "proceed 30 degrees left".

0021The invention has been described in an illustrative manner, and it is to be understood that the terminology that has been used is intended to be in the nature of words of description rather than of limitation. Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that the scope of the invention is defined by the appended claims.