AU6148400A - Method of route calculation and navigation system - Google Patents

Description

WO01/01078 PCT/DEOO/01955 1 Method of Route Computation and Navigation Device 5 Prior Art The invention relates to a method and navigation device for calculating a route from a 10 starting point to a destination according to the type of the independent patent claims. Navigation devices are known, in particular for operation in vehicles, which, following the input of a destination dependent on a current position, dependent on a current position with the aid of stored map information compute a route and guide the 15 driver of the vehicle optically and/or acoustically along this route from the current starting point to a destination. In a first group of known navigation devices, an input of the navigation destination takes place by means of the literal input of the place or city name and at least of a 20 street name of the navigation destination and possibly added information such as a part of a city or a house number. In navigation devices intended for installation into a 1-DIN housing of a vehicle, the front face surface is often not sufficient to provide all the letters of the alphabet with their own key, so that as a rule control elements for the input of letters are at least doubled, often four times occupied. The literal input of a 25 navigation destination is, in the case of these devices, comparatively laborious and time consuming. Another form of input of navigation destinations has therefore been realised in which, analogous to the described method of procedure, place and street names and possibly 30 further information can be literally input, in which a list is produced in which only those navigation destinations are contained to which already input letter combinations suit and in which the desired navigation destination can be selected by means of a -WO01/01078 PCT/DEUU/U1933 2 choice from the list. This input of navigation destinations is, over against the first named input, more convenient, however because of the required input of the letters, it is still not uncomplicated. 5 Furthermore, navigation devices are known in which the input of the navigation destination takes place by means of marking the destination by means of a controllable cursor on a map depicted on the display unit of the navigation device. Necessary aso, however, is relatively detailed knowledge of the exact location of the navigation destination on the map. Furthermore, before marking the actual navigation 10 destination, it is necessary to firstly select a suitable section of the map, which contains the navigation destination, and then to choose a map scale which shows the navigation destination with sufficiently high resolution. 15 Advantages of the invention The method of the invention and the navigation device of the invention with the characteristics of the independent patent claims have, over against prior art, the advantage that, following the determining of a route from a point of departure to a 20 destination, a new route computation a new route computation to the original starting point can be instigated with minimal operating effort. It is also of advantage to store a large number of points of departure, as consequently the number of especially simply input navigation destinations increases. In the 25 connection of a simpler operation, it is further of particular advantage, when the navigation device is switched on, to display a list of stored starting locations from which the new navigation destination can be selected. Moreover, the display of stored starting points at the time of or immediately before the input of the navigation destination is for this reason also advantageous, because the stored starting point can 30 be brought to the attention of the driver of the vehicle, so that an involved, customary input can, in certain circumstances, be dispensed with.

IWO01/01078 3FVMUI? 3 A particularly simple form of the destination selection makes possible a cursor moveable over the list by means of a cursor key to mark a starting point in connection with a confirmation key for selecting a marked starting point in the list as a new navigation destination. 5 Drawings Embodiments of the invention are represented in the Figures and will be described in 10 the following in some detail. Shown are: Figure 1 a block diagram of a preferred embodiment of a navigation device of 15 the invention, Figure 2A schematically, the second memory 70 with starting points at a first point in time, Figure 2B the second memory 70 at a second, later point in time. 20 Description of the embodiments The object of the present invention will be described in the following on the basis of the example of a vehicle navigation system 10, a block diagram of which is depicted 25 in Figure 1. On a device control 20 of the navigation device 10, which among other things comprises the actual navigation computer, are means 30, 35, 40, which provide information about current location, direction of movement and the conditions 30 surrounding movement of the vehicle.

.WO01/01078 PCT/DEOO/01955 4 In the present embodiment it is a matter of a rotation rate sensor 30, with the aid of which, by means of integration via the detected changes in rotational rate, the orientation of the vehicle in which the navigation device is installed, is detected with regard to directions. Furthermore, one has here to do with a route measurer 35, 5 which, for example, detects impulses emitted by wheel sensors of an antiblock system for brakes of vehicles and from the established number of impulses and a known wheel circumference, determines a route travelled. Finally there is a GPS (Global Positioning System) receiver 40 for the reception and for the evaluation of radio signals emitted by GPS satellites, on the basis of which the position of the vehicle is 10 established. Furthermore, connected to the control 20 is a first memory 60 in which information of a map or street directory, especially traffic route information, such as information about freeways, highways, country roads and regional roads as well as inner city 15 roads and at least place and street names are stored in digital form. In the present embodiment, the first memory 60 is realised in the form of a CD-ROM drive with inserted CD-ROM as data carrier for the map information. It can equally be planned that the first memory 60 is realised in the form of a ROM- or RAM semiconductor memory. In the latter case of a RAM memory, the stored map information can easily 20 be actualised for example via radio connection between the navigation device 10 and a central or by means of receivable radio signals of transmitted information. Furthermore, an output unit 50 for the display and/or acoustic output of travel instructions is connected to the control. To it, during the actual destination guidance 25 procedure, travel instructions for the driver, for example in the form of an arrow indicating direction in the case of imminent turns and a remaining distance display before the turn, are depicted. Alternatively or complementary to the optical output of the travel instructions, an acoustic reproduction of the travel instructions, for example in the form of "after 100 metres turn right". For generating the travel instructions, the 30 control 20 has a corresponding, not depicted and known generator, in the case of an acoustic output of the driving instructions for example in the form of a language synthesiser for the conversion of a travel instruction into understandable language.

-WO01/01078 PCT/DEOO/01955 5 Furthermore, connected to the control 20 is an input unit 45 with operating elements such as, for example, knobs for the input of a navigation destination and for the handling of other functions of the device. In the case of the present invention, the 5 input unit is preferably constructed in the form of a cursor control with cursor keys 47a, 47b, 47c, 47d and a confirmation key 48 which enable in particular an especially simple selection of a destination point or of another parameter value to be selected from a selection list preferably by means of the marking of the corresponding list entry by means of a controllable cursor 49 and the concluding confirmation of the 10 marked list entry. Finally a second memory 70 is provided on the control for the filing of a navigation starting point. In a first embodiment of the invention the second memory 70 is constructed in such a way that in it, a single starting point 71, a data record marking a 15 starting point consisting, for example, of information about coordinates of the starting point within the map stored in the first memory 60 or consisting of information on the geographical length and breadth of the starting point or consisting of at least one place and street name of the starting point and possibly also complementary further information such as a house number or a number sequence which can be allocated 20 clearly to a navigation destination, for example a telephone number can be stored. In addition, the control 20 is designed in such a way that at the beginning of a destination guide procedure, after the starting of the navigation device and setting the vehicle in motion in which the navigation device is operated, the starting point is 25 written in the second memory 70. In a second embodiment of the navigation device of the invention, it is planned that a majority of starting point data records 71, 72, 73, 74, 75 can be stored in the second memory 70. In addition, the second memory 70 is preferably designed in the form 30 usually of a LIFO (Last In First Out) memory, so that the control 20, in the case of access to the data record stored in the second memory 70 firstly accesses the last stored data record.

WO01/01078 PCT/DE0O/01955 6 For storing a multiplicity of starting point data sets in the second memory 70 the control 20 is designed in such a way that, preferably at the beginning of the route computation or for example immediately after the determining of location or at the 5 commencement of the destination guide procedure after closing of the route calculation the corresponding starting point 74, 75 is written in the second memory 70. Alternatively however, it is also possible that before the storing of a starting point 10 data set, the driver of the vehicle is required to confirm a storing of the data set. The described navigation device operates as follows. With the switching on of the navigation device the sensors 30,35,40, namely the 15 rotational rate sensor 30, the route distance measurer 35 and the GPS receiver 40 provide information about the state of movement, the direction and current location of the vehicle in which the navigation device 10 is operated. The navigation computer of the control 20 calculates the current vehicular position from the signals of the sensors 30 and 35. These are corrected if necessary by means of a comparison with 20 the map information stored in the first memory 60 in terms of a plausibility check. This procedure is known by the term "map matching". Finally or immediately after the device has been switched on, that is simultaneous with the determining of position, the driver inputs a navigation destination, for 25 example in the known way by means of the literal input of place and street name of the navigation destination and/or through its selection from a destination list. Alternatively, the destination input can be made in the form of a marking of the navigation destination on a map represented on the output unit 50 by means of a controllable cursor or by means of the input of a number clearly allocated to the 30 navigation destination, for example a telephone number.

WO01/01078 PCT/DEOO/01955 7 Alongside this, it is planned for the invention that the input of the navigation destination take place also by means of a selection, in the case of the first embodiment, of the starting point stored in the second memory 70, in the case of the second embodiment of one of the starting points 71, 72, 73, 74 stored in the second 5 memory 70. In the case of the second embodiment example, in addition, with the starting of the navigation device, a list of stored starting points 71 to 74 is shown on its display 50, the last stored starting point 74 being noted at the first position on the list, the possible 10 further starting points 71 to 73 being shown, for example, sorted in reversed order of its storing or according to another criterion, such as, for example alphabetically according to city names. For the selection of a stored starting point as a new destination point, a shiftable cursor 49 exists over the displayed list by means of cursor keys 47a to 47d, which with a first display of the list at the starting of the 15 navigation device 10, the last stored starting point 74 is stored. This can be selected by means of a simple confirmation by means of a confirmation key. Should, instead of the last stored starting point an older starting point 71 to 73 be selected, the cursor 49 is shifted by means of the cursor keys 47a to 49d to the appropriate list entry and the starting point marked in this way will be selected by means of the confirmation 20 key 48 (Figure 2A). After input of the navigation destination and determining of the current vehicle location, a route computation from the current vehicle location to the user defined destination, that is, to the navigation destination with the aid of the map information 25 stored in the first memory 60, takes place in the navigation computer of the control 20 automatically or at the explicit instigation of the driver of the vehicle. Simultaneously, at the beginning of the route computation, the current vehicle location is written as starting point 75 in the second memory 70 (Figure 2B). 30 Alternatively, the writing of the starting point in the second memory 70 can take place not until after the vehicle is set in motion, at the beginning of the destination guidance procedure or immediately after the determining of the location after the navigation WOO1/01078 PCT/DEOO/01955 8 device 10 is switched on or to one of the named points in time at the instigation of the user. If, with the second memory 70 according to the first embodiment, one memory with 5 storage location for only one starting point is involved, then an already stored starting point is overwritten. If, with the second memory 70 according to the second embodiment, one memory for recording a multiplicity of starting point data sets is involved, then the already stored 10 entries 71 to 74 are moved back one place in their order of priority and the current starting point 75 is written in first place in the second memory 70. If the current vehicle location and therefore the starting point agrees with a starting place already stored in the second memory 70, then this will preferably not be written again in the second memory 70 but the contents of the memory are sorted if applicable in such a 15 way that the current location is again at first position in the second memory 70. If the capacity of the second memory 70 is exhausted due to the amount of entries, then in the present embodiment it is provided that the oldest entry 71 is erased with the writing of a new starting point 75. 20 In another embodiment it can be planned that all entries except the most current or all entries can be erased in given time intervals or at time intervals predetermined by the user of, for example, one or more days or one or more weeks with the switching on of the navigation device or before its being turned off. 25 After the computing of the route from the current starting point 75 to the selected destination point, the actual destination guiding, in the course of which the navigation device 10 guides the driver of the vehicle by means of optical and/or acoustic travel instructions along the computed route to the input destination, commences at the beginning of the trip. If the driver departs from the given route, it is planned that after 30 determining of the current vehicle location, a new computation takes place, the further travel instructions taking place on the basis of the newly computed route.

Claims (7)

1. Method for computing a route from a starting point to a destination point, characterised in that the starting point is stored and that the stored starting point can be selected as the destination point for a new route computation. 10

2. Method according to Claim 1, characterised in that the starting point in a list is stored and that as destination point for a new route computation a starting point can be selected from the list. 15

3. Method according to Claim 2, characterised in that the list of the starting points to the navigation destination are indicated.

4. Method according to Claim 3, characterised in that the navigation destination can be selected through the marking of a starting point within the list, preferably by 20 means of a cursor (48) controllable with a cursor key (47a, 47b, 47c, 47d) and then the confirmation of the marked starting point.

5. Method according to one of the Claims 2 to 4, characterised in that the starting points stored in the list are erased after a given period of time. 25

6. Navigation device for the computing of a route from a starting point to a destination point, characterised by a second memory (70) for the storing of the starting point (74, 75) and means (47a, 47b, 47c, 47d, 48, 49) for selecting the stored starting point (74, 75) as the destination point for a new computation. 30

7. Navigation device according to Claim 4, characterised in that the second memory (70) is designed in the form of a list for storing a multiplicity of destination points IWOO1/01078 PCT/DEOO/01955 10 (71, 72, 73, 74, 75) and that a starting point can be selected as a new destination point. 5