GB2334102A

GB2334102A - A navigation system

Info

Publication number: GB2334102A
Application number: GB9802441A
Authority: GB
Inventors: Gary Micheal James Harding
Original assignee: MG Rover Group Ltd
Current assignee: MG Rover Group Ltd
Priority date: 1998-02-06
Filing date: 1998-02-06
Publication date: 1999-08-11
Anticipated expiration: 2018-02-06
Also published as: GB9802441D0; GB2334102B

Abstract

A navigation system for an off-road vehicle includes a single display which shows simultaneously true or magnetic north 22, the direction of travel 21 of the vehicle, and the direction 23 in which the vehicle needs to travel to reach a desired destination.

Description

A Navigation Svstem The invention relates to a navigation system and particularly to an offroad navigation system for land vehicles.

Conventional navigation systems display directions to the user to a predetermined destination along streets stored in a memory store such as a CD ROM. The directions are normally displayed as arrows on a plan view or a perspective view on a street map.

The present invention relates generally to off-road navigation systems where street navigation displays are not normally appropriate.

It is an object of the present invention to provide an improved navigation system.

According to the invention there is provided a navigation system comprising means for determining a reference direction, means for automatically determining intended direction of travel and display means indicating the reference direction and the intended direction.

In that way, the user receives an indication of the direction in which he is supposed to travel in relation to an absolute direction. such as magnetic or geographical north.

Preferably, the system comprises means for determining position and means for determining intended position and the display indicates a direction vector from the current position to the intended position.

Alternatively, the system comprises means for determining current position, means for determining intended position and means for determining the presence of difficult terrain between the current position and the intended position, the system including means for determining an alternative direction to circumvent the difficult terrain and displaying the alternative direction on the display. The means for determining the presence of difficult terrain may be a map stored in a memory store in the apparatus and a processor which determines that the direct route from current position to intended position crosses an area of difficult terrain.

Difficult terrain could be standing water. marshland, impenetrable forest or an incline too steep for the vehicle in which the system is located to traverse.

The display is preferably a liquid crystal display.

The system is preferably an off-road navigation system, most preferably an off-road navigation system for a land vehicle.

The means for determining the reference direction is preferably a compass.

The system preferably further comprises means for determining current vehicle heading and the current vehicle heading is preferably displayed on the display.

In one embodiment the reference direction is fixed on the display and the intended direction moves in relation to the fixed reference direction. In another embodiment the intended direction is fixed on the display and the reference direction moves in relation to the intended direction and in the most preferred embodiment, the current vehicle heading is a fixed position on the display and the reference direction and intended direction both move relative to the current vehicle heading in response to vehicle movement.

Thus. if the reference direction is due north. the intended direction is due west and the current vehicle heading is north west, the display will show a first arrow indicating current vehicle heading, a second arrow indicating due north and a third arrow indicating due west. The user can then turn the vehicle to the left in order to bring the vehicle about so that it heads in a westerly direction. As the vehicle comes about the arrow indicating north and the arrow indicating the intended direction will rotate around the display in relation to the arrow indicating current vehicle heading. The three arrows are preferably indicated differently, either by the use of different shapes or the use of different colours.

The display preferably further includes degree markings spaced around the periphery of the display. Nlost preferably the degree markings begin at zero in relation to due north and are indicated even 5 degrees around the periphery of the display.

The means for determining the intended direction of travel preferably comprises a map stored in a memory store and means for automatically sensing the position of the vehicle on the earth, for example, a satellite navigation system such as the global positioning system (GPS). It will be appreciated that any system which can determine the position of the vehicle on the earth is appropriate.

The system preferably comprises a map stored on a CD RONI, a satellite positioning system receiver. a compass and a micro-processor which receives data from the CD ROM. the satellite positioning system receiver and the compass to determine vehicle position, intended position, the presence of difficult terrain. the reference direction and supplies display data to the display so as to show a reference direction arrow and an intended route arrow, together with current vehicle heading.

An embodiment of the invention will now be described in detail with reference to the accompanying drawing which is a schematic drawing of the navigation system in accordance with the invention.

The navigation system 10 comprises a micro-processor 12, a CD ROM reader 14, with a cassette of CD ROMs (not shown), a compass 16, a satellite positioning system receiver 18, such as a GPS receiver and a liquid crystal display 20.

The display 20 is preferably located within the vehicle as to position it to be readily viewable by the driver. In one embodiment the display may be incorporated into the dashboard, most preferably adjacent to the speedometer etc. .Alternatively, the display may be provided in the centre of the steering wheel. In another embodiment the display is provided as a head up display (HUD). That version is advantageous since the driver does not have to take his eyes from the path ahead of the vehicle in order to read the display.

The compass 16 is preferably located at a point in the vehicle, such as the boot. that is free from interference from magnetic sources.

The GPS receiver 18 preferably includes an aerial 18a which may be located on the roof of the vehicle to allow better reception.

As can be seen in the drawing, the display includes three direction indicators in the form of arrows. The first arrow 21 indicates current vehicle heading, the second arrow 22 indicates magnetic north and the third arrow 23 indicates the intended route that the vehicle needs to take.

Accordingly, in the version shown in the drawings the vehicle is heading approximately west/south west as shown by arrow 21, arrow 22 always indicates magnetic north and the intended direction indicated by arrow 23 is approximately west north west. The display 20 may also show the vehicle heading in the form of a number of degrees from north. The current vehicle position may also be displayed by longitude/latitude or by a map reference.

The display may also show further information such as the presence of dangerous terrain in the vicinity of the vehicle and other points of interest.

Claims

CLAIMS CLAIMS 1. A navigation system comprising means for determining a reference direction, means for automatically determining intended direction of travel and display means indicating the reference direction and the intended direction.
2. A navigation system according to claim 1 wherein the system comprises means for determining position and means for determining intended position and the display indicates a direction vector from the current position to the intended position.
3. X navigation system according to claim 1 wherein the system comprises means for determining current position, means for determining intended position and means for determining the presence of difficult terrain between the current position and the intended position, the system including means for determining an alternative direction to circumvent the difficult terrain and displaying the alternative direction on the display.
4. A navigation system according to claim 3 wherein the means for determining the presence of difficult terrain is a map stored in a memory store in the apparatus and a processor which determines that the direct route from current position to intended position crosses an area of difficult terrain.
5. A navigation system according to any foregoing claim which is an off road navigation system for a land vehicle.
6. .R navigation system according to any foregoing claim further comprising means for determining current vehicle heading and the current vehicle heading is preferably displayed on the display.
7. X navigation system according to claim 6 wherein reference direction is fixed on the display and the intended direction moves in relation to the fixed reference direction.
8. A navigation system according to claim 6 wherein the intended direction is fixed on the display and the reference direction moves in relation to the intended direction.
9. A navigation system according to claim 6 the current vehicle heading is a fixed position on the display and the reference direction and intended direction both move relative to the current vehicle heading in response to vehicle movement.
10. A navigation system according to any foregoing claim wherein the means for determining the intended direction of travel comprises a map stored in a memory store and means for automatically sensing the position of the vehicle on the earth.
11. A navigation system according to any foregoing claim comprising a map stored on a CD ROM, a satellite positioning system receiver, a compass and a micro-processor which receives data from the CD RONI, the satellite positioning system receiver and the compass to determine vehicle position, intended position, the presence of difficult terrain, the reference direction and supplies display data to the display so as to show a reference direction arrow and an intended route arrow, together with current vehicle heading.
12. A navigation system substantially as hereinbefore described with reference to the accompanying drawings.