GB2340241A

GB2340241A - Speed warning device with GPS

Info

Publication number: GB2340241A
Application number: GB9816363A
Authority: GB
Inventors: David Roger Southcott
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-07-28
Filing date: 1998-07-28
Publication date: 2000-02-16
Also published as: GB9816363D0

Description

1 2340241 Device and Method The invention relates to a device and method

for a speed warning for motorised vehicles, in particular cars, but also boats, aeroplanes, etc.

GB 2284055 B discloses an automatic speed warning unit for vehicles, which receives speed information in pulse form from the vehicle speedometer. Simple controls are provided to select between a few pre-set speed limits. The device issues audible and/or visual warnings when these limits are exceeded.

One problem with the known device is that it requires tampering with the vehicle electronics, and particularly the speedometer unit. Many users are either not competent or not willing to take such steps, as they may invalidate warranties, raise suspicions over mileage when selling the vehicle, and so forth.

The invention proposes a vehicle speed warning which includes a GPS or similar satellite radio receiver, means for extracting speed information from received satellite radio signals, means for comparing the extracted speed information with one or more pre-determined limits, and means for providing an indication to the user 20 when a speed limit is approached or exceeded.

The GPS-based device can be self-contained in one unit, or one unit plus separate antenna. It may be powered by its own battery and/or a 12 volt or similar supply from the vehicle.

In another aspect of the invention, which may be applied in a satellitebased or speed ometer-b ased system, the device provides the facility for a user command to input a desired alarm speed limit by reference to current vehicle speed, rather than absolute limits.

An embodiment of the invention will now be described with reference to the accompanying drawings in which:

2 Figure 1 is a block diagram of hardware for a device according to one embodiment of the present invention.

Figure 2 illustrates the operating method of the device in figure 1.

In figure 1 a GPS receiver module 100 with antenna 102 is provided. A suitable GPS receiver module is available from Rockwell Semiconductor Systems under the trade mark JUPITER. This includes receiving, decoding and power management circuits. An output 104 of the receiver module provides NMEA-0183 standard data on a standard RS 232 serial interface (NMEA = Nautical Marine Electronics Association). These signals, according to a standard format, indicate latitude, longitude, height, velocity, heading, time, status and control information.

Data sheets of the JUPITER receiver module are available at http://www.rss.rockwell.com/platforms/wireless/gps/Jupiter/main.htinl. Contents of this and the aforementioned British patent are incorporated herein by way of reference. Similar GPS receivers are available from other manufacturers, such as Motorola.

A microcontroller-based processing unit 106 receives the serial data stream, and also receives input from a keypad 108. This keypad may be of "calculator" style as proposed in GB 2284055 mentioned above, or maybe of a simpler format. The priority of course is to minimise distractions for the driver. A display 110 is driven by the microcontroller which may comprise simply one LED, and/or alternatively a numeric display showing current limit, current speed or other information. A loudspeaker or other sounder 112 is provided, also driven by the microcontroller 106.

Figure 2 shows the sequence of operations performed by the device of Figure 1 in the present embodiment. At step 200, the GPS receiver 100 is activated to obtain a serial data stream according to the NMEA-0183 format. At 202, the velocity or speed figure contained in the NMEA-0 183 format signals is extracted.

3 At 204, one or more alarm levels are set, either by the manufacturer of the device or by the user, for example as described in the aforementioned British patent. As indicated by dotted line 206, the speed extracted from the GPS signal may also be used to set an alarm level, for example by a simple button press causing capture of the cur-rent speed. The alarm level may be set at the current speed, or a predetermined amount above or below it.

At 210, the alarm level(s) and current speed from the GPS receiver are compared. Depending on the results of the comparison, an audible and/or visual 10 alarm is activated at step 212.

The person skilled in the art will readily understand how the various blocks and steps discussed above may be put into practice. It will further be appreciated that many variations on the structure and operation of the device are possible, without 15 departing from the spirit and scope of the invention.

4

Claims

1. A vehicle speed warning device comprising means for deriving a measurement of vehicle speed from received satellite radio signals, means for establishing at least one speed alarm value, and means for providing an indication to the user when the derived speed exceeds the established alarm value.

2. A device as claimed in claim 1, in the form of a self-contained unit separate from the vehicle.

3. A device according to claim 1 or 2, wherein the means for establishing said alarm value(s) is responsive to user input.

4. A device according to claim 3, wherein, upon user command, a present speed value, as derived from said satellite radio signals, is used automatically as a basis for setting the alarm value.

5. A device as claimed in any preceding claim, wherein said indication is an audible alarm signal.

6. A device according to any preceding claim, wherein said indication is a visual alarm signal.

7. A device as claimed in any preceding claim having minimal display facilities, excluding for example displays of latitude and longitude.

8. A method of providing an over-speed alarm to a user of a motorised vehicle, wherein actual speed measurements are compared with a pre-set speed alarm value, the measured speed being derived from received satellite radio signals.

9. A speed warning device substantially as described herein with reference to the accompanying drawings.

10. A speed warning method substantially as described herein with reference to figure 2 of the accompanying drawings.