WO2008010178A2

WO2008010178A2 - A position alert system

Info

Publication number: WO2008010178A2
Application number: PCT/IB2007/052824
Authority: WO
Inventors: Valagam Raghunathan
Original assignee: Raghavan, Vijaya
Priority date: 2006-07-17
Filing date: 2007-07-16
Publication date: 2008-01-24
Also published as: WO2008010178A3

Abstract

A position alert system comprises a position logging unit (1 ) and a data retrieving unit (2). The position logging unit (1 ) comprises a receiver (12) for receiving information defining a position (Pi) of the logging unit (1 ), a storage medium (14) comprising pre-stored information defining a border (B2), and a first processor (13) for: (i) storing a sequence of positions (Pi) at predetermined sequential time instants (ti) defining a route (R) of the position logging unit (1 ), (ii) determining a distance (D1 ) between an actual position (Pi) of the logging unit (1 ) and the border (B2), and (iii) checking whether the distance (D1 ) is smaller than a threshold value (TH1 ), an alerting device (17) coupled to the processor (13) for alerting a user if the distance (D1 ) becomes smaller than the threshold value (TH1 ). The position logging unit (1 ) further comprises a first communication circuit (15). The data retrieving unit (2) comprises a second communication unit (21 ) for establishing a wired or wireless communication with the first communication unit (15), and a second processor for retrieving the sequence of positions (Pi) stored in the storage medium (14) of the position logging unit (1 ) via the second communication circuit (21 ) and for controlling an indicator to indicate whether the route (R) of the position logging unit (1 ) crossed the border (B2) or not.

Description

A POSITION ALERT SYSTEM.

Field of the invention

The invention relates to a position alert system comprising a position logging unit and a data retrieving unit. The invention further relates to the position logging unit, the data retrieving unit, and a cap comprising the position logging unit.

Background of the invention

In many situations it is not clear to a person where exactly a border between two states is running. Therefore, the person may cross the border unintentionally which may cause him a lot of trouble if detected by the authorities guarding the border. On the other hand, also the people representing the authorities may be mistaken in where exactly the border is, thereby causing a lot of nuisance to a person who actually did not cross the border. This is especially true on borders on land in sparsely populated areas or on water. For example, a fishing boat may enter the territorial waters of a particular state without actually knowing.

Summary of the invention

It is an object of the invention to provide a system which warns a user of the position logging unit when being too close to a border and which allows the user of the data retrieving unit to check whether the user crossed the border.

A first aspect of the invention provides a position alert system as claimed in claim 1. A second aspect of the invention provides a position logging unit as claimed in claim 18. A third aspect of the invention provides a data retrieving unit as claimed in claim 19. A fourth aspect of the invention provides a cap as claimed in claim 21. Advantageous embodiments are defined in the dependent claims. A position alert system in accordance with the first aspect of the invention comprises a position logging unit and a data retrieving unit.

The position logging unit comprises a receiver, a storage medium, a processor, an alerting device and a first communication circuit.

The receiver receives information which defines a position of the logging unit. The position of the logging unit on earth may be determined by using GPS (Global Positioning System) signals broadcasted by satellites, but alternatively may use signal beacons on earth. It is well known in the art how to determine the position from GPS or beacon signals.

The storage medium comprises pre-stored information defining a border. For example, the border is a state border on land or water. Alternatively, the border may also define any other area than a state. For example, the border may surround the premises of a house or factory.

The processor stores a sequence of positions in time. The processor may store only the positions, or the positions and a date if the time instants at which the position is sampled are known, for example because successive time instants occur equidistant. The processor may store the time instants and the positions at these time instants. The sequence of positions and time instants if relevant define a route of the position logging unit. This sequence may comprise a date.

The processor determines a distance between an actual position of the logging unit and the border, and checks whether the distance is smaller than a threshold value. The processor commands an alerting device to alert the user if the distance becomes smaller than the threshold value. If the threshold value is a non-zero value, the user is warned well ahead that he or she is near to the border. If the threshold value is zero, the user is warned when he crosses the border. The processor further comprises a first communication circuit which allows retrieving the stored positions (and if stored and relevant, also time instants) from the data logging unit.

The data retrieving unit comprises a second communication unit and a second processor. The second communication unit communicates with the first communication unit. The second processor retrieves the sequence of positions stored in the storage medium of the position logging unit via the first and the second communication circuit and controls an indicator to indicate whether the route of the position logging unit crossed the border or not. The indicator may be a visual or audio signal. In an embodiment, the data retrieving unit has a display and the processor supplies data to the display to display the positions and, if relevant, the time instants together with the border. The user of the data retrieving unit, which, for example, may be a police officer or a customs officer, in one glance is able to see the route the position logging unit took and thus is immediately able to detect whether the position logging unit crossed the border or not.

This system prevents both that the user of the position logging unit crosses the boundary unintentionally, and that the officer erroneously of opinion that the user crossed the border while it is actually not true.

In an embodiment, the receiver for receiving the information defining the position is a GPS receiver which supplies a longitude and latitude of the position of the logging unit to the processor. This embodiment has the advantage that the already present GPS satellites are used on it is not required to set up a dedicated system of signal beacons on earth.

In an embodiment, the storage medium comprises a non-volatile memory for storing the border. This has the advantage that it is not easy for the user to alter the stored border without exchanging the non-volatile memory. If a non-volatile memory is used outside the processor, the border information may be stored in a scrambled manner or may be encrypted to prevent tampering therewith.

In an embodiment, the processor comprises the non-volatile memory. This has the advantage that the user has no access at all to the non-volatile memory. Consequently, it becomes very difficult to change the stored border.

In an embodiment, the information defining the border comprises a list of border positions which are points on the border curve. The processor interpolates the border from the border points. This approach has the advantage that a relatively low number of border positions is required to indicate the border. The interpolation may be a simple linear interpolation or one of more sophisticated interpolation algorithms such as, for example, a spline algorithm. The number of border points may be larger for segments of the border which vary more than other segments of the border.

In an embodiment, the position logging unit further comprises a clock circuit which generates a clock signal. The processor receives the clock signal to determine equidistant time instances which form the predetermined sequential time instants. This has the advantage that the instances at which the position is stored are all known if one of the instances is linked to the real time. For example, the real time is stored when the first position is stored. Usually this will be the instant when the position logging unit is activated or reset. For example when used on a vessel at the instant the vessel starts moving. Only saving one time instant saves a lot of storage space.

In an embodiment, the alerting device provides a visual and/or audio signal to the user. The visual signal may be the color of a light source, for example a LED (Light Emitting Diode). For example, a green color indicates that the distance of the position logging unit is further away from the border than the threshold distance. A yellow color indicates that the position logging unit has a position which is nearer to the border than the threshold distance, and a red color indicates that the position logging unit has crossed the border. Alternatively, a sound signal may be generated to indicate to the user in which area he or she is, for example different tones or speech may be used to alert the user.

In an embodiment, the processor checks whether the distance is smaller than a further threshold value which is smaller than the first mentioned threshold value to provide a first alert to the user if the distance is smaller than the first mentioned threshold value but larger than the further threshold value, and a second alert different than the first alert if the distance is smaller than the further threshold value. This approach has the advantage that an extra warning can be given just before the position logging unit crosses the border.

In an embodiment, a unique identification code is stored in the position logging unit. In this manner the position logging unit is uniquely defined. The unique identification code may comprise data on the user. The data may comprise a photograph of the user. In this manner the position logging unit can be used as identification, such as for example a passport. This enables an easy check whether the position logging unit belongs to the user who is using it, and it is not anymore required to also carry a passport.

In an embodiment, the processor of the data retrieving unit retrieves the pre-stored information defining the border from the position logging unit. This has the advantage that can be checked whether the user of the position logging unit behaved faithfully or not, even when the border stored in his position logging unit does not exactly match the real border.

In an embodiment, the processor of the data retrieving unit retrieves the pre-stored border from a non-volatile memory of the data retrieving unit. This has the advantage that even when the user of the position logging unit tampered with the stored border, the user of the data retrieving unit is able to detect whether the border was crossed or not. In an embodiment, the border stored in the data retrieving unit and the border stored in the position logging circuit are supplied by the same supplier such that they are identical. In an embodiment, the data retrieving unit comprises a display on which both the sequence of positions and the border are shown. This visual representation makes it very simple to detect whether the position logging circuit crossed the border or not. In an embodiment, a unique data code is stored in the data retrieving unit.

This unique code can be retrieved by the position logging unit giving prove to the user which data retrieving unit and which (temporary) user thereof interrogated him or her.

In an embodiment, the second processor is arranged to send the unique data code of the data receiving unit to the position logging unit before, during or after retrieving the sequence of positions from the position logging unit. Or said differently, in this embodiment it is impossible for the owner of the data retrieving unit to retrieve the stored route from the position logging unit without providing the identification code of the data retrieving unit to the position logging unit. This has the advantage that the rights of the user of the position logging unit are optimally ensured. He or she always has proof who requested the route stored in the position logging unit.

In an embodiment, the first communication circuit and the second communication circuit automatically set up a link when they are in each others range. The first processor and the second processor automatically transfer (i) the sequence of positions and the unique identification code of the data logging unit to the data retrieving unit, and (ii) the unique identification code of the data retrieving unit to the data logging unit. This embodiment has the advantage that it is impossible for the user of the data retrieving unit to misuse his or her power without getting known.

The position logging unit may be provided in a cap. The cap comprises an antenna, the data retrieving unit, and a battery to supply power to the data retrieving unit. The receiver of the data retrieving unit has an input coupled to the antenna to receive signals indicating the position of the data retrieving unit. The antenna, the data retrieving unit and the battery may be sealed or covered to prevent moisture to enter these elements. In an embodiment, the cap may further comprise a solar panel for charging the battery. In an embodiment the antenna may be a GPS antenna.

These and other aspects of the invention are apparent from and will be elucidated with reference to the embodiments described hereinafter.

Brief description of the drawings

In the drawings: Fig. 1 schematically shows a block diagram of an embodiment of a position alert system,

Fig. 2 schematically shows a cap which comprises the position logging unit, and

Fig. 3 schematically shows an example of a route of a vessel between two states and their borders indicating territorial waters.

It should be noted that items which have the same reference numbers in different Figures, have the same structural features and the same functions, or are the same signals. Where the function and/or structure of such an item has been explained, there is no necessity for repeated explanation thereof in the detailed description.

Detailed description

Fig. 1 schematically shows a block diagram of an embodiment of a position alert system. The position logging unit 1 comprises a receiver 12, a processor 13, a memory 14, a communication unit 15, a clock circuit 16, and an alerting device 17. The receiver 12 receives an input signal via an antenna 11 and supplies position data Pi to the processor. If the antenna 11 is a GPS antenna to receive GPS signals, the receiver 12 processes the GPS signals to determine the position on earth. Usually, in the present invention it suffices to know the latitude and the longitude. However, optionally the elevation may be used. The processor 13 is clocked by the clock signal CLK from the clock circuit

16. The processor uses the clock signal CLK to define the instants ti at which the position data Pi which indicates the position of the position logging unit 1 is stored in the memory 14. The sequence of position data Pi stored form the route R (see Fig. 3) traveled by the position logging unit 1. Many possibilities exist to store useful information defining the route R. For example, if the position data Pi is sampled at equidistant instants ti, it suffices to store the position data Pi without a time indication for each one of the positions. The rate of sampling may be pre-selected, for example once per second, or once per minute, or once per 15 minutes. Alternatively, the position data Pi may be stored together with the instant ti at which the position data Pi is obtained. Now, the sampling instants ti may but need not be equidistant. For example, if the distance D1 (see Fig. 3) from the actual position Pi with respect to the border B2 (see Fig. 3) is relatively large, longer intervals may be used, than when near to the border B2. The sampling intervals may also depend on the speed of movement of the position logging unit 1. Using a low sampling rate when still far away from the border B2 decreases the power consumption of the position logging unit 1. To prevent fraud, preferably this memory 14 is not accessible by the user. For example, the processor 13 is programmed to block any write access to the memory 14 via the communication unit 15. Alternatively, the memory 14 may comprise a small circuit which requires a special handshake procedure or identification code to be able to write information into the memory 14 thereby preventing the user to change the route stored.

Further, the border B2, dependent on the nationality of the user may be stored in the memory 14 if sufficiently secured against fraud. Preferably, the border B2 is stored in non-volatile memory in the processor 13 such that it is not accessible to the user.

The processor 13 is coupled to the communication unit 15 to enable communication with the data retrieving unit 2. The processor 13 is coupled to the alerting device 17 to provide an alerting signal to the user. For example, if the alerting device comprises light sources generating different colored light, a green color indicates that the distance of the position logging unit is further away from the border than the threshold distance. A yellow color indicates that the position logging unit has a position which is nearer to the border than the threshold distance, and a red color indicates that the position logging unit has crossed the border. The threshold distance may be predefined, for example 1 km or 1 mile, or may be user definable. Alternatively, a sound signal may indicate the user in which area he or she is, for example different tones or speech may be used to alert the user.

An identification code ID1 may be stored in the position logging unit 1 to uniquely define the position logging unit 1. The identification code may be stored in the non-volatile memory of the processor 13 and may comprise information identifying the user of the position logging unit 1. The information identifying the user may comprise all items of a passport, including a photograph of the user. Consequently, it easy to check whether the position logging unit 1 belongs to the user who is using it.

The data retrieving unit 2 comprises a communication unit 21 , a processor 22, a memory 24 and a display 23. The processor 22 is able to retrieve the route R stored in the memory 14 via the communication unit 21. The processor 22 may store the retrieved route R in the memory 24 and controls the display 23 to display the route R. The border B2 may also be pre-stored in the memory 24 or in non-volatile memory in the processor 22, or alternatively, the border B2 may be retrieved from the memory 14 or the non-volatile memory in the processor 13. The processor 22 drives the display 23 to also display the border B2. The user of the data retrieving unit 2 is able to see in one glance whether the position logging system 1 crossed the border B2 or not. The data retrieving unit 2 may be a PDA (Personal Digital Assistant) running a suitable software program. The display 23 is optional, the data retrieving unit 2 may make clear with sounds, speech, or light signals whether or not the border was crossed.

The data retrieving unit 2 comprises a unique code ID2. In an embodiment, always when the data retrieving unit 2 retrieves the route stored in the position logging unit 1 it is communicating with, this unique code ID2 is sent to the position logging unit 1. In an even more sophisticated embodiment, this unique code ID2 and also the present position Pi of the position logging unit 1 is stored in the non-volatile memory of the processor 13. This greatly improves the legal position of the user of the position logging unit 1 if the user of the data retrieving unit 2 misuses his or her power. Often, the user of the data retrieving unit 2 is an officer of an authority or a boss of the user. If for example, the user can prove that he did not cross the border B2, and that at the time the data retrieving unit 2 was retrieving the route R the user still had not crossed the border B2, the officer was misusing his power. Also the time at which the data retrieving unit 2 retrieved the route may be stored in the position logging unit 1.

The borders B2 need not be limited to borders of states on land, but may also be borders on sea, for example to indicate fishing grounds assigned to a particular state, or the territorial waters around a particular state.

Fig. 2 schematically shows a cap 3 which comprises the position logging unit 1. The cap 3 comprises an antenna 11 , the position logging unit 1 , a battery 31 , and a solar panel 32. The antenna 11 , which is connected to the position logging unit 1 , and which may be a GPS antenna, receives the signals which enable the position logging unit 1 to determine the position of the cap 3. The battery 31 powers the position logging unit 1. The optional solar panel 32 is coupled to the battery 31 to charge it.

Fig. 3 schematically shows an example of a route of a vessel between two states and their borders indicating territorial waters. The vessel starts near the land border of the state S1 and heads towards fishing grounds near the territorial waters T2 of the other state S2. The territorial waters T1 of the state S1 occur in-between the land border of the state S1 and the border B1 which indicates the outer border of the territorial waters T1 of the state S1. The territorial waters T2 of the state S2 occur in- between the land border of the state S2 and the border B2 which indicates the outer border of the territorial waters T2. The borders B1 and/or B2 may be stored in the nonvolatile memory of the position logging unit 1 as a number of boundary positions BPi. The route R of the vessel is indicated by dots which show the position Pi of the vessel at the sample instants ti. These positions Pi and optionally the corresponding instants ti are stored in the memory 14 of the position logging unit 1. Regularly, for example at each of the time instants ti the minimal distance D1 of the vessel to the border B2 is determined. This minimal distance D1 may be determined for the position Pi at the instant ti by checking the distances Dij from the position Pi towards the boundary positions BPi which define the border B2. The minimal distance D1 is the minimal value of the distances Dij found. Alternatively, the boundary B2 may be interpolated from the boundary positions BPi and the distances Dij are determined between the position Pi and intersection points of lines through the position Pi and the interpolated boundary B2.

If the distance D1 is larger than the threshold value TH1 , the vessel is in safe waters. If the distance D1 becomes smaller than the threshold value TH1 but is still larger than the threshold value TH2, a warning is provided indicating to the user that the vessel is coming near to the border D2. If the distance D1 becomes smaller than the threshold value TH2, the user is warned to go back because he or she is very near to the border B2. If the distance D1 is zero or negative (a position Pi between the border B2 and the border of the land of the state S2), a warning is provided to the user to indicate that the border is crossed. In an alternative embodiment, the threshold value TH1 may be selected equal to zero, such that the user is warned when near to the border B2 when the distance D1 is smaller than the threshold value TH2, and when crossing the border B2.

The border which may not be crossed need not be the border of the territorial waters of a state. For example, the border B3 borders fishing grounds which are allocated to a particular state and nationals of other states are not allowed to enter these fishing grounds. Now, the position logging unit 1 indicates to the user when the vessel is too near to the border B3.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. Although the embodiments shown in the Fig. 3 are directed to borders on sea, the borders may be present on land or on a lake. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb "comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Claims

1. A position alert system comprising a position logging unit (1 ) and a data retrieving unit (2), wherein the position logging unit (1 ) comprises: a receiver (12) for receiving information defining a position (Pi) of the logging unit

(1 ), a storage medium (14) comprising pre-stored information defining a border (B2), a first processor (13) for: storing a sequence of positions (Pi) at predetermined sequential time instants (ti) defining a route (R) of the position logging unit (1 ), determining a distance (D1 ) between an actual position (Pi) of the logging unit (1 ) and the border (B2), and checking whether the distance (D1 ) is smaller than a threshold value (TH1 ), an alerting device (17) coupled to the processor (13) for alerting a user if the distance (D1 ) becomes smaller than the threshold value (TH1 ), and a first communication circuit (15), and wherein the data retrieving unit (2) comprises a second communication unit (21) for establishing a wired or wireless communication with the first communication unit (15), and a second processor for retrieving the sequence of positions (Pi) stored in the storage medium (14) of the position logging unit (1 ) via the second communication circuit (21 ) and for controlling an indicator to indicate whether the route (R) of the position logging unit (1) crossed the border (B2) or not.

2. A position alert system as claimed in claim 1 , wherein the receiver (12) for receiving the information defining the position (Pi) is a GPS receiver for supplying a longitude and latitude of the position (Pi) logging unit (1 ) resides to the processor (13).

3. A position alert system as claimed in claim 1 , wherein the storage medium (14) comprises a non-volatile memory for storing the border (B2).

4. A position alert system as claimed in claim 3, wherein the processor (13) comprises the non-volatile memory.

5. A position alert system as claimed in claim 1 , wherein the border (B2) is a border between two states or countries (S1 , S2).

6. A position alert system as claimed in claim 1 , wherein the information defining the border comprises a list of border points (BPi), and wherein the processor (13) is arranged for interpolating the border (B2) from the border points (BPi).

7. A position alert system as claimed in claim 1 , wherein the position logging unit (1 ) further comprises a clock circuit (16) for generating a clock signal (CLK), and wherein the processor (13) is arranged for receiving the clock signal (CLK) to determine equidistant time instances being the predetermined sequential time instants (ti).

8. A position alert system as claimed in claim 1 , wherein the alerting device (17) is arranged for providing a visual and/or audio signal to the user.

9. A position alert system as claimed in claim 1 , wherein the processor (13) is arranged for checking whether the distance (D1 ) is smaller than a further threshold value (TH2) being smaller than the first mentioned threshold value (TH1 ) to provide a first alert to the user if the distance is smaller than the first mentioned threshold value (TH1 ) but larger than the further threshold value (TH2), and a second alert different than the first alert if the distance (D1 ) is smaller than the further threshold value (TH2).

10. A position alert system as claimed in claim 1 , wherein a unique identification code (ID1 ) is stored in the position logging unit (1) for uniquely defining the position logging unit (1 ).

11. A position alert system as claimed in claim 1 , wherein the unique identification code (ID1 ) comprises data on the user.

12. A position alert system as claimed in claim 1 , wherein the second processor (22) is arranged for further retrieving the pre-stored information defining the border (B2) from the position logging unit (1 ).

13. A position alert system as claimed in claim 1 , wherein the data retrieving unit (2) comprises a non-volatile memory (24) also comprising the pre-stored border (B2), and wherein the second processor (22) retrieves the border (B2) from the nonvolatile memory (24) of the data retrieving unit (2).

14. A position alert system as claimed in claim 12, wherein the data retrieving unit (2) comprises a display (23) for displaying the sequence of positions (Pi) and the border (B2).

15. A position alert system as claimed in claim 12, wherein a unique data code (ID2) is stored in the data retrieving unit (2).

16. A position alert system as claimed in claim 15, wherein the second processor (22) is arranged to send the unique data code (ID2) of the data receiving unit (2) to the position logging unit (1 ) before, during or after retrieving the sequence of positions (Pi) from the position logging unit (1 ).

17. A position alert system as claimed in claim 16, wherein the first communication circuit (15) and the second communication circuit (21 ) are constructed for automatically setting up a link when in range, and wherein the first processor (13) and the second processor (22) are arranged for automatically transferring the sequence of positions (Pi) and the unique identification code (ID1 ) of the data logging unit (1 ) to the data retrieving unit (2), and for automatically providing the unique identification code (ID2) of the data retrieving unit (2) to the data logging unit (1 ).

18. A position logging unit (1 ) for use in the position alert system as claimed in claim 1 , the data retrieving unit (1 ) comprises: the receiver (12) for receiving the information defining the position (Pi) of the data logging unit (1 ), the storage medium (14) comprising pre-stored information defining the border

(B2), the processor (13) for storing the sequence of positions (Pi) at predetermined sequential time instants (ti) in the storage medium (14), for determining the distance (D1 ) between the positions (Pi) and the border (B2), and for checking whether the distance (D1 ) is smaller than the threshold value (TH1 ), the alerting device (17) coupled to the processor (13) for alerting the user if the distance (D1 ) becomes smaller than the threshold value (TH1 ), and the first communication circuit (15).

19. A data retrieving unit (2) for use in the position alert system as claimed in claim 1 , the data retrieving unit (2) comprises the second communication unit (21 ) for establishing the wired or wireless communication with the first communication unit (15), and the second processor for retrieving the sequence of positions (Pi) stored in the storage medium (14) of the position logging unit (1 ) via the second communication circuit (21 ) and for controlling the indicator to indicate whether the route (R) of the position logging unit (1) crossed the border (B2) or not .

20. A data retrieving unit (2) as claimed in claim 19, further comprising a display (23), and wherein the second processor is arranged for displaying the sequence of positions (Pi) and the border (B2) on the display (23) as the indicator.

21. A cap (3) comprising: an antenna (11 ), the data retrieving unit (1) as claimed in claim 7, wherein the receiver (12) has an input coupled to the antenna (11) to receive signals indicating the position of the data retrieving unit (1), and a battery (31 ) for supplying power to the data retrieving unit (1 ).

22. A cap as claimed in claim 21 further comprising a solar panel (32) for charging the battery (31 ).