Position locating system, server, position locating method, and program

• US 6,810,325 B2
• Filed: 01/28/2003
• Issued: 10/26/2004
• Est. Priority Date: 01/30/2002
• Status: Expired due to Fees

• Current Assignee: Increment P Corporation, Pioneer Corporation
• Original Assignee: Increment P Corporation, Pioneer Corporation
• Inventors: Nozaki, Takashi, Amano, Kouji
• Primary Examiner(s): LOUIS JACQUES, JACQUES H
• Application Number:
  US10/352,212
• Publication Number:
  US 20030144792A1
• Time in Patent Office: 637 Days
• Field of Search: 340/988-993, 701/207-213, 455/456.1, 455/456.2, 455/456.3, 455/456.5, 455/456.6, 455/457, 455/517, 455/421, 342/257.01, 342/357.06, 342/357.07, 342/357.09, 342/357.13
• US Class Current: 701/207
• CPC Class Codes: G08G 1/0962 having an indicator mounted inside the vehicle, e.g. giving voice messages

Abstract

A server includes a position estimation section for estimating the current position of a client apparatus based on the already acquired position information when the server cannot acquire position information from the client apparatus and the server requests the client apparatus to transmit position information in response to a search instruction from an information terminal.

Claims

1. A position locating system comprising:

a client apparatus for detecting current position of the client apparatus and transmitting obtained position information at a predetermined frequency;

an information terminal for transmitting an instruction for searching for the current position of the client apparatus; and

a server for receiving the current position search instruction from the information terminal and transmitting map image data containing the current position of the client apparatus to the information terminal based on the position information transmitted from the client apparatus,

wherein the server includes a position estimation section for estimating the current position of the client apparatus based on the already acquired position information when the server cannot acquire the position information from the client apparatus and the server requests the client apparatus to transmit position information in response to the search instruction from the information terminal,

wherein the server further includes a database, which stores geographic data indicating a reception failure position where there is a possibility that reception of the position information from the client apparatus may stop dead; and

wherein the position estimation section estimates the current position of the client apparatus based on the geographic data.

2. The position locating system comprising:

a client apparatus for detecting current position of the client apparatus and transmitting obtained position information at a predetermined frequency;

an information terminal for transmitting an instruction for searching for the current position of the client apparatus; and

a server for receiving the current position search instruction from the information terminal and transmitting map image data containing the current position of the client apparatus to the information terminal based on the position information transmitted from the client apparatus,

wherein the server includes a position estimation section for estimating the current position of the client apparatus based on the already acquired position information when the server cannot acquire the position information from the client apparatus and the server requests the client apparatus to transmit position information in response to the search instruction from the information terminal,

wherein the server further includes a database, which stores geographic data indicating a reception failure position where there is a possibility that reception of the position information from the client apparatus may stop dead,

wherein the position estimation section estimates the current position of the client apparatus based on the geographic data,

wherein an estimated area where it is estimated that the client apparatus exists is set based on the already acquired position information, and

wherein the position estimation section estimates the reception failure position in the estimated area as a candidate for the current position of the client apparatus.

3. The position locating system comprising:

a client apparatus for detecting current position of the client apparatus and transmitting obtained position information at a predetermined frequency;

an information terminal for transmitting an instruction for searching for the current position of the client apparatus; and

a server for receiving the current position search instruction from the information terminal and transmitting man image data containing the current position of the client apparatus to the information terminal based on the position information transmitted from the client apparatus,

wherein the server includes a position estimation section for estimating the current position of the client apparatus based on the already acquired position information when the server cannot acquire the position information from the client apparatus and the server requests the client apparatus to transmit position information in response to the search instruction from the information terminal,

wherein the server further includes a database, which stores geographic data indicating a reception failure position where there is a possibility that reception of the position information from the client apparatus may stop dead,

wherein the position estimation section estimates the current position of the client apparatus based on the geographic data,

wherein an estimated area where it is estimated that the client apparatus exists is set based on the already acquired position information,

wherein the position estimation section estimates the reception failure position in the estimated area as a candidate for the current position of the client apparatus,

wherein the position estimation section sets variably the estimated area based on history information up to the most recent position of the client apparatus.

4. A server comprising:

a transmission-reception section for receiving position information from a client apparatus at a predetermined frequency, receiving a position search instruction from an information terminal, and transmitting map image data containing current position of the client apparatus to the information terminal;

a position locating processing section for generating the map image containing the current position of the client apparatus located based on the position information transmitted from the client apparatus;

a position estimation section for generating the map image data containing the current position of the client apparatus estimated based on the already acquired position information when the position information from the client apparatus cannot be acquired and the client apparatus is requested to transmit position information in response to the search instruction from the information terminal; and

a database, which stores geographic data indicating a reception failure position where there is a possibility that reception of the position information from the client apparatus may stop dead,

wherein the position estimation section estimates the position of the client apparatus based on the geographic data.

5. A server comprising:

a transmission-reception section for receiving position information from a client apparatus at a predetermined frequency, receiving a position search instruction from an information terminal, and transmitting map image data containing current position of the client apparatus to the information terminal;

a position locating processing section for generating the map image containing the current position of the client apparatus located based on the position information transmitted from the client apparatus;

a position estimation section for generating the map image data containing the current position of the client apparatus estimated based on the already acquired position information when the position information from the client apparatus cannot be acquired and the client apparatus is requested to transmit position information in response to the search instruction from the information terminal; and

further comprising a database, which stores geographic data indicating a reception failure position where there is a possibility that reception of the position information from the client apparatus may stop dead,

wherein the position estimation section estimates the position of the client apparatus based on the geographic data,

wherein an estimated area where it is estimated that the client apparatus exists is set based on the already acquired position information, and

wherein the position estimation section estimates the reception failure position in the estimated area as a candidate for the current position of the client apparatus.

6. A position locating method comprising the steps of:

requesting a client apparatus to transmit position information in response to current position search instruction;

locating current position of the client apparatus based on the position information transmitted from the client apparatus;

estimating the current position of the client apparatus based on already acquired position information when the client information is requested to transmit the position information in response to the current position search instruction and the position information from the client apparatus cannot be acquired;

transmitting map image data containing the current position of the client apparatus which is located or estimated;

detecting as to whether the position information from the client apparatus cannot be acquired when the client apparatus is requested to transmit position information in response to the current position search instruction; and

setting an estimated area where it is estimated that the client apparatus exists based on the already acquired position information,

wherein in the estimating step, a reception failure position where there is a possibility that reception of the position information from the client apparatus may stop dead in the estimated area is estimated as a candidate for the current position of the client apparatus.

7. A position locating method comprising the steps of:

requesting a client apparatus to transmit position information in response to current position search instruction;

locating current position of the client apparatus based on the position information transmitted from the client apparatus;

estimating the current position of the client apparatus based on already acquired position information when the client information is requested to transmit the position information in response to the current position search instruction and the position information from the client apparatus cannot be acquired;

transmitting map image data containing the current position of the client apparatus which is located or estimated;

detecting the current position of the client apparatus; and

transmitting the obtained position information at a predetermined frequency;

further the comprising the steps of;

detecting as to whether the position information from the client apparatus cannot be acquired when the client apparatus is requested to transmit position information in response to the current position search instruction; and

setting an estimated area where it is estimated that the client apparatus exists based on the already acquired position information,

wherein in the estimating step, a reception failure position where there is a possibility that reception of the position information from the client apparatus may stop dead in the estimated area is estimated as a candidate for the current position of the client apparatus;

detecting as to whether the position information from the client apparatus cannot be acquired when the client apparatus is requested to transmit position information in response to the current position search instructions; and

setting an estimated area where it is estimated that the client apparatus exists based on the already acquired position information,

wherein in the estimating step, a reception failure position where there is a possibility that reception of the position information from the client apparatus may stop dead in the estimated area is estimated as a candidate for the current position of the client apparatus.

8. A program embodied on a computer readable medium when executed by a server causes a computer to function as:

a transmission-reception section for receiving position information from a client apparatus at a predetermined frequency and receiving a position search instruction from an information terminal and transmitting map image data containing the current position of the client apparatus to the information terminal;

a position locating processing section for generating the map image data containing the current position of the client apparatus located based on the position information transmitted from the client apparatus; and

a position estimation section for generating the map image data containing the current position of the client apparatus estimated based on the already acquired position information when the position information from the client apparatus cannot be acquired and the client apparatus is requested to transmit position information in response to the search instruction from the information terminal,

wherein the position estimation section estimates the position of the client apparatus based on geographic data indicating a reception failure position where there is a possibility that reception of the position information from the client apparatus may stop dead.

9. A program embodied on a computer readable medium when executed by a server causes a computer to function as:

a transmission-reception section for receiving position information from a client apparatus at a predetermined frequency and receiving a position search instruction from an information terminal and transmitting map image data containing the current position of the client apparatus to the information terminal;

a position locating processing section for generating the map image data containing the current position of the client apparatus located based on the position information transmitted from the client apparatus; and

a position estimation section for generating the ap image data containing the current position of the client apparatus estimated based on the already acquired position information when the position information from the client apparatus cannot be acquired and the client apparatus is requested to transmit position information in response to the search instruction from the information terminal,

wherein the position estimation section estimates the position of the client apparatus based on geographic data indicating a reception failure position where there is a possibility that reception of the position information from the client apparatus may stop dead,

wherein an estimated area where it is estimated that the client apparatus exists is set based on the already acquired position information, and

wherein the position estimation section estimates that the reception failure position in the estimated area is candidate for the current position of the client apparatus.

10. A position information transmission apparatus being installed in a mobile unit, for detecting position of the apparatus and transmitting acquired position information to a server for locating the position of the apparatus, the position information transmission apparatus comprising:

a position information transmission frequency setting section for setting transmission frequency of the position information in response to move speed of the mobile unit,

wherein the position information transmission frequency setting section sets the transmission frequency based on time reference responsive to the move speed of the mobile unit,

wherein when the move speed of the mobile unit is equal to or higher than predetermined speed, the position information transmission frequency setting section sets the transmission frequency based on the distance reference responsive to the move speed of the mobile unit,

wherein when the move speed of the mobile unit is less than the predetermined speed, the position information transmission frequency setting section sets the transmission frequency based on time reference responsive to the move speed of the mobile unit,

wherein when the move speed of the mobile unit is equal to or less than a second predetermined speed lower than the predetermined speed, the transmission section immediately transmits the position information accumulated in the accumulation section, and

wherein when the move speed of the mobile unit remains the second predetermined speed after the transmission section immediately transmits the position information, the later transmission frequency is set to the frequency set by the position information transmission frequency setting section.

11. The position information transmission apparatus according to claim 10, further comprising:

a position detection section for detecting position information indicating the current position of the mobile unit every predetermined interval;

an accumulation section for accumulating the position information; and

a transmission section for transmitting the position information accumulated in the accumulation means to the server based on the transmission frequency set by the position information transmission frequency setting section.

12. The position information transmission apparatus according to claim 11, wherein the transmission section transmits only the position information, which has not been transmitted to the server, of the position information accumulated in the accumulation section.

13. The position information transmission apparatus according to claim 10, wherein the position information transmission frequency setting section sets the transmission frequency based on distance reference responsive to the move speed of the mobile unit.

14. A position information transmission method comprising the steps of:

detecting position of a mobile unit;

transmitting acquired position information to a server for locating the position of the mobile unit;

determining move speed of the mobile unit; and

setting transmission frequency of the position information in response to the move speed of the mobile unit,

wherein the position information transmission frequency setting section sets the transmission frequency based on time reference responsive to the move speed of the mobile unit,

wherein when the move speed of the mobile unit is equal to or higher than predetermined speed, the position information transmission frequency setting section sets the transmission frequency based on the distance reference responsive to the move speed of the mobile unit,

wherein when the move speed of the mobile unit is less than the predetermined speed, the position information transmission frequency setting section sets the transmission frequency based on time reference responsive to the move speed of the mobile unit,

wherein when the move speed of the mobile unit is equal to or less than a second predetermined speed lower than the predetermined speed, the transmission section immediately transmits the position information accumulated in the accumulation section, and

wherein when the move speed of the mobile unit remains the second predetermined speed after the transmission section immediately transmits the position information, the later transmission frequency is set to the frequency set by the position information transmission frequency setting section.

15. The position information transmission method according to claim 14, wherein in the transmission frequency setting step,

the transmission frequency is set based on distance reference responsive to the move speed of the mobile unit when the move speed of the mobile unit is equal to or higher than predetermined speed; and

the transmission frequency is set based on time reference responsive to the move speed of the mobile unit when the move speed of the mobile unit is less than the predetermined speed.

16. The position information transmission method according to claim 15, further comprising the steps of immediately transmitting the acquired position information when the move speed of the mobile unit is equal to or less than a second predetermined speed lower than the predetermined speed.

17. The position information transmission method according to claim 16, further comprising the steps of setting the later transmission frequency to the frequency set in the transmission frequency setting step when the move speed of the mobile unit remains the second predetermined speed after the position information is immediately transmitted.

18. A program, for detecting the position of a mobile unit and transmitting acquired position information to a server for locating the position of the mobile unit, embodied on a computer readable medium when executed by a computer causes said computer to function as:

a section for determining move speed of the mobile unit; and

a section for setting transmission frequency of the position information in response to the move speed of the mobile unit,

wherein the position information transmission frequency setting section sets the transmission frequency based on time reference responsive to the move speed of the mobile unit,

wherein when the move speed of the mobile unit is equal to or higher than predetermined speed, the position information transmission frequency setting section sets the transmission frequency based on the distance reference responsive to the move speed of the mobile unit,

wherein when the move speed of the mobile unit is less than the predetermined speed, the position information transmission frequency setting section sets the transmission frequency based on time reference responsive to the move speed of the mobile unit,

wherein when the move speed of the mobile unit is equal to or less than a second predetermined speed lower than the predetermined speed, the transmission section immediately transmits the position information accumulated in the accumulation section, and

wherein when the move speed of the mobile unit remains the second predetermined speed after the transmission section immediately transmits the position information, the later transmission frequency is set to the frequency set by the position information transmission frequency setting section.