Positional information management system, positional information management method, recording medium, and mobile terminal

• US 20030217070A1
• Filed: 04/11/2003
• Published: 11/20/2003
• Est. Priority Date: 04/15/2002
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Masuya, Takashi, Gotoh, Hideo, Iwata, Shigeo
• Granted Patent: US 7,640,268 B2
• Time in Patent Office: Days
• US Class Current: 707/102
• CPC Class Codes: G01C 21/16 by integrating acceleration or speed, i.e. inertial navigation
• CPC Class Codes: G01S 19/09 providing processing capability normally carried out by the receiver
• CPC Class Codes: G01S 19/49 whereby the further system is an inertial position system, e.g. loosely-coupled
• CPC Class Codes: G01S 5/0018 Transmission from mobile station to base station
• CPC Class Codes: G01S 5/0284 Relative positioning
• CPC Class Codes: G08G 1/0104 Measuring and analyzing of parameters relative to traffic conditions

Abstract

A worker transfers GPS signals to a communication system at each node of traveling using a cellular phone terminal, and the communication system specifies the position of the cellular phone terminal and notifies positional information to a management system. When the cellular phone terminal cannot receive GPS signals or is outside a range accessible to the communication system, it starts recording acceleration data using an accelerometer. When a communicable state is recovered, the cellular phone terminal sends GPS signals and the recorded acceleration data to the communication system. A management computer determines whether the position notified by the communication system is an intended node. If the notified position is not an intended node, the management computer derives the position of the intended node using the acceleration data, and predicts the travel route based on the node position.

Claims

1. A positional information management system comprising:

a mobile terminal which acquires acceleration data at a predetermined position;

a management server which is connected to said mobile terminal through a network and predicts a travel route of said mobile terminal; and

a communication system which specifies a current position of said mobile terminal and sends positional data representing the specified current position to said management server,

wherein said management server;

is connected to a positional data storage unit which stores positional data representing that said mobile terminal is at a predetermined position, which is sent from said communication system in association with a reception time at which the positional data is received, and to an acceleration data storage unit which stores an acceleration log representing acceleration data in time series, which is sent from said mobile terminal in association with a reception time at which the acceleration log is received;

selects positional data for two positions which are recorded adjacently time-wise in said positional data storage unit, and which are included in a travel route which is a target of prediction;

extracts an acceleration log whose reception time corresponds to a reception time of any of the selected positional data; and

predicts a travel route of said mobile terminal based on the selected positional data and the extracted acceleration log.

2. The positional information management system according to claim 1,

wherein said management server:

is further connected to a motion pattern data storage unit which stores a velocity pattern and an acceleration pattern for each means of transportation; and

specifies means of transportation used for traveling between the two positions, by deriving an average travel velocity between the two positions based on the selected positional data and their reception times and then comparing the average travel velocity with the velocity pattern stored in said motion pattern data storage unit, or by comparing the extracted acceleration log with the acceleration pattern stored in said motion pattern data storage unit.

3. A positional information management method for predicting a travel route from a notification point at which a mobile terminal should notify that it is at the point, based on positional data representing a current position of said mobile terminal which acquires acceleration data at a predetermined position, and an acceleration log representing acceleration data in time series acquired by said mobile terminal, the positional data and the acceleration log being notified through a predetermined network, said method comprising:

a step of storing positional data and an acceleration log in association with times at which they are notified;

a step of selecting positional data for two positions which are recorded adjacently time-wise, and which are included in a travel route which is a target of prediction;

a step of extracting an acceleration log corresponding to any of the selected positional data; and

a step of predicting a travel route based on the selected positional data and the extracted acceleration log.

4. The positional information management method according to claim 3, further comprising a step of storing map data representing predetermined means of transportation, and places to get on and off the means of transportation,

wherein:

the notification point includes the places to get on and off the means of transportation; and

said step of predicting the travel route includes specifying means of transportation which includes the notification point in its running course, by using the map data.

5. The positional information management method according to claim 3, wherein said step of predicting the travel route includes:

a step of specifying the notification point based on the extracted acceleration log corresponding to the selected positional data and the selected positional data, in a case where any of the selected positional data is not positional data representing the notification point; and

a step of predicting the travel route based on positional data representing the notification point or based on the extracted acceleration log.

6. The positional information management method according to claim 5, wherein said step of specifying the notification point specifies the notification point by:

deriving a travel distance based on the extracted acceleration log; and

searching for the notification point that exists within a radius of the derived travel distance from the position represented by the selected positional data from the map data.

7. The positional information management method according to claim 3, further comprising a step of storing a velocity pattern for each predetermined means of transportation,

wherein said step of predicting the travel route specifies means of transportation by calculating an average travel velocity between the two positions based on the selected positional data and the times at which the positional data are notified, and by comparing the average travel velocity with the velocity pattern.

8. The positional information management method according to claim 3, further comprising a step of storing an acceleration pattern for each predetermined means of transportation,

wherein said step of predicting the travel route specifies means of transportation by comparing the extracted acceleration log with the acceleration pattern.

9. A computer-readable recording medium which stores a program for controlling a computer to execute all or a part of the steps of the positional information management method according to any one of claims 3 to 8.

10. A carrier wave which can be run on a computer and which carries a program for controlling a computer to execute all or a part of the steps of the positional information management method according to any one of claims 3 to 8.

11. A mobile terminal which comprises:

an acceleration measuring unit which senses an acceleration and measures an acceleration log;

a positional information acquiring unit which acquires predetermined positional information;

a control unit which controls said acceleration measuring unit and said positional information acquiring unit; and

a storage unit which stores predetermined data, and which sends predetermined information to a management system for managing the positional information,

wherein said control unit;

determines whether or not data for specifying a position of said mobile terminal can be acquired by said positional information acquiring unit;

stores an acceleration log measured by said acceleration measuring unit in said storage unit, in a case where the positional information can not be acquired; and

sends data regarding the position of said mobile terminal acquired by said positional information acquiring unit and the acceleration log stored in said storage unit to said management system, in a case where acquisition of the positional information becomes possible.

12. The mobile terminal according to claim 11,

wherein said control unit further:

derives a time cycle as a function of an acceleration measured by said acceleration measuring unit; and

sends data regarding the position of said mobile terminal to said management system in accordance with the time cycle.