Mobile terminal, system and method

• US 8,886,452 B2
• Filed: 11/28/2011
• Issued: 11/11/2014
• Est. Priority Date: 12/02/2010
• Status: Expired due to Fees

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Takahashi, Makoto
• Primary Examiner(s): Jen, Ian
• Application Number:
  US13/880,086
• Publication Number:
  US 20130211708A1
• Time in Patent Office: 1,079 Days
• Field of Search: 701/1, 701/411
• US Class Current: 701/411
• CPC Class Codes: G01C 21/206 specially adapted for indoor navigation
• CPC Class Codes: G01C 21/3896 Transmission of map data from central databases

Abstract

One aspect of the present invention relates to a mobile terminal having an autonomous navigation function, including an anchor management unit configured to acquire a directional change point, set the acquired directional change point as an anchor point and store the anchor point, wherein the directional change point is assumed for a user to change direction on a route from a departure point to a destination point of the user of the mobile terminal on map information, a measurement unit configured to detect movement of the mobile terminal and provide sensor information indicative of the movement, a position calculation unit configured to calculate a current position of the mobile terminal based on the sensor information, a rotation detection unit configured to detect rotation of the user based on the sensor information and determine a rotation point associated with the detected rotation and a current position correction unit configured to determine an anchor point corresponding to the determined rotation point from the anchor points stored in the anchor management unit and correct the current position of the mobile terminal with a position of the determined anchor point.

Claims

1. A mobile terminal having an autonomous navigation function, comprising:

an anchor management unit configured to acquire a directional change point, set the acquired directional change point as an anchor point and store the anchor point, wherein the directional change point is assumed for a user to change direction on a route from a departure point to a destination point of the user of the mobile terminal on map information;

a measurement unit configured to detect movement of the mobile terminal and provide sensor information indicative of the movement;

a position calculation unit configured to calculate a current position of the mobile terminal based on the sensor information;

a rotation detection unit configured to detect rotation of the user based on the sensor information and determine a rotation point associated with the detected rotation; and

a current position correction unit configured to determine an anchor point corresponding to the determined rotation point from the anchor points stored in the anchor management unit and correct the current position of the mobile terminal with a position of the determined anchor point.

2. The mobile terminal as claimed in claim 1, wherein the directional change point corresponds to a point associated with directional change in the route greater than or equal to a predefined angle.

3. The mobile terminal as claimed in claim 1, wherein the measurement unit includes:

a pedometer unit configured to detect a number of steps of the user of the mobile terminal; and

a travelling direction detection unit configured to detect a travelling direction of the mobile terminal, and

the position calculation unit calculates the current position of the mobile terminal based on the number of steps of the user detected by the pedometer unit and the travelling direction detected by the travelling direction detection unit.

4. The mobile terminal as claimed in claim 3, wherein the rotation detection unit detects the rotation of the user based on a sum of change amounts of the travelling direction detected by the travelling direction detection unit.

5. The mobile terminal as claimed in claim 4, wherein the rotation detection unit

determines whether the change amounts of the travelling direction detected by the travelling direction detection unit is less than or equal to a predefined first threshold, when the change amounts are not less than or equal to the first threshold, the rotation detection unit estimating that the user is rotating, subsequently upon the change amounts becoming less than or equal to the first threshold, estimating that the user has rotated;

and

determines, when the user has rotated, whether the sum of change amounts during the rotation is greater than or equal to a predefined second threshold, when the sum of change amounts is greater than or equal to the second threshold, the rotation detection unit determining that the user has rotated and determining a point associated with a middle time point between a start time point and an end time point in the rotation as the rotation point.

6. The mobile terminal as claimed in claim 4, wherein the rotation detection unit

determines whether the change amounts of the travelling direction detected by the travelling direction detection unit are greater than or equal to a predefined third threshold, when the change amounts are greater than or equal to the third threshold, the rotation detection unit estimating that the user is changing the travelling direction;

and

determines whether the sum of change amounts while the user is changing the travelling direction is greater than or equal to a predefined fourth threshold and determines a point associated with a time point when the sum of change amounts becomes greater than or equal to the fourth threshold as the rotation point.

7. The mobile terminal as claimed in claim 1, wherein the current position correction unit calculates distance between the determined rotation point and the anchor points stored in the anchor management unit and determines an anchor point having the shortest distance as the anchor point corresponding to the determined rotation point.

8. The mobile terminal as claimed in claim 7, wherein for the stored anchor point, the anchor management unit sets a neighboring area centered at the anchor point as an anchor area of the anchor point, and the current position correction unit determines whether the determined rotation point is within the anchor area of the determined corresponding anchor point and if the determined rotation point is within the anchor area of the corresponding anchor point, corrects the current position of the mobile terminal based on a difference between a position of the determined rotation point and a position of the corresponding anchor point.

9. A system comprising:

a mobile terminal having an autonomous navigation function; and

a server communicatively connected to the mobile terminal,

the server comprising;

a route determination unit configured to, upon receiving data indicative of a departure point and a destination point of a user of the mobile terminal, determine a route from the departure point to the destination point with reference to map information; and

an anchor point determination unit configured to extract a directional change point and transmit the extracted directional change point to the mobile terminal, wherein the directional change point is assumed for a user to change direction on the determined route,

the mobile terminal comprising;

an anchor management unit configured to set and store the received directional change point as an anchor point;

a measurement unit configured to detect movement of the mobile terminal and provide sensor information indicative of the movement;

a position calculation unit configured to calculate a current position of the mobile terminal based on the sensor information;

a rotation detection unit configured to detect rotation of the user based on the sensor information and determine a rotation point of the detected rotation; and

a current position correction unit configured to determine an anchor point corresponding to the determined rotation point from the anchor points stored in the anchor management unit and correct the current position of the mobile terminal with a position of the determined anchor point.

10. A method for use in a mobile terminal having an autonomous navigation function, comprising:

acquiring a directional change point, setting the acquired directional change point as an anchor point and storing the anchor point, wherein the directional change point is assumed for a user to change direction on a route from a departure point to a destination point of the user of the mobile terminal on map information;

detecting movement of the mobile terminal and providing sensor information indicative of the movement;

calculating a current position of the mobile terminal based on the sensor information;

detecting rotation of the user based on the sensor information and determining a rotation point associated with the detected rotation; and

determining an anchor point corresponding to the determined rotation point from the stored anchor points and correcting the current position of the mobile terminal with a position of the determined anchor point.