Attitude determination method, position calculation method, and attitude determination device

• US 9,494,428 B2
• Filed: 03/01/2012
• Issued: 11/15/2016
• Est. Priority Date: 03/02/2011
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Mizuochi, Shunichi, Kumar, Anand, Sato, Akinobu, Onda, Kenji, Sanjay, Rama
• Primary Examiner(s): Black, Thomas G
• Assistant Examiner(s): Kong, Sze-Hon
• Application Number:
  US14/002,696
• Publication Number:
  US 20130338915A1
• Time in Patent Office: 1,720 Days
• Field of Search: 701/469, 701/472, 701/479, 701/500, 701/501, 701/511, 701/473, 702/94, 702/95, 702/141, 702/142, 702/153, 702/150
• US Class Current: 1/1
• CPC Class Codes: B60G 17/018 characterised by the use of a specific signal treatment or control method
• CPC Class Codes: B60G 17/019 characterised by the type of sensor or the arrangement thereof B60G17/01941 takes precedence
• CPC Class Codes: B60G 17/0195 characterised by the regulation being combined with other vehicle control systems conjoint control of vehicle sub-units including control of suspension systems B60W10/22
• CPC Class Codes: B60G 2400/05 Attitude
• CPC Class Codes: B60G 2400/0512 Pitch angle
• CPC Class Codes: B60G 2400/0513 Yaw angle
• CPC Class Codes: G01C 21/10 by using measurements of speed or acceleration G01C21/24, G01C21/26 take precedence
• CPC Class Codes: G01C 21/12 executed aboard the object being navigated; Dead reckoning
• CPC Class Codes: G01C 21/188 for accumulated errors, e.g. by coupling inertial systems with absolute positioning systems
• CPC Class Codes: G01C 21/28 with correlation of data from several navigational instruments
• CPC Class Codes: G01C 25/005 initial alignment, calibration or starting-up of inertial devices
• CPC Class Codes: G01C 9/08 Means for compensating acceleration forces due to movement of instrument
• CPC Class Codes: G01G 19/086 wherein the vehicle mass is dynamically estimated
• CPC Class Codes: G01S 19/42 Determining position
• CPC Class Codes: H04W 52/0254 detecting a user operation or a tactile contact or a motion of the device
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A new method for determining an attitude of a sensor with respect to a moving body is proposed. A movement vector is measured by a sensor mounted in the moving body. In addition, the attitude of the sensor with respect to the moving body is determined using the movement vector measured by the sensor when the moving body starts to move.

Claims

1. An attitude determination method comprising:

measuring local coordinate movement vectors v_x^L, v_y^L, and v_z^L by a sensor system which is mounted in a moving body and measures the movement vectors, wherein v_x^L is a velocity vector in a local coordinate system in an X direction, v_y^L is a velocity vector in a local coordinate system in a Y direction, and v_z^L is a velocity vector in a local coordinate system in a Z direction;

measuring an absolute coordinate attitude measurement in an absolute coordinate system by the sensor system;

converting the local coordinate movement vectors into absolute coordinate movement vectors using the absolute coordinate attitude measurement; and

determining an attitude of the sensor with respect to the moving body using the absolute coordinate movement vectors and the absolute coordinate attitude measurement after the moving body starts to move from a stop position and has reached a predetermined threshold velocity or a predetermined threshold acceleration,

wherein the determining the attitude of the sensor is delayed until the moving body has reached the predetermined threshold velocity or the predetermined threshold acceleration following the stop position.

2. The attitude determination method according to claim 1, further comprising:

compensating for a measurement result of the sensor system using a first constraint condition regarding a velocity of the moving body when the moving body is in a stop state.

3. The attitude determination method according to claim 1, wherein the step of determining the attitude does not determine a roll component of the attitude with respect to the moving body.

4. A position calculation method comprising:

a step of determining the attitude using the attitude determination method according to claim 1; and

a step of calculating a position of the moving body using the attitude and the movement vector.

5. The position calculation method according to claim 4, wherein the step of calculating the position includes:

a step of calculating an absolute coordinate position of the moving body in the absolute coordinate system;

a step of performing coordinate transformation of the absolute coordinate position to a moving body coordinate position based on the moving body using the attitude and a direction of the sensor system expressed in the absolute coordinate system; and

a step of correcting the absolute coordinate position using the moving body coordinate position and a second constraint condition regarding a movement direction of the moving body.

6. An attitude determination method comprising:

measuring local coordinate movement vectors v_x^L, v_y^L, and v_z^L by a sensor system which is mounted in a moving body and measures the movement vectors, wherein v_x^L is a velocity vector in a local coordinate system in an X direction, v_y^L is a velocity vector in a local coordinate system in a Y direction, and v_z^L is a velocity vector in a local coordinate system in a Z direction;

measuring an absolute coordinate attitude measurement in an absolute coordinate system by the sensor system;

converting the local coordinate movement vectors into absolute coordinate movement vectors using the absolute coordinate attitude measurement and

determining an attitude of the sensor with respect to the moving body using the absolute coordinate movement vectors and the absolute coordinate attitude measurement after the moving body starts to move from a stop position and has reached a predetermined threshold velocity or a predetermined threshold acceleration,

wherein the determining the attitude of the sensor is delayed until the moving body has reached the predetermined threshold velocity or the predetermined threshold acceleration following the stop position.