MOVING TRAJECTORY CALIBRATION METHOD AND MOVING TRAJECTORY GENERATION METHOD

• US 20130035890A1
• Filed: 08/03/2012
• Published: 02/07/2013
• Est. Priority Date: 08/04/2011
• Status: Abandoned Application

• Current Assignee: National Cheng KUNG University (Government of The Republic of China)
• Original Assignee: National Cheng KUNG University (Government of The Republic of China)
• Inventors: WANG, Jeen-Shing, Hsu, Yu-Liang
• Application Number:
  US13/566,651
• Publication Number:
  US 20130035890A1
• Time in Patent Office: Days
• US Class Current: 702/92
• CPC Class Codes: G06F 3/03 Arrangements for converting the position or the displacement of a member into a coded form
• CPC Class Codes: G06F 3/0346 with detection of the device orientation or free movement in a 3D space, e.g. 3D mice, 6-DOF [six degrees of freedom] pointers using gyroscopes, accelerometers or tilt-sensors
• CPC Class Codes: G06F 3/0354 with detection of 2D relative movements between the device, or an operating part thereof, and a plane or surface, e.g. 2D mice, trackballs, pens or pucks
• CPC Class Codes: G06V 30/1423 the instrument generating sequences of position coordinates corresponding to handwriting preprocessing or recognising digital ink G06V30/32

Abstract

A moving trajectory calibration method is applied to receive a moving trajectory signal generated by a writing device while moving on a written plane and includes the following steps of: generating a first axial signal, a second axial signal and a third axial signal according to the moving trajectory signal by a detecting-calibration unit of an orientation calculation module, wherein the written plane is composed of the first axis and the second axis, and the third axis is perpendicular to the written plane; calibrating the first axial signal according to the third axial signal by the detecting-calibration unit, so as to generate a first axial trajectory signal; and calibrating the second axial signal according to the third axial signal by the detecting-calibration unit, so as to generate a second axial trajectory signal. In addition, a moving trajectory generation method is also disclosed.

Claims

1. A moving trajectory calibration method, which is applied to receive a moving trajectory signal generated by a writing device while moving on a written plane, the calibration method comprising the steps of:

generating a first axial signal, a second axial signal, and a third axial signal according to the moving trajectory signal by a detecting-calibration unit of an orientation calculation module, wherein the written plane is composed of a first axis and a second axis, and a third axis is perpendicular to the written plane;

calibrating the first axial signal according to the third axial signal by the detecting-calibration unit, so as to generate a first axial trajectory signal; and

calibrating the second axial signal according to the third axial signal by the detecting-calibration unit, so as to generate a second axial trajectory signal.

2. The calibration method of claim 1, wherein the moving trajectory signal comprises an angular velocity signal, an acceleration signal, a magnetic-field intensity signal, a geomagnetic orientation signal, or their combinations in three axes with respect to a moving trajectory at different time points.

3. The calibration method of claim 1, wherein the first axis, the second axis, and the third axis are perpendicular to one another.

4. The calibration method of claim 1, wherein the step of calibrating the first axial signal further comprises:

when a variation of the third axial signal within a time interval exceeds a preset signal value, the detecting-calibration unit zeros the first axial signal within the time interval.

5. The calibration method of claim 1, wherein the step of calibrating the second axial signal further comprises:

when a variation of the third axial signal within a time interval exceeds a preset signal value, the detecting-calibration unit zeros the second axial signal within the time interval.

6. A moving trajectory generation method, comprising the steps of:

sensing a moving trajectory while a writing device moves on a written plane by a moving trajectory sensing module of the writing device, and generating a moving trajectory signal;

generating a first axial signal, a second axial signal, and a third axial signal according to the moving trajectory signal by a detecting-calibration unit of an orientation calculation module, wherein the written plane is composed of a first axis and a second axis, and a third axis is perpendicular to the written plane;

calibrating the first axial signal and the second axial signal according to the third axial signal by the detecting-calibration unit, so as to generate a first axial trajectory signal and a second axial trajectory signal; and

displaying the calibrated moving trajectory by a display module according to the first axial trajectory signal and the second axial trajectory signal.

7. The generation method of claim 6, wherein the moving trajectory signal comprises an angular velocity signal, an acceleration signal, a magnetic-field intensity signal, a geomagnetic orientation signal, or their combinations in three axes with respect to a moving trajectory at different time points.

8. The generation method of claim 7, further comprising the step of:

generating a coordinate transformation matrix according to the angular velocity signal by an orientation transformation unit of the orientation calculation module, and performing a coordinate transformation to the acceleration signals according to the coordinate transformation matrix.

9. The generation method of claim 8, wherein the orientation transformation unit integrates the angular velocity signal to obtain an orientation angle so as to generate the coordinate transformation matrix, and transforms the acceleration signals with the coordinate transformation matrix so as to transform the acceleration signals from a body frame of the writing device to a local level frame.

10. The generation method of claim 9, further comprising the step of:

performing a gravity compensation to the acceleration signal in the local level frame by a gravity compensation unit of the orientation calculation module.

11. The generation method of claim 6, wherein the step of calibrating the first axial signal further comprises:

when a variation of the third axial signal within a time interval exceeds a preset signal value, the detecting-calibration unit zeros the first axial signal within the time interval.

12. The generation method of claim 6, wherein the step of calibrating the second axial signal further comprises:

when a variation of the third axial signal within a time interval exceeds a preset signal value, the detecting-calibration unit zeros the second axial signal within the time interval.

13. The generation method of claim 6, further comprising the step of:

performing a calculation to the first axial trajectory signal and the second axial trajectory signal by a trajectory calculation unit of the orientation calculation module.

14. The generation method of claim 6, wherein the written plane comprises a horizontal plane, a vertical plane, or a slant plane.