ORIENTATION CALCULATION APPARATUS AND STORAGE MEDIUM HAVING ORIENTATION CALCULATION PROGRAM STORED THEREIN

• US 20090326848A1
• Filed: 06/29/2009
• Published: 12/31/2009
• Est. Priority Date: 06/30/2008
• Status: Active Grant

• Current Assignee: Nintendo Company Limited
• Original Assignee: Nintendo Company Limited
• Inventors: SATO, Kenta, OHTA, Keizo, SUZUKI, Ichiro
• Granted Patent: US 8,219,347 B2
• Time in Patent Office: Days
• US Class Current: 702/94
• CPC Class Codes: A63F 13/211 using inertial sensors, e.g. accelerometers or gyroscopes
• CPC Class Codes: A63F 13/428 involving motion or position input signals, e.g. signals representing the rotation of an input controller or a player's arm motions sensed by accelerometers or gyroscopes
• CPC Class Codes: A63F 2300/1006 having additional degrees of freedom
• CPC Class Codes: A63F 2300/105 using inertial sensors, e.g. accelerometers, gyroscopes

Abstract

A game apparatus calculates a gravitational vector Vg, which represents a gravitational direction viewed from an input device, based on operation data. Then, a motion acceleration vector VA, which represents an acceleration applied by a motion of the input device, is calculated based on an acceleration represented by acceleration data and the gravitational vector Vg. The gravitational vector Vg is corrected such that the motion acceleration vector VA approaches a motion acceleration (vector VA′) satisfying a relationship with an angular rate (vector Vω) represented by angular rate data, the relationship being predefined between the motion acceleration and the angular rate for the input device making a predetermined motion (rotational motion). Furthermore, the game apparatus calculates an orientation of the input device corresponding to the corrected gravitational vector.

Claims

1. An orientation calculation apparatus for calculating an orientation of an input device based on operation data acquired from the input device, the input device including at least an angular rate sensor and an acceleration sensor, the operation data including angular rate data and acceleration data, the apparatus comprising:

gravitational direction calculation means for calculating based on the operation data a gravitational vector representing a gravitational direction viewed from the input device;

motion acceleration calculation means for calculating a motion acceleration vector based on an acceleration represented by the acceleration data and the gravitational vector, wherein the motion acceleration vector represents an acceleration applied by a motion of the input device;

first correction means for correcting the gravitational vector such that the motion acceleration vector approaches a motion acceleration satisfying a relationship with the angular rate represented by the angular rate data, the relationship being predefined between the motion acceleration and the angular rate for the input device making a predetermined motion; and

first orientation calculation means for calculating an orientation of the input device corresponding to the gravitational vector corrected by the first correction means.

2. The orientation calculation apparatus according to claim 1, further comprising second orientation calculation means for calculating an orientation of the input device from the angular rate data, wherein,

the gravitational direction calculation means calculates the gravitational vector based on the orientation calculated by the second orientation calculation means, and

the first orientation calculation means corrects the orientation calculated by the second orientation calculation means, based on the gravitational vector corrected by the first correction means, thereby calculating the orientation of the input device.

3. The orientation calculation apparatus according to claim 1, wherein,

the predetermined motion is a rotational motion about a predetermined position, and

the first correction means includes:

perpendicular vector calculation means for calculating based on the angular rate data a perpendicular vector perpendicular to a direction of the motion acceleration of the input device making the rotational motion; and

vector correction means for correcting the gravitational vector based on the relationship between the motion acceleration and the angular rate of the input device, the relationship exhibiting the motion acceleration vector perpendicular to the perpendicular vector.

4. The orientation calculation apparatus according to claim 3, wherein the perpendicular vector calculation means calculates an angular acceleration based on a transition of the angular rate data acquired from the input device, and also calculates the perpendicular vector based on the angular rate represented by the angular rate data and the angular acceleration.

5. The orientation calculation apparatus according to claim 3, wherein,

the predetermined motion is a rotational motion about the predetermined position at a constant angular rate, and

the perpendicular vector calculated by the perpendicular vector calculation means is an angular rate vector representing a central axis of the rotational motion.

6. The orientation calculation apparatus according to claim 3, wherein the vector correction means corrects the gravitational vector such that an inner product of the perpendicular vector and the motion acceleration vector is small.

7. The orientation calculation apparatus according to claim 3, wherein the first correction means corrects the gravitational vector such that the lower the amount of correction of the gravitational vector is, the lower the angular rate is represented by the angular rate data.

8. The orientation calculation apparatus according to claim 7, further comprising second correction means for correcting the gravitational vector so as to approach a direction of the acceleration represented by the acceleration data, wherein,

the second correction means corrects the gravitational vector such that the lower the amount of correction of the gravitational vector is, the higher the angular rate is represented by the angular rate data, and

the first orientation calculation means calculates the orientation of the input device based on the gravitational vector corrected by the first correction means and the second correction means.

9. The orientation calculation apparatus according to claim 3, wherein the first correction means corrects the gravitational vector such that the lower the amount of correction of the gravitational vector is, the higher the amount of change per unit time for the acceleration is represented by the acceleration data.

10. The orientation calculation apparatus according to claim 1, wherein the first correction means corrects the gravitational vector so as to rotate in such a direction that, when the gravitational vector is rotated by a predetermined angle, a motion acceleration vector calculated from a post-rotation gravitational vector approaches closest to the motion acceleration satisfying the predefined relationship with the angular rate represented by the angular rate data.

11. The orientation calculation apparatus according to claim 1, further comprising second correction means for correcting the gravitational vector so as to approach a direction of the acceleration represented by the acceleration data, wherein the first orientation calculation means calculates the orientation of the input device based on the gravitational vector corrected by the first correction means and the second correction means.

12. The orientation calculation apparatus according to claim 11, wherein the second correction means corrects the gravitational vector such that the lower the amount of correction of the gravitational vector is, the higher the angular rate is represented by the angular rate data.

13. The orientation calculation apparatus according to claim 11, wherein the second correction means corrects the gravitational vector such that the lower the amount of correction of the gravitational vector is, the higher the amount of change per unit time for the acceleration is represented by the acceleration data.

14. A computer-readable storage medium having stored therein an orientation calculation program to be executed by a computer in an orientation calculation apparatus for calculating an orientation of an input device based on operation data acquired from the input device, the input device including at least an angular rate sensor and an acceleration sensor, the operation data including angular rate data and acceleration data, the program causing the computer to function as:

gravitational direction calculation means for calculating based on the operation data a gravitational vector representing a gravitational direction viewed from the input device;

motion acceleration calculation means for calculating a motion acceleration vector based on an acceleration represented by the acceleration data and the gravitational vector, wherein the motion acceleration vector represents an acceleration applied by a motion of the input device;

first correction means for correcting the gravitational vector such that the motion acceleration vector approaches a motion acceleration satisfying a relationship with the angular rate represented by the angular rate data, the relationship being predefined between the motion acceleration and the angular rate for the input device making a predetermined motion; and

first orientation calculation means for calculating the orientation of the input device based on the gravitational vector corrected by the first correction means.

15. The storage medium according to claim 14, wherein,

the orientation calculation program causes the computer to further function as second orientation calculation means for calculating the orientation of the input device from the angular rate data,

the gravitational direction calculation means calculates the gravitational vector based on the orientation calculated by the second orientation calculation means, and

the first orientation calculation means corrects the orientation calculated by the second orientation calculation means, based on the gravitational vector corrected by the first correction means, thereby calculating the orientation of the input device.

16. The storage medium according to claim 14, wherein,

the predetermined motion is a rotational motion about a predetermined position, and

the first correction means includes:

perpendicular vector calculation means for calculating based on the angular rate data a perpendicular vector perpendicular to a direction of the motion acceleration of the input device making the rotational motion; and

vector correction means for correcting the gravitational vector based on the relationship between the motion acceleration and the angular rate of the input device, the relationship exhibiting the motion acceleration vector perpendicular to the perpendicular vector.

17. The storage medium according to claim 16, wherein the perpendicular vector calculation means calculates an angular acceleration based on a transition of the angular rate data acquired from the input device, and also calculates the perpendicular vector based on the angular rate represented by the angular rate data and the angular acceleration.

18. The storage medium according to claim 16, wherein,

the predetermined motion is a rotational motion about the predetermined position at a constant angular rate, and

the perpendicular vector calculated by the perpendicular vector calculation means is an angular rate vector representing a central axis of the rotational motion.

19. The storage medium according to claim 16, wherein the vector correction means corrects the gravitational vector such that an inner product of the perpendicular vector and the motion acceleration vector is small.

20. The storage medium according to claim 16, wherein the first correction means corrects the gravitational vector such that the lower the amount of correction of the gravitational vector is, the lower the angular rate is represented by the angular rate data.

21. The storage medium according to claim 20, wherein,

the orientation calculation program causes the computer to further function as second correction means for correcting the gravitational vector so as to approach a direction of the acceleration represented by the acceleration data,

the second correction means corrects the gravitational vector such that the lower the amount of correction of the gravitational vector is, the higher the amount of change per unit time for the acceleration is represented by the acceleration data, and

the first orientation calculation means calculates the orientation of the input device based on the gravitational vector corrected by the first correction means and the second correction means.

22. The storage medium according to claim 16, wherein the first correction means corrects the gravitational vector such that the lower the amount of correction of the gravitational vector is, the higher the amount of change per unit time for the acceleration is represented by the acceleration data.

23. The storage medium according to claim 14, wherein the first correction means corrects the gravitational vector so as to rotate in such a direction that, when the gravitational vector is rotated by a predetermined angle, a motion acceleration vector calculated from a post-rotation gravitational vector approaches closest to the motion acceleration satisfying the predefined relationship with the angular rate represented by the angular rate data.

24. The storage medium according to claim 14, wherein,

the orientation calculation programs causes the computer to further function as second correction means for correcting the gravitational vector so as to approach a direction of the acceleration represented by the acceleration data, and

the first orientation calculation means calculates the orientation of the input device based on the gravitational vector corrected by the first correction means and the second correction means.

25. The storage medium according to claim 24, wherein the second correction means corrects the gravitational vector such that the lower the amount of correction of the gravitational vector is, the higher the angular rate is represented by the angular rate data.

26. The storage medium according to claim 24, wherein the second correction means corrects the gravitational vector such that the lower the amount of correction of the gravitational vector is, the higher the amount of change per unit time for the acceleration is represented by the acceleration data.

27. An orientation calculation apparatus for sequentially calculating a gravitational vector representing a gravitational direction viewed from an input device based on angular rate data and acceleration data sequentially acquired from the input device, the input device including at least an angular rate sensor and an acceleration sensor, the apparatus comprising:

gravitational vector calculation means for calculating the gravitational vector based on an angular rate represented by the angular rate data;

first correction means for correcting the gravitational vector so as to approach at a first rate an acceleration vector represented by the acceleration data;

second correction means for correcting the gravitational vector so as to approach at a second rate a gravitational direction estimated based on a relationship between the acceleration data and the angular rate data, the relationship being predefined for the input device making a predetermined motion; and

third correction means for correcting the gravitational vector so as to approach at a third rate an average of acceleration vectors during a predetermined period.

28. The orientation calculation apparatus according to claim 27, wherein the first correction means sets the first rate such that the higher the first rate is, the closer the magnitude of the acceleration represented by the acceleration data is to the magnitude of the gravitational acceleration.

29. The orientation calculation apparatus according to claim 27, further comprising motion acceleration calculation means for calculating a motion acceleration vector based on the acceleration data and the gravitational vector, the motion acceleration vector representing an acceleration applied by a motion of the input device, wherein,

the second correction means corrects the gravitational vector so as to approach at the second rate a gravitational vector allowing the predefined relationship to be satisfied between the angular rate represented by the angular rate data and the motion acceleration vector.

30. The orientation calculation apparatus according to claim 27, wherein the third correction means sets the third rate to a value lower than maximum values of the first and second rates.

31. The orientation calculation apparatus according to claim 27, wherein,

the first correction means changes the first rate in accordance with at least one of the acceleration data and the angular rate data;

the second correction means changes the second rate in accordance with at least one of the acceleration data and the angular rate data; and

the third correction means sets the third rate as a fixed value.

32. The orientation calculation apparatus according to claim 27, further comprising:

acceleration data storage means for sequentially storing acquired acceleration data; and

block average calculation means for calculating a block average vector being an average of acceleration vectors represented by a block of acceleration data, the block consisting of plural pieces of acceleration data, wherein,

the third correction means corrects the gravitational vector so as to approach at the third rate an overall average vector being an average of block average vectors for a predetermined number of blocks in reverse chronological order.

33. The orientation calculation apparatus according to claim 32, further comprising updating means for updating each of the block average vectors by rotating the block average vector in a direction opposite to the angular rate represented by the angular rate data, wherein,

the third correction means calculates the overall average vector based on the block average vectors updated by the updating means.

34. A computer-readable storage medium having stored therein an orientation calculation program to be executed by a computer in an orientation calculation apparatus for sequentially calculating a gravitational vector representing a gravitational direction viewed from an input device based on angular rate data and acceleration data sequentially acquired from the input device, the input device including at least an angular rate sensor and an acceleration sensor, the program causing the computer to function as:

gravitational vector calculation means for calculating the gravitational vector based on an angular rate represented by the angular rate data;

first correction means for correcting the gravitational vector so as to approach at a first rate an acceleration vector represented by the acceleration data;

second correction means for correcting the gravitational vector so as to approach at a second rate a gravitational direction estimated based on a relationship between the acceleration data and the angular rate data, the relationship being predefined for the input device making a predetermined motion; and

third correction means for correcting the gravitational vector so as to approach at a third rate an average of acceleration vectors during a predetermined period.

35. The storage medium according to claim 34, wherein the first correction means sets the first rate such that the higher the first rate is, the closer the magnitude of the acceleration represented by the acceleration data is to the magnitude of the gravitational acceleration.

36. The storage medium according to claim 34, wherein,

the orientation calculation program causes the computer to further function as motion acceleration calculation means for calculating a motion acceleration vector based on the acceleration data and the gravitational vector, the motion acceleration vector representing an acceleration applied by a motion of the input device, and

the second correction means corrects the gravitational vector so as to approach at the second rate a gravitational vector allowing the predefined relationship to be satisfied between the angular rate represented by the angular rate data and the motion acceleration vector.

37. The storage medium according to claim 34, wherein the third correction means sets the third rate to a value lower than maximum values of the first and second rates.

38. The storage medium according to claim 34, wherein,

the first correction means changes the first rate in accordance with at least one of the acceleration data and the angular rate data;

the second correction means changes the second rate in accordance with at least one of the acceleration data and the angular rate data; and

the third correction means sets the third rate as a fixed value.

39. The storage medium according to claim 34, wherein,

the orientation calculation program causes the computer to further function as:

acceleration data storage means for sequentially storing acquired acceleration data; and

block average calculation means for calculating a block average vector being an average of acceleration vectors represented by a block of acceleration data, the block consisting of plural pieces of acceleration data, and

the third correction means corrects the gravitational vector so as to approach at the third rate an overall average vector being an average of block average vectors for a predetermined number of blocks in reverse chronological order.

40. The storage medium according to claim 39, wherein,

the orientation calculation program causes the computer to further function as updating means for updating each of the block average vectors by rotating the block average vector in a direction opposite to the angular rate represented by the angular rate data, and

the third correction means calculates the overall average vector based on the block average vectors updated by the updating means.