Motion Sensing System

• US 20110285623A1
• Filed: 05/24/2010
• Published: 11/24/2011
• Est. Priority Date: 05/24/2010
• Status: Active Grant

• Current Assignee: China Mobile Hong Kong Company Limited (Central People's Government of The People's Republic of China)
• Original Assignee: CyWee Group Ltd.
• Inventors: Liou, Shun-Nan, Hsieh, Ching-Lin, Lu, Ying-Ko, Ye, Zhou
• Granted Patent: US 8,373,658 B2
• Time in Patent Office: Days
• US Class Current: 345/158
• CPC Class Codes: G06F 2203/0384 Wireless input, i.e. hardware and software details of wireless interface arrangements for pointing devices
• 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 3/038 Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry
• CPC Class Codes: G06F 3/0383 Signal control means within the pointing device

Abstract

A motion sensing system includes a hand-held device and a receiver device. The hand-held device includes a microcontroller, a G-sensor (one 3-axis accelerometer), only one 2-axis gyroscope, and a wireless transmitter. The receiver device is preferably a dongle and includes a microcontroller and a wireless receiver. A first axis of the 2-axis gyroscope is parallel to the Z axis of the hand-held device and the second axis of the 2-axis gyroscope forms an acute angle α with the X axis of the hand-held device. The acute angle α allows the microcontroller of the receiver device to calculate rotational data around each of the three axis of the hand-held device.

Claims

1. A motion sensing system comprising;

a motion sensing device having three perpendicular axes, a pointing direction along a first axis of the three perpendicular axes, and only two rotational sensors arranged to form a non-zero acute angle between a second axis of the three perpendicular axes and an axis of a first of the rotational sensors; and

a receiver device for generating rotational data for the three axes based on the non-zero acute angle.

2. The motion sensing system of claim 1 wherein the motion sensing device further comprises a 3-axis accelerometer having axes aligned with the three perpendicular axes.

3. The motion sensing system of claim 2 wherein the motion sensing device further comprises a first microprocessor coupled receive output from the 3-axis accelerometer and output from the two rotational sensors.

4. The motion sensing system of claim 3 wherein the motion sensing device further comprises a transmitter coupled to receive output of the first microprocessor.

5. The motion sensing system of claim 4 wherein the receiver device comprises a receiver coupled to output to a second microprocessor.

6. The motion sensing system of claim 5 wherein the receiver device is a Universal Serial Bus dongle.

7. The motion sensing system of claim 5 wherein the transmitter is a wireless transmitter and the receiver is a wireless receiver.

8. The motion sensing system of claim 1 wherein an axis of a second of the rotational sensors is substantially parallel with a third axis of the three perpendicular axes.

9. A motion sensing hand-held device comprising;

a 3-axis accelerometer having axes forming 3 perpendicular axes of the hand-held device;

only two rotational sensors arranged to form a non-zero acute angle between an axis of a first of the two rotational sensors and a first axis of the 3 perpendicular axes;

a microprocessor coupled receive output from the 3-axis accelerometer and output from the two rotational sensors; and

a wireless transmitter coupled to receive output of the microprocessor.

10. The motion sensing hand-held device of claim 9 wherein a second axis of the 3 perpendicular axes is a pointing direction of the motion sensing hand-held device.

11. The motion sensing hand-held device of claim 10 wherein a third axis of the 3-axis accelerometer points is substantially parallel with an axis of a second of the two rotational sensors.

12. The motion sensing hand-held device of claim 9 wherein the first axis of the 3-axis accelerometer is a pointing direction of the motion sensing hand-held device.

13. The motion sensing hand-held device of claim 12 wherein a second axis of the 3-axis accelerometer points is substantially parallel with an axis of a second of the two rotational sensors.

14. A method for operating a motion sensing system, the motion sensing system comprising a hand-held device and a receiver device, the hand-held device including a wireless transmitter, a first microprocessor, a 3-axis accelerometer, and only two rotational sensors, an axis of a first of the two rotational sensors forming an acute angle with at least one axis of the 3-axis accelerometer, the receiver device comprising a wireless receiver and a second microprocessor, the method comprising:

the first microprocessor receiving sensed acceleration data from the 3-axis accelerometer and rotational data from the two rotational sensors and outputting the received data to the wireless transmitter;

the wireless transmitter transmitting the received data to the wireless receiver;

the wireless receiver transmitting the received data to the second microprocessor; and

the second microprocessor generating rotational data around 3 axes of the hand-held device according to the acute angle.

15. The method of claim 14 further comprising the second microprocessor calculating a tilt angle θ

of the hand-held device.

16. The method of claim 15 further comprising calculating the tilt angle θ

according to

A·

B=|A|×

|B|×

cos θ

cos θ

=A·

B/(|A|×

|B|)

where “

A”

is the sensed acceleration data and “

B”

is a unit vector of a normal vector to a ground plane.

17. The method of claim 16 further comprising the second microprocessor calculating 3-axis angular speeds of the hand-held device.

18. The method of claim 17 further comprising calculating 3-axis angular speeds of the hand-held device according to

Z_rotation=Wz×

cos θ

+(Wxy/sin α

)×

sin θ

X_rotation=−

Wz×

sin θ

+(Wxy/sin α

)×

cos θ

Y_rotation=Wxy/sin(90°

−

α

)

where “

W”

is the angular speed, “

α

”

is the acute angle, and “

θ

”

is the tilt angle θ

.

19. The method of claim 17 further comprising outputting game control signals based on the 3-axis angular speeds.