POINTING DEVICE

• US 20120274560A1
• Filed: 04/29/2011
• Published: 11/01/2012
• Est. Priority Date: 04/29/2011
• Status: Active Grant

• Current Assignee: Movea
• Original Assignee: Movea
• Inventors: Caritu, Yanis, Riccardi, Sébastien, Neyton, Olivier
• Granted Patent: US 8,884,877 B2
• Time in Patent Office: Days
• US Class Current: 345/158
• 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

Abstract

An improved air pointing device which is capable of compensating for the roll angle imparted to said device by a user of said device. The device of the invention includes at least two gyrometers and two accelerometers, the latter being each used for different roll angles. The correction of the roll angle is effected by using the measurements of the first accelerometer, the output of the second accelerometer being simulated as an approximated function of the measurements of the first accelerometer, using a polynomial approximation of the relation between the output of the two accelerometers, the order of the polynomial being chosen as a function of the computing power which is available and the precision which is needed. In an embodiment of the invention, the first and second accelerometers are advantageously swapped at a value of the roll angle which is substantially equal to 45°.

Claims

1. An air pointing device comprising at least two angular rate sensors and two linear sensors capable of transmitting motion signals to a first processor, said processor being capable of transmitting processed signals to a second processor in connection with a display, wherein said signals control the movements of a virtual cursor on said display with the measurements of said angular rate sensors, said angular rate sensor measurements being corrected by said first processor for the tilt of said air pointing device, the value of said tilt correction being calculated by using only the measurements from one of said at least two linear sensors for a range of tilt values within a first half space.

2. The air pointing device of claim 1, wherein the value of said tilt correction is modified by the sign of the measurement of another one of said at least two linear sensors within a second half space.

3. The air pointing device of claim 1, wherein said tilt correction uses for a range of tilt values the raw measurements Ay from one linear sensor and an algebraic transformation of said measurements of the form.

4. The air pointing device of claim 1, wherein said tilt correction uses for a range of tilt values the raw measurements Ay from one linear sensor and an approximation of an algebraic transformation of said measurements of the form.

5. The air pointing device of claim 4, wherein said approximation includes a polynomial approximation of said algebraic transformation.

6. The air pointing device of claim 5, wherein said polynomial approximation is of the form.

7. The air pointing device of claim 5, wherein said polynomial approximation includes a best fit polynomial the coefficients of which are calculated to minimize a weighted sum of distances between values of the algebraic transformation at selected points and values of the polynomial at the same points.

8. The air pointing device of claim 5, wherein said polynomial approximation includes a series of limited developments of the algebraic transformation in a number of selected points.

9. The air pointing device of claim 4, wherein said approximation is calculated at a given point as the limit for a definite precision of the zeros of the difference between the algebraic transformation and its first order limited development.

10. An air pointing device comprising at least two angular rate sensors and two linear sensors capable of transmitting motion signals to a first processor, said processor being capable of transmitting processed signals to a second processor in connection with a display, wherein said signals control the movements of a virtual cursor on said display with the measurements of said angular rate sensors, said angular rate sensor measurements being corrected by said first processor for the tilt of said air pointing device, said tilt correction using only the measurements from a first linear sensor for a first range of tilt values and only the measurements from a second linear sensor for a second range of tilt values within a half space.

11. The air pointing device of claim 10, wherein said first and second tilt corrections respectively use for said first and second ranges of tilt values the raw measurements Ay and AZ from said first and second linear sensors and algebraic transformations of said measurements of the forms and.

12. The air pointing device of claim 10, wherein said first and second tilt corrections respectively use for said first and second ranges of tilt values the raw measurements Ay and AZ from said first and second linear sensors and approximations of algebraic transformations of said measurements of the forms and.

13. The air pointing device of claim 12, wherein said approximations include polynomial approximations of said algebraic transformations.

14. The air pointing device of claim 13, wherein said polynomial approximations are of the form for the first linear sensor and of the form for the second linear sensor.

15. The air pointing device of claim 13, wherein said polynomial approximations include best fit polynomials the coefficients of which are calculated to minimize a weighted sum of distances between values of the algebraic transformation at selected points and values of the polynomial at the same points.

16. The air pointing device of claim 13, wherein said polynomial approximations include series of limited developments of the algebraic transformations in a number of selected points.

17. The air pointing device of claim 13, wherein said approximation are calculated at given points as the limits for a definite precision of the zeros of the difference between the algebraic transformations and their first order limited developments.

18. An air pointing method comprising a step of processing in a first processor motion signals from at least two angular rate sensors and one linear sensor, a step of transmitting the output from said first processor to a second processor in connection with a display, a step of controlling the movements of a virtual cursor on said display with the measurements of said angular rate sensor, said angular rate sensors measurements being corrected by said first processor for the tilt of said air pointing device, the value of said tilt correction being calculated by using only the measurements from one of said at least two linear sensors for a range of tilt values within a first half space.

19. An air pointing method comprising a step of processing in a first processor motion signals from at least two angular rate sensors and one linear sensor, a step of transmitting the output from said first processor to a second processor in connection with a display, a step of controlling the movements of a virtual cursor on said display with the measurements of said angular rate sensors, said angular rate sensor measurements being corrected by said first processor for the tilt of said air pointing device, said tilt correction using only the measurements from a first linear sensor for a first range of tilt values and only the measurements from a second linear sensor for a second range of tilt values, said first and second range of tilt values within a first half space.

20. The air pointing method of claim 19, wherein said first range of tilt values covers a first half of a quadrant and said second range of tilt values covers a second half of a quadrant within said first half space.

21. A computer program comprising a module stored in an air pointing device comprising at least two angular rate sensors and one linear sensor capable of transmitting motion signals to a first processor, said processor being capable of transmitting processed signals to a second processor in connection with a display, wherein a second module uses said signals to control the movements of a virtual cursor on said display with the measurements of said angular rate sensors, said angular rate sensor measurements being corrected by said first processor for the tilt of said air pointing device, said tilt correction using only the measurements from one linear sensor for a range of tilt values within a first half space.

22. A computer program comprising a module stored in an air pointing device comprising at least two angular rate sensors and one linear sensor capable of transmitting motion signals to a first processor, said processor being capable of transmitting processed signals to a second processor in connection with a display, wherein a second module uses said signals to control the movements of a virtual cursor on said display with the measurements of said angular rate sensors, said angular rate sensor measurements being corrected by said first processor for the tilt of said air pointing device, said tilt correction using only the measurements from a first linear sensor for a first range of tilt values and only the measurements from a second linear sensor for a second range of tilt values, said first and second range of tilt values within a first half space.