Inertial input apparatus with six-axial detection ability and the operating method thereof

• US 7,973,766 B2
• Filed: 08/31/2010
• Issued: 07/05/2011
• Est. Priority Date: 12/12/2006
• Status: Expired due to Fees

• Current Assignee: Industrial Technology Research Institute
• Original Assignee: Industrial Technology Research Institute
• Inventors: Tsai, Ming-Jye, Huang, Shih-Ching, Jeng, Sheng-Wen, Liou, Shun-Nan
• Primary Examiner(s): Shankar; Vijay
• Application Number:
  US12/872,551
• Publication Number:
  US 20100328210A1
• Time in Patent Office: 308 Days
• Field of Search: 345156-169
• US Class Current: 345/158
• CPC Class Codes: G01P 15/18 in two or more dimensions
• 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 3/0485 Scrolling or panning

Abstract

An inertial input apparatus with six-axial detection ability, structured with a gyroscope and an acceleration module capable of detecting accelerations of X, Y, Z axes defined by a 3-D Cartesian coordinates, which is operable either being held to move on a planar surface or in a free space. When the inertial input apparatus is being held to move and operate on a planar surface by a user, a two-dimensional detection mode is adopted thereby that the gyroscope is used for detection rotations of the inertial input apparatus caused by unconscious rolling motions of the user and thus compensating the erroneous rotations, by which the technical disadvantages of prior-art inertial input apparatuses equipped with only accelerometer can be overcame and thus control smoothness of using the input apparatus is enhanced.

Claims

1. An inertial input apparatus with six-axial detection ability, comprising:

an accelerometer module, structured with at least three accelerometers for detecting accelerations in three perpendicular directions with respect to a Cartesian coordinate system of X-, Y-, and Z-axes; and

a gyroscope, used for detecting an angular velocity measured with respect to the Z-axis;

wherein, an angle of rotation is obtained by integrating the angular velocity of the rotation detected by the gyroscope while calculating a centrifugal force as well as a centripetal force exerting upon the inertial input apparatus during the rotation so as to using those for compensating acceleration signals measured along the Y-axis and thus obtaining a pitch angle basing on the compensated Y-axis acceleration signal, thereafter defining movements of an object displayed on a screen of an interactive computer by the use of the pitch angle and the angle of rotation.

2. The inertial input apparatus of claim 1, wherein

one accelerometer of the accelerometer module, referring hereinafter as an X-axis accelerometer, is being enabled for detecting an acceleration generated by a rolling of the inertial input apparatus about the Y-axis while referring hereinafter such acceleration as X-axis acceleration;

another accelerometer of the accelerometer module, referring hereinafter as a Y-axis accelerometer, is being enabled for detecting an acceleration generated by a pitching of the inertial input apparatus about the X-axis while referring hereinafter such acceleration as Y-axis acceleration; and

one another accelerometer of the accelerometer module, referring hereinafter as an Z-axis accelerometer, is being enabled for detecting an acceleration with respect to the Z-axis while the inertial sensing input apparatus is experiencing an up-and-down displacement.

3. The inertial input apparatus of claim 1, wherein the gyroscope is used for detecting and measuring a rotation about the Z-axis.

4. An operating method for an inertial input apparatus with six-axial detection ability being held to move in a free space, comprising the steps of:

recording two accelerations (g_xs,g_ys) measured along two perpendicular directions with respect to a Cartesian coordinate system of X-, and Y-axes at an initial operating stage of the inertial input apparatus along with an initial angular velocity ω

_zs of a gyroscope while setting an initial angle θ

_p of the inertial input apparatus to be zero;

calculating a yawing angle θ

_z with respect to a Z-axis of the Cartesian coordinate system and a pitch angle θ

_y with respect to the Y-axis; and

using the two angles (θ

_z,θ

_y) to define a position coordinate (M_x, M_y) for an object displayed on a screen of an interactive computer.

5. The method of claim 4, wherein the calculating of the yawing angle θ

_z and the pitch angle θ

_y further comprises the steps of;

calculating the yawing angle θ

_z with respect to the Z-axis;

compensating a Y-axis acceleration detected by a Y-axis accelerometer of an accelerometer module; and

calculating the pitch angle θ

_y.