Patent ID: 11947739
Assignee: CEVA TECHNOLOGIES, INC.
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 4:
5. An input/gesture device comprising:
a sensor;
a 3-axis gyroscope;
a 3-axis accelerometer; and
a processor configured to:
measure 3D linear motion or obtaining measurements of the 3D linear motion of the input/gesture device based on reading from the 3-axis accelerometer and the 3-axis gyroscope of the input/gesture device;
measure 2D planar linear motion or obtaining measurements of the 2D planar linear motion of the input/gesture device based on reading from a third type of sensor;
correlate the 3D linear motion with the 2D planar linear motion; and
determine the roll angle of the input/gesture device relative to the surface of the mobile device by solving for frame alignment between an inertial frame and a mobile device frame using a result of the correlate step,
wherein the processor is further configured to perform the determine step by:
applying a rigid body formula to estimate an acceleration of the tip of input/gesture device, rather than a location of the 3-axis accelerometer;
representing the 2D planar linear motion coordinates of the tip in 3D;
if a size of the surface is known, applying scaling to convert from pixels to distance;
applying a DC-blocking filter on both a 3D pointer trajectory from the surface and double integrated 3-axis accelerometer data to generate two signals; and
determining a frame alignment that aligns the two signals.