Method and device for enhancing accuracy in ultrasonic range measurement
First Claim
1. A method for short range detection using ultrasonic sensing, comprising:
- shaping a pulse signal to produce a pulse shaped signal;
transmitting the pulse shaped signal, the pulse shaped signal reflecting off a finger to produce a reflected signal;
receiving the reflected signal;
identifying a relative phase of the reflected signal with respect to a previously received reflected signal;
tracking a location and a movement of the finger from an arrival time of the reflected signal and the relative phase;
saving most recent echoes to a history, and selectively discarding echoes less recently saved in the history based on a similarity measure between echoes in the history; and
providing touchless control to a user interface control in accordance with the location and the movement of the finger,wherein the shaping uses a combination of amplitude modulation, frequency modulation, and phase modulation.
1 Assignment
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Accused Products
Abstract
A device (100) and method (300) for enhancing range detection accuracy in ultrasonic touchless sensing applications can include transmitting (302) an ultrasonic signal intended to reflect off a finger and produce an echo, receiving (304) the echo, saving (306) most recent echoes to a history (400), selectively discarding (308) echoes less recently saved in the history to produce a sparse history, identifying (310) a relative phase of the echo with respect to a previously received echo in the sparse history, tracking (312) a location and a movement of the finger from an arrival time of the echo and the relative phase, and providing (314) touchless control to a user interface control in accordance with the location and the movement of the finger.
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Citations
13 Claims
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1. A method for short range detection using ultrasonic sensing, comprising:
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shaping a pulse signal to produce a pulse shaped signal; transmitting the pulse shaped signal, the pulse shaped signal reflecting off a finger to produce a reflected signal; receiving the reflected signal; identifying a relative phase of the reflected signal with respect to a previously received reflected signal; tracking a location and a movement of the finger from an arrival time of the reflected signal and the relative phase; saving most recent echoes to a history, and selectively discarding echoes less recently saved in the history based on a similarity measure between echoes in the history; and providing touchless control to a user interface control in accordance with the location and the movement of the finger, wherein the shaping uses a combination of amplitude modulation, frequency modulation, and phase modulation. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method for enhancing range detection accuracy suitable for use in ultrasonic touchless sensing applications, comprising
transmitting an ultrasonic signal intended to reflect off a finger and produce an echo; -
receiving the echo and saving most recent echoes to a history; selectively discarding echoes less recently saved in the history to produce a sparse history; identifying a relative phase of the echo with respect to a previously received echo in the sparse history; comparing the echoes in the history for similarity and selectively pruning echoes in the history with high similarity; replacing the pruned echoes with echoes having low similarity; tracking a location and a movement of the finger from an arrival time of the echo and the relative phase; and providing touchless control to a user interface control in accordance with the location and the movement of the finger. - View Dependent Claims (8, 9, 10, 11, 12, 13)
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Specification