发明名称 |
DISTANCE SENSING BY IQ DOMAIN DIFFERENTIATION OF TIME OF FLIGHT (TOF) MEASUREMENTS |
摘要 |
A system and method for identifying a position of a moving object, regardless of static objects present in the optical field of an active infrared (IR) proximity detector, is provided. Moreover, a modulated light emitting diode (LED) signal is captured and processed through I/Q demodulation. Specifically, the reflections received at an IR sensor are demodulated to generate in-phase (I) and quadrature phase (Q) signals and the derivative of I/Q signals is obtained to isolate motion. For example, an I/Q domain differentiator or a high pass filter is employed to calculate the derivative, which actively remove the effects of all forms of static interference. Further, the phase of the derivative I/Q signals is determined and is utilized to reconstruct the distance at which the motion occurred. |
申请公布号 |
US2014327900(A1) |
申请公布日期 |
2014.11.06 |
申请号 |
US201414296277 |
申请日期 |
2014.06.04 |
申请人 |
INTERSIL AMERICAS LLC |
发明人 |
Ritter David W.;Hiromi Itaru |
分类号 |
G01N21/55;G01S17/08;G01J9/00 |
主分类号 |
G01N21/55 |
代理机构 |
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代理人 |
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主权项 |
1. A method for use by or with a system that includes
a driver configured to produce a drive signal that drives a light emitting element to thereby cause a light signal to be emitted, an optical sensor configured to produce a sensor signal that is indicative of a portion of the light signal that reflects from one or more objects and is incident on the optical sensor, and a demodulator configured to perform quadrature demodulation of the sensor signal to produce in-phase (I) and quadrature phase (Q) signals, the method comprising:
(a) receiving the in-phase (I) and quadrature phase (Q) signals;(b) determining derivatives of the in-phase (I) and quadrature-phase (Q) signals; and(c) determining a phase of the derivatives of the in-phase (I) and quadrature-phase (Q) signals. |
地址 |
Milpitas CA US |