公开(公告)号：US20150330831A1

公开(公告)日：2015-11-19

申请号：US14712658

申请日：2015-05-14

Applicant: Texas Instruments Incorporated

Inventor： Amardeep Sathyanarayana ,  Nitish Murthy ,  Sourabh Ravindran ,  Brian Paul Burk

IPC: G01H13/00

CPC classification number: G01H3/08 ,  G01H1/00 ,  G01H13/00

Abstract: A method and apparatus for determining properties of at least one of a surface or materials adjacent to a portable device. The method includes windowing a segment of the received signal to remove an edge transients, computing the FFT power spectral density of the signal, determining a peak in the spectral energy at a frequency, finding local peaks by determining the difference in the signal amplitude is relation to a pre-determined threshold, and computing harmonic energy according to the local peaks and the difference and determining at least one property of the surface or material.

Abstract translation: 一种用于确定与便携式设备相邻的表面或材料中的至少一个的属性的方法和装置。 该方法包括：对接收到的信号进行加窗以去除边缘瞬变，计算信号的FFT功率谱密度，确定频谱中的频谱能量的峰值，通过确定信号幅度差异来找到局部峰值关系 根据局部峰值和差值计算谐波能量，并确定表面或材料的至少一个性质。

公开(公告)号：US09880046B2

公开(公告)日：2018-01-30

申请号：US14712658

申请日：2015-05-14

Applicant: Texas Instruments Incorporated

Inventor： Amardeep Sathyanarayana ,  Nitish Murthy ,  Sourabh Ravindran ,  Brian Paul Burk

IPC: G01H1/00 ,  G01H13/00 ,  G01H3/08

CPC classification number: G01H3/08 ,  G01H1/00 ,  G01H13/00

Abstract: A method and apparatus for determining properties of at least one of a surface or materials adjacent to a portable device. The method includes windowing a segment of the received signal to remove an edge transients, computing the FFT power spectral density of the signal, determining a peak in the spectral energy at a frequency, finding local peaks by determining the difference in the signal amplitude is relation to a pre-determined threshold, and computing harmonic energy according to the local peaks and the difference and determining at least one property of the surface or material.