公开(公告)号：US20180080954A1

公开(公告)日：2018-03-22

申请号：US15554186

申请日：2016-03-17

Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.

Inventor： Kazuo ONO ,  Daisuke MAEDA ,  Takashi OSHIMA

IPC: G01P15/125 ,  B81B3/00

Abstract: In a capacitance detection type sensor system, a sensitivity of the sensor system deteriorates because a low frequency noise typified by a 1/f noise cannot be separated in frequency from a signal band. A carrier wave used for capacity detection is modulated with two kinds of frequencies, sampled at a first modulation frequency, subjected to a C/V conversion, and synchronously detected at a second modulation frequency to obtain a signal.