The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 13, 2025
Filed:
Apr. 23, 2019
Hitachi Automotive Systems, Ltd., Hitachinaka, JP;
Yuki Isoya, Hitachinaka, JP;
Hiroaki Hoshika, Hitachinaka, JP;
HITACHI ASTEMO, LTD., Hitachinaka, JP;
Abstract
It is possible to reduce a degradation in accuracy after switching of a heating state or after change of the flow rate. A physical quantity detection device includes a flow rate measuring element which is equipped with a heating element and measures a flow rate of a measurement target fluid; a heating element control unit which switches a control state of the heating element to one of a heat generation state or a heat generation suppression state; and a signal processing unit which includes a buffer and a frequency analysis block, and processes a measured value of the flow rate measuring element, using a main frequency calculated by the frequency analysis block, in which the measured value for a past predetermined period is recorded in the buffer, the frequency analysis block calculates the main frequency by performing a frequency analysis of the measured value recorded in the buffer, when an occurrence of an event is detected, the signal processing unit performs a calculation, using the main frequency calculated immediately before for a predetermined period from the occurrence of the event, and the event is a sudden change in the measured value and switching of the control state performed by the heating element control unit.