Physical quantity detection device

Patent metadata

Field	Value
Publication number	US-10006392-B2
Application number	US-201515126298-A
Country	US
Kind code	B2
Filing date	Jan 7, 2015
Priority date	Mar 31, 2014
Publication date	Jun 26, 2018
Grant date	Jun 26, 2018

Abstract

To achieve a physical quantity detection device capable of obtaining a desired overall device accuracy without unnecessarily raising the tolerances of detection elements, the present invention is characterized by having a plurality of physical quantity detection units for respectively detecting plurality of physical quantities, a storage unit for storing the error characteristics of individual physical quantity detection units, a physical quantity calculation unit for using at least two physical quantities detected by at least two of the plurality of physical quantity detection units to calculate a separate physical quantity, and an error calculation unit for reading the error characteristics of the plurality of physical quantity detection units from the storage unit and calculating the error of the separate physical quantity.

First claim

The invention claimed is:

1. A physical quantity detection device comprising:
a plurality of physical quantity detection units including a relative humidity sensor and a temperature sensor configured to detect a plurality of physical quantities, the plurality of physical quantities including at least a relative humidity of an intake air of an internal combustion engine detected by the relative humidity sensor and the temperature of the intake air of the internal combustion engine detected by a temperature sensor;
a storage unit configured to store error characteristics of the respective physical quantity detection units, the error characteristics indicating a change of an error according to the temperature;
a physical quantity calculation unit configured to calculate an absolute humidity by using the detected relative humidity and the detected temperature; and
a total error calculation unit configured to calculate a total error of the absolute humidity by reading and using the error characteristics of the relative humidity sensor and the temperature sensor stored in the storage unit.

2. The physical quantity detection device according to claim 1 , wherein
information on the total errors of the first and second physical quantities is joined.

3. The physical quantity detection device according to claim 2 , wherein
the total error calculation unit calculates the total error of the third physical quantity by conducting a search in a map arranged in a grid shape or a plurality of tables by using the first and second physical quantities.

4. The physical quantity detection device according to claim 3 , wherein
the total error calculation unit collectively outputs the information on the total error according to a request from outside or a time from power supply.

Assignees

• Hitachi Automotive Systems Ltd

Inventors

• Hoshika Hiroaki
• Yogo Takayuki
• Miki Takahiro
• Hosokawa Takeo
• Isoya Yuki

Classifications

• F02D2041/281

  between sensors and control unit · CPC title

• G01N27/223

  for determining moisture content, e.g. humidity (rain detectors on vehicle windows B60S1/0825) · CPC title

• F02D2200/0414

  Air temperature · CPC title

• G01N33/0073

  Control unit therefor · CPC title

• G01D3/0365

  the undesired influence being measured using a separate sensor, which produces an influence related signal · CPC title