公开(公告)号：US20200003887A1

公开(公告)日：2020-01-02

申请号：US16490805

申请日：2018-01-25

Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.

Inventor： Takafumi MATSUMURA ,  Masayuki SATOU

IPC: G01S13/60 ,  G01S15/60

Abstract: A speed measurement device and a speed measurement method are proposed which can calculate a speed even in a case where an intensity of a reflection wave is weakened with respect to an irradiation wave emitted from a radar module. A speed measurement device mounted in a vehicle generates an irradiation wave to emit the wave to a ground, receives a reflection wave from the ground of the irradiation wave, and generates a frequency difference signal between the emitted irradiation wave and the received reflection wave. Then, in a case where the intensity of the generated frequency difference signal is equal to or more than a predetermined value (amplitude threshold), a measurement speed is calculated on the basis of the frequency difference signal. Further, in the speed measurement device, the amplitude threshold used at the time of next measuring is changed based on a state of a system.

公开(公告)号：US20200326217A1

公开(公告)日：2020-10-15

申请号：US16757614

申请日：2018-12-14

Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.

Inventor： Tomoaki SAITO ,  Masayuki SATOU ,  Akira TAKASAGO ,  Noboru TOKUYASU

IPC: G01F1/684 ,  G01F1/696

Abstract: Provided is a thermal flowmeter that can achieve both measurement accuracy and antifouling performance with a simple and space-saving passage structure. In the thermal flowmeter of the invention, a housing is disposed in a main passage through which a gas to be measured flows, and the gas to be measured is taken from the main passage into an auxiliary passage provided in a housing, and a flow rate detection unit disposed in the auxiliary passage measures a flow rate of the gas to be measured. The auxiliary passage includes an inlet opening that opens to be inclined with respect to the main flow direction of the gas to be measured flowing through the main passage, and an inclined passage that extends in a direction inclined with respect to the main flow direction of the gas to be measured flowing from the inlet opening through the main passage.