Denso Corporation

Toyota Jidosha Kabushiki Kaisha

Hisato Kuramoto

Noboru Kitahara

A flow rate measurement system outputs a measurement value which represents a magnitude of a flow rate and a flow direction of a fluid that flows through a particular main passage. The system includes a bypass passage disposed in the main passage, a detection unit disposed in the bypass passage that outputs a detection value corresponding to a magnitude of a flow rate and a flow direction of the fluid flowing through the bypass passage, and a calculation unit that, by using the detection value, calculates the measurement value by compensating as needed for a delay in the change in flow rate in the bypass passage with respect to the change in flow rate in the main passage. The compensation is based on whether a change of flow direction has occurred in the main passage or the bypass passage.

Flow rate measurement system

An intake air amount measuring device includes a by-pass-type air flowmeter and a processor that calculates an intake air amount of an engine based on the measurement result of the air flowmeter. When calculating the intake air amount, the processor performs lag or lead compensation for a response delay of a change in an intake flow rate in the bypass passage in relation to a change in an intake flow rate in the main passage based on loss coefficients of the main passage and the bypass passage. The processor causes values of the loss coefficients of the main passage and the bypass passage, which are used in the compensation, to be different between a forward flow state, in which the intake air flows through the main passage in a forward direction, and a backflow state, in which the intake air flows through the main passage in a reverse direction.

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Anjou, Japan

Hisato Kuramoto