The purpose of the present invention is to reduce a load of preventing dew condensation, and to provide a highly reliable humidity detection device. In order to achieve the purpose, this humidity detection device is provided with: a humidity sensor having a humidity detection unit and a temperature detection unit; a heating resistor that heats the humidity sensor; and a heating control unit that controls a heating temperature of the heating resistor. The humidity detection device is characterized in having a target temperature storage unit that stores target temperatures of the heating resistor, said target temperatures having been determined corresponding to temperatures and humidities.

A method provides a diagnostic on a combined humidity and temperature sensing device including a humidity sensor having a humidity sensing element, a temperature sensor, and a heater. The method comprises obtaining a first temperature and a first relative humidity, heating the humidity sensing element with the heater, obtaining a second temperature and a second relative humidity after heating the humidity sensing element, and determining a difference between the first temperature and the second temperature and a difference between the first relative humidity and the second relative humidity. Diagnostic information representative of a possible malfunction of the humidity sensor is output when the difference between the first temperature and the second temperature is higher than a predetermined temperature difference threshold and the difference between the first relative humidity and the second relative humidity is lower than a predetermined humidity difference threshold.

Methods and systems are provided for diagnosing whether one or more intake air oxygen sensors positioned in an intake of an engine of a vehicle, are functioning as desired. In one example, a method comprises injecting fuel into one or more cylinders of the engine without combustion, routing un-combusted hydrocarbons from the one or more cylinders to the intake via a crankcase ventilation system, and indicating whether the one or more intake air oxygen sensors are functioning as desired based on a response of the one or more intake air oxygen sensors. In this way, the one or more intake air oxygen sensors may be periodically diagnosed which may improve engine operation, and reduce engine degradation, particularly with regard to hybrid electric vehicles with limited engine run-time.

An estimation method to determine the concentration of recirculated exhaust gas present in a cylinder of an internal combustion engine; the concentrations of recirculated exhaust gas in a gas mixture flowing through an intake duct are periodically stored in a buffer; a first instant is determined, in which a programming of a following combustion in the cylinder is carried out; an advance time is determined, which elapses between the first instant and a second instant in the future, in which air will be taken into the cylinder for the following combustion in the cylinder; a transport time is determined; a third instant in the past is determined by subtracting from the first instant an amount of time which is equal to the difference between the transport time and the advance time; and the concentration of recirculated exhaust gas present in the cylinder in the second instant is estimated depending on a concentration of recirculated exhaust gas contained in the buffer (30) and corresponding to the third instant.

Methods and systems are provided for removing moisture from engine intake manifold and exhaust manifold. In one example, a method may include, during an engine non-combusting condition, while the ambient humidity is higher than a threshold humidity, operating an intake electric booster to route pressurized air via each of the intake manifold and the exhaust manifold, thereby removing accumulated moisture from the engine components. The electric booster may also be operated immediately prior to an anticipated vehicle key-on event to remove condensate from engine components prior to an actual engine start.

In a physical quantity measurement device using a printed circuit board, breakage of a wiring on the printed circuit board is suppressed. Provided are a flange 110 for fixing to a main passage, a housing 101 provided so as to protrude toward an inside of the main passage from the flange 110, and a printed circuit board 140 which is fixed to the housing 101 and on which a measuring element that measures a physical quantity is mounted. A wiring of the printed circuit board 140 has a plurality of irregularities formed along one direction of a surface, and is arranged such that a formation direction of the irregularities is oriented along a protruding direction of the housing 101 toward an inside of the main passage.

A precleaner system for an air intake system. The precleaner system includes precleaners each having flow paths that induce a rotation to air flow and separate out particulate matter. The particulate matter is ejected from an outlet port in each of the flow paths and out of a dust ejector. The precleaned air is collected into a plenum from each of the precleaners. The precleaned air can flow from the plenum to a precleaner system outlet and the precleaned air can be received by an air intake system. A cover can be used to block air flow through one of the precleaners to tune the precleaner system to the desired airflow.

In order to provide a temperature and humidity sensor with improved reliability, the temperature and humidity sensor in which all or part of a case of the temperature and humidity sensor is inserted into a main duct for causing gas to pass through and which detects humidity of the gas, includes: a first sub-passage configured as a part of the case, a part of the gas passing through the main duct flowing in substantially the same direction as a flow in the main duct; a throttle section provided between an inlet and an outlet of the first sub-passage and on an inner surface of the first sub-passage, the throttle section having a throttle whose cross-sectional area is smaller than an average cross-sectional area of the entire first sub-passage; and a second sub-passage which connects an upstream side and a downstream side of the throttle section and is different from the first sub-passage. The first sub-passage and an inlet and an outlet of the second sub-passage are connected via respective connection ports, and the connection port between the inlet of the second sub-passage and the first sub-passage or the connection port between the outlet of the second sub-passage and the first sub-passage is provided on a side where a throttle is not provided when viewed from an axis in an upstream and downstream direction of the flow in the first sub-passage.

The purpose of the present invention is to enhance the detection accuracy of an absolute humidity determined from at least temperature and relative humidity when carrying out temperature control using a heating element according to detection characteristics for temperature and relative humidity. A physical quantity detection device according to the present invention is provided with a humidity sensor for detecting relative humidity and temperature, a heater for heating the humidity sensor, and a microcomputer and controls the heat generation amount of the heater by using the heater for heating and stopping heating such that an environment under measurement is at least a room temperature and is a temperature at which a relative humidity detection characteristic and temperature detection characteristic for the humidity sensor improve, thereby enhancing the accuracy of absolute humidity detection.

To obtain a physical quantity detection device that can prevent a thermal influence on a sensor due to downsizing. A physical quantity detection device of the present invention includes a chip package in which a flow sensor and an electronic component are sealed using resin and a circuit board on which the chip package is mounted. The chip package is fixed to a circuit board surface of the circuit board with a part of the chip package protruding laterally from an end of the circuit board, and the circuit board includes a flat margin region S wider than a width of the chip package, the margin region S being provided at a position on a circuit board surface and at a position biased in an opposite direction to a protruding direction from the chip package.