Ngk Spark Plug Company, Limited

Japan Science and Technology Agency

Yoshinori Inoue

Norikazu Ieda

Hiroshi Inagaki

Masahiro Tanaka

Akihiro Kobayashi

Katsunori Yazawa

Kaoru Hisada

Shinji Kumazawa

Keigo Banno

Yuichi Goto

Tomonori Uemura

Reina Fukagai

Koji Ikuta

Ryosuke Noda

Tatsuki Hirabayashi

Toshio Nakanishi

Hiroyuki Tsukada

Wenjing Ma

Reina Kito

A particulate measurement apparatus comprises a control section, which provisionally determines in an anomaly determination process that a corona core wire is in a short anomaly state when a linear voltage is equal to or lower than a particular voltage value and increments a sensor anomaly counter CNS or a chassis anomaly counter. The control section determines that the corona core wire is in a short anomaly state when the count value of one of the anomaly counters is equal to or greater than a determination threshold.

Particulate measurement apparatus and particulate measurement system

In a particulate measurement apparatus () of a particulate measurement system (), a control section () provisionally determines in an anomaly determination process at Sthat a corona core wire () is in a wire-breakage anomaly state; namely, that the corona core wire () is broken, when a corona low-side current Cis equal to or smaller than a current determination value Cand increments a wire-breakage anomaly counter CNB at SThe control section () determines that the corona core wire () is in the wire-breakage anomaly state at Swhen the count value of the wire-breakage anomaly counter CNB is equal to or greater than a wire-breakage determination threshold Cth; namely, that the result of the determination at Sis 'Yes'.

A measurement apparatus includes a plurality of modules and a main unit for collecting measurement data output from the modules. The housing of the main unit can be carried by a user of the measurement apparatus, and the plurality of modules are removably accommodated in the housing. A controller area network interface circuit of the main unit collects the measurement data output from the modules accommodated in the housing. A main CPU of the main unit outputs the collected measurement data to, for example, a personal computer connected to the main unit. An internal memory and a USB memory connected to a USB memory module store the collected measurement data.

Modular measurement apparatus

A load drive apparatus () includes a pulse drive circuit () which applies a pulse voltage PS to a resistive load (); current detection means (S) for detecting the current flowing to the resistive load () through the pulse drive circuit (); level detection means (SS) for determining whether an output terminal voltage VD of the pulse drive circuit () is a high potential level or a low potential level; anomaly detection means (SSS) for detecting a wire breakage anomaly, a short-to-power anomaly, and a short-to-ground anomaly based on the level of the output terminal voltage VD detected by the level detection means (SS) and the current detected by the current detection means (S), when the pulse drive circuitis turned on and off.

Load drive apparatus and sensor control apparatus

Three-dimensional microstereolithographic objects fabricated by microstereolithography are exposed to UV light for one hour to accelerate hardening. The structures are then heated at 175&#xb0; C. or above for at least 6 hours. The heating temperature may exceed the glass transition temperature, which is the index of thermal softening temperature of materials. The present invention relates to three-dimensional microstructures formed by microstereolithography. Deformation due to a structure's own weight, which generally poses a problem in heat treatment, is reduced with microstructures due to the size effect. As a result, the dimensions of the three-dimensional structure fabricated by the present invention remain almost unchanged before and after the heat treatment.

Cytocompatible three-dimensional structures fabricated by microstereolithography

A gas sensor system including a gas sensor; a current control unit; a constant control unit; and a temperature acquisition unit. The gas sensor includes a measurement chamber, a pump cell and an electromotive force cell. The current control unit performs feedback control on current flowing through the pump cell in response to the voltage of the electromotive force cell and in accordance with a control constant which characterizes the feedback control. Further, the constant control unit changes the control constant of the feedback control in accordance with a value (for example, a resistance value of the electromotive force cell) corresponding to the temperature of the gas sensor.

Gas sensor system and method for controlling gas sensor

A gas sensor control apparatusis connected to a gas sensor () including cells () each having a pair of electrodes provided on a solid electrolyte body (), and includes a sensor drive circuit (). The gas sensor control apparatus () includes an instruction unit for outputting an instruction for setting the sensor drive circuit () to a deenergization state so as to stop the supply of electricity to the cells () and an instruction for setting the sensor drive circuit () to an energization state so as to supply electricity to the cells (); a setting unit () for setting the sensor drive circuit () to the deenergization state or the energization state; and a wiring anomaly detection unit () for detecting a wiring anomaly of the sensor drive circuit () or the gas sensor (). The gas sensor control apparatus () further includes an anomaly final determination unit, operable when a wiring anomaly is detected, for performing return-from-anomaly checking processing so as to cause the instruction unit to output the deenergization instruction and then output the energization instruction.

Gas sensor control device and gas sensor control method

A gas concentration detection apparatus and system including a gas sensor. Voltage Vd generated across detection resistor Rd through which pump current Ip flows is differentially amplified by OPand offset voltage Vofs is superposed thereon to obtain a detection voltage Vout. The amplification factor applied to the differential amplification of the voltage Vd is changed by turning switch SWon and off. When switch SWis turned on, the input terminal potentials of the operational amplifier OPare equalized, so that voltage Vofs is output as the detection voltage Vout. The detection voltage Vout contains an error attributable to the electronic components which form the circuit. The detection voltage Vout containing the error when SWis turned on is acquired as a correction voltage for each amplification factor, and is used for correction at the time of detection of the concentration so as to cancel the error.

Gas concentration detection apparatus and gas concentration detection system

A sensor control apparatus comprising an air/fuel ratio sensor having a sensor cell with a pair of electrodes, a current source capable of supplying a predetermined current between the electrodes, a current control section that turns on/off the current source, a voltage detecting section that detects voltages generated between the electrodes at respective times when the current source is turned on and off, a differential voltage detecting section that detects a differential voltage between the voltages that are generated at the respective times when the current source is turned on and off, a first voltage comparing section that compares the differential voltage with a first threshold voltage, and a half-activated state determining section that determines that the sensor cell has reached a half-activated state when the differential voltage is lower than the first threshold voltage. A sensor control method is also provided.

Sensor control apparatus and method

To provide a malfunction diagnosing method and apparatus capable of reliably determining a malfunction even where the malfunction occurs in a common wire connecting a gas sensor and a control circuit for driving it. In a gas concentration measurement unithaving a sensor control circuitwhich is connected to a sensor elementincluding an oxygen pump celland an oxygen concentration detection celland controls and drives this sensor element, a variation state of a terminal voltage at one connecting point (specifically, a Vs+ terminal) other than connecting points between electrodes facing a measurement chamber of each cellandand a common wireis detected by a malfunction detection circuitand an arithmetic processor. Based on this variation state of the terminal voltage, diagnosis of malfunction in the common wireis executed. When the common wireis broken, the terminal voltage at the Vs+ terminal varies with oscillations. Therefore, the malfunction detection circuitand the arithmetic processordetect this voltage variation with oscillations to output a malfunction determination signal to a CPU.

Method of diagnosing malfunction in gas concentration detecting unit and malfunction diagnostic apparatus thereof

A gas sensor apparatusin an air-fuel ratio detection systemincludes a gas sensor elementwhich outputs a detection signal corresponding to air-fuel ratio, and a gas sensor control circuitwhich includes a detection sectionfor outputting a first output signal VIP, a second output signal VIP, and a third output signal VIPin accordance with the detection signal. This detection sectionoutputs the first output signal VIPwhich changes in accordance with the air-fuel ratio at least within a wide first air-fuel ratio zone, the second output signal VIPwhich changes in accordance with the air-fuel ratio within a narrow zone in the vicinity of the stoichiometric ratio, and the third output signal VIPwhich changes in accordance with the air-fuel ratio within a narrow zone in the lean region.

Sensor control device and air fuel ratio detecting apparatus

In an activation state of a sensor device, when voltage on the connection points between the sensor device and the sensor control circuit becomes a preset abnormal value, electric cut off is made between the sensor control circuit and the connection point. Then, the delivery of power to the heater is ceased to lower the temperature of the cells to a below of an activation temperature, thereby increasing the internal resistance of the cell. Thereafter, the sensor control circuit supplies to the sensor device a current in a degree not to damage the sensor device, to detect voltages on the connection points at that time. By comparing between the voltages on the respective connection points detected, a content and location of abnormality occurred is identified for the sensor device.

Method and apparatus for diagnosing an abnormality of a gas-concentration measuring apparatus

A gas sensor system includes a gas sensor capable of producing an output signal responsive to the concentration of a specific gas component in measurement gas, a gas concentration determination device that makes electrical connections to the gas sensor and determines the concentration of the specific gas component according to the output signal of the gas sensor, a failure detection device that detects a potential failure in any one of the electrical connections, a sensor temperature determination device that judges whether the gas sensor has been cooled to a predetermined temperature or lower with reference to a sensor temperature parameter and a failure identification device that, when the gas sensor has been cooled to the predetermined temperature or lower, outputs a diagnosis signal to the gas sensor, measures potentials of the electrical connections under the diagnosis signal and identifies in which of the electrical connections the potential failure is occurring based on the measured potentials.

Gas sensor system with failure diagnostic function and failure diagnosis method for gas sensor system

NOx sensor element of oxygen-ion conductive solid electrolyte body; flow passage () provided within the body for introducing analyte gas; oxygen partial pressure detection cell; first oxygen pump cellfor controlling oxygen partial pressure of the gas in the flow passage; and nitrogen oxides detection cellfor decomposing nitrogen oxides in the gas having a controlled oxygen partial pressure and for causing dissociated oxygen to migrate through the solid electrolyte body (see FIG.). Operational amplifieris connected between the nitrogen oxides detection celland a 12 V battery power source to generate a voltage applied to the nitrogen oxides detection cell; and diodeconnected to a point between the operational amplifierand the nitrogen oxides detection cell. The diode clamps the voltage to an activation voltage higher than the measurement voltage during activation.

NOx measurement apparatus

An abnormality diagnosis method for a gas concentration measuring device, includes electrically shutting off measurement means from an oxygen concentration detecting cell and an oxygen pump cell of a gas sensor when a voltage at one of electrical connection points through which the measurement means is electrically connected to the oxygen concentration detecting cell and the oxygen pump cell becomes equal to a predetermined abnormal voltage value, and thereafter, electrically connecting the measurement means to the oxygen concentration detecting cell and the oxygen pump cell of the gas sensor to perform an abnormality diagnosis of the gas sensor. An abnormality diagnosis apparatus for a gas concentration measuring device is also provided.

Growing community of inventors

Nagoya, Japan

Yoshinori Inoue