Abstract:
In a particulate measurement apparatus (300) of a particulate measurement system (10), a control section (600) provisionally determines in an anomaly determination process at S130 that a corona core wire (202) is in a wire-breakage anomaly state; namely, that the corona core wire (202) is broken, when a corona low-side current C1 is equal to or smaller than a current determination value C1min, and increments a wire-breakage anomaly counter CNB at S140. The control section (600) determines that the corona core wire (202) is in the wire-breakage anomaly state at S170 when 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 S160 is “Yes”.
Abstract:
A particulate detection apparatus (3) controls a particulate sensor (2) for detecting the amount of particulates contained in exhaust gas and which has a pump (203) for supplying air to a detection section of the particulate sensor (2) into which the exhaust gas is introduced. The particulate detection apparatus (3) detects the flow rate of air supplied from the pump (203) to the particulate sensor (2) by a flow rate sensor (207). The particulate detection apparatus (3) maintains a consistent detection accuracy of the particulate sensor (2) based on the result of the detection by the flow rate sensor (207).
Abstract:
An in-vehicle sensor (1) mounted on a vehicle VE and connected to a communication bus CAN including a bus connection connector (40) for connection to the CAN and external terminals (T3, T4) for communication, and one or a plurality of external terminals (T5, T6) for setting each brought into either of a first connection state not connected to any potential and a second connection state connected to a ground potential GND; a judgment section S1-S4, S5-S7 for setting whether the connection state is the first connection state or the second connection state; and an identifier setting section S8 which sets an identifier ID of the in-vehicle sensor (1) used on the communication bus CAN based on the judged connection state(s) for setting of the one or plurality of external terminals (T5, T6).
Abstract:
A particulate measurement apparatus controls a particulate sensor which includes an ion generation section (110), an exhaust gas electrification section (120), an ion trapping section (130), and a second electrode (132). The second electrode (132) is maintained at a potential repulses the ions to assist the trapping of the ions at the ion trapping section (130). The particulate measurement apparatus includes a second isolation transformer (720b) and an auxiliary electrode current measurement circuit (780). The second isolation transformer (720b) applies a voltage to the second electrode (132) through a second wiring line (222). The auxiliary electrode current measurement circuit (780) detects an auxiliary electrode current Iir flowing to the second wiring line (222). The particulate measurement apparatus determines at least one of the state of the particulate sensor and the state of the second wiring line (222) based on the auxiliary electrode current Iir.
Abstract:
A particulate measurement system (10) includes an auxiliary electrode current measurement circuit (780), which can determine whether or not an auxiliary electrode current Iir has flowed to a second wiring line (222) as well as its magnitude. When a particulate sensor (100) is operating normally, since a second electrode (132) and a casing CS are electrically insulated from each other, no current flows to the second wiring line (222). However, when the second electrode (132) and the casing CS are electrically shorted by soot or the like, the auxiliary electrode current Iir flows to the second wiring line (222). Therefore, by providing the auxiliary electrode current measurement circuit (780), the particulate measurement system (10) can determine the state of adhesion of particulates, etc., in the particulate sensor (100), and can determine whether or not the particulate measurement system (10) is in an anomalous state.
Abstract:
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.
Abstract:
In a particulate detection system (10), a control board (911), a high voltage generation board (913) and an isolation transformer (720) are respectively disposed in a first space (921d) and a second space (921e) separated from each other by an inner case (923). When electromagnetic noise is generated in the high voltage generation board (913) and the isolation transformer (720); specifically, at the primary winding of the isolation transformer 720, at the time of switching the primary current supply, the electromagnetic noise is blocked by the inner case (923). This configuration reduces the influence of electromagnetic noise generated in the primary winding on the control board (911).
Abstract:
A gas detector includes a detecting element, a circuit board, a housing case having a gas introduction hole, and a metal member which covers the gas introduction hole. The detecting element is disposed under the metal member. The gas detector further includes a detecting element wiring fusing prevention member which is electrically conductive and is electrically connected to a grounding line of the circuit board. The detecting element wiring fusing prevention member is disposed at a position such that the shortest distance between the metal member and the detecting element wiring fusing prevention member is smaller than that between the metal member and the detecting element.
Abstract:
A heater control method and apparatus for a gas sensor which can quickly activate a detection element while reducing load due to heating even when a higher power supply voltage is applied. A heater element is connected to a power supply whose voltage is higher than 16 V, and power is supplied under PWM control such that a temperature rise of the heater element follows a temperature rise curve obtained when a voltage of 12 V is applied to the heater element. Even though a higher voltage is applied, the temperature rise per unit time during the ON time of the PWM control is decreased. This is because the ON time per cycle is shortened by increasing the PWM frequency to 30 Hz or higher. Thus, the temperature rise per cycle is kept low, whereby the temperature rise per 0.1 second is rendered less than 25° C.