CN1800843A - Method and apparatus for diagnosing an abnormality of a gas-concentration measuring apparatus - Google Patents
Method and apparatus for diagnosing an abnormality of a gas-concentration measuring apparatus Download PDFInfo
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- CN1800843A CN1800843A CN 200510135730 CN200510135730A CN1800843A CN 1800843 A CN1800843 A CN 1800843A CN 200510135730 CN200510135730 CN 200510135730 CN 200510135730 A CN200510135730 A CN 200510135730A CN 1800843 A CN1800843 A CN 1800843A
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Abstract
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.
Description
Technical field
The present invention relates to a kind of method and apparatus that is used to diagnose the gas concentration measuring apparatus abnormality.
Background technology
In correlation technique, in the burning control that comprises petrolic internal combustion engine, a kind of known method for controlling combustion is arranged, wherein fuel feed places under the FEEDBACK CONTROL of response predetermined portions exhaust gas concentration, and the air/fuel of the air by the control IC engine supply and the mixed gas of fuel recently reduces CO, the NO in the waste gas
XAnd HC.
As the gas sensor that is used to control this air/fuel ratio, known have oxygen sensor, gamut air/fuel ratio sensor (being also referred to as the UEGO sensor) and a NO
X(nitrogen oxide) sensor.Oxygen sensor is provided with battery (cell), described battery all has electrode on its two surfaces based on the solid electrolyte of zirconia etc., make one of them electrodes exposed in sample gas, and another electrodes exposed is in air, so that measure the concentration of sample gas by the electric potential difference that produces between sample gas and air.Gamut air/fuel ratio sensor is provided with two batteries, this battery is provided with electrode on two surfaces of its solid electrolyte, the measurement chamber is arranged therebetween, by diffusion damping piece (diffusion resistance member) sample gas is introduced the measurement chamber, can detect oxygen concentration various sample gas from high to low thus.And NO
XSensor comes measuring N O by a battery is set in addition
XGas content.
And, recently automobile adopts the gas concentration measuring apparatus that is suitable for automatic diagnosis, as previously described, when utilizing the burning of gas sensor control engine, this pick-up unit can be notified unusual (self diagnosis on the so-called car) of sensor and sensor controller to the driver.
In these gas concentration measuring apparatus, in fact described battery is remained on predetermined temperature (about 800 ℃) and activate this battery (temperature is elevated to and makes oxonium ion can pass through the state that solid electrolyte fully conducts) by well heater is set on battery, thereby make gas sensor battery operated and irrelevant with the temperature of waste gas.As the method that is used to diagnose this gas concentration measuring apparatus abnormality, known have under battery activated state the diagnosis short circuit or disconnect unusual diagnostic method (seeing J-A-11-107830).
Simultaneously, in aforesaid abnormality diagnostic method, abnormity diagnosis is in by well heater and makes state that battery remains on predetermined temperature (in other words, at battery activated state), therefore the problem that exists is, flow through battery in correlation time by making the abnormity diagnosis electric current, carry out under the abnormality diagnostic situation, might be used in the respective ends that the needed voltage of abnormity diagnosis does not output to this battery according to cell voltage.
That is, at battery activated state, this battery has and approaches zero internal resistance.For example, under the situation of the shorted to earth (being also referred to as GND) in battery electrode, the electric potential difference of battery becomes and approaches zero.The problem of Chan Shenging is not know that electrode pair ground short circuit like this.
For fear of this problem, consider to be increased in the abnormity diagnosis electric current that flows through this battery under the battery activated state, but this needs power supply that very big capacity is arranged, cause cost to increase like this.Simultaneously, also have another problem, promptly big electric current flows through battery and causes battery to quicken to degenerate.
Summary of the invention
Propose the present invention at these problems, therefore the objective of the invention is in gas concentration measuring apparatus, to take place to carry out abnormity diagnosis under the unusual situation and do not damage gas sensor.
In order to address this problem, a first aspect of the present invention is the unusual method that is used to diagnose gas concentration measuring apparatus, this gas concentration measuring apparatus comprises: gas sensor, this gas sensor comprises the sensing device that is used for exporting with the proportional signal of concentration of the predetermined gas in sample gas space, this sensing device comprises solid electrolyte and the electrode that is arranged in pairs on this solid electrolyte, with the heating part that is used for this sensing device is heated to activationary temperature, the output and the proportional signal of concentration of predetermined gas under this temperature, from the outside to this heating part energize; Measure portion, be used for measuring the concentration of the predetermined gas in sample gas space according to the output signal of this sensing device, this measure portion is electrically connected on the electrode of the sensing device of this gas sensor, this method comprises: be heated at this sensing device under the state of activationary temperature, when the voltage on any tie point between the sensing device of this measure portion and this gas sensor became predetermined abnormal voltage value, the energy of this heating part was supplied with in restriction; Diagnose the abnormality of this gas sensor then.
In view of the above, take place in gas concentration measuring apparatus such as under the unusual situation such as short circuit, the energy of supplying with heating part by restriction reduces the temperature of this heating part.Like this temperature of sensing device is reduced to and is lower than activationary temperature.Because cause increasing the internal resistance of this sensing device like this,, must determine abnormality therefore by under this high internal resistance state of this sensing device, carrying out abnormity diagnosis.
Therefore, conduct at the abnormity diagnosis electric current under the situation of this induction device, for example, when this sensing device produces big electric potential difference, voltage according to this sensing device carries out diagnosing abnormal, because current supply is to carry out, therefore can carry out reliable abnormity diagnosis under the high internal resistance state of sensing device.
Here, activationary temperature is represented such temperature, under this state, and can fully conduction in solid electrolyte such as the ion of oxonium ion.
Simultaneously, also have to use by having solid electrolyte and being arranged in pairs in sensing device that a plurality of batteries of the electrode on it constitute situation as the sensing device of the sensor of gas concentration measuring apparatus.Preferably, the method for the gas concentration measuring apparatus diagnosing abnormal by using this sensing device that is made of a plurality of batteries is implemented in a second aspect of the present invention.
Just, in gas concentration measuring apparatus, this sensing device preferably includes: through spreading the measurement chamber that damping piece is communicated with the sample gas space; With a plurality of batteries, each battery is arranged to towards this measurement chamber, and have solid electrolyte and be arranged in pairs in this electrolyte top electrode, construct the feasible a plurality of batteries that are electrically connected on this sensing device of this measure portion, and measure the concentration of the predetermined gas in this sample gas space according to the output signal of these a plurality of batteries, wherein, when the voltage on any tie point between a plurality of batteries of this measure portion and this gas sensor became the abnormal voltage value, the energy of this heating part was supplied with in restriction.
Equally, in gas concentration measuring apparatus,, have the sensing device that constitutes by a plurality of batteries and (for example, have the gamut air/fuel ratio sensor of two batteries, or have the NO of three batteries as top
XSensor) as sensor, taking place under the situation unusual such as short circuit etc., the energy of heating part is supplied with in restriction, to reduce the temperature of this heating part.This also is reduced to the temperature of battery and is lower than activationary temperature.Because increased the internal resistance of battery like this,, can understand abnormality reliably by under the high internal resistance state of this battery, carrying out abnormity diagnosis.
According to a third aspect of the invention we, use the abnormity diagnosis of the gas concentration measuring apparatus of this sensor, preferably supply with predetermined current and the tie point that detected during at supplying electric current detects to compare between the voltage and carries out abnormity diagnosis to sensing device by tie point.
Can determine to take place unusual content and position so reliably.
When carrying out abnormity diagnosis, the needed current amplitude that is transmitted to sensing device of abnormity diagnosis can reduce to minimum, therefore, can carry out abnormity diagnosis and does not damage sensing device.
Simultaneously, according to a forth aspect of the invention, be lower than activationary temperature, preferably, supply with the energy of heating part and close preset time for the supply by the restriction energy is reduced to the temperature of sensing device.
By disconnecting the plain mode that the energy of heating part is supplied with, can reduce the temperature of sensing device.
Secondly, in order to realize aforementioned purpose, a fifth aspect of the present invention is a kind of device of diagnosing gas concentration measuring apparatus unusual of being used to, this gas measurement device comprises: gas sensor, this gas sensor is used to export the sensing device with the proportional signal of concentration of the predetermined gas in sample gas space, this sensing device comprises solid electrolyte and the paired electrode that is arranged on this solid electrolyte, and heating part, be used for this sensing device is heated to activationary temperature, output and the proportional signal of predetermined gas under this temperature, this heating part is by outside energize; And measure portion, being used for measuring the concentration of the predetermined gas of this sample space according to the output signal of this sensing device, this measure portion is electrically connected on the electrode of the sensing device of this gas sensor.Be used to diagnose the unusual device of gas concentration measuring apparatus to comprise: judge part, whether the voltage that is used on the tie point between definite this measure portion and this sensing device is the improper magnitude of voltage of being scheduled to; Energy supply control part branch is used for when the voltage of tie point is defined as improper magnitude of voltage by the judgement part, and restriction is supplied with the energy of this heating part; And the abnormity diagnosis part, be used for divide the supply of restriction energy by the energy supply control part after, diagnosing the unusual of this gas sensor.
In view of the above, as previously mentioned, such as taking place in gas concentration measuring apparatus under the unusual situation such as short circuit, restriction is supplied with the energy of heating part, is reduced to the internal resistance that is lower than activationary temperature and increases this sensing device with the temperature with sensing device.Therefore, according to the method for the diagnosing abnormal that proposes in first aspect present invention, can carry out abnormity diagnosis reliably.
Simultaneously, as previously mentioned, this gas concentration measuring apparatus comprises the gas concentration measuring apparatus that uses the gas sensor with the sensing device that is made of a plurality of batteries.Use is preferably configured as sixth aspect present invention illustrated by the gas concentration measuring apparatus of the sensing device that a plurality of batteries constitute.
Just, in gas concentration measuring apparatus, this sensing device comprises: measure the chamber, it is communicated with the sample gas chamber by the diffusion damping piece; With a plurality of batteries, each battery is arranged to towards this measurement chamber, and has solid electrolyte and the electrode that is arranged in pairs on this solid electrolyte; Structure measure portion structure makes it be electrically connected on a plurality of batteries of this sensing device, and measures the concentration of the predetermined gas in this sample gas space according to the output signal of these a plurality of batteries; Judge part, judge whether the voltage on the tie point between a plurality of batteries of this measure portion and this sensing device is the improper magnitude of voltage of being scheduled to; And the energy supply control part limits the energy supply of this heating part when dividing voltage between this tie point to be judged to be improper magnitude of voltage by this judgements part.
By constructing gas concentration measuring apparatus by this way, the abnormality diagnostic method according to proposing in second aspect present invention can carry out abnormity diagnosis reliably.
Be used to use the abnormity diagnosis part of gas concentration measuring apparatus of this gas sensor preferred illustrated, comprise the current supply part, be used for supplying with scheduled current to sensing device by this tie point as seventh aspect present invention; And current detection section, be used for this current supply part supplying electric current the time, detecting the voltage on this tie point, wherein this abnormity diagnosis part is by comparing diagnosing abnormal between the detection voltage of this tie point that is detected by this voltage detection department branch.
Can determine the unusual content and the position that are taken place so reliably.
When carrying out abnormity diagnosis, can be reduced to through the electric current of this sensing device and to be used for the needed minimum amplitude of abnormity diagnosis, therefore can carry out abnormity diagnosis and do not damage this sensing device.
Be lower than activationary temperature for the temperature with sensing device is reduced to, preferably, propose, the energy of heating part is supplied with the disconnection predetermined periods by the energy control section as eighth aspect present invention.
Pass through the plain mode of the energy supply of disconnection heating part like this, can reduce the temperature of sensing device.
Description of drawings
Fig. 1 is the structural drawing of gas concentration measuring apparatus;
Fig. 2 is the circuit diagram that electronic control unit 5 sketch maps are shown;
Fig. 3 is the figure that is illustrated on off state in the various operator schemes of sensor drive driving circuit 52;
Fig. 4 is the figure that the condition for identification that is used to discern the abnormal patterns that occurs in this terminal is shown;
Fig. 5 is a main flow chart, is illustrated in the treatment step of carrying out in the microcomputer 7; And
Fig. 6 is a subroutine flow chart, is illustrated in the flow process of the treatment step of carrying out in the microcomputer 7.
Embodiment
Embodiments of the invention are described below with reference to the accompanying drawings.
Fig. 1 is the structural representation that the gas concentration measuring apparatus 1 that the present invention is suitable for is shown.Gas concentration measuring apparatus 1 in the present embodiment is used for measuring the oxygen concentration that is included in engine exhaust gas.
As shown in Figure 1, gas concentration measuring apparatus 1 in the present embodiment has gas sensor 2 and electronic control unit 5 (below be also referred to as ECU 5), and this control module is electrically connected on this gas sensor 2, can measure the oxygen concentration of sample gas etc.
This gas sensor 2 comprises the sensor device 10 of the oxygen concentration that can detect the sample gas in the waste gas and the well heater 70 that this sensing device is remained on activationary temperature.
This sensor device 10 is gamut air/fuel ratio sensors, and it has pump battery (pump cell) 14, thermofin 15, and oxygen concentration detects battery 24 and stiffening plate 30, is placed on above another according to one of said order.
This pump battery 14 is made of first pump electrode (pump electrode) 12a and the second pump electrode 12b of the front and back of the solid electrolyte 11a that is arranged in pairs in conduct oxygen ions of sheet.Wherein, the first pump electrode 12a is electrically connected with the end of line L3, and simultaneously, the second pump electrode 12b is electrically connected with the end of line L2.The other end of this line L3, L2 is electrically connected on the 3rd and second link terminal T3, the T2 of this ECU 5 respectively.
Be similar to pump battery 14, oxygen concentration detection battery 24 is made of the first detecting electrode 13a and the second detecting electrode 13b of the front and back of the solid electrolyte 11c that is arranged in pairs in conduct oxygen ions of sheet.Wherein, the first detecting electrode 13a is electrically connected on the second pump electrode 12b, and therefore, the second pump electrode 12b and the first detecting electrode 13a are connected in the end of line L2.Simultaneously, the end of line L1 is connected in the second detecting electrode 13b.The other end of line L1 is electrically connected on the first splicing ear T1 of this ECU 5.
Here, electrolyte 11a, 11c are made of the material based on zirconium.Pump electrode 12a, 12b and detecting electrode 13a, 13b are made of the porosint based on platinum.
Insulation course 15 is arranged on pump battery 14 and oxygen concentration detects between the battery 24, so that detect electrical isolation between the battery 24 at pump battery 14 and oxygen concentration.This insulation course 15 is made of the material based on alumina.
Detect between the battery 24 at this pump battery 14 and this oxygen concentration, measure chamber 20 around forming by insulation course 15.The first detecting electrode 13a of second pump electrode 12b of pump battery 14 and oxygen concentration detection battery 24 is arranged in this measurement chamber 20 and faces.Insulation course 15 is partly by constituting with the sample gas side with the diffusion layer 18 of measuring the porous that chamber 20 is communicated with, so that the sample gas of waste gas is introduced measurement chamber 20.The diffusion layer 18 of this porous is used for sample gas and introduces the diffusion control of measuring chamber 20.This porous diffusion layer 18 is formed by the porosint based on alumina.
Stiffening plate 30 is arranged on the surface that this oxygen concentration detects battery 24, and chamber 20 is relative with measuring, so that the second detecting electrode 13b is placed between them.Guarantee the intensity of sensor device 10 so on the whole.
Simultaneously, this stiffening plate 30 shields the second detecting electrode 13b that this oxygen concentration detects battery 24 from the outside, to form an enclosure space around this second detecting electrode 13b.In such apparatus structure, by the mobile very little electric current I of the direction along the second detecting electrode 13b that detects battery 24 from this oxygen concentration to the first detecting electrode 13a
CP, towards the second detecting electrode 13b pumping oxygen.Be used as the reference oxygen that detects the oxygen concentration of sample gas in this sensor device 10 at the oxygen of in the enclosure space of this second detecting electrode 13b, assembling.For this reason, this second detecting electrode 13b also is called self-generating reference electrode 13b.
This stiffening plate 30 is approximately equal to solid electrolyte 11a, the 11c of this pump battery 14 of formation and the size that this oxygen concentration detects battery 24 dimensionally, and is formed by the board-like material based on pottery.
By well heater 70 this battery is remained on 550-900 ℃, the solid electrolyte layer of this battery is in the state of complete conduct oxygen ions, promptly so-called state of activation.For this reason, pump battery 14 be can be used in transport oxonium ion, and make oxygen concentration detection battery 24 can produce and measure the proportional voltage of oxygen concentration difference between chamber 20 and the self-generating reference electrode 13b.
This electronic control unit 5 comprises the sensor control circuit 50 that is electrically connected on this sensor device 10 and is used to control this sensor device 10, be electrically connected on this well heater 70 and be used to the microcomputer 7 controlling the control circuit for heater 60 of this well heater 70 and be used to control this sensor control circuit 50 and this control circuit for heater 60.
Wherein, though do not illustrate, this microcomputer 7 comprises as the CPU of CPU (central processing unit), is used for the RAM and the ROM of storage data and program etc. and is used for from the external circuit input signal with to the input and output port of outside circuit output signal.According to being stored in program among this RAM etc., the instruction that control microcomputer 7 is carried out such as operation or data transmission.In this microcomputer 7, the signal that is input to its input port is reflected in the content of input port register, and the content that is stored in this output register is output as the signal of output port.
This sensor control circuit 50 has terminal Vs+, COM and Ip+.These terminals are electrically connected on first to the 3rd splicing ear T1-T3 of this ECU 5.Therefore, the second detecting electrode 13b of this sensor device 10 is electrically connected on terminal Vs+ by the line L1 and the first splicing ear T1.The second pump electrode 12b of this sensor device 10 and the first detecting electrode 13a are electrically connected on terminal COM by the line L2 and the second splicing ear T2.And the first pump electrode 12a of this sensor device 10 is electrically connected on terminal Ip+ by line L3 and the 3rd splicing ear T3.
In sensor device 10, the oxygen in this sample gas is diffused into by porous diffusion layer 18 and measures in the chamber 20, and is proportional with the oxygen concentration of sample gas.Air-fuel mixture at supply engine remains under the situation of stoichiometric(al) ratio, because the oxygen concentration of measuring between chamber 20 and this enclosure space is poor, this sensor device 10 has characteristic, can detect in oxygen concentration and generate electric power 450mV in the battery 24, provide around the oxygen concentration reference of this second detecting electrode 13b.Just, between this first and second detecting electrode 13a, 13b, produce the electric potential difference of 450mV.
Simultaneously, the oxygen concentration that is included in the waste gas changes along with the variation of the air/fuel ratio of the potpourri of supply engine.This causes the variation of the oxygen concentration in the gas in the measurement chamber 20 of sensor device 10.Therefore, in the gas concentration measuring apparatus 1 of present embodiment, under the control with the sensor control circuit 50 of explanation after the electric current I p by pump battery 14 placed, and between the first and second detecting electrode 13a, 13b, provide 450mV electric potential difference.That is,, make the air/fuel ratio that gas in measuring chamber 20 becomes and equals stoichiometric(al) by pump battery 14 pumping oxygen.According to electric current I p, can measure the oxygen concentration of this sample gas.
Structure and the operation of ECU 5 are described according to Fig. 2 below.Fig. 2 is the circuit diagram that the sketch map of this ECU 5 is shown.
As shown in Figure 2, this ECU 5 comprise the sensor control circuit 50 that is used to control sensor device 10, be used to control this well heater energy control control circuit for heater 60 and be used to control the microcomputer 7 of this sensor control circuit 50 and control circuit for heater 60.
This sensor control circuit 50 comprises: sensor drive driving circuit 52 is used to drive-control the pump battery 14 and the oxygen concentration that constitute this sensor device 10 and detects battery 24; Abnormal detection circuit 53, be used for when having surpassed predetermined voltage range, to this microcomputer 7 output abnormality certification mark DIAG=1 as terminal Vs+, the COM of the tie point between this sensor device 10 and this sensor drive driving circuit 52 and any each terminal voltage on the Ip+; And terminal voltage output circuit 54, be used for the terminal voltage on terminal Vs+, COM and the Ip+ is outputed to microcomputer 7.This sensor control circuit 50 is for example realized by ASIC (appliance-specific IC).
This sensor control circuit 52 comprises: operational amplifier 32 is used for streaming current Ip to drive this pump battery 14; PID control circuit 56 is used for the Control of Voltage of oxygen concentration detection battery 24 is become target voltage (for example 450mV); Constant current source 46 is used to make steady current Icp to flow to oxygen concentration and detects battery 24, and is constant so that the oxygen concentration at this self-generating reference electrode 13b place keeps; Constant pressure source 48 is used for the controlled target voltage of supplying electric current Ip; Terminal Vs+, COM and Ip+ are with owing to be connected between this sensor drive driving circuit 52 and this sensor device 10; Terminals P 1, P2 and Pout are used for providing respectively the device of the control characteristic of determining PID control circuit 56; And switch SW 1-SW7, be used for basis changes this sensor drive driving circuit 52 from the mode transitions signal of microcomputer 7 outputs operator scheme.Notice that Vs+, COM and Ip+ are connected respectively to first to the 3rd splicing ear T1, T2, T3.
The first pump electrode 12a that constitutes in the pair of electrodes of this pump battery 14 is connected in terminal Ip+ by line L3 and the 3rd terminal T3.This second pump electrode 12b is connected in terminal COM by the line L2 and the second terminal T2, and this terminal COM provides public reference voltage for sensor device 10.This second pump electrode 12b also is connected in Vcent by line L2, the second splicing ear T2 and resistance R 1 except being connected in terminal COM.The second detecting electrode 13b in a pair of detecting electrode of formation oxygen concentration detection battery 24 is connected in terminal Vs+ by the line L1 and the first splicing ear T1, and this first detecting electrode 13a is connected in terminal COM by the line L2 and the second splicing ear T2.
Resistance R 7, resistance R 8 and operational amplifier 32 are connected to terminal Ip+.Wherein, an end of this resistance R 7 is connected in terminal Ip+, and the other end of resistance R 7 is connected in the 5V power supply by switch SW 6.One end of resistance R 8 is connected in terminal Ip+, and the other end of resistance R 8 is by switch SW 7 ground connection.Here, the resistance value of resistance R 7, R8 preferably approximately is 50k Ω, prevents leakage of current when being the described gas concentration measurement pattern in back with the operator scheme of convenient sensor drive driving circuit 52.This operational amplifier 32 has PID control circuit 56 and applies non-inverting input thereon and the lead-out terminal that is connected in terminal Ip+ by switch SW 3 by resistance R 2 connected reverse input end, 3.6V voltage.These have constituted the negative-feedback circuit of control sensor device 10.
This PID control circuit 56 and operational amplifier 32,34 are connected to terminal COM.Wherein, this PID control circuit 56 has the function that the deviation delta V that detects 24 pairs of output voltages of battery from oxygen concentration with respect to controlled target voltage 450mV does the PID operation, and with its control to controlled target voltage (as, 450mV).This PID control circuit 56 is by PID control circuit 40, resistance R 3-R5 and be connected to terminals P 1 and P2 constitutes with the capacitor C 1-C3 of the control characteristic of determining this PID control circuit 56.PID control circuit 56 is connected in terminal Vs+ by operational amplifier 42, is used for the output voltage of this oxygen concentration detection battery 24 is input to this PID control circuit 56.This PID control circuit 56 is connected in terminals P out by switch SW 2.This terminals P out is connected to terminal Vcent by resistance R 2, and finally is connected to non-inverting input of this operational amplifier 32.This PID control circuit 56 is connected in terminal COM by switch SW 2 and resistance R 1, R2.Notice that the output of this PID control circuit 56 is controlled on-off by switch SW 2.
This constant pressure source 48 is connected in this PID control circuit 40.This constant pressure source 48 is the circuit that are used for to PID control circuit 56 supply controlled target voltage 450mV, with Control current Ip.
Non-inverting input of this operational amplifier 32 is connected in terminal COM by resistance R 1.
This operational amplifier 34 is connected to terminal Vcent by switch SW 1.Operational amplifier 34 is a kind of circuit, and it supplies with unusual identification electric current to diagnose the unusual of this sensor device 10 as hereinafter described.
This constant current source 46 and operational amplifier 42,44 are connected to terminal Vs+.Wherein, constant current source 46 is connected in terminal Vs+ by switch SW 5.This constant current source 46 is that supply steady current Icp (for example, 17 μ A) flows to the circuit that oxygen concentration detects battery 24, and is constant with the oxygen concentration around the self-generating reference electrode 13b that keeps this oxygen detection battery 24.This operational amplifier 44 is connected in terminal Vs+ by switch SW 4.This operational amplifier 44 is similar to operational amplifier 34, is to supply with unusual identification electric current so that diagnose the unusual circuit of this sensor device 10, also will mention this back.This operational amplifier 34 has non-inverting input that is connected in terminal Vs+.
Insert an antihunt circuit 59 that forms by the series circuit of resistance R 6 and capacitor C 4 between terminal Vs+ and the terminal Ip+, so that prevent this sensor drive driving circuit 52 vibrations.
In the sensor drive driving circuit 52 that constitutes like this, switch SW 2, SW3, SW5, SW6 and SW7 connect, and switch SW 1 and SW4 disconnect, so that measure the oxygen concentration of sample gas.When sample gas was in the state of excessive fuel supply (rich fuel), with respect to the air/fuel ratio of stoichiometric(al), this measured the oxygen concentration deficiency in chamber 20, and the output voltage that this oxygen concentration detects battery 24 is higher than controlled target voltage 450mV.Therefore cause that output voltage V s is with respect to controlled target voltage deviation Δ Vs.This deviation delta Vs be by this PID control circuit 56 come PID operation and by operational amplifier 32 feedbacks.Therefore, make electric current I p flow to pump battery 14, so that the amount of oxygen with deficiency is pumped into measurement chamber 20 by pump battery 14.
And when sample gas was in the situation (poor fuel) of fuel undersupply, with respect to the air/fuel ratio of stoichiometric(al), the oxygen concentration in measuring chamber 20 was excessive, and the output voltage V s of this oxygen detection battery 24 is lower than controlled target voltage 450mV.Therefore be similar to above-mentioned, described operational amplifier 32 feedback deviation Δ Vs.This makes electric current I p flow through this pump battery 14, so that by pump battery 14 too much amount of oxygen is pumped this measurement chamber 20.
By this way, in the gas measurement device 1 of present embodiment, measure the electric current I p that is used for 14 controls of pump battery, the output voltage that makes this oxygen concentration detect battery 24 is 450mV, therefore can measure the oxygen concentration of sample gas.Note, the gas measurement device 1 of structure present embodiment, come voltage transitions to flow through the electric current I p of this pump battery 14 by resistance R 2, and the voltage of this resistance R 2 (voltage between terminal Vcent and the Pout specifically) is outputed to the input port of microcomputer 7 by unshowned differentiating amplifier circuit.According to the oxygen concentration of measuring at microcomputer 7, can effectively control engine combustion.
Secondly, this abnormal detection circuit 53 is made of window comparator 58a, 58b, 58c and OR circuit 58d.This window comparator 58a, 58b, 58c have the lead-out terminal that is parallel to OR circuit output end separately.Though omitted connecting line in the drawings, this comparer has the input terminal that is connected to terminal Vs+, COM, IP+.
Construct this window comparator 58a, 58b, 58c, make output low level signal when the terminal voltage on terminal Vs+, COM, the IP+ is in predetermined voltage range, when the terminal voltage on these terminals surpasses predetermined voltage range, export high level signal.
The voltage of terminal Vs+ remains on 4.05V usually, and this is the value of the output voltage V s (450mV) of the reference voltage 3.6V oxygen concentration detection battery 24 on the COM terminal.But for some reason in the short circuits such as line L1 that are connected in terminal Vs+ (being also referred to as the Vs+ line) under the situation of electrical source voltage or earth potential, the Vs+ terminal voltage becomes supply voltage or ground voltage.So excessive abnormal current flows through sensor device 10, this electric current may damage sensor device 10.For this reason, structure window comparator 58a is used for the Vs+ terminal voltage is compared with predetermined threshold value, output high level signal when the Vs+ terminal voltage surpasses this threshold value.Specifically, the upper limit of the threshold value of this window comparator 58a is set to 9V or deducts the predetermined voltage of predetermined value (for example 1.5V) from supply voltage under the situation of the mains voltage variations of considering sensor control circuit 50.Simultaneously, the lower limit of this threshold value is set to 1V, and this is to consider that earth level is that the ground connection of 0V is floated.Therefore, provide such structure to make and be elevated to when being higher than upper limit 9V or predetermined value when the Vs+ terminal voltage, or drop to when being lower than lower limit 1V when the Vs+ terminal voltage, this window comparator 58a exports high level signal.
This terminal COM voltage is controlled at reference voltage 3.6V by operational amplifier 32 usually.But for a certain reason, under the situation of electrical source voltage or ground potential, this terminal COM voltage becomes electrical source voltage or ground potential in the short circuits such as line L2 that are connected in terminal COM (being also referred to as line COM).For this reason, structure window comparator 58b is used for terminal COM voltage and predetermined threshold value are compared, output high level signal when terminal COM voltage surpasses this threshold value.Especially, be similar to window comparator 58a, the upper limit of the threshold value of window comparator 58b is set to 9V or predetermined value.Simultaneously, the lower limit of this threshold value is set to 1V.Therefore, the structure of Gou Chenging like this when terminal COM voltage is elevated to when being higher than upper limit 9V or predetermined value, or is reduced to when being lower than this lower limit 1V when terminal COM voltage, and this window comparator 58b exports high level signal.
At terminal Ip+, short circuit is under the situation of electrical source voltage or ground potential for a certain reason as line L3 that is connected in terminal Ip+ (being also referred to as the Ip+ line) etc., and this Ip+ terminal voltage becomes electrical source voltage or ground potential.For this reason, structure window comparator 58c is used for the Ip+ terminal voltage is compared with predetermined threshold, output high level signal when the Ip+ terminal voltage surpasses this threshold value.Specifically, be similar to window comparator 58b, for the window comparator 58c of input Ip+ terminal voltage, according to the mode that includes reference voltage 3.6V therebetween, its higher limit is set to 9V or scheduled voltage, and and its lower limit is set to 1V.Such structure is provided, makes to be elevated to when being higher than upper limit 9V or scheduled voltage when the Ip+ terminal voltage, or drop to when being lower than lower limit 1V when the Ip+ terminal voltage, this window comparator 58c exports high level signal.
This OR circuit 58d calculate from the logic of the signal of window comparator 58a, 58b, 58c and.When any one high level signal is imported in existing from window comparator 58a, 58b, 58c, be DIAG=1 to abnormality detection mark DIAG assignment, and export to microcomputer 7.When the terminal voltage of terminal Vs+, COM, Ip+ each in predetermined voltage range the time, 53 pairs of these abnormality detection marks of this abnormal detection circuit DIAG assignment is DIAG=0, and outputs it to microcomputer 7.By this way, when the terminal voltage of any one be short-circuited unusual and terminal Vs+, COM, Ip+ surpasses threshold value to the abnormal voltage value among online Vs+, COM, the Ip+ (in other words, when generation in the sensor device 10 is unusual), this abnormal detection circuit 53 can be abnormality detection mark DIAG assignment DIAG=1.Notice that this window comparator 58a, 58b, 58c are corresponding to the judgement part that proposes among the present invention.
When the operator scheme of this sensor drive driving circuit 52 is during below with the abnormity diagnosis pattern described, this terminal voltage output circuit 54 is the circuit that are used for the terminal voltage of terminal Vs+, COM, Ip+ is exported to microcomputer 7.Notice that though connecting line is omitted in the accompanying drawings, the input terminal of terminal voltage output circuit 54 is connected to terminal Vs+, COM, Ip+.
This microcomputer 7 is connected in sensor drive driving circuit 52, abnormal detection circuit 53 and terminal voltage output circuit 54.Specifically, when the output signal of the abnormality detection mark DIAG of this abnormal detection circuit 53, this terminal voltage output circuit 54 and the voltage signal on the resistance R 2 are connected in the input port of this microcomputer 7, the switching signal that is used to change these sensor drive driving circuit 52 operator schemes (control signal that is used for specifically, the on-off of gauge tap SW1-SW7) that to mention after a while is connected in the output port of this microcomputer 7.Therefore, this microcomputer 7 can be controlled the operator scheme of sensor drive driving circuit 52, and is used to obtain about exist/there is not unusual information on the measured oxygen concentration of terminal voltage on this sensor device 10, the terminal and sample gas.Simultaneously, this microcomputer 7 carries out the abnormity diagnosis of sensor device 10 according to the input signal from abnormal detection circuit 53 and terminal voltage output circuit 54.Notice that this microcomputer 7 is corresponding to current detection section of the present invention and abnormity diagnosis part.
Simultaneously, it is 0% that control circuit for heater 60 is adjusted to dutycycle with the on-off dutycycle (duty ratio) of well heater energy supply switch, thereby stops the energy of well heater 70 is supplied with.Notice that this control circuit for heater 60 is corresponding to energy supply control part branch of the present invention.
In the sensor drive driving circuit 52 of present embodiment, with on/off gas concentration measurement pattern, protected mode or abnormality detection pattern are carried out the conversion of operator scheme by making switch SW 1-SW7.
The gas concentration detecting pattern is the operator scheme that is used to carry out engine combustion control.Do not take place in sensor device 10 under the normal condition of abnormal conditions, sensor drive driving circuit 52 is in this operator scheme.In this operator scheme, switch SW 2, SW3, SW5, SW6, SW7 are switched in sensor drive driving circuit 52, and switch SW 1, SW4 be disconnected, as shown in Figure 3.
When switch SW 2, SW3, SW5, SW6, SW7 being connected and SW1, SW4 are disconnected, according to the output voltage that detects battery 24 as the oxygen concentration of negative feedback voltage, pump battery 14 places under the negative feedback control of being controlled by operational amplifier 32.Can be by measuring the oxygen concentration that electric current I p measures this sample gas.Therefore, can effectively carry out engine combustion control according to measured oxygen concentration.
Protected mode is when abnormal detection circuit 53 determines that any one terminal voltage is outside predetermined voltage range among terminal Vs+, COM, the Ip+; the operator scheme that all outputs of 10 are disconnected from sensor drive driving circuit 52 to sensor device (in other words; TURP is disconnected between sensor drive driving circuit 52 and the sensor device 10); therefore, can protect this sensor device 10.
In this operator scheme, because all switch SW 1-SW7 are disconnected as shown in Figure 3 in sensor drive driving circuit 52, from operational amplifier 32,34,44, the signal of PID control circuit 40 and constant current source 46 inputs is disconnected, thereby TURP is disconnected between this sensor device 10 and this sensor drive driving circuit 52.Therefore, prevent the abnormal current continuous stream like this to sensor device 10, so electric protection sensor device 10.
The abnormity diagnosis pattern is to diagnose the unusual terminal of this abnormality and the operator scheme of unusual content when generation is unusual on sensor device 10 during the vehicle operating.
In this operator scheme, it is 0% that the well heater energy supply switch of control circuit for heater 60 at first is controlled to dutycycle, therefore, stops to supply with from the energy of 60 pairs of well heaters 70 of control circuit for heater.By stopping the energy supply to well heater 70, the temperature of this sensor device 10 is reduced to non-activationary temperature (being lower than 550 ℃ in the present embodiment), therefore reduces the internal resistance that pump battery 14 and oxygen concentration detect battery 24.
After stopping the energy of well heater 70 supplied with, the switch SW 1 of the moving circuit 52 of sensor gas drive, SW4, SW6, SW7 connect and switch SW 2, SW3, SW5 disconnect, as shown in Figure 3.
In this manner, because switch SW 3 disconnects, do not come driving pump battery 14 from operational amplifier 32 supplying electric currents.Simultaneously,, do not have electric current to supply with, therefore stop Current Control pump battery 14 from PID control circuit 40 because switch SW 2 disconnects.Thereby do not carry out the negative feedback control of pump battery 14.
Because switch SW 1, SW4, SW6, SW7 conducting, so detect battery 24 supplying electric currents to pump battery 14 and oxygen concentration from operational amplifier 34,44.Notice that operational amplifier 34,44 is corresponding to current supply part of the present invention.
When the electric current from operational amplifier 34,44 output flow to battery 14,24 (below be also referred to as unusual identification electric current), the corresponding terminal voltage of locating at each terminal (terminal Vs+, COM and Ip+) (also being called voltage Vs+, voltage COM and voltage Ip+ respectively) was input to the microcomputer 7 from terminal voltage output circuit 54.The terminal voltage that this miniature calculating 7 is relatively imported, and discern that condition that this terminal voltage falls into the condition shown in Fig. 4, thus determine unusual terminal and unusual content.
Specifically, take place under the situation of potential to ground short circuit (being also referred to as the GND short circuit) on any one of online Vs+, COM and Ip+, when terminal voltage satisfies when concerning voltage Vs+＜voltage COM and voltage Vs+＜voltage Ip+, the GND short circuit takes place on the online Vs+ so.When terminal voltage satisfies when concerning voltage Ip+＜voltage COM and voltage Ip+＜voltage Vs+, the GND short circuit takes place on the online Ip+ so.In other cases, determine that the GND short circuit takes place on the online COM.
Equally, take place on any one of online Vs+, COM and Ip+ under the situation to electrical source voltage short circuit (below be also referred to as the VB short circuit), when terminal voltage satisfies when concerning voltage Vs+＞voltage COM and voltage Vs+＞voltage Ip+, the VB short circuit takes place on the online Vs+ so.When terminal voltage satisfies when concerning voltage Ip+＞voltage COM and voltage Ip+＞voltage Vs+, the VB short circuit takes place on the online Ip+ so.In other cases, determine that the VB short circuit takes place on the online COM.
, considering that output voltage that pump battery 14 and oxygen concentration detect battery 24 changes according to the oxygen concentration of sample gas here, is 5mA or bigger from the unusual identification current settings of operational amplifier 34,37 outputs.This electric current is set, makes the voltage that when the unusual identification of supply electric current, appears on the terminal detect the voltage that battery 24 is exported by pump battery 14 or oxygen concentration greater than oxygen concentration for response sample gas.Can correctly carry out abnormity diagnosis like this.
Existing face illustrates the flow process of carrying out according to Fig. 5 and Fig. 6 on microcomputer 7.
Fig. 5 is the main flow chart that is illustrated on the microcomputer 7 the processing stream of carrying out, and the process flow diagram of Fig. 6 subroutine that to be the main flow in Fig. 5 call.
As shown in Figure 5, when when automobile powers up, microcomputer 7 its processing of beginning, and after this microcomputer 7 of internal initialization, make control circuit for heater 60 to well heater 70 energizes (step S100).After activating this sensor device 10, this microcomputer 7 is used for mode transitions to gas concentration measurement pattern (being transformed into the gas concentration measurement mode signal) (step S101) to sensor drive driving circuit 52 output signals.By the described gas concentration measurement mode signal that is transformed into is input to sensor drive driving circuit 52, its switch SW 2, SW3, SW5, SW6, SW7 are switched on, and switch SW 1, SW4 are disconnected.Mode transitions with sensor drive driving circuit 52 arrives the gas concentration measurement pattern like this.At step S102, carry out measurement processing about the oxygen concentration of sample gas.
At step S103, determine DIAG=1 whether from the abnormality detection mark DIAG of abnormal detection circuit 53 outputs.If not DIAG=1, if i.e. each of the terminal voltage of sensor device 10 all in predetermined voltage range (when in sensor device 10, not taking place when unusual), process turns back to step S102, repeats the oxygen concentration of measuring sample gas at step S102.
And if at step S103, DIAG=1, then sensor drive driving circuit 52 cut-off switch SW1-SW7 are arranged to protected mode (step S104) to the operational mode of sensor drive driving circuit 52.Broken by TURP between this sensor device 10 and this sensor drive driving circuit 52 like this, to prevent damaging this sensor device 10 owing to abnormal current flows into this sensor device 10.
At step S105, determine whether DIAG=1 continues.If DIAG=1 continues, then this process enters step S106, increases progressively abnormality numeration N at step S106, and then this process enters S108.If DIAG=1 no longer continues, then this process enters step S107, at step S107, and the abnormality of successively decreasing numeration N, then this process enters S108.
At step S108, determine whether this abnormality numeration N is equal to or greater than predetermined numeration.If this abnormality numeration N is equal to or greater than predetermined numeration, then be based upon the unusual fact of generation in this sensor device 10, and this process enters step S110.Also be not more than predetermined numeration if this abnormality numeration N is not equal to, then this process enters step S109.
At step S109, determine whether this abnormality numeration N equals zero, if this abnormality numeration N=0, it is unusual to determine that then this sensor device 10 does not take place, and this process turns back to step S101.Thereafter, this process proceeds to step S102, at step S102, repeats the processing of the oxygen concentration of measuring sample gas.If at step S109, the abnormality numeration is not equal to 0, then repeats the processing of S105-S108.
At step S110, carry out the terminal voltage reading and get.With reference to figure 6 reading of the sub-voltage in opposite end is described.In terminal voltage read, it was 0% that the well heater energy supply switch of control circuit for heater 60 at first is controlled so as to dutycycle, to stop to well heater 70 energizes (S200).The unshowned timer that utilizes this microcomputer 7 to have then, this process are waited for predetermined periods (100 milliseconds-1 second, for example 1 second) (step S201).Carry out this process and wait for that the reason of scheduled time slot is because following reason.Promptly, even if be controlled to dutycycle by the well heater energy supply switch with this control circuit for heater 60 is that the temperature that this pump battery 14 and oxygen concentration detect battery 24 is not to be reduced to non-activationary temperature immediately under 0% situation that stops the energy of well heater 70 is supplied with.Therefore, carry out the process of waiting for scheduled time slot and be reduced to non-activationary temperature up to the temperature of this pump battery 14 and oxygen concentration detection battery 24.Simultaneously, this sensor drive driving circuit 52 has oscillation preventing circuit 59.Operator scheme by this sensor drive driving circuit 52 is set to protected mode to be made between this sensor device 10 and the sensor drive driving circuit 52 and is broken by TURP, and the terminal voltage transient state ground that the inherent terminal of scheduled time slot after this (Vs+, COM, Ip+) is located is in non-steady state.Under such non-steady state, can not correctly obtain the voltage on this terminal.For this reason, the wait process of execution scheduled time slot becomes steady state (SS) up to the voltage of each terminal.After waiting for scheduled time slot, this process enters S202.
At step S202, being used for mode transitions is that the signal (being transformed into the abnormity diagnosis mode signal) of abnormity diagnosis pattern is output to sensor drive driving circuit 52.By importing the described abnormity diagnosis mode signal that is transformed into, this sensor drive driving circuit 52 is connected switch SW 1, SW4, SW6, SW7, and cut-off switch SW2, SW3, SW5.Mode transitions with sensor drive driving circuit 52 arrives the abnormity diagnosis pattern like this.
Read the terminal voltage of terminal Vs+ at step S203, this voltage is from 54 outputs of terminal voltage output circuit.The terminal voltage Vs+ that this reads is stored among the unshowned RAM of this microcomputer 7.
At step S204, being used for mode transitions is that the signal (being transformed into guard signal) of protected mode outputs to sensor drive driving circuit 52.By the described guard signal that is transformed into is input to sensor drive driving circuit 52, switch SW 1-SW7 is disconnected.Mode transitions with sensor driving circuit 52 is a protected mode like this.
At step S205, be similar to S201, this process is waited for predetermined periods, and enters S206 then.At step S206, be transformed into the diagnostic mode signal and output to sensor drive driving circuit 52.Be input to sensor drive driving circuit 52 by being transformed into the diagnostic mode signal, switch SW 1, SW4, SW6, SW7 are switched on, and switch SW 2, SW3, SW5 are disconnected.Mode transitions with sensor drive driving circuit 52 arrives the abnormity diagnosis pattern like this.
At step S207, read terminal voltage COM, this voltage is from 54 outputs of terminal voltage output circuit.The terminal voltage COM that this reads is stored among the unshowned RAM of this microcomputer 7.
At step S208, be transformed into the protected mode signal and be output to sensor drive driving circuit 52.Be input to sensor drive driving circuit 52 by being transformed into the protected mode signal, switch SW 1-SW7 is disconnected.Mode transitions with sensor driving circuit 52 is a protected mode like this.
At step S209-S212, be similar to top processing, promptly after step S209 waits for scheduled time slot, output to sensor drive driving circuit 52, the mode transitions of sensor drive driving circuit 52 is arrived the abnormity diagnosis pattern by being transformed into the abnormity diagnosis mode signal at step S210.At step S211, read terminal voltage Ip+ thereafter.The terminal voltage Ip+ that this reads is stored among the unshowned RAM of this microcomputer 7.At step S212, output to sensor drive driving circuit 52 by being transformed into the protected mode signal, the mode transitions of sensor drive driving circuit 52 is a protected mode.
Process enters the unusual terminal identification step (S111) of main flow (Fig. 5) then.At S111, be identified in terminal voltage among the RAM that S203, S207 and S111 be stored in microcomputer 7 according to condition for identification shown in Figure 4, thereby determine unusual content and terminal take place.This recognition result is stored among the unshowned RAM of this microcomputer 7.By unusual terminal identification, what determine in sensor device 10 to take place is GND short circuit or VB short circuit unusually, and what determine to take place is that terminal in Vs+, COM, the Ip+ terminal unusually.
After automobile power source disconnected, this process finished.
By this way, in this gas concentration measuring apparatus 1 of present embodiment, whether the tie point (terminal Vs+, COM, Ip+) that is detected between this sensor device 10 and this sensor drive driving circuit 52 by window comparator 58a, 58b, 58c has the abnormal voltage generation.Under the situation of any tie point generation abnormal voltage; the operational mode of this sensor drive driving circuit 52 converts protected mode to; it is disconnected to do TURP between this sensor device 10 and this sensor drive driving circuit 52; therefore avoid abnormal current to continue to flow into this sensor device 10, therefore protect this sensing device not to be damaged.
Simultaneously, in this gas concentration measuring apparatus 1 of present embodiment, during the abnormity diagnosis of this sensor device 10,, can carry out abnormity diagnosis and do not damage this sensing device by making the needed unusual identification current supply predetermined periods of abnormity diagnosis.
And, in this gas concentration measuring apparatus 1 of present embodiment, during abnormity diagnosis, stop the heater fed energy, be reduced to the activationary temperature that is lower than battery with temperature with the battery of sensor device 10 (pump battery 14 and gas concentration detect battery 24).As a result, the internal resistance of battery increases.Therefore, at this state, the unusual identification electric current that flows through this battery increases the electric potential difference between this battery electrode, and the state that is in activationary temperature with battery is compared, and can carry out abnormity diagnosis more reliably.
And, in this gas concentration measuring apparatus 1 of present embodiment, resistance 7 and resistance 8 being set, they are respectively pull-up resistor and pull down resistor with respect to terminal Ip+, so that apply predetermined voltage (being 2.5V in this example) to terminal Ip+ during abnormity diagnosis.Therefore, because voltage Ip+ even the GND short circuit takes place online Vs+, can not take place yet and become unstable, thereby guarantee abnormity diagnosis in the high internal resistance of battery during abnormity diagnosis.
" disconnection ", " cut-out " in instructions not only comprise complete not on-state, but also comprise the state that the Weak current of operations such as not influencing circuit, sensor flows through.
Though embodiments of the invention are illustrated till now, the invention is not restricted to previous embodiment, and can adopt the various forms that belongs in the technology of the present invention scope.
For example, though this embodiment adopts gamut air/fuel ratio sensor as sensor device 10, this is not restrictive, just, can use by sensor device 10 is added the NO that a battery has two measurement chambeies
XSensor.
In addition, also can use the oxygen sensor that constitutes by a battery.
In this embodiment, during abnormity diagnosis, making dutycycle by on-off well heater energy supply switch is 0%, thereby stops the well heater energy supply, the temperature of sensing device is reduced to be lower than activationary temperature.But the temperature of sensing device is reduced to the method that is lower than activationary temperature is not limited to this method.For example, by reducing the energy of well heater is supplied with the temperature that also can reduce sensor, this energy is supplied with less than the required energy of gas concentration measurement and is supplied with, and this is by in abnormity diagnosis the on-off dutycycle of well heater energy supply switch being reduced to less than making sensor temperature to the dutycycle realization of activationary temperature.
Require the whole disclosure of each foreign patent application of foreign priority to incorporate into herein for your guidance in this application, as narrating in full at this.
Claims (8)
1. one kind is used for the method for diagnosing gas concentration measuring apparatus unusual, and this gas concentration measuring apparatus comprises:
Gas sensor, this gas sensor comprises
Be used for exporting the sensing device with the proportional signal of concentration of the predetermined gas in sample gas space, this sensing device comprise solid electrolyte and be arranged in pairs on this solid electrolyte electrode and
Be used for this sensing device is heated to the heating part of activationary temperature, the output and the proportional signal of concentration of this predetermined gas under this temperature, from the outside to this heating part energize; And
Measure portion is used for measuring according to the output signal of this sensing device the concentration of the predetermined gas in described sample gas space, and this measure portion is electrically connected on the electrode of the sensing device of this gas sensor, and this method comprises:
Be heated at this sensing device under the state of activationary temperature, when the voltage on any tie point between the sensing device of this measure portion and this gas sensor became default abnormal voltage value, restriction was supplied with the energy of this heating part; And
Diagnose the unusual of this gas sensor then.
2. the method for diagnosing abnormal as claimed in claim 1, wherein this sensing device comprises:
By spreading the measurement chamber that damping piece is communicated with this sample gas space; With a plurality of batteries, each battery is arranged to towards this measurement chamber, and has solid electrolyte and the electrode that is arranged in pairs on this solid electrolyte,
Construct this measure portion and make it be electrically connected on a plurality of batteries of this sensing device, and measure the concentration of the predetermined gas in this sample gas space according to the output signal of these a plurality of batteries,
Wherein, when the voltage on any tie point between a plurality of batteries of this measure portion and this gas sensor became the abnormal voltage value, restriction was supplied with the energy of this heating part.
3. the method for diagnosing abnormal as claimed in claim 1 wherein, is supplied with predetermined current by described tie point to described sensing device, and is being compared between the detection voltage at each tie point that is detected during the supplying electric current, carries out abnormity diagnosis thus.
4. the method for diagnosing abnormal as claimed in claim 1 wherein, is closed preset time and is limited the energy of described heating part is supplied with by described energy is supplied with.
5. one kind is used for the device of diagnosing gas concentration measuring apparatus unusual, and this gas measurement device comprises:
Gas sensor, this gas sensor comprises
Be used to export the sensing device with the proportional signal of concentration of the predetermined gas in sample gas space, this sensing device comprise solid electrolyte and be arranged on this solid electrolyte paired electrode and
Heating part is used for this sensing device is heated to activationary temperature, the proportional signal of concentration of output and described predetermined gas under this temperature, and this heating part is by outside energize; And
Measure portion, be used for measuring the concentration of the predetermined gas in this sample gas space according to the output signal of this sensing device, this measure portion is electrically connected to the electrode of the sensing device of this gas sensor, is used for diagnosing the unusual device of gas concentration measuring apparatus to comprise:
Judge part, be used to judge whether the voltage on each tie point between this measure portion and this sensing device is the abnormal voltage value of being scheduled to;
Energy supply control part branch is used for when this judgement part judges that voltage on any described tie point is the abnormal voltage value, and restriction is supplied with the energy of this heating part; And
The abnormity diagnosis part is used for diagnosing the unusual of this gas sensor divide the supply of restriction energy by this energy supply control part after.
6. the device that is used for diagnosing abnormal as claimed in claim 5, wherein this sensing device comprises: measure the chamber, it is communicated with this sample gas space by the diffusion damping piece; With a plurality of batteries, each battery is arranged to towards this measurement chamber, and has solid electrolyte and the electrode that is arranged in pairs on this solid electrolyte;
Construct this measure portion so that be electrically connected on a plurality of batteries of this sensing device, and measure the concentration of the predetermined gas in this sample gas space according to the output signal of these a plurality of batteries;
This judgement part judges whether the voltage on the tie point between a plurality of batteries of this measure portion and this sensing device is the abnormal voltage value of being scheduled to, and
When the voltage on any described tie point was judged to be the abnormal voltage value by this judgement part, this energy supply control part branch limited the energy of this heating part and supplies with.
7. the device that is used for diagnosing abnormal as claimed in claim 5 comprises:
The current supply part is used for supplying with scheduled current by this tie point to this sensing device; With
Current detection section is used for detecting the voltage on this tie point by this current supply part supplying electric current the time,
Wherein, this abnormity diagnosis part is by comparing diagnosing abnormal between the detection voltage on each tie point that detects at this voltage detection department branch.
8. the device that is used for diagnosing abnormal as claimed in claim 5, wherein, this energy supply control part divides closes predetermined periods the energy of this heating part is supplied with.
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| JP2004381746 | 2004-12-28 | ||
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Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101251052B (en) * | 2007-02-21 | 2012-04-25 | 日本特殊陶业株式会社 | Diagnostic method and control apparatus for gas sensor |
| CN102656354A (en) * | 2009-10-22 | 2012-09-05 | 欧陆汽车有限责任公司 | Device and method for diagnosing an exhaust gas sensor |
| CN102667462A (en) * | 2009-12-23 | 2012-09-12 | 依维柯发动机研究公司 | Improved control method and device for oxygen pump cells of sensors in internal combustion engines or exhaust gas after treatment systems of such engines |
| CN103718031A (en) * | 2011-06-08 | 2014-04-09 | 阿尔法莫斯公司 | Chemoresistor type gas sensor having a multi-storey architecture. |
| CN105026922A (en) * | 2014-02-14 | 2015-11-04 | 罗斯蒙特分析公司 | Solid state gas detection sensor diagnostic |
| CN107632054A (en) * | 2016-07-19 | 2018-01-26 | 富士通天株式会社 | The controller and method for detecting abnormality of air-fuel ratio sensor |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101251052B (en) * | 2007-02-21 | 2012-04-25 | 日本特殊陶业株式会社 | Diagnostic method and control apparatus for gas sensor |
| CN102656354A (en) * | 2009-10-22 | 2012-09-05 | 欧陆汽车有限责任公司 | Device and method for diagnosing an exhaust gas sensor |
| CN102656354B (en) * | 2009-10-22 | 2015-04-29 | 大陆汽车有限公司 | Device and method for diagnosing an exhaust gas sensor |
| CN102667462B (en) * | 2009-12-23 | 2015-11-25 | Fpt发动机研究公司 | For control method and the equipment of the improvement of the oxygen pumping cell of the sensor in the exhaust after treatment system of explosive motor or this engine |
| CN102667462A (en) * | 2009-12-23 | 2012-09-12 | 依维柯发动机研究公司 | Improved control method and device for oxygen pump cells of sensors in internal combustion engines or exhaust gas after treatment systems of such engines |
| CN103718031A (en) * | 2011-06-08 | 2014-04-09 | 阿尔法莫斯公司 | Chemoresistor type gas sensor having a multi-storey architecture. |
| CN103718031B (en) * | 2011-06-08 | 2016-03-30 | 阿尔法莫斯公司 | There is the change sensitive resistor type gas sensor of multiple-unit layer structure |
| CN105026922A (en) * | 2014-02-14 | 2015-11-04 | 罗斯蒙特分析公司 | Solid state gas detection sensor diagnostic |
| CN107632054A (en) * | 2016-07-19 | 2018-01-26 | 富士通天株式会社 | The controller and method for detecting abnormality of air-fuel ratio sensor |
| US10656115B2 (en) | 2016-07-19 | 2020-05-19 | Fujitsu Ten Limited | Controller and abnormality detecting method of air-fuel-ratio sensor |
| CN107643747A (en) * | 2016-07-20 | 2018-01-30 | 富士通天株式会社 | The controller and method for detecting abnormality of air-fuel ratio sensor |
| CN113270655A (en) * | 2020-02-17 | 2021-08-17 | 丰田自动车株式会社 | Battery system and method for determining abnormality of battery |
| CN113270655B (en) * | 2020-02-17 | 2024-05-14 | 丰田自动车株式会社 | Battery system and battery abnormality determination method |
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