WO1999025965A1 - SYSTEME DE SURVEILLANCE DE BORD POUR VEHICULE, DETECTANT LES EMISSIONS HC/NOx POUR L'EVALUATION DU CONVERTISSEUR CATALYTIQUE - Google Patents

SYSTEME DE SURVEILLANCE DE BORD POUR VEHICULE, DETECTANT LES EMISSIONS HC/NOx POUR L'EVALUATION DU CONVERTISSEUR CATALYTIQUE Download PDF

Info

Publication number
WO1999025965A1
WO1999025965A1 PCT/US1998/022782 US9822782W WO9925965A1 WO 1999025965 A1 WO1999025965 A1 WO 1999025965A1 US 9822782 W US9822782 W US 9822782W WO 9925965 A1 WO9925965 A1 WO 9925965A1
Authority
WO
WIPO (PCT)
Prior art keywords
emission
signals
vehicle
excessive
threshold
Prior art date
Application number
PCT/US1998/022782
Other languages
English (en)
Other versions
WO1999025965A9 (fr
Inventor
Patrick W. Blosser
Original Assignee
Engelhard Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Engelhard Corporation filed Critical Engelhard Corporation
Priority to AU12821/99A priority Critical patent/AU1282199A/en
Publication of WO1999025965A1 publication Critical patent/WO1999025965A1/fr
Publication of WO1999025965A9 publication Critical patent/WO1999025965A9/fr

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/22—Safety or indicating devices for abnormal conditions
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N11/00—Monitoring or diagnostic devices for exhaust-gas treatment apparatus, e.g. for catalytic activity
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N11/00—Monitoring or diagnostic devices for exhaust-gas treatment apparatus, e.g. for catalytic activity
    • F01N11/007—Monitoring or diagnostic devices for exhaust-gas treatment apparatus, e.g. for catalytic activity the diagnostic devices measuring oxygen or air concentration downstream of the exhaust apparatus
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
    • F01N13/009—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having two or more separate purifying devices arranged in series
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/14—Introducing closed-loop corrections
    • F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
    • F02D41/1444—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases
    • F02D41/146—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being an NOx content or concentration
    • F02D41/1463—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being an NOx content or concentration of the exhaust gases downstream of exhaust gas treatment apparatus
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2550/00—Monitoring or diagnosing the deterioration of exhaust systems
    • F01N2550/02—Catalytic activity of catalytic converters
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2560/00—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics
    • F01N2560/02—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics the means being an exhaust gas sensor
    • F01N2560/023—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics the means being an exhaust gas sensor for measuring or detecting HC
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2900/00—Details of electrical control or of the monitoring of the exhaust gas treating apparatus
    • F01N2900/04—Methods of control or diagnosing
    • F01N2900/0421—Methods of control or diagnosing using an increment counter when a predetermined event occurs
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2900/00—Details of electrical control or of the monitoring of the exhaust gas treating apparatus
    • F01N2900/04—Methods of control or diagnosing
    • F01N2900/0422—Methods of control or diagnosing measuring the elapsed time
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/14—Introducing closed-loop corrections
    • F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
    • F02D41/1444—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases
    • F02D41/1459—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being a hydrocarbon content or concentration
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/14—Introducing closed-loop corrections
    • F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
    • F02D41/1444—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases
    • F02D41/146—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being an NOx content or concentration
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
    • Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/40—Engine management systems

Definitions

  • This invention relates generally to an on-board system for monitoring vehicular emissions and more particularly to a diagnostic system for monitoring such emissions.
  • the invention is particularly relevant to an emissions monitoring system in compliance with government regulatory emissions standards such as OBD II mandated by the State of California and will be described with specific reference to such systems. However, those skilled in the art will recognize that the invention may have broader applications and could be used for monitoring, evaluating and/or predicting the functional operation of any number of vehicle components whether or not related to the vehicle's emissions.
  • the present invention is also related to United States patent applications: EXHAUST GAS SENSOR (Docket No. 300.002); GAS SENSOR HAVING A POROUS DIFFUSION BARRIER LAYER AND METHOD OF MAKING SAME (Docket No. 300.003); and EXHAUST GAS SENSOR WITH FLOW CONTROL WITHOUT A DIFFUSION BARRIER (Docket No. 300.004); APPARATUS AND METHOD FOR DIAGNOSIS OF CATALYST PERFORMANCE (Docket No. 4077-A) , each application being filed of even date herewith and the disclosures of which are hereby expressly incorporated herein by reference. Additionally, this patent relates to United States application entitled "Apparatus and Method for Diagnosis of Catalyst Performance” filed on November 3, 1997 bearing attorney Docket No. 4077 incorporated by reference herein.
  • TWC Three Way Catalyst - NO x , hydrocarbons and oxides, i.e., CO
  • the catalytic converter typically a TWC (Three Way Catalyst - NO x , hydrocarbons and oxides, i.e., CO) .
  • TWCs store oxygen when the engine operates lean and release stored oxygen when the engine operates rich to combust gaseous pollutants such as hydrocarbons or carbon monoxide.
  • combust gaseous pollutants such as hydrocarbons or carbon monoxide.
  • Conventional systems in use today monitor the ability of TWCs to store oxygen to determine failure of the catalyst.
  • an EGO exhaust gas oxygen sensor
  • an oxygen sensor is placed either within or downstream of the TWC to sense the oxygen content in the exhaust gas .
  • any HC system which attempts to evaluate the efficiency of the catalytic converter by ascertaining the combustibles of an exhaust stream before and after the TWC is inherently flawed for a number of reasons.
  • the pre-catalyst and post-catalyst signals have to be time adjusted to assure measurement of the same gas mixture. The speed of the gas has to be precisely determined even though the gas stream passes through a tortuous path within the converter conducive to producing uneven flow for various gas stream slips.
  • the pre-catalyst and post-catalyst sensors must make measurements in significantly different gas mixtures which produce different reactions over the sensors.
  • the hydrocarbon conversion efficiency is determined from the difference between a large signal developed by the pre-catalytic converter sensor resulting from the unburnt hydrocarbons compared to a small signal (typically on a ppm basis for ULEV applications) resulting from the post-catalytic converter sensor. Differentiation becomes increasingly difficult as hydrocarbon emission standards tighten.
  • the two sensors are not expected to age at equal rates owing to different gaseous environments and temperatures experienced during operation. Thus, long term reliability using a direct, dual measurement to ascertain catalyst efficiency is suspect.
  • ECMs Engine microprocessors or ECMs (engine control modules) used in today's vehicles are sophisticated, high powered devices capable of processing input from any number of sensors depicting operating conditions of the vehicle and rapidly issuing engine control signals in response thereto. It is known to program the ECM to perform onboard monitoring of the emissions system.
  • United States patent No. 5,490,064 to Minowa illustrates such a control unit which includes in its functions an on-board self diagnostic emissions monitoring process using conventional precatalytic and postcatalytic 0 2 sensors, digital filtering and exhaust gas speed to correlate the sensor readings to one another to determine failure of the catalytic converter.
  • the signals are stored on a time basis and factored and compared to a threshold value indicative of a regulatory standard at which an emissions failure is deemed to have occurred.
  • training of the neural network is accomplished by simply inserting whatever sensor probe is used by the government regulatory agency in the vehicle's exhaust pipe to generate emissions data correlated to the sensed parameter.
  • Puskorius discloses a more sophisticated neural network and additionally uses an EGO sensor position rearwardly of the catalytic converter to provide two neural artificial intelligence networks with feedback. One network establishes emissions before the catalytic converter and the' second network establishes emissions after the catalytic converter. Training data for the networks is provided from a data bank of a large number of similar vehicles with data accumulated over the expected vehicle life.
  • a trained neural network provides an efficiency ratio accumulated over time which is compared against stored data to predict when failure of the catalytic converter will occur. While an artificial intelligence computerized network may appear theoretically sound, in practice, it is only as good as the training data which cannot be precisely correlated to that one specific vehicle which is being sampled. The assumption is made that any specific vehicle will produce emissions at the level of that produced by the vehicle(s) from which the training data was assimilated.
  • a system which includes a process (and apparatus) for on-board monitoring and detecting a failure of the catalytic converter of a vehicle.
  • the process includes the steps of providing at least one emission sensor downstream of the catalytic converter generating emission signals indicative of the emissions in the vehicle's exhaust gas and providing at least one qualifying condition sensor for sensing at least one vehicular operating condition affecting the performance of the catalytic converter, the qualifying condition sensor generating qualifying condition signals indicative of the vehicle's operating condition.
  • the qualifying condition signals are sampled at periodic intervals during an operating run of the vehicle and each sampled qualifying condition signal is compared to a set threshold which, if met or exceeded, establishes a validated qualifying condition signal.
  • the process also samples the emission signals only at the time a validated qualifying condition signal is produced and each sampled or validated emission signal is compared against a set emission threshold to determine if the validated emission signal exceeds the set emission threshold to become an excessive emission signal.
  • the process includes the final step of activating a warning indicator after completion of a vehicle run, (established either on a timed or validated condition signal count basis), if a statistical evaluation of excessive emission signal occurrence, i.e., frequency, exceeds a stored emission value corresponding to a regulatory emission standard.
  • the emission sensor senses NO x separately from HC and simultaneously generates NO x signals indicative of NO x concentrations in the exhaust stream and HC signals indicative of the HC concentration in the exhaust stream.
  • the emission signal is sampled or counted only when the emission signal exceeds a set threshold for N0 X , i.e., a validated emission signal, whereby variations in the driving cycle, such as speed or the air to fuel ratio, have no effect on the ability of the monitoring process to determine if the catalytic converter satisfies emission regulation requirements.
  • this aspect of the invention includes the discovery that the presence of NO x emissions in the exhaust gas at or greater than a set limit allows direct sensing of hydrocarbon emissions to produce accurate and consistent hydrocarbon readings with the engine operating at lean, rich or stoichiometric conditions.
  • the stored value corresponding to a regulatory emission standard has an upper limit and a lower limit associated therewith, and in the event the system produces a calculated emission value falling between the upper and lower limits for any given run, additional operating runs are conducted and the calculated values for each run are statistically factored as a group to produce an average value of excessive emission signals compared to the actual stored value to determine if the warning mechanism is to be activated thereby avoiding false warnings of failure of the catalytic converter. Additionally should the calculated emissions for the run fall below the lower limit, sampling of additional runs can be delayed to prolong sensor life since the system indicates a measure of the effectiveness of the catalyst.
  • the set emission threshold can be varied to include a plurality of different hydrocarbon threshold concentrations, with each run producing different pluralities of excessive emission signals for each of the various hydrocarbon threshold concentrations.
  • the process includes the additional step of comparing the frequencies at which the number of excessive emission signals exceeded each hydrocarbon threshold concentration to determine an actual sensed hydrocarbon emission level produced by the vehicle whereby the process senses actual hydrocarbon emissions which may be directly compared to regulatory hydrocarbon emission levels without the need for extrapolation and correlation present in other monitoring systems .
  • a still more specific feature of the invention is the further step, after a failure has been detected, of determining whether the excessive emission signals in the run exceeded the stored value for all hydrocarbon threshold concentrations whereby the monitoring process determines whether or not the sensed emission failure is attributed to the catalytic converter or some other operating system within the vehicle without the necessity of having to undergo extensive diagnostic routines.
  • a system for on-board monitoring and detecting a failure of a vehicle's exhaust emission to meet governmental regulatory emission standards for various operating speeds and conditions of a vehicle powered by an internal combustion engine includes a) a catalytic converter through which the vehicle's exhaust gasses pass; b) a qualifying condition sensor arrangement for sensing an operating condition of the vehicle and generating a qualifying condition signal indicative of the sensed operating condition; and c) an emission sensor - immediately downstream of the catalytic converter for sensing at least hydrocarbons in the exhaust gas and generating hydrocarbon emission signals indicative of the concentrations of hydrocarbon emissions in the exhaust gas .
  • the vehicle ' s on-board computer causes periodic sampling of the qualifying condition sensor to generate a plurality of qualifying condition signals, with each qualifying condition signal compared against a stored qualifying condition threshold to determine if a validated qualifying condition signal has occurred.
  • the computer also causes periodic sampling of the hydrocarbon emission signals but only the hydrocarbon emission signals generated when a simultaneously generated validated qualifying condition signal has occurred are counted each of which are compared against a set emission threshold whereby each hydrocarbon emission signal exceeding the set emission threshold is deemed an excessive emission signal.
  • the computer calculates, by statistically factoring, the number of "excessive emission signals occurring during a given operating run of the vehicle to determine if a warning condition is present whereby a warning indicator mechanism is actuated to alert the operator of the vehicle of a failure of the vehicle to meet regulatory emission standards-?
  • the monitoring system thus allows easily implemented counting routines established by relative signal size comparisons to determine vehicle emission compliance without the need of sophisticated algorithms requiring sophisticated computer systems.
  • a particularly unique feature of the invention resides in the catalytic converter arrangement which includes a close-coupled catalyst positioned in close proximity to the exhaust header of the vehicle for reacting with approximately 60 to 80% of the hydrocarbon emissions in the exhaust gas and a TWC catalytic converter downstream of the close-coupled catalyst.
  • the sensor arrangement includes a first hydrocarbon sensor downstream of the close-coupled catalyst and a second emissions sensor downstream of the TWC catalytic converter with different stored emission values for each of the sensors whereby the first hydrocarbon sensor i) insures compliance with emission standards during "cold” or “warm-up” operation of the vehicles and/or ii) is a predictor, from statistical evaluation of its excessive emission signals, of the remaining life of the TWC and/or iii) aids the ECM in adjusting the A/F ratio of the vehicle as a result of the frequency of the excessive emission signals.
  • the second hydrocarbon sensor arrangement downstream of the TWC not only senses the hydrocarbon emissions but also separately senses the nitrous oxide emissions in the exhaust gas and generates HC and NO x signals indicative, respectively, of the hydrocarbon emissions and nitrous oxide emissions in the exhaust gas prior to release to the atmosphere.
  • the computer samples on a periodic basis simultaneously generated HC and NO x signals produced by the second emission sensor and compares each simultaneously sampled HC and NO x signal against a set emission HC and NO x threshold, respectively, so that each simultaneously generated HC and NO x signal pair exceeding each's respective stored emission threshold is an excessive emission signal whereby the warning arrangement is actuated when a set number or set frequency of excessive emission signals occur without regard to the operating speed or any other operating conditions of the vehicle.
  • an on-board system for a vehicle equipped with an internal combustion engine which monitors the exhaust emissions produced by the vehicle and indicates a failure of the catalytic converter(s) in the vehicle to satisfy emission regulatory standards characterized by any one or any combination of or all of the following: a) continuous monitoring of the vehicle's emissions irrespective of the operating condition of the vehicle such as its speed, it's A/F ratio, etc; b) actual sensing of hydrocarbon emissions assuring strict conformance with emission regulations including LEV and ULEV standards; c) recording specific levels of hydrocarbon emissions during vehicle runs corresponding to FTPs and other regulatory driving cycles; ' d) simple processing (algorithms) steps permitting implementation into existing ECM's without significant upgrading; e) monitoring of vehicle's compliance with emission standards during vehicle start-up or warm-up period; f) diagnosing emission failures attributed to failure of the catalytic converter or to other engine operating systems; g) reducing catalytic converter costs by minimizing can
  • a further object of the invention is to provide a monitoring system for exhaust emissions which utilizes varying threshold evaluation levels to tailor the monitoring system to meet any specified range of emission limits resulting in a flexible monitoring system.
  • a specific but important object of the invention is to provide a monitoring system of the afore described type which can be easily modified or refined through changes in qualifying conditions to further compensate for driving variables which render other monitoring systems unreliable.
  • Another object of the invention is to provide a monitoring system which reduces the requirements of the hydrocarbon sensor by reliance on threshold levels thus minimizing to some extent the requirement that the hydrocarbon sensor sense absolute ppm measurements resulting in less expensive hydrocarbon sensors than otherwise required.
  • Another object of the invention is to provide a monitoring system which produces a more reliable catalyst diagnosis than current EGO switching ratio approaches resulting in fewer erroneous malfunction indicator light (MIL) warnings for the catalyst and reduced warrantee repair bills for the automotive manufacturers.
  • MIL malfunction indicator light
  • Another object of the invention is to provide an emissions monitoring system which can quickly determine the presence of an adequately functioning catalytic converter and then be shut off to increase the life of the emission sensors.
  • Another object of the invention is to provide an emissions monitoring system which uses a process in which gas flow rate has minimal importance thus permitting utilization of economical sensors which measure gas concentrations and are flow independent.
  • Another object of the invention is to provide an emissions monitoring system capable of being operated under rich or lean conditions so that the system can function with new engine control strategies being developed today, such as partial lean burn and gasoline direct injection engine control strategies.
  • Figure 1 is a general diagrammatic illustration of the vehicular components of an emission system
  • FIGS. 2 and 3 are graphs of TWC conversion efficiencies for emissions (HC, CO, NO x ) as a function of Lambda for "good” and “aged” catalysts, respectively;
  • Figure 4 is a graph of speed and speed change as a function of time for the FTP-75 driving cycle
  • Figure 5 is a graph of speed and speed change as a function of time for a steady state (SS) driving cycle
  • Figure 6 is a plot of HC concentrations as single data points resulting from the SS and FTP driving cycles with average HC concentrations plotted on the y-axis and calculated FTP g HC/mile plotted on the x-axis;
  • Figure 7 is a plot similar to Figure 6 but with low temperature data points for the SS run discarded;
  • Figure 8 is a diagrammatic flow chart of a simple statistical algorithm used in the present invention.
  • Figure 9 is a diagrammatic logic flow chart illustrating one method of analyzing data resulting from Fig. 8.
  • Figure 10 shows a series of trendline graphs indicating the percentage of times a set emission threshold is exceeded as the catalyst ages
  • Figure 11 is a trendline plot of an FTP cycle and a trendline plot of a SS cycle indicating the percentage of times a common emission threshold for both cycles is exceeded as the catalyst ages;
  • Figure 12 is a graph similar to Figures 10 and 11 showing a common trendline for both FTP and SS drive cycles in accordance with the invention
  • Figure 13 is a schematic representation indicative of the ' coupled effects of catalyst aging, depicted on the y axrs (vertical), and lambda, depicted on the x axis (horizontal) ;
  • Figure 14 is a plot of HC and NO x emissions at various vehicle speeds for a fresh TWC;
  • Figure 15 is a plot similar to Figure 14 but for an aged TWC :J
  • Figure 16 shows a series of trendline plots similar to
  • Figure 17 shows a series of trendline plots similar to Figure 16 but at a higher set NO x level than that used to construct the trendlines of Figure 16;
  • Figure 18 shows two trendline plots taken from Figures 16 and 17 with each trendline constructed at a fixed HC level.
  • FIG. 1 the principal components of a vehicular emission control system 10.
  • the vehicle has an internal combustion engine 12 which discharges gaseous pollutants or emissions through an exhaust system 14.
  • Internal combustion engine 12 is conventionally under the control of an electronic control module or ECM 15 (controller or computer) .
  • ECM 15 electronice control module
  • Exhaust system 14 is conventional and includes an exhaust header 16, a close-coupled or light-off catalyst 17 closely adjacent header 16, a three-way catalyst or TWC 18 positioned downstream of exhaust header 16, a muffler 19 downstream of TWC 18 and a tailpipe 20 downstream of muffler 19 which is open to atmosphere for discharging or emitting the emissions or gaseous pollutants produced by internal combustion engine 12.
  • ECM 15 is conventional and includes well known elements such as a central processing unit or CPU 22, RAM (Random Access Memory) 23, ROM (Read Only Memory) 24, and NVRAM (Non Volatile Random Access Memory) 25. Also included is a look-up table 29 separate and apart from ROM 24 (or alternatively included as a component of ROM 24).
  • I/O unit 28 for receiving and transmitting appropriate instructions from and to ECM 15.
  • I/O unit 28 typically transmits appropriate instructions to activate a display failure light or warning mechanism 30 situated in the vehicle.
  • Communication between ECM 15 and actuation units on the vehicle including sensors associated therewith is typically carried out via conventional two-way communication links which may be, for example, bi-directional serial data links in 8-bit, 16-bit or 24-bit formats.
  • ECM 15 operates in a well established known manner to control the engine and process engine control and diagnostic routines, such as that stored in step by step instructions in ROM 24.
  • engine operating parameters are read into ECM as input signals which are then processed into output signals or control signals outputted from ECM to actuation units on the vehicle controlling vehicular operation, specifically, the operation of internal combustion engine 12 "as well as warning mechanism 30.
  • input sensor signals are read into ECM, processed by RAM 23 and NVRAM 25 under the control of CPU 22 from algorithm routines stored in ROM 24 and emission correlation data typically stored in look-up table (LUT) 29 to generate signals outputted by I/O unit 28 to display 30 and to optimally use the signals to either monitor or control engine 12.
  • LUT look-up table
  • Typical sensors which generate operative signals indicative of an operating condition of the vehicle include a vehicle speed sensor generating vehicle speed signals on line 34; an A/F sensor system (which includes several sensors sensing EGO, manifold air pressure, mass air flow) is shown schematically as generating signals on line 37 indicative of the estimated ratio of air to fuel fed to engine 12 controlling combustion at or above stoichiometric ranges in engine 12; and, an EGO sensor generating signals on line 38 indicative of the oxygen present in the exhaust gas upstream of TWC 18 for controlling several vehicular functions such as the exhaust gas recirculation (EGR) system on the vehicle.
  • EGR exhaust gas recirculation
  • certain of the operating signals conventionally generated to control engine 12 may be used to trigger the sampling of emission signals.
  • an operating condition sensor signal when used in the invention's monitoring system, it will be referred to as a qualifying condition signal.
  • qualifying condition signals include, but are not necessarily limited to, time from engine start, exhaust gas and/or catalyst temperatures, vehicle speed (line 34), engine rpm, EGO sensor signals
  • line 38 A/F (line 37), manifold air pressure (MAP), mass air flow (MAF) signals from hot wire anemometers, throttle position, exhaust gas recirculation (EGR) solenoid position, manifold inlet air temperature, engine coolant temperature, transmission position, and other gearing or drive shaft torque information.
  • MAP manifold air pressure
  • MAF mass air flow
  • an emission sensor arrangement 40 is shown positioned immediately downstream of TWC 18 and a second emission sensor 40a is optionally positioned immediately downstream of light-off catalyst 17 also generating emission sensor signals on line 41a.
  • emission sensor 40 generates gas sensor signals which correspond to temperature or concentrations of non-methane hydrocarbon (NMHC), methane, total HC, NO x , CO, SO x , total combustibles, oxygen, carbon dioxide, or combinations of these gases.
  • emission sensor includes any sensor or combination of sensors which can sense separately HC and NO x emissions.
  • Sensor 40 per se, does not form part of the invention and any conventionally designed sensor can be utilized in the invention. In fact, the inventive system contemplates that developments in the sensor art will further enhance its utilization and capabilities.
  • sensor arrangement includes a separate hydrocarbon sensor and a separate NO x sensor spaced closely adjacent exit end of TWC 18 and at diametrically opposed, axially aligned positions in the exhaust so that both sensors are simultaneously sampling the same exhaust stream.
  • a valving arrangement to siphon a stream of exhaust gas to a compartment for measuring same as disclosed in Hamburg United States patent numbers 5,177,464 and 5,408,215 may be utilized.
  • a hydrocarbon sensor 40a is utilized for close-coupled catalyst 17.
  • Hydrocarbon sensor of the type shown in United States patent numbers 5,265,417 to Visser et al. and 5,451,371 to Zanini-Fisher et al. may be utilized.
  • Nitrous oxide sensors of the type shown in United States patent numbers 4,927,517 to Mizutani et al. and 5,486,336 to Dalla Betta et al. (incorporated by reference herein) may be used.
  • Electrochemical oxygen sources such as shown in U. S. patent No. 5,505,837 to Friese et al. may be utilized with such sensors, also incorporated by reference herein.
  • these electrochemical sensor devices are calorimetric or Pellistor type sensors in which the gas is passed over a catalyst portion of the sensor causing a chemical reaction producing a temperature change (in theory the reaction could cause other physical changes which could be measurable).
  • the temperature change is measured electrically, usually by comparing the catalyst coated channel in the device to a non-coated reference channel, to produce a difference signal which is correlated to the concentration of the specific gaseous component which is being measured.
  • An oxygen source such as shown in Friese is provided to supply oxygen if needed to produce the catalyst reaction.
  • the vehicle emission control system will sample one or more qualifying condition sensor signals corresponding to regulatory standards dictating emission requirements of the vehicle at specified vehicle operating conditions, i.e., FTP (Federal Test Procedure) .
  • ECM 15 senses the operating conditions and then reads and interpolates emission sensor signals on lines 41, 41a to determine the compliance with emission standards.
  • a number of catalytic converters can be interposed within exhaust system 14 to assure compliance with emission standards such as light-off catalyst 17, which insures catalytic hydrocarbon reactions during warmup of the vehicle while also assisting in the efficiency of TWC 18.
  • TWC 18 simultaneously catalyzes the oxidation of hydrocarbons and carbon monoxide and the reduction of nitrogen oxides in a gas stream by contacting the exhaust gas at reaction temperatures with a catalyst composition.
  • compositions typically comprise a catalytically active component.
  • a useful and preferred component is a precious metal, preferably a platinum group metal and a support for the precious metal.
  • Preferred supports are refractory oxides such as alumina, silica, titania, and zirconia.
  • a catalyst system useful with the method and apparatus of the present invention comprises at least one substrate comprising a catalyst composition located thereon.
  • the composition comprises a catalytically active material, a support and preferably an oxygen storage component .
  • Useful catalytically active components include at least one of palladium, platinum, rhodium, ruthenium, and iridium co ponents, with platinum, palladium and/or rhodium preferred.
  • Precious metals are typically used in amounts of up to 300 g/ft 3 , preferably 5 to 250 g/ft 3 and more preferably 25 to 200 g/ft 3 depending on the metal. Amounts of materials are based on weight divided by substrate ( honeycomb) volume .
  • Useful supports can be made of a high surface area refractory oxide support.
  • Useful high surface area supports include one or more refractory oxides selected from alumina, titan a, silica and zirconia. These oxides include, for example, silica and metal oxides such as alumina, including mixed oxide forms such as silica- alumina, aluminosilicates which may be amorphous or crystalline, alumina-zirconia, alumina-chromia, alumina- ceria and the like.
  • the support is substantially comprised of alumina which preferably includes the members of the gamma or activated alumina family, such as gamma and eta aluminas, and, if present, a minor amount of other refractory oxide, e.g., about up to 20 weight percent.
  • the active alumina has a specific surface area of 60 to 300 m 2 /g.
  • a useful and preferred catalyzed article can be a layered catalyst composite comprises a first (bottom) layer comprising a first layer composition and the second (top) layer comprising a second layer composition. Such articles are disclosed in WO95/00235, incorporated by reference herein.
  • the first layer comprises a first platinum group metal component, which comprises a first palladium component, which can be the same or different than that in the second layer.
  • a first oxygen storage component is used in intimate contact with the platinum group metal. It is preferred to use an alkaline earth metal component believed to act as a stabilizer, a rare earth metal selected from lanthanum and neodymium metal components which is believed to act as a promoter, and a zirconium component.
  • the second layer comprises a second palladium component and optionally, at least one second platinum group metal component other than palladium.
  • the second layer additionally comprises a second zirconium component, at least one second alkaline earth metal component, and at least one second rare earth metal component selected from the group consisting of lanthanum metal components and neodymium metal components .
  • each layer contains a zirconium component, at least one of the alkaline earth metal components and the rare earth component.
  • each layer includes both at least one alkaline earth metal component and at least one rare earth component.
  • the first layer optionally further comprises a second oxygen storage composition which comprises a second oxygen storage component.
  • the second oxygen storage component and/or the second oxygen storage composition are preferably in bulk form and also in intimate contact with the first platinum group metal component .
  • compositions When the compositions are applied as a thin coating to a monolithic carrier substrate, preferably a honeycomb carrier, the proportions of ingredients are conventionally expressed as grams of material per cubic inch of catalyst as this measure accommodates different gas flow passage cell sizes in different monolithic carrier substrates. Platinum group metal components are based on the weight of the platinum group metal.
  • any suitable carrier may be employed, such as a monolithic carrier of the type having a plurality of fine, parallel gas flow passages extending therethrough from an inlet or an outlet face of the carrier, so that the passages are open to fluid flow therethrough.
  • the passages which are essentially straight from their fluid inlet to their fluid outlet, are defined by walls on which the catalytic material is coated as a "washcoat" so that the gases flowing through the passages contact the catalytic material.
  • the flow passages of the monolithic carrier are thin-walled channels which can be of any suitable cross- sectional shape and size such as trapezoidal, rectangular, square, sinusoidal, hexagonal, oval, circular. Such structures may contain from about 60 to about 600 or more gas inlet openings ("cells") per square inch of cross section.
  • the ceramic carrier may be made of any suitable refractory material, for example, cordierite, cordierite- alpha alumina, silicon nitride, zircon mullite, spodumene, alumina-silica magnesia, zircon silicate, sillimanite, magnesium silicates, zircon, petalite, alpha alumina and aluminosilicates.
  • the metallic honeycomb may be made of a refractory metal such as a stainless steel or other suitable iron based corrosion resistant alloys.
  • Such monolithic carriers may contain up to about 700 or more flow channels ("cells") per square inch of cross section, although far fewer may be used.
  • the carrier may have from about 60 to 600, more usually from about 200 to 400, cells per square inch (“cpsi").
  • washcoats can be coated onto a suitable carrier with, preferably, the first coat adhered to the carrier and the second coat overlying and adhering to the first coat.
  • the gas being contacted with the catalyst e.g., being flowed through the passageways of the catalytic material-coated carrier, will first contact the second or top coat and pass therethrough in order to contact the underlying bottom or first coat.
  • the second coat need not overlie the first coat but may be provided on an upstream (as sensed in the direction of gas flow through the catalyst composition) portion of the carrier, with the first coat provided on a downstream portion of the carrier.
  • an upstream longitudinal segment only of the carrier would be dipped into a slurry of the second coat catalytic material, and dried, and the undipped downstream longitudinal segment of the carrier would then be dipped into a slurry of the first coat catalytic material and dried.
  • separate carriers may be used, one carrier on which the first coat is deposited and a second carrier on which the second coat is deposited, and then the two separate carriers may be positioned within a canister or other holding device and arranged so that the exhaust gas to be treated is flowed in series first through the catalyst containing the second coat and then through the catalyst containing the first coat thereon.
  • it is preferred to utilize a catalyst composition in which the second coat overlies and adheres to the first coat because such configuration is believed both to simplify production of the catalyst composition and to enhance its efficacy
  • emission sensor 40 of the present invention is also used as a hydrocarbon sensor in combination with a stable close-coupled catalyst.
  • a system comprising such a close-coupled catalyst and a related method of operation as disclosed in W096/17671 incorporated by reference herein.
  • Close-coupled catalysts have been designed to reduce hydrocarbon emissions from gasoline engines during cold starts. More particularly, the close-coupled catalyst is designed to reduce pollutants in automotive engine exhaust gas streams at temperatures as low as 350°C, preferably as low as 300°C and more preferably as low as 200°C.
  • the close- coupled catalyst of the present invention comprises a close-coupled catalyst composition which catalyzes low temperature reactions. This is indicated by the light-off temperature.
  • the light-off temperature for a specific component is the temperature at which 50% of that component reacts.
  • Close-coupled catalyst 17 is placed close to engine 12 to enable it to reach reaction temperatures as soon as possible.
  • the proximity of the close-coupled catalyst to engine 12 typically less than one foot, more typically less than six inches and commonly attached directly to the outlet of the exhaust manifold exposes the close-coupled catalyst composition to exhaust gases at very high temperatures of up to 1100°C.
  • the close-coupled catalyst in the catalyst bed is heated to high temperature by heat from both the hot exhaust gas and by heat generated by the combustion of hydrocarbons and carbon monoxide present in the exhaust gas.
  • the close-coupled catalyst composition should be stable at high temperatures during the operating life of the engine.
  • TWC 18 downstream of the close-coupled catalyst can be an underfloor catalyst or a downstream catalyst.
  • TWC 18 When TWC 18 is heated to a high enough temperature to reduce the pollutants, the reduced conversion of carbon monoxide in the close-coupled catalyst results in a cooler close-coupled catalyst 17 and enables the downstream catalyst TWC 18, typically the underfloor three-way catalyst to burn the carbon monoxide and run more effectively at a higher temperature.
  • the downstream or underfloor catalyst preferably comprises an oxygen storage component as described above.
  • Close-coupled catalyst 17 preferably is in the form of a carrier supported catalyst where the carrier comprises a honeycomb type carrier.
  • a preferred honeycomb type carrier comprises a composition having at least about 50 grams per cubic foot of palladium component, from 0.5 to 3.5 g/in 3 of activated alumina, and from 0.05 to 0.5g/in 3 of at least one alkaline earth metal component, most preferably, strontium oxide. Where lanthanum and/or neodymium oxide are present, they are present in amounts up to 0.6g/in 3 '
  • HC conversion is directly related to the air-to-fuel (A/F) ratio, space velocity and temperature. Understanding the significance of a signal obtained from an HC sensor requires some knowledge of these parameters.
  • the A/F ratio varies according to operating conditions (such as speed and load) based upon look-up tables used for engine calibration in the ECM. Therefore, it is necessary to know the parameters and values associated with engine calibration.
  • Space velocity can be estimated in some vehicles using mass air flow (MAF) sensor signals, but many vehicles do not
  • MAP MAP
  • TPS throttle position sensor
  • engine rpm engine rpm
  • the HC conversion efficiency of a TWC decreases as the
  • A/F ratio decreases. This is shown in Figures 2 and 3 which show the A/F ratio as lambda, ⁇ . Lambda is a dimensionless parameter used to define the mixture's A/F ratio. It can be expressed by the following equation 1.
  • FIG. 2 is a plot of the efficiency of the TWC conversion of emissions for various lambda numbers. Specifically, HC emissions are shown by solid line designated as reference numeral 50; NO x emissions are shown by dotted line designated by reference numeral 51 and CO emissions are shown by dash lines designated by reference numeral 52. Figure 2 illustrates the conversion efficiency for a new TWC while Figure 3 shows the conversation efficiency of a TWC which is aged. Conversion efficiency for HC decreases under rich operating conditions.
  • FIG 4 is a plot of speed and speed change (acceleration) as a function of time for the FTP-75 driving cycle (FTP).
  • Speed is shown by the trace indicated by reference numeral 54 at the lower portion of the graph and acceleration is indicated by a trace 55 at the mid-portion of the Figure 4 graph.
  • the FTP drive cycle contains extensive transient driving with a high frequency of speed changes.
  • This drive cycle should be compared with the speed and speed change traces likewise designated by reference numerals 54, 55 respectively, illustrated in the graph of Figure 5 which shows a "steady state” (SS) driving cycle.
  • the SS cycle contains extensive constant speed driving with a low frequency of speed change. It is desirable to have a catalyst diagnostic strategy which yields equivalent results independent of the drive cycle.
  • Example 1 Demonstration of derived cycle variability under idle conditions.
  • average HC concentrations were calculated under idle conditions defined as time > 200 seconds, speed ⁇ 1 mph.
  • the idle conditions defined as time and mph will be designated "qualifying conditions”. These qualifying conditions were met for each run listed in Table 2 and the value plotted in Figure 6 as a single data point with the Y-axis being an average HC concentration and the X-axis being FTP g HC/mile calculated from the run.
  • data points in the form of a triangle indicated by reference numeral 57 are extracted from SS runs for various aged catalysts and data points shown as a diamond indicated by reference numeral 58 is data extracted from the FTP run for various aged catalysts.
  • Table 2 shows that the average idle temperature of the catalyst (again measured one inch from the inlet face) for SS runs was typically 510-520°C. Because the temperature difference could account for the trend, elimination of lower temperature points ( ⁇ 530°C) from the SS runs brought the average of the SS runs to within the range for the FTP runs as is shown in Table 3. However, the new average idle HC concentration points still remain above the trend associated with the FTP runs as shown in Figure 7.
  • Figure 7 is the plot shown in Figure 6 with the SS data points 57 corrected for temperature. FTP points 58 are unchanged. From comparing Figures 6 and 7 the need for accurate temperature measurement of the catalytic converter when using an HC signal is obvious.
  • the invention recognizes that OBD emission monetary systems using HC sensors alone will produce variations in HC sensor output depending on the drive cycle of the vehicle. This means that it is not possible to develop a monitoring system using HC sensors unless the drive cycle variability is accounted for. This forms one of the underpinnings of the invention. ' Other possible explanations for the differences observed between the cycles (especially for the aged catalyst) exist. Poisoning of the catalyst or EGO sensors by sulphur in the fuel could lead to differences such as those described under idle conditions. Such plausible explanations are inherent in the engine operation and cannot be removed from the system.
  • Qualifying condition with reference to a qualifying condition sensor, a qualifying condition threshold, or a qualifying condition signal means an operating condition of the vehicle which is being sensed.
  • vehicular qualifying conditions include but are not necessarily limited to the time from the engine start, the exhaust gas and/or catalyst temperatures, the vehicle speed, the engine RPM, EGO sensor signals, A/F ratio, manifold air pressure (MAP), mass air flow (MAF), signals from hot wire anemometers, throttle position, exhaust gas recirculation (EGR), solenoid position, manifold inlet air temperature, engine coolant temperature, transmission position, and other gearing or drive shaft torque information.
  • a qualifying condition can include an emission signal. In the preferred embodiment NO x , even though an emission signal, can be viewed as a qualifying condition.
  • Validation qualifying condition means a qualifying conditionJfeignal which meets or exceeds a set threshold.
  • the threshold is established at a value which insures that an emission signal sampled at the time a validated qualifying condition is sensed will in turn be a valid emission signal suitable for use in the system of the invention.
  • a validated qualifying condition means that emission signals being sampled have been filtered.
  • Emission signal is a signal indicative of the tailpipe emissions of the vehicle which include, but are not limited to exhaust gas sensor signals which correspond to either temperature or concentrations of non-methane hydrocarbon (NMHC), methane, total HC, N0 X , CO, SOX, total combustibles, oxygen, carbon dioxide, or any combination of such gases.
  • NMHC non-methane hydrocarbon
  • methane methane
  • total HC N0 X
  • CO CO
  • SOX total combustibles
  • oxygen, carbon dioxide or any combination of such gases.
  • the emission signals in the preferred embodiment of this invention will be HC or HC and NO x .
  • the invention in its broader application is not limited to the emissions HC, NO x .
  • Excessive emission signal means a sampled emission signal or a validated emission signal occurring when a validated qualifying condition signal occurs which emission signal exceeds a set emission threshold which, in turn, bears a correlation to an emission regulatory standard. Assuming that a statistical approach was not used, an excessive emission signal would trigger the vehicle's warning indicator 30. In the preferred embodiment only the HC "signal can become an excessive emission signal.
  • Stored value means a value, typically stored in ECM 15, which corresponds to a regulatory emission level for a specific or alternatively, general, drive cycle, or still alternatively, a specific operating mode or condition of the vehicle. More specifically, the stored value is a number against which a calculated value resulting from a statistical analysis of the emission signals is compared to determine whether or not warning mechanism 30 should be activated, and in further embodiments or applications of the invention, whether or not additional diagnostic steps should be conducted. "Operating run” or “run” means a set operating period of the vehicle during which sensors are sampled at periodic intervals to produce qualifying condition signals and emission signals.
  • a run could be either a fixed time of vehicle operation or a fixed distance over which the vehicle is driven, or a vehicle operating time which occurs until a set number of events have happened.
  • Sampling rates are expected to be in the range of 0.3 to 10 Hz which is determined mainly by the response time of the sensors used and the speed at which conditions can be conveniently obtained from the vehicle's power control module or other sources. In the examples and tabulations a sampling rate of 1 Hz was used.
  • FIG. 8 there is shown a flow chart 60 describing a simple statistical algorithm used in the system of the invention.
  • the engine is started at block 62 and the operating condition and emission counters are reset to zero at block 63.
  • the first filter or qualifying condition is shown to be at block 65 which is a wait block delaying processing of any further signals until the catalyst has been deemed sufficiently hot to be sensed. Wait block 65 of the preferred embodiment is simply a time delay arbitrarily set at 200 seconds.
  • periodic emission signals and qualifying condition signals are being sampled under the control of ECM 15 at set time intervals shown to be one Hz for illustrative purposes at start sample block 68.
  • the qualifying condition signal is then compared against a set threshold operating condition at a speed qualifying condition threshold comparator 70. If the threshold is met or exceeded, a validated operating condition is determined to have occurred which, in turn, outputs a validated qualifying condition signal to a validated qualifying condition 72 counter to increase its numerical count by one and also, outputs the qualifying condition signal to actuate an emission (HC) threshold comparator 73.
  • speed qualifying condition threshold comparator 70 simply compares the speed of the vehicle developed on sensor speed line 34 against a set threshold of 50 mph. If the vehicle speed is less than 50 mph, the qualifying condition is validated and the hydrocarbon signal from sensor 40 sensed at the time of the validated qualifying condition signal is evaluated against a set emission threshold in emission (HC) threshold comparator 73.
  • the HC threshold is set at a concentration of 25 ppm or higher. If the emission signal exceeds a concentration 25 ppm HC, an "excessive emissions counter 75 records this event by increasing its count storage value by one. If the emission signal failed to exceed the set emission threshold of 25 ppm, the emission signal would not be counted.
  • the flow chart of Figure 8 is thus keeping a count of two events.
  • Validated qualifying condition counter 72 is keeping track of the total numbers of events or times that an emission signal was sampled.
  • Excessive emission counter 75 keeps track of the number of times emission sensor 40 exceeded an HC concentration of a set level which is correlated to an emission regulatory standard.
  • Equation 3 calculated % ⁇ stored set %
  • the number of validated condition signals can be set at some arbitrary number such as 100 but the value of the number of occurrences should be set high enough to insure catalyst evaluation within a reasonable amount of time for most drive cycles or runs.
  • the stored set percentage is equal to a stored or "regulated" threshold percentage as determined for any particular vehicle platform through testing of catalyst aged to various FTP g HC/mile performance level. At this stored "regulated" percentage threshold value, the catalyst is performing at a level which is just allowable by governmental regulations. If the calculated value or calculated % is below the stored regulated threshold value of stored %, the catalyst passes the diagnostic test. If the calculated value or calculated % is above this regulated threshold value, the catalyst fails the diagnostic test and malfunctioning catalyst indicator display light 30 is illuminated to alert the driver of the problem.
  • the results of any operating run can be passed through an evaluation process such as that illustrated in Figure 9. Since the stored value represents a regulatory value, it lends itself easily to establishing upper and lower limits so that if the emission results, i.e., calculated %, was less than the lower limit, one would have a high confidence that the catalyst is performing in a satisfactory manner while if the calculated % for any run exceeded the upper limits of the stored value, one could be fairly comfortable that the catalyst had failed. More particularly, if an operating run passed the low threshold, the sensors could be turned off to extend the life of the sensors until the next scheduled operating run of the vehicle was to occur.
  • the flow diagram shown in Figure 9 illustrates a simple procedure for such evaluation.
  • the calculated percentage for any given operating run indicated at block 80 is compared to the lower limit of stored value in low threshold block 81. If the low threshold is not exceeded the diagnosis is deemed complete and a signal is sent to pass block 83 whereat ECM 15 schedules the next operating run of the vehicle and sensor 40 can be turned off. If the lower stored limit is exceeded in low threshold block 81, the signal is compared against the upper limit of the stored value in high threshold block 84. If the upper limit is exceeded, the catalyst is deemed to fail and a signal is sent to fail block 86 whereat ECM 15 causes warning light 30 to be activated.
  • the signal is transferred to a stored summing block 87.
  • stored summing block 87 the calculated percentage for that specific run is stored as "value N" .
  • Both the qualifying condition counter 72 and the excessive emission counter 75 in Figure 8 are reset to zero.
  • the value of N is increased by one and data sampling resumes until another operating run is completed and the calculated percentage for that run is also stored in stored summing block 87.
  • the counter are again reset and the process continues until a calculated percentage for a set number of runs has been sampled which, in the flow chart of Figure 9, total three operating runs.
  • the average of the three operating runs as a percentage is computed by the equation 4 :
  • the calculated average value is then compared to the stored value in final comparison block 88. If the value is below the stored value, pass block 83 is activated and if the value is above the stored value fail block 86 is activated.
  • One method to modify the overall catalyst evaluation is to simultaneously run multiple algorithms with different qualifying conditions and emission conditions. Combining the results is one method of adding reliability to the system and possibly tailoring the catalyst diagnosis to classes of driving styles and cycles. Comparison of different qualifying condition counters could be used to characterize the drive cycle. For example, the transient nature of the drive cycle could be determined by evaluating parameters such as speed change or throttle position movement. Thresholds can be set and a counter used to determine the frequency with which the threshold is exceeded. Adjusting emission thresholds may be appropriate based upon the nature of the drive cycle.
  • the stored regulated value can be picked from any number of values correlated to specific regulated driving cycles and the results then used to indicate pass/fail of the catalytic converter. While somewhat complicated, relatively speaking, this is a simple approach to resolving what would otherwise be an unsolvable problem.
  • a validated qualifying condition counter counts the vehicle's speed within a set range and an excessive counter counts the number of acceleration/deceleration occurrences within the sensed speed range.
  • a counting based algorithm determines an acceleration frequency which is matched vis-a-vis look-up tables 29 with a regulated drive cycle. This is done through a flow chart process similar to that illustrated in Figure 8 but separate and apart from the catalytic evaluation simultaneously performed in Figure 8. The stored value for the matched drive cycle is then used to evaluate catalytic performance.
  • an operating run of the vehicle was defined to include a collection of a fixed number of validated qualifying condition signals resulting from a number of operating signals taken at a fixed rate or period.
  • time from engine start is used in the remaining examples as a qualifying condition. Sampling of signals is at 1 Hz throughout each drive cycle run.
  • FTP g HC/mile values are assumed from the equally aged catalyst. It is worth noting that some run to run variability is expected and observed in the data of column "FTP HC" in Table 1. After the accelerated aging cycle used (a fuel cut strategy), the catalysts were regenerated by exposure to stoichiometric engine exhaust for one hour. Some of the variability comes from slight differences in the effectiveness of the regeneration process. Additionally, the data presented in the remaining examples come from multiple catalysts with varied metal loadings . Note that catalyst metal loading does not appear to affect catalyst evaluation using the system of this invention.
  • FIG 10 there is shown trendline curves when the emission threshold for determining excessive emission signals is changed for different levels of HC concentration.
  • the emissions data used to construct the trendlines in Figure 10 was taken from multiple chassis dynamometer FTP drive cycle runs (no SS runs) and analyzed using the simple percentage algorithm based on a fixed number of validated operating condition events .
  • the qualifying conditions were defined as time > 200 seconds and vehicle speed ⁇ 50 mph.
  • the results are presented in Table 4 and shown graphically in Figure 10. Calculations were based on four emission thresholds.
  • the first threshold was set at 10 ppm HC and data representing the percentage of time that excessive emission signals were generated beyond the ten ppm HC threshold is represented by diamond s designated as reference numeral 90 producing trendline curve 91.
  • data indicating percentage of excessive emission signals exceeding a second hydrocarbon emission threshold set at 15 ppm HC is indicated by circles designated by reference numeral 92 producing trendline 93.
  • Data indicated by squares designated by reference numeral 94 producing aging trendline 95 indicates the percentage of excessive emission signals exceeding a third hydrocarbon threshold set at 20 ppm HC while triangles indicated by reference numeral 96 producing trendline 97 indicates the percentage of excessive emission signals exceeding a fourth hydrocarbon level set at 25 ppm HC.
  • Figure 10 demonstrates that the choice of a tailpipe emission condition threshold provides a useful means for tailoring the algorithm to maximize catalysts evaluation capabilities at specific "regulated" emission thresholds. For example, if the greater than 15 ppm HC threshold value is used, trendline 93 results in a "hockey stick" shaped curve which allows for easy differentiation of any catalyst performing below 0.12g HC/mile (percentage ⁇ 11) from one at 0.14g HC/mile (percentage > 70). Under these qualifying conditions, if the 25 ppm HC emission threshold is used, a much less reliable differentiation of catalyst at these performance levels can be made.
  • Trendlines 101, 103 clearly demonstrate the influence of drive cycle using catalyst evaluation with qualifying conditions (time > 200 seconds and speed ⁇ 50 mph) and tailpipe emission threshold (> 25 ppm HC) conditions. It may be possible to merge the curve for the two drive cycles using an HC signal alone if sufficient operating condition restrictions were placed in the algorithm demonstrated in Figure 8. Alternatively, additional routines can be added to classify the run so that it can be correlated to a drive cycle and the stored value for that drive cycle used to evaluate the catalyst. At the same time, it has to be recognized that increasing the number of qualifying conditions or filters will inevitably require more time to obtain sufficient data points to make a fair statistical analysis of the data. If the conditions are too restrictive, a diagnosis would not be completed even during many drive cycles or runs.
  • Figures 6 and 7 demonstrate that even under conditions using restrictive operating conditions, evaluation data from the two driving cycles (FTP vs. SS) will not merge into a single evaluation curve. For this reasons, if a sole HC sensor were used in accordance with the invention, operating condition data would inevitably have to be obtained for each run and statistically evaluated to arrive at a set emission threshold correlated to that specific driving cycle.
  • Example 5 Combined Use of HC and NO x Sensing for
  • Figure 8 would be modified by inclusion of an NO x threshold comparator block positioned between speed qualifying condition comparator 70 and emission threshold comparator 73.
  • Validated qualifying counter 72 would be moved and positioned adjacent NO x threshold comparator block so that the HC signal would be sampled in excessive emissions counter 75 only if sensor signals had met the start-up delay imposed by wait block 65, * the speed requirement imposed by speed qualifying condition comparator 70 and the NO x concentration imposed by NO x qualifying condition comparator.
  • the validated qualifying counter signals and the excessive emission signals would then be factored as discussed with respect to Figure 8. ⁇
  • Figure 12 is a plot of a trendline for steady state run data indicated by rectangles designated by reference numeral 105 and a plot of a trendline based on FTP run data indicated by circles designated by reference numeral 106. Both trendlines superimpose themselves as one curve shown by reference numeral 108.
  • Figure 12 thus shows that if an additional filter requiring the presence of NO x in a concentration > 15 ppm, variations in the drive cycle can be ignored. This significantly reduces the complexities of systems which otherwise have to account for the variations in the drive cycle to determine compliance with emission regulations.
  • Figure 13 is a pictorial representation of catalytic observations divided into four quadrants labeled clockwise as a first quadrant 110, a second quadrant 111, a third quadrant 112, and a fourth quadrant 113.
  • Lambda designated by reference numeral 115 is shown increasing in the direction of first and fourth (rich) quadrants, 110, 113 to second and third (lean) quadrants 111, 112, respectively.
  • Catalyst aging is shown increasing as indicated by reference numeral 116 from first and second (fresh) quadrants 110, 111 to third and fourth (aged) quadrants 112, 113, respectively.
  • Figure 12 is thus a pictorial representation showing the coupled effects of aging (top/bottom) 116 and lambda (left-right) 115.
  • the value of lambda is constantly switching between the rich first and fourth quadrants 110, 113 and the lean second and third quadrants 111, 112.
  • the expected emissions result from combining the results of the lean and rich quadrants.
  • the probability that both HC and NO x emissions will occur simultaneously increase, especially during rich excursions such as occurs during acceleration.
  • Figure 14 shows plots of hydrocarbon emissions in ppm concentrations designated by solid line 120; NO x emissions in ppm concentrations shown by dashed lines 121 for a vehicle operated at speeds shown by dotted line 122 for a fresh catalyst.
  • Figure 15 likewise shows HC plots 120, NO x plots 121 and speed plots 122 for an aged catalyst.
  • Figure 14 is based on FTP run number 8299 and Figure 15 is based on FTP run number 8513. The loss of catalyst metal surface area and oxygen storage capacity combined with a constant A/F ratio perturbation were the causes. The most noteworthy differences are observed under accelerations.
  • the catalyst Before aging, the catalyst infrequently emitted N0 X during accelerations. After aging, N0 X was emitted consistently upon acceleration. During acceleration the A/F ratio was typically rich and HC emissions under these conditions were expected to increase as the catalyst aged. The net result during acceleration was an increased probability of simultaneous HC and N0 X tailpipe emissions.
  • Figure 16 is a graph of trendlines for various hydrocarbon emission thresholds similar to that described above with reference to Figure 10. However, the additional qualifying condition requirement of NO x being present in excess of 15 ppm is required before a validated qualifying condition occurs.
  • the hydrocarbon emission threshold is * set at HC > 10 ppm
  • the percentage of time excessive emission signals occur is represented by data points in the form of a diamond indicated by reference numeral 130 and generates an HC > 10 aging trendline 131.
  • data points in the form of a block designated by reference numeral 132 indicate the percentage of times excessive emission signals exceeding an HC > 15 threshold occurs and produce an HC > 15 aging trendline on 133.
  • Data points in the form of a triangle designated by reference numeral 134 generate an HC > 20 aging trendline 135 and data points in the form of a circle designated by reference numeral 136 generate an HC > 25 aging trendline 137.
  • Trendlines 131, 133, 135 and 137 hold irrespective of the driving cycle so long as qualifying conditions indicative of a speed less than 50 mph occurs and the vehicle has been operated for at least 200 seconds and the NO x emissions have a concentration greater than 15 ppm.
  • a stored value equal to some set percentage correlated to an emission regulatory standard determines when a failure of the catalytic converter has occurred.
  • the stored percentage value is set at 50 percent (i.e., 50% of the validated emission signals or more turn out to be excessive emission signals) and is shown by line 140 in Figure 16.
  • a direct correlation between stored value, set emission threshold and emission regulatory standard is thus established without significant computer modeling.
  • the specific HC concentration can be extrapolated for any given run (or averaged for a plurality of runs) and directly compared as a hard number to the regulated HC emission standard.
  • Figures 17 and 18 illustrate the fact that changing the threshold limit for NO x does not significantly impact the sensing of hydrocarbon emissions.
  • Figure 17 shows a graph constructed in the same manner as that used to construct the trendlines shown in Figure 16 but with an NO x emission threshold set as N0 X > 50 and reference numerals used in Figure 16 are also used to apply to the same data points and trendlines shown in Figure 17 but with the subscript (a) added to the numeral.
  • Figure 18 is a graph showing trendline 133 (for HC > 15 and NO x > 15) shown in Figure 16 and with trendline 133(a) (for HC > 15 and NO x > 50) shown in Figure 17.
  • the variation in FTP g HC/mile at a 50% stored value is not significant. This is because in general, NO x is emitted in "bursts" with concentrations very often > 50 ppm. Thus, the ability to control the range is mainly controlled by changes in HC.
  • the system as described in Part II is inherently suited for functioning as an OBD for light-off catalyst 17 and provides a system for monitoring emissions during cold start of the engine.
  • light-off catalyst is effective to convert hydrocarbons.
  • the vehicle is not operated at hard acceleration during its first 200 seconds thus permitting formation of a drivability curve to establish a set HC emission limit and a stored value.
  • light-off catalyst 17 is used as an adjunct to TWC 18 and the algorithm monitoring systems employed for each can be used as a predictor for catalytic converter replacement.
  • the system disclosed herein can accommodate onboard monitoring by the addition of hydrocarbon sensor 40a.
  • the on-board diagnostic requirements also require that the monitoring system determine whether or not the emission failure is attributed to a failure of the catalytic converter.
  • the system of the present invention inherently provides this determination and this can be explained by reference to Figure 16. Assume that an emission threshold of HC > 15 and N0 X > 15 with a stored value of excessive emissions occurring over 50% of the time is chosen to indicate failure and that a failure occurs such that warning light 30 is to be triggered. At that time, all the other ranges, i.e., HC > 10, HC > 20 and HC > 25 are also checked and if the stored value is exceeded for all of the ranges, then the failure is not attributed to TWC 18. However, if one of the ranges such as HC > 25 does not indicate a failure, then TWC 18 has failed.
  • the use of both HC and NO x sensing could eliminate the need for current sensors such as the rear HEGO sensor.
  • the N0 X sensor used for emission control can be used for engine control during lean operation.
  • HAA Hyundai aging cycle - fuel cut aging . specified temperature - 4 mg Pb fuel TABLE 2

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Combined Controls Of Internal Combustion Engines (AREA)
  • Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)

Abstract

Un système de surveillance de bord détecte les émissions d'hydrocarbures produites par le moteur à combustion interne d'un véhicule, au moyen de capteurs d'état de fonctionnement qui détectent les conditions de fonctionnement du véhicule sélectionnées et d'un détecteur d'hydrocarbures détectant les émission de HC. Les signaux d'émission de HC sont comptés et comparés à un seuil de concentration de HC établi, ce qui permet de déterminer la présence d'une émission excessive seulement si le véhicule a atteint les valeurs limites tolérables pour chaque capteur de condition de fonctionnement. En calculant le nombre de signaux d'émission excessive par rapport au nombre total de signaux d'émission comptés pendant une phase de fonctionnement du véhicule, on détermine si le véhicule se trouve dans les normes de réglementation sur les émissions. En sélectionnant une condition de fonctionnement comme étant la concentration de NOx présente à une concentration limite déterminée dans le gaz d'échappement, on élimine l'impact négatif des changements de cycle de conduite sur les relevés de HC répétés et cohérents.
PCT/US1998/022782 1997-11-14 1998-10-27 SYSTEME DE SURVEILLANCE DE BORD POUR VEHICULE, DETECTANT LES EMISSIONS HC/NOx POUR L'EVALUATION DU CONVERTISSEUR CATALYTIQUE WO1999025965A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU12821/99A AU1282199A (en) 1997-11-14 1998-10-27 Vehicular on-board monitoring system sensing combined hc/nox emissions for catalytic converter evaluation

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US97102497A 1997-11-14 1997-11-14
US08/971,024 1997-11-14

Publications (2)

Publication Number Publication Date
WO1999025965A1 true WO1999025965A1 (fr) 1999-05-27
WO1999025965A9 WO1999025965A9 (fr) 1999-08-26

Family

ID=25517835

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1998/022782 WO1999025965A1 (fr) 1997-11-14 1998-10-27 SYSTEME DE SURVEILLANCE DE BORD POUR VEHICULE, DETECTANT LES EMISSIONS HC/NOx POUR L'EVALUATION DU CONVERTISSEUR CATALYTIQUE

Country Status (2)

Country Link
AU (1) AU1282199A (fr)
WO (1) WO1999025965A1 (fr)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10316810B4 (de) * 2003-04-11 2006-03-16 Siemens Ag Verfahren zur Regelung einer Regeneration eines Partikelfilters
FR2927948A1 (fr) * 2008-02-27 2009-08-28 Renault Sas Procede et systeme de diagnostic de dysfonctionnement d'un systeme de traitement des gaz d'echappement.
EP2282038A1 (fr) * 2001-03-30 2011-02-09 Toyota Jidosha Kabushiki Kaisha Appareil de contrôle et procédé pour véhicule doté d'un moteur à combustion interne et d'une transmission variable continue
EP2525060A3 (fr) * 2011-05-19 2016-08-10 MAN Truck & Bus AG Procédé et dispositif de vérification de la capacité de fonctionnement, en particulier de la capacité d'oxydation, d'un catalyseur d'oxydation NO intégré dans une conduite de gaz d'échappement d'un moteur à combustion entraîné avec un excès d'air
WO2017004647A1 (fr) * 2015-07-08 2017-01-12 Avl List Gmbh Procédé permettant de faire fonctionner un moteur à combustion interne
EP3222833A1 (fr) * 2016-03-25 2017-09-27 AVL DiTest GmbH Procédé de contrôle des émissions de nox d'un véhicule
US10451010B2 (en) 2016-08-26 2019-10-22 Ford Global Technologies, Llc Systems and methods for diagnosing components in a vehicle evaporative emissions system
CN113804517A (zh) * 2021-09-28 2021-12-17 浙江富春江环保科技研究有限公司 一种基于边界报警的二噁英在线检测系统
US11274625B2 (en) 2020-02-11 2022-03-15 Ford Global Technologies, Llc Method of controlling a vehicle assembly
CN115628143A (zh) * 2022-09-07 2023-01-20 重庆金康赛力斯新能源汽车设计院有限公司 汽车排放控制方法、装置、计算机设备和存储介质

Citations (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3809082A1 (de) * 1987-03-30 1988-10-13 Volkswagen Ag Verfahren zur zumindest annaehernd zeitgleichen analyse mehrerer gasproben
US4927517A (en) 1988-04-30 1990-05-22 Ngk Insulators, Ltd. NOx sensor having catalyst for decomposing NOx
US5119628A (en) * 1990-07-09 1992-06-09 Nissan Motor Co., Ltd. Catalyst degradation diagnosing apparatus for air fuel ratio control system
US5177464A (en) 1991-09-04 1993-01-05 Ford Motor Company Catalyst monitoring using a hydrocarbon sensor
US5237818A (en) 1991-03-20 1993-08-24 Hitachi, Ltd. Conversion efficiency measuring apparatus of catalyst used for exhaust gas purification of internal combustion engine and the method of the same
US5265417A (en) 1993-01-07 1993-11-30 Ford Motor Company Method and apparatus for determining the hydrocarbon conversion efficiency of a catalytic converter
US5337556A (en) * 1992-03-30 1994-08-16 Fuji Jukogyo Kabushiki Kaisha Detecting device and method for engine catalyst deterioration
EP0619420A1 (fr) * 1993-04-08 1994-10-12 Ford Motor Company Limited Système de réglage air-combustible avec surveillance de l'activité d'un catalyseur
US5363646A (en) * 1993-09-27 1994-11-15 Ford Motor Company Engine air/fuel control system with catalytic converter monitoring
WO1995000235A1 (fr) 1993-06-25 1995-01-05 Engelhard Corporation Catalyseur composite en couches
EP0641920A1 (fr) * 1993-09-08 1995-03-08 Hitachi, Ltd. Appareil de diagnose du fonctionnement défectueux d'un moteur à combustion interne
US5408215A (en) 1991-09-04 1995-04-18 Ford Motor Company Catalyst monitoring using a hydrocarbon sensor
US5426934A (en) 1993-02-10 1995-06-27 Hitachi America, Ltd. Engine and emission monitoring and control system utilizing gas sensors
US5431011A (en) 1993-12-14 1995-07-11 General Motors Corporation Catalytic converter diagnostic
US5431042A (en) 1994-03-10 1995-07-11 General Motors Corporation Engine emissions analyzer
US5444974A (en) 1993-07-09 1995-08-29 General Motors Corporation On-board automotive exhaust catalyst monitoring with a calorimetric sensor
US5451371A (en) 1994-06-09 1995-09-19 Ford Motor Company High-sensitivity, silicon-based, microcalorimetric gas sensor
US5486336A (en) 1990-06-12 1996-01-23 Catalytica, Inc. NOX sensor assembly
US5490064A (en) 1993-07-26 1996-02-06 Hitachi, Ltd. Control unit for vehicle and total control system therefor
US5505837A (en) 1993-04-10 1996-04-09 Robert Bosch Gmbh Sensor arrangement for determining gas components and/or gas concentrations of gas mixtures
US5522219A (en) * 1995-08-31 1996-06-04 Ford Motor Company Exhaust system with bypass catalytic converter and diagnostics
WO1996017671A1 (fr) 1994-12-06 1996-06-13 Engelhard Corporation Catalyseur a accouplement direct
US5539638A (en) 1993-08-05 1996-07-23 Pavilion Technologies, Inc. Virtual emissions monitor for automobile
US5625750A (en) 1994-06-29 1997-04-29 Ford Motor Company Catalyst monitor with direct prediction of hydrocarbon conversion efficiency by dynamic neural networks

Patent Citations (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3809082A1 (de) * 1987-03-30 1988-10-13 Volkswagen Ag Verfahren zur zumindest annaehernd zeitgleichen analyse mehrerer gasproben
US4927517A (en) 1988-04-30 1990-05-22 Ngk Insulators, Ltd. NOx sensor having catalyst for decomposing NOx
US5486336A (en) 1990-06-12 1996-01-23 Catalytica, Inc. NOX sensor assembly
US5119628A (en) * 1990-07-09 1992-06-09 Nissan Motor Co., Ltd. Catalyst degradation diagnosing apparatus for air fuel ratio control system
US5237818A (en) 1991-03-20 1993-08-24 Hitachi, Ltd. Conversion efficiency measuring apparatus of catalyst used for exhaust gas purification of internal combustion engine and the method of the same
US5408215A (en) 1991-09-04 1995-04-18 Ford Motor Company Catalyst monitoring using a hydrocarbon sensor
US5177464A (en) 1991-09-04 1993-01-05 Ford Motor Company Catalyst monitoring using a hydrocarbon sensor
US5337556A (en) * 1992-03-30 1994-08-16 Fuji Jukogyo Kabushiki Kaisha Detecting device and method for engine catalyst deterioration
US5265417A (en) 1993-01-07 1993-11-30 Ford Motor Company Method and apparatus for determining the hydrocarbon conversion efficiency of a catalytic converter
US5426934A (en) 1993-02-10 1995-06-27 Hitachi America, Ltd. Engine and emission monitoring and control system utilizing gas sensors
EP0619420A1 (fr) * 1993-04-08 1994-10-12 Ford Motor Company Limited Système de réglage air-combustible avec surveillance de l'activité d'un catalyseur
US5505837A (en) 1993-04-10 1996-04-09 Robert Bosch Gmbh Sensor arrangement for determining gas components and/or gas concentrations of gas mixtures
WO1995000235A1 (fr) 1993-06-25 1995-01-05 Engelhard Corporation Catalyseur composite en couches
US5444974A (en) 1993-07-09 1995-08-29 General Motors Corporation On-board automotive exhaust catalyst monitoring with a calorimetric sensor
US5490064A (en) 1993-07-26 1996-02-06 Hitachi, Ltd. Control unit for vehicle and total control system therefor
US5539638A (en) 1993-08-05 1996-07-23 Pavilion Technologies, Inc. Virtual emissions monitor for automobile
EP0641920A1 (fr) * 1993-09-08 1995-03-08 Hitachi, Ltd. Appareil de diagnose du fonctionnement défectueux d'un moteur à combustion interne
US5363646A (en) * 1993-09-27 1994-11-15 Ford Motor Company Engine air/fuel control system with catalytic converter monitoring
US5431011A (en) 1993-12-14 1995-07-11 General Motors Corporation Catalytic converter diagnostic
US5431042A (en) 1994-03-10 1995-07-11 General Motors Corporation Engine emissions analyzer
US5451371A (en) 1994-06-09 1995-09-19 Ford Motor Company High-sensitivity, silicon-based, microcalorimetric gas sensor
US5625750A (en) 1994-06-29 1997-04-29 Ford Motor Company Catalyst monitor with direct prediction of hydrocarbon conversion efficiency by dynamic neural networks
WO1996017671A1 (fr) 1994-12-06 1996-06-13 Engelhard Corporation Catalyseur a accouplement direct
US5522219A (en) * 1995-08-31 1996-06-04 Ford Motor Company Exhaust system with bypass catalytic converter and diagnostics

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
"SAE Paper 920831", 1992, article J.S. HEPHURN AND H.S. GANDHI: "The Relationship Between Catalyst Hydrocarbon Conversion Efficiency and Oxygen Storage Capacity"
"SAE paper 931034", 1993, article G.B. FISCHER, J.R. THEIS, M.V. CASARELLA AND S.T. MAHAN: "The Roll of Ceria in Automotive Exhaust Catalysis and OBD-II Catalyst Monitoring"

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2282038A1 (fr) * 2001-03-30 2011-02-09 Toyota Jidosha Kabushiki Kaisha Appareil de contrôle et procédé pour véhicule doté d'un moteur à combustion interne et d'une transmission variable continue
DE10316810B4 (de) * 2003-04-11 2006-03-16 Siemens Ag Verfahren zur Regelung einer Regeneration eines Partikelfilters
FR2927948A1 (fr) * 2008-02-27 2009-08-28 Renault Sas Procede et systeme de diagnostic de dysfonctionnement d'un systeme de traitement des gaz d'echappement.
EP2525060A3 (fr) * 2011-05-19 2016-08-10 MAN Truck & Bus AG Procédé et dispositif de vérification de la capacité de fonctionnement, en particulier de la capacité d'oxydation, d'un catalyseur d'oxydation NO intégré dans une conduite de gaz d'échappement d'un moteur à combustion entraîné avec un excès d'air
US10711714B2 (en) 2015-07-08 2020-07-14 Avl List Gmbh Method for operating an internal combustion engine
WO2017004647A1 (fr) * 2015-07-08 2017-01-12 Avl List Gmbh Procédé permettant de faire fonctionner un moteur à combustion interne
EP3222833A1 (fr) * 2016-03-25 2017-09-27 AVL DiTest GmbH Procédé de contrôle des émissions de nox d'un véhicule
US10451010B2 (en) 2016-08-26 2019-10-22 Ford Global Technologies, Llc Systems and methods for diagnosing components in a vehicle evaporative emissions system
US11274625B2 (en) 2020-02-11 2022-03-15 Ford Global Technologies, Llc Method of controlling a vehicle assembly
CN113804517A (zh) * 2021-09-28 2021-12-17 浙江富春江环保科技研究有限公司 一种基于边界报警的二噁英在线检测系统
CN113804517B (zh) * 2021-09-28 2022-05-03 浙江富春江环保科技研究有限公司 一种基于边界报警的二噁英在线检测系统
CN115628143A (zh) * 2022-09-07 2023-01-20 重庆金康赛力斯新能源汽车设计院有限公司 汽车排放控制方法、装置、计算机设备和存储介质
CN115628143B (zh) * 2022-09-07 2024-05-03 重庆金康赛力斯新能源汽车设计院有限公司 汽车排放控制方法、装置、计算机设备和存储介质

Also Published As

Publication number Publication date
AU1282199A (en) 1999-06-07
WO1999025965A9 (fr) 1999-08-26

Similar Documents

Publication Publication Date Title
KR101707759B1 (ko) 배기 가스 촉매 변환기의 진단 방법, 진단 장치 및 상기 장치를 구비한 자동차
US5444974A (en) On-board automotive exhaust catalyst monitoring with a calorimetric sensor
US6694243B2 (en) Method and apparatus for determining oxygen storage capacity time of a catalytic converter
US5941918A (en) Automotive on-board monitoring system for catalytic converter evaluation
US8191413B2 (en) Method for determining the nitrogen dioxide concentration in exhaust gases
US6497092B1 (en) NOx absorber diagnostics and automotive exhaust control system utilizing the same
JP4625194B2 (ja) 排気ガス浄化用触媒の作動能力を点検するための方法
US6003307A (en) OBD calorimetric sensor system with offset error correction
US6631611B2 (en) Methodology of robust initialization of catalyst for consistent oxygen storage capacity measurement
CN105765188B (zh) 用于经催化基材的车载诊断系统和诊断方法
US9234474B2 (en) Control oriented model for LNT regeneration
CN110939501B (zh) 催化器劣化诊断系统及催化器劣化诊断方法
JP2013181526A (ja) 触媒診断装置及び触媒診断方法
JP5563602B2 (ja) 排気システムを作動するための方法
WO1999025965A1 (fr) SYSTEME DE SURVEILLANCE DE BORD POUR VEHICULE, DETECTANT LES EMISSIONS HC/NOx POUR L'EVALUATION DU CONVERTISSEUR CATALYTIQUE
JP7265449B2 (ja) 触媒劣化診断方法
EP0814242A1 (fr) Lutte contre la pollution atmosphérique
Theis An engine test to measure the oxygen storage capacity of a catalyst
Ingram et al. On-line oxygen storage capacity estimation of a catalyst
US7513104B2 (en) Diagnostic apparatus for internal combustion engine
US6978598B2 (en) Deteriorated state evaluation device for exhaust emission control equipment
Theis Catalytic converter diagnosis using the catalyst exotherm
JP4607541B2 (ja) 三元触媒の劣化診断方法
JP4275046B2 (ja) エンジンの制御装置
US20230184625A1 (en) Method for diagnosing an exhaust component in an exhaust passage for an internal combustion engine of a vehicle

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AL AM AT AU AZ BA BB BG BR BY CA CH CN CU CZ DE DK EE ES FI GB GE GH GM HR HU ID IL IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT UA UG UZ VN YU ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW SD SZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
AK Designated states

Kind code of ref document: C2

Designated state(s): AL AM AT AU AZ BA BB BG BR BY CA CH CN CU CZ DE DK EE ES FI GB GE GH GM HR HU ID IL IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT UA UG UZ VN YU ZW

AL Designated countries for regional patents

Kind code of ref document: C2

Designated state(s): GH GM KE LS MW SD SZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN GW ML MR NE SN TD TG

COP Corrected version of pamphlet

Free format text: PAGES 1/18-18/18, DRAWINGS, REPLACED BY NEW PAGES 1/18-18/18; DUE TO LATE TRANSMITTAL BY THE RECEIVING OFFICE

REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

NENP Non-entry into the national phase

Ref country code: CA

122 Ep: pct application non-entry in european phase