A controller and method for an oxygen sensor in an exhaust conduit of a vehicle
A single oxygen sensor downstream of the catalyst unit, with position-specific threshold values, addresses the complexity and cost of dual sensor systems by optimizing lambda control and catalyst monitoring, achieving efficient emissions management.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- ROBERT BOSCH GMBH
- Filing Date
- 2025-11-17
- Publication Date
- 2026-06-04
AI Technical Summary
Existing vehicle emission control systems require two oxygen sensors, one upstream and one downstream of the catalyst, to manage closed loop lambda control and catalyst monitoring, which increases complexity and cost, especially with new emission legislation like Bharat Stage 6 and On-Board Diagnostics 2 (BS6 OBD2) necessitating switching type sensors.
A controller and method utilizing a single oxygen sensor positioned downstream of the catalyst unit, with calibrated threshold values specific to its position, performs both closed loop lambda control and catalyst monitoring, optimizing emissions by maintaining ideal lambda and monitoring catalyst health.
The system achieves efficient emissions control and catalyst monitoring with reduced sensor complexity and cost by using a single sensor, ensuring optimal lambda control and detecting catalyst aging, meeting stringent emission standards.
Smart Images
Figure EP2025083198_04062026_PF_FP_ABST
Abstract
Description
FORM 2THE PATENTS ACT, 1970(39 of 1970) & The Patents Rules 2003COMPLETE SPECIFICATION (SECTION 10 and Rule 13)1. Title of the Invention:A CONTROLLER AND METHOD FOR AN OXYGEN SENSOR IN AN EXHAUST CONDUIT OF A VEHICLE2. Applicants: a. Name: Bosch LimitedNationality: INDIAAddress: Post Box No 3000, Hosur Road, Adugodi, Bangalore- 560030, Karnataka, India b. Name: Robert Bosch GmbHNationality: GERMANYAddress: Postfach 300220, 0-70442, Stuttgart, GermanyComplete Specification:The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed:Reference:The present invention relates to an improvement in or modification of the application for main invention described in the patent application 202341030693 filed on 28 April 2023.Field of the invention:
[0001] The present disclosure relates to a controller, and method for an oxygen sensor in an exhaust conduit of a vehicle.Background of the invention:
[0002] The present solution for emission norms dictates the requirement for two oxygen sensors, placed upstream and downstream of the catalyst respectively. The upstream sensor is mainly used for closed loop lambda control and the downstream sensor is used for catalyst monitoring and lambda corrections. The new emission legislation, such as Bharat Stage 6, On-Board Diagnostics 2 (BS6 OBD2) Engine Management System (EMS), requires the use of two switching type oxygen sensors in the exhaust system. The upstream oxygen sensor placed before the catalyst is utilized primarily for closed loop lambda control such that three-way catalyst converter is used optimally for emission conversion. The downstream oxygen sensor placed after the catalyst is utilized for catalyst monitoring and further corrections to upstream lambda control. Due to the benefits of split and tandem catalyst system and cost efficient catalyst design, Original Equipment Manufacturers (OEMs) prefer split catalyst setup in their applications with the primary catalyst placed very close to the exhaust port.
[0003] According to a prior art KR20110116581 discloses a lambda controlling system and method thereof. A fuel-air ratio control system and method are provided to reduce the manufacturing cost of a vehicle because a single lambda sensor is installed only on the rear end of a catalyst converter and air-fuel ratio control and diagnosis of catalyst purification efficiency are simultaneously implemented by the lambda sensor. A fuel-air ratio control system comprises a sensing part, a fuelcorrection quantity calculation part, a catalyst diagnosis part, and a fuel correction part. The sensing part is installed on the backend of a catalytic converter. The sensing part measures the oxygen content of exhaust gas. The fuel correction quantity calculation part measures the transition duration of a sensing signal outputted from the sensing part and computes a fuel correction value based on the transition duration. The catalyst diagnosis part diagnoses a catalyst based on the measured transition duration. The fuel correction part controls the supply of fuel based on the fuel correction value.Brief description of the accompanying drawings:
[0004] An embodiment of the disclosure is described with reference to the following accompanying drawings,
[0005] Fig. 1 illustrates a block diagram of a controller for an oxygen sensor in an exhaust conduit of a vehicle, according to an embodiment of the present invention;
[0006] Fig. 2 illustrates plots of signals from an oxygen sensor with different positioning in the exhaust conduit, according to an embodiment of the present invention, and
[0007] Fig. 3 illustrates a method for processing signal from the oxygen sensor in the exhaust conduit of the vehicle, according to the present invention.Detailed description of the embodiments:
[0008] Fig. 1 illustrates a block diagram of a controller for an oxygen sensor in an exhaust conduit of a vehicle, according to an embodiment of the present invention. The exhaust conduit 104 comprises a catalyst unit 120. The oxygen sensor 110 is positioned downstream of the catalyst unit 120. The controller 112 configured to receive signal detected by oxygen sensor 110, compare the detected signal with at least one calibrated threshold value 206 (shown in Fig. 2). The at least one calibrated / configured threshold value 206, is stored in a memory element. The controller 112 is then configured to perform at least one selected from a group comprising a closed loop lambda control and catalyst monitoring using signals from said oxygen sensor 110 based on a result of the comparison, characterized in that,the at least one threshold value 206 is specific to position of the oxygen sensor 110 downstream of the catalyst unit 120. The at least one threshold value 206 is provided for at least one operating condition of the engine 102 of the vehicle 100 for the oxygen sensor 110 positioned downstream of the catalyst unit 120. The at least one threshold value 206 is calibrated and pre-stored in the memory element. The signal from oxygen sensor 110 is shown as input to the controller 112, but the same must not be understood in limiting manner as the controller 112 is developed to take all necessary and required conventional inputs for the operation of the engine 102 and the vehicle 100.
[0009] In accordance to an embodiment of the present invention, the controller 112 is provided with necessary signal detection, acquisition, and processing circuits. The controller 112 is the control unit which comprises input / output interfaces having pins or ports, the memory element such as Random Access Memory (RAM) and / or Read Only Memory (ROM), Analog-to-Digital Converter (ADC) and a Digital-to-Analog Convertor (DAC), clocks, timers, counters and at least one processor (capable of implementing machine learning) connected with each other and to other components through communication bus channels. The memory element is pre-stored with logics or instructions or programs or applications or modules / models and / or threshold / values / ranges / amplitude, predefined / predetermined criteria, correction factor based maps / table which is / are accessed by the at least one processor as per the defined routines. The internal components of the controller 112 are not explained for being state of the art, and the same must not be understood in a limiting manner. The controller 112 may also comprise communication units to communicate with external computer or server / cloud computer through wireless or wired means such as Global System for Mobile Communications (GSM), 3G, 4G, 5G, Wi-Fi, Bluetooth, Ethernet, serial networks, and the like. The controller 112 is implementable in the form of System- in-Package (SiP) or System-on-Chip (SOC) or any other known types. Examples of controller 112 comprises but not limited to, microcontroller, microprocessor, microcomputer, etc.
[0010] The at least one threshold value 206 is calibrated and pre-stored in the memory element. The at least one threshold value 206 is a voltage (or switching point) at which the switching from rich phase to lean phase and lean phase to rich phase is done to ensure the ideal or best or optimal lambda is maintained to ensure least possible emissions at the tailpipe. The at least one threshold value 206 is obtained after testing of the engine 102 in the vehicle 100 in various operating conditions. The at least one threshold value 206 is also done because of single lambda sensor being used downstream of the catalyst unit 120. Further, the distance of the oxygen sensor 110 from the catalyst unit and engine exhaust port 120 has impact or variations during calibration phase , and is considered during the testing and development phase itself.
[0011] According to an embodiment of the present invention, the catalyst unit 120 is any one selected from a group comprising a single catalyst block, a split catalyst block and a tandem catalyst block. A primary catalyst (first catalyst brick) 106 and the secondary catalyst (second catalyst brick) 108 are part of any one of the split catalyst block and the tandem catalyst block of the catalyst unit 120. The gap in split catalyst block is more than the tandem catalyst block. The oxygen sensor 110 is positioned after or at rear end of a last of the catalyst unit 120 in flow direction of exhaust gases. The engine 102 of the vehicle 100 operates on fuel selected from a group comprising gasoline / petrol, ethanol blended with gasoline (E0-E100), Compressed Natural Gas (CNG) and Liquified Petroleum Gas (LPG) and other hydrocarbon based fuels.
[0012] According to an embodiment of the present invention, the vehicle 100 is any one selected from a group comprising a two-wheeler vehicle 100 such as a scooter, a motorcycle, a three-wheeler vehicle 100 such as autorickshaw, a four-wheeler vehicle 100, such as a car, and other types of vehicles 100 such as buses, watersports vehicle the like. Alternatively, the present invention is also applicable for those vehicle 100 which makes use of small size catalysts in split setup or tandem setup.Thus, the present invention is applicable for other types of vehicles 100 as well such as cars, buses, watersports vehicles 100 and the like.
[0013] According to an embodiment of the present invention, the controller 112 is implementable in different types of configurations of catalyst unit 120. The configurations are shown with engine 102 in left and exhaust conduit 104 as a line to the right. In a first configuration 116, the catalyst unit 120 is single and big, the oxygen sensor 110 is positioned downstream of the catalyst unit 120. In a second configuration 118, the catalyst unit 120 is tandem (two small catalysts, the primary catalyst 106 and the secondary catalyst 108 in a single outer casing or two small catalysts with negligible distance between them). The oxygen sensor 110 is positioned downstream of the secondary catalyst 108 of the catalyst unit 120. In a third configuration 122, the catalyst unit 120 is split, and the oxygen sensor 110 is positioned downstream of the secondary catalyst 108 of the catalyst unit 120. In all the three configurations, the first configuration 116, the second configuration 118 and the third configuration 122, the oxygen sensor 110 is possible to be positioned either on the housing of the catalyst unit 120 or away from the housing of the catalyst unit 120. In a first position, the oxygen sensor 110 is positioned on the housing of the catalyst unit 120 but at the end of the secondary catalyst 108, and in a second position, the oxygen sensor 110 is positioned in the exhaust conduit 104 away from the housing and downstream of the catalyst unit 120 but at a distance which does not adversely affect the sensing of the oxygen sensor 110. The first position is shown only for third configuration 122 for simplicity in illustration. The similar first position is applicable for the first configuration 116 and the second configuration 118 as well. The position 114 is shown for the oxygen sensor 110 positioned upstream of the catalyst unit 120 along with the oxygen sensor 110 positioned downstream of the catalyst unit 120. If available, the oxygen sensor 110 in the upstream position is usable to perform lambda control and catalyst diagnosis along with the oxygen sensor 110 positioned downstream of the catalyst unit 120.
[0014] In an embodiment of the preset invention, the controller 112 is provided for the vehicle 100 which comprises a first oxygen sensor and a second oxygen sensor positioned upstream and downstream of the catalyst unit 120 respectively. In case, if the first oxygen sensor experiences malfunction or error or faults, the controller 112 is configured to enable use of the second oxygen sensor alone, which is positioned downstream of the catalyst unit 120, to perform dual functions, i.e., catalyst monitoring and lambda control.
[0015] Fig. 2 illustrates plots of signals from an oxygen sensor with different positioning in the exhaust conduit, according to an embodiment of the present invention. A first graph 200 is shown where X-axis is time and Y-axis is voltage in respective suitable units. The first graph 200 illustrates a plot for the oxygen sensor 110 when positioned upstream of the primary catalyst 106 shown by the first curve 202 and when positioned downstream of the primary catalyst 106 shown by the second curve 204. Further, each of the first curve 202 and the second curve 204 is provided with respective reference line indicating the threshold value 206.
[0016] When positioned upstream of the primary catalyst 106, the signal detected by the oxygen sensor 110 contains high fluctuations in sensor amplitude, the reason being to switch around the switching point to maintain close loop lambda. Also when the oxygen sensor 110 is placed after the primary catalyst 106, the sensor signal softens / amplitude reduces when compared to upstream oxygen sensor 110 due to the utilization of O2 / redox reactions occurring in the Three-Way Catalyst (TWC). The controller 112 considers 0.5 volts (as an example) as conventional threshold value 208. Similarly, when positioned downstream of the primary catalyst 106, the signal detected by the oxygen sensor 110 is of lower amplitude in comparison to the first curve 202. The reason for the low amplitude is less oxygen after being treated with the primary catalyst 106. The controller 112 considers 0.75 volts (as an example) as the threshold value 206 for switching. There is a shift in threshold value 206 between the first curve 202 and the second curve 204 because of redox reactions / oxygen utilization during redox reactions from the catalyst, andthen is calibrated and used in the present invention for closed loop lambda control and catalyst monitoring.
[0017] A second graph 210 is also shown for illustrating working of closed loop lambda control of the engine 102. Consider second curve 204 is taken for explanation. In the second graph 210, the second curve 204 in first graph 200 is used where Y-axis is in voltage in suitable units. A third curve / plot 212 is shown in the second graph 210 for fuel control in respective unit. The X-axis for both the curves / plot is time in suitable units. For every instance of the second curve 204 crossing the threshold value 206, either by going from low value to high value or higher value to the lower value, the controller 112 controls the fuel injection accordingly. When the value of the second curve 204 goes above the threshold value 206 (i.e. rich phase), the controller 112 reduces the fuel injection as shown with corresponding value in the third curve 212. Similarly, when the value of the second curve 204 goes below the threshold value 206, the controller 112 increases the fuel injection as shown in corresponding part of the third curve 212 within the same time period.
[0018] According to an embodiment of the present invention, the controller 112 is configured to perform closed loop lambda control using the only one oxygen sensor 110. The assembly requires an exhaust system with catalyst unit 120 with split / tandem catalyst setup where the oxygen sensor 110 is positioned after the last or secondary catalyst 108, or the catalyst unit 120 is single catalyst block. The signal from the downstream oxygen sensor 110 when placed after the secondary catalyst 108 in single / dual cylinder engine 102 has lambda pulsations. This pulsation is primarily from oxygen storage and removal in the three-way catalyst. This is used an input to the two-point lambda control to optimally use the primary catalyst 106 in the emission conversion window. Since the downstream lambda is mostly in the rich state due to Oxygen Storage Capacity (OSC) of the primary catalyst 106, the lambda control logic in the controller 112 has to switch between lean and rich mixture using a rich lambda control point (X<1) to obtain best possible emission atthe tailpipe. The increased lambda control dead time due to the sensor position and catalyst is mitigated by appropriate primary catalyst 106 sizing and its position. The dead time is a standard term which implies a time duration between a start of an event until the event is detected by the sensor, during which the sensor is unable to provide an output signal.
[0019] The controller 112 provides a closed loop feedback to the fuel control algorithm based on the signal from the downstream oxygen sensor 110, as shown by the third curve 212. The fuel control algorithm determines the fuel quantity to be injected for each engine cycle based on the engine operating point and the calibrations. An oscillation in this fuel quantity in the form of a Proportional jump and an Integral ramp is added to the fuel quantity signal by the controller 112. The aforementioned corrections are determined by the controller 112 based on the signal from the oxygen sensor 110, operating point as well as the calibrations made. Before the oxygen sensor 110 readiness is achieved, the fuel control is based on a calibrated open loop map. Switching points or threshold values (voltage) are identified on the signal from the oxygen sensor 110, calibrated for the range of operating points of the vehicle 100. Either there is only one threshold value 206 for the vehicle 100 or two or more threshold values 206 for two or more operating points / regions of the engine 102. At each instance where the O2 sensor signal crosses the switching point voltage during its transition from low to high or high to low voltage, a fuel correction towards lean side or rich side respectively is provided by the SLSC controller 112. This form of a closed loop fuel correction maintains the O2 sensor signal in a sinusoidal waveform.
[0020] At every instance of signal detected by the oxygen sensor 110 crossing the at least one threshold value 206 during transition from high to low and low to high, the fuel correction towards lean side and rich side, respectively is performed by the controller 112. This form of a closed loop fuel correction maintains the signal from the oxygen sensor 110 in a sinusoidal waveform.
[0021] According to an embodiment of the present invention, the controller 112 is configured to perform catalyst monitoring. The OSC of the three-way catalyst is a measure of the catalyst’s ability to reduce the rich lean oscillations in the exhaust gas composition by regulating the oxygen partial pressure by means of the oxygen storage material present in the catalyst (primary catalyst 106). Thus, the high OSC of a fresh catalyst contributes to efficient emission conversion by maintaining the oxygen availability at the stoichiometric levels required for the redox reactions. With aging of the catalyst, its OSC reduces and hence the conversion efficiency decreases.
[0022] The controller 112 measures the amplitude of the signal detected by the oxygen sensor 110 and compares against threshold amplitude. The primary catalyst 106 is considered to be aged based on the comparison. The threshold amplitude is obtained by considering an aged primary catalyst 106 and then measuring from the oxygen sensor 110 during testing phase. In other words, a model based on the borderline catalyst (for example, which is approx. 95+% aged, considering the durability limit of l,00,000kms) is considered as reference. The amplitude of fluctuation in the downstream oxygen sensor 110 is compared with respect to the amplitude of model from borderline catalyst, and reported that the primary catalyst 106 is aged or not. The amplitude measurement is done considering the single oxygen sensor 110 positioned downstream of the catalyst unit 120 which is contrast different from when the oxygen sensor 110 is positioned upstream of the catalyst unit 120.
[0023] According to the present invention, a working of the controller 112 as per the assembly is envisaged. Consider a motorcycle is fit with a split / tandem / single catalyst unit 120 with one oxygen sensor 110 positioned after the catalyst unit 120. The controller 112 is calibrated with the at least one threshold value 206 for the oxygen sensor 110 positioned downstream of the secondary catalyst 108. The controller 112 receives the signal from the oxygen sensor 110 and determines the voltage detected. The real-time voltage is compared with the threshold value 206as per the operating condition. The operating condition / point / region is based on engine speed and throttle position. The entire operating region is either considered as one or split into multiple regions with respective threshold value 206. In the prior / typical state of art, only one threshold value 206 is taken for entire operating region.
[0024] Once the threshold value 206 is detected, the controller 112 performs the closed loop lambda control using for the downstream oxygen sensor 110. Similarly, the signal of the oxygen sensor 110 is used by the controller 112 for catalyst monitoring by comparing the real-time amplitude of the signal with the threshold amplitude. The controller 112 then determines that the primary catalyst 106 is aged or not.
[0025] Fig. 3 illustrates a method for processing signal from the oxygen sensor in the exhaust conduit of the vehicle, according to the present invention. The exhaust conduit 104 comprises the catalyst unit 120, and the oxygen sensor 110 positioned downstream of the catalyst unit 120. The method comprise plurality of steps of which a first step 302 comprises receiving signal, by the controller 112, as detected by the oxygen sensor 110. A step 304 comprises comparing, by the controller 112, the detected signal with at least one calibrated threshold value 206. The at least one calibrated threshold value 206 is stored, in the memory element. A step 306 comprises performing based on the comparison, by the controller 112, at least one function selected from the group comprising the closed loop lambda control and catalyst monitoring using signals from the one oxygen sensor 110. The method is characterized by, the at least one threshold value 206 corresponds to specific position of the oxygen sensor 110 downstream of the catalyst unit 120, and is provided for at least one operating condition of the engine 102 of the vehicle 100 for the oxygen sensor 110 positioned downstream of the catalyst unit 120. The at least one threshold value 206 is calibrated and pre-stored in the memory element.
[0026] According to the step 306, the method for closed loop lambda control is provided which comprises applying fuel correction towards lean side and rich side at every instance of the signal detected by the oxygen sensor 110 crossing the at least one threshold value 206 during transition from high to low and low to high, respectively.
[0027] According to the present invention, the method for catalyst monitoring is provided. The method comprises detecting an aged primary catalyst 106 by comparing the amplitude of the signal detected by the oxygen sensor 110 against the threshold amplitude stored in the memory element. The aging of the primary catalyst 106 is determined based on the comparison. The method determines the whether the primary catalyst 106 is aged or not without knowing the degree of aging. In other words, the method determines if the primary catalyst 106 has reached End Of Life (EOL). The method is performed by the controller 112.
[0028] According to the present invention, the catalyst unit 120 is any one selected from the group comprising a single catalyst block, a split catalyst block and a tandem catalyst block. The oxygen sensor 110 is positioned after or at rear end of a last of the catalyst unit 120 in flow direction of exhaust gases. The engine 102 of the vehicle 100 operates on fuel selected from a group comprising gasoline / petrol, ethanol blended with gasoline (E0-E100), Compressed Natural Gas (CNG) and Liquified Petroleum Gas (LPG) and other hydrocarbon based fuels.
[0029] According to the present invention, the vehicle 100 is any one selected from the group comprising the two-wheeler vehicle such as the scooter, the motorcycle, the three-wheeler vehicle such as the autorickshaw, the four-wheeler vehicle such as the car, and other types of vehicles 100 such as buses, watersports vehicle the like.
[0030] According to an embodiment of the present invention, the controller 112 and the method for lambda control and catalyst monitoring using single oxygen sensor110 is provided. The present invention provides lambda control based on only one oxygen sensor 110 positioned downstream of the catalyst unit 120 (catalytic converter) in the single catalyst or split catalyst or tandem catalyst system. The Single Lambda Sensor Control (SLSC) setup requires an exhaust system of the vehicle 100 with one or single oxygen sensor 110 placed downstream of the catalyst unit 120. Since the three-way catalyst in the two-wheeler and three-wheeler has reduced Oxygen Storage Capacity (OSC) and sizing compared to that of four or higher wheeler vehicles 100, it is possible to generate the sensor signal amplitudes in the oxygen sensor 110 at the downstream position. With this setup and processing, the SLSC system and other mentioned sensor positions is possible and technically advantageous. The amplitude is optimizable based on dead time, switching point and other controlling parameters. The switching point is kept either leaner or richer depending on the application and operating point. However, least emissions are achieved at the tailpipe / exhaust conduit 104 if there is slightly rich switching point. The other influencing factors for switching point and dead time are catalyst bed temperature, lambda at the combustion chamber, catalyst ageing and sensor ageing itself where it must be corrected accordingly to have least possible emissions at the tailpipe.
[0031] The oxygen sensor 110 also provides input for catalyst monitoring based on the OSC of the catalyst unit 120. The present invention provides lambda control based on the signal from single oxygen (O2) sensor 110 downstream of the catalyst unit 120 and eliminates the requirement for another lambda / oxygen sensor positioned upstream of the catalyst unit 120. For example, a two-point lambda controller 112 is usable to control the rich-lean mixture oscillations based on the oxygen sensor 110 set-point at downstream position.
[0032] The assembly / setup is conducive for using only one switching type oxygen sensor 110 for both closed loop lambda control and catalyst monitoring. The life of oxygen sensor 110 is increased due the being positioned away from the directexhaust gases. A method / controlling action for lambda control and catalyst monitoring using single Binary / oxygen sensor 110 for split and tandem catalytic convertor setup vehicles 100 is provided. The present invention uses passive catalyst monitoring method. This is a passive monitoring strategy which must be done to meet In-Use Monitor Performance Ratio (IUMPR) as per legislation.
[0033] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.
Claims
We claim:
1. A controller (112) for an oxygen sensor (110) in an exhaust conduit (104) of a vehicle (100), said exhaust conduit (104) comprises a catalyst unit (120), and said oxygen sensor (110) positioned downstream of said catalyst unit (120), said controller (112) configured to, receive signal detected by said oxygen sensor (110), compare said detected signal with at least one calibrated threshold value (206), said at least one calibrated threshold value (206), is stored in a memory element, and perform at least one selected from a group comprising a closed loop lambda control and catalyst monitoring using signals from said oxygen sensor (110) based on the comparison, characterized in that, said at least one threshold value (206) is specific to position of said oxygen sensor (110) downstream of said catalyst unit (120), and said at least one threshold value (206) is provided for at least one operating condition of an engine (102) of said vehicle (100) for said oxygen sensor (110) positioned downstream of said catalyst unit (120), said at least one threshold value (206) is calibrated and prestored in said memory element.
2. The controller (112) as claimed in claim 1, wherein at every instance of signal detected by said oxygen sensor (110) crossing said at least one threshold value (206) during transition from high to low and low to high, a fuel correction towards lean side and rich side, respectively is performed.
3. The controller (112) as claimed in claim 1, wherein an amplitude of said signal detected by said oxygen sensor (110) is compared against threshold amplitude for determination of aging of said catalyst unit (120).
4. The controller (112) as claimed in claim 1, wherein said catalyst unit (120) is any one selected from a group comprising a single catalyst block, a splitcatalyst block and a tandem catalyst block, and wherein said oxygen sensor (110) is positioned after or at rear end of a last of said catalyst unit (120) in flow direction of exhaust gases, and wherein an engine (102) of said vehicle (100) operates on fuel selected from a group comprising gasoline / petrol, ethanol blended with gasoline (E0-E100), Compressed Natural Gas (CNG) and Liquified Petroleum Gas (LPG) and other hydrocarbon based fuels.
5. The controller (112) as claimed in claim 1, wherein said vehicle (100) is any one selected from a group comprising a two-wheeler vehicle such as a scooter, a motorcycle, a three-wheeler vehicle such as autorickshaw, a four- wheeler vehicle, such as a car, and other types of vehicles such as buses, watersports vehicle the like.
6. A method for processing signal of an oxygen sensor (110) in an exhaust conduit (104) of a vehicle (100), said exhaust conduit (104) comprises a catalyst unit (120), and said oxygen sensor (110) positioned downstream of said catalyst unit (120), said method comprising the steps of, receiving signal detected by said oxygen sensor (110), comparing said detected signal with at least one calibrated threshold value (206), said at least one calibrated threshold value (206), is stored in a memory element, and performing at least one function selected from a group comprising a closed loop lambda control and catalyst monitoring using signals from said oxygen sensor (110) based on the comparison, characterized by, said at least one threshold value (206) corresponds to specific position of said oxygen sensor (110) downstream of said catalyst unit (120), and is provided for at least one operating condition of an engine (102) of said vehicle (100) for said oxygen sensor (110) positioned downstream of said catalyst unit (120), said at least one threshold value (206) is calibrated and pre-stored in said memory element.
7. The method as claimed in claim 6, comprises applying fuel correction towards lean side and rich side at every instance of signal detected by said oxygen sensor (110) crossing said at least one threshold value (206) during transition from high to low and low to high, respectively.
8. The method as claimed in claim 6, comprises detecting an aged primary catalyst (106) by comparing an amplitude of said signal detected by said oxygen sensor (110) against threshold amplitude stored in said memory element.
9. The method as claimed in claim 6, wherein said catalyst unit (120) is any one selected from a group comprising a single catalyst block, a split catalyst block and a tandem catalyst block, and wherein said oxygen sensor (110) is positioned after or at rear end of a last of said catalyst unit (120) in flow direction of exhaust gases, and wherein an engine (102) of said vehicle (100) operates on fuel selected from a group comprising gasoline / petrol, ethanol blended with gasoline (E0-E100), Compressed Natural Gas (CNG) and Liquified Petroleum Gas (LPG) and other hydrocarbon based fuels.
10. The method as claimed in claim 6, wherein said vehicle (100) is any one selected from a group comprising a two-wheeler vehicle such as a scooter, a motorcycle, a three-wheeler vehicle such as autorickshaw, a four-wheeler vehicle, such as a car, and other types of vehicles such as buses, watersports vehicle the like.Dated 27 November 2024 (Digitally signed)Siddharth Karkhanis (IN / PA- 1195) On-behalf of the Applicants