Description:Complete Specification:
The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed:


Field of the invention:
[0001] The present disclosure relates to a controller to diagnose a heater element of a lambda sensor and method thereof.

Background of the invention:
[0002] In binary lambda sensors, a heater element is being diagnosed by measuring the internal resistance of heater elements, but some type of binary lambda sensors are not capable to measure the resistance value of heater element.

[0003] According to a prior art CN114961954, a catalytic converter rear oxygen sensor fault detection method is disclosed. The invention discloses a catalyst rear oxygen sensor fault detection method. The method comprises the following steps: judging whether conditions of a fault detection preparation stage are met or not; if yes, determining the voltage stability of the rear oxygen sensor; after quitting GPF regeneration request air-fuel ratio thinning execution, whether the condition of the fault detection evaluation stage is met or not is judged; if yes, fault evaluation is carried out, and time of T1 is calculated; recording a time interval T2 in which the fluctuation range does not exceed a second preset value when the conditions of the oxygen sensor in the fault detection and evaluation stage are met after reality; if the absolute value of the difference between T1-T2 exceeds C1, the rear oxygen sensor has a fault; if the absolute value of the difference between the T1-T2 does not exceed C2, the rear oxygen sensor has no fault; c1 is greater than or equal to C2. According to the method, the air-fuel ratio is enriched after the air-fuel ratio thinning control is finished, whether the rear oxygen sensor breaks down or not is monitored by monitoring the performance of the voltage of the rear oxygen sensor after the air-fuel ratio is enriched, and the phenomenon of excessive NOx in emission is improved.

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 to diagnose a heater element of a lambda sensor, according to an embodiment of the present invention, and
[0006] Fig. 2 illustrates a method flow diagram for diagnosing the heater element of the lambda sensor, according to the present invention.

Detailed description of the embodiments:
[0007] Fig. 1 illustrates a block diagram of a controller to diagnose a heater element of a lambda sensor, according to an embodiment of the present invention. The lambda sensor 112 is positioned in an exhaust conduit 118 of an engine 116 of a vehicle 100, characterized in that, the controller 110 configured to supply/apply a voltage to a heater element 114 of the lambda sensor 112, monitor activation time of the lambda sensor 112 based on output voltage of the lambda sensor 112 due to application of heat through the heater element 114, and diagnose the heater element 114 to be abnormal if the activation time is beyond a pre-determined threshold time 106. Once diagnosed, the same is indicated to user through an alert on the instrument cluster, dashboard, or sound or to connected smart devices.

[0008] The activation time is monitored until output voltage of the lambda sensor 112 crosses a dead band. The activation time is dependent on starting temperature of the engine 116. The starting temperature corresponds to temperature of the engine 116 when the diagnosis of the heater element 114 of the lambda sensor 112 is initiated.

[0009] According to an embodiment of the present invention, the controller 110 measures starting temperature of the engine 116 and correspondingly selects the pre-determined threshold time 106. Thus, table is stored in a memory element 108 of the controller 110 which stores different start temperature of the engine 116 and the pre-determined threshold time 106.

[0010] According to an embodiment of the present invention, the application of the voltage to the heater element 114 is initiated once pre-conditional checks are satisfied. The pre-conditional checks comprises the lambda sensor 112 reaching dew point, an exhaust temperature within a temperature range, and a battery voltage is within a voltage range. The exhaust temperature is measured using the temperature sensor 102. The battery voltage is measured by the voltage sensor 104 as known in the art. The dew point is calibrated temperature which is set and stored in the controller 110.

[0011] In accordance to an embodiment of the present invention, the controller 110 is provided with necessary signal detection, acquisition, and processing circuits. The controller 110 is the one which comprises input interface, output interfaces having pins or ports, the memory element 108 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 108 is pre-stored with logics or instructions or programs or applications or modules/models and/or threshold values/ranges, reference values, predefined/predetermined criteria/conditions, which is/are accessed by the at least one processor as per the defined routines. The internal components of the controller 110 are not explained for being state of the art, and the same must not be understood in a limiting manner. The controller 110 may also comprise communication units such as transceivers to communicate 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 110 is implementable in the form of System-in-Package (SiP) or System-on-Chip (SOC) or any other known types. Examples of controller 110 comprises but not limited to, microcontroller, microprocessor, microcomputer, etc.

[0012] Further, the processor may be implemented as any or a combination of one or more microchips or integrated circuits interconnected using a parent board, hardwired logic, software stored in the memory element 108 and executed by a microprocessor, firmware, an application specific integrated circuit (ASIC), and/or a field programmable gate array (FPGA). The processor is configured to exchange and manage the processing of various Artificial Intelligence (AI) modules.

[0013] According to the present invention, a working of the controller 110 is explained. Consider a motorcycle is fit with heated lambda sensor 112 but without resistance based diagnosis. The rider starts the motorcycle, rides for a distance, and stops and completes one drive cycle. In the drive cycle, the controller 110 checks the pre-conditions and satisfies that the lambda sensor 112 is above the dew point, the exhaust temperature is within the threshold temperature range and the battery voltage is within the threshold voltage range. Once the preconditions checks are fulfilled, the controller 110 supplies power to the heater element 114 from the battery. In other words, the controller 110 applies the voltage to the heater element 114. As soon as the voltage is applied, the controller 110 starts a timer. The timer runs until the voltage of the lambda sensor 112 crosses the dead band. The dead band corresponds to the region where there is not output voltage on application of heat up to certain temperature. Once crossed, the controller 110 stops the timer. The measured time is compared with the predetermined threshold time. If the measured time is greater, then the controller 110 diagnoses the heater element 114 to be abnormal or aged or faulty and thus the lambda sensor 112 is also detected to be abnormal. The controller 110 is configured to then adapt the aging and correct the abnormality.

[0014] Fig. 2 illustrates a method flow diagram for diagnosing the heater element of the lambda sensor, according to the present invention. The method comprises plurality of steps of which a step 202 comprises supplying, by the controller 110, the power/voltage to the heater element 114 of the lambda sensor 112. A step 204 comprises monitoring, by the controller 110, activation time of the lambda sensor 112 based on output voltage of the lambda sensor 112. The activation time is dependent on starting temperature of the engine 116. A step 206 comprises diagnosing, by the controller 110, the heater element 114 to be abnormal if the activation time is beyond the pre-determined threshold time 106. The pre-determined threshold time 106 is stored in the memory element 108 of the controller 110 and retrieved in step 210. Thereby, the method also diagnosis the abnormality in the lambda sensor 112.

[0015] The step 202 of the method, i.e. applying the voltage to the heater element 114, is initiated after satisfying pre-conditional checks in step 208. The pre-conditional checks, performed by the controller 110, comprises reaching dew point of the lambda sensor 112, the exhaust temperature within the temperature range, and the battery voltage is within the voltage range. In the method, the activation time is monitored till voltage of the lambda sensor 112 crosses a dead band. The method comprises measuring starting temperature of the engine 116 and correspondingly selecting the pre-determined threshold time 106.

[0016] In the present invention, the strategy of diagnosing (such as aging) the heater element 114 of the lambda sensor 112 is based on the time period between the start time of the application of voltage to the heater element 114 and the time at which output voltage of the lambda sensor 112 is crossing the dead band. After the pre-condition checks are done, the supply voltage is given to the heater element 114 of the lambda sensor 112. Depending on the aging characteristics, the time taken for the output voltage of the lambda sensor 112 to cross the dead band varies. The time period is depending on start temperature of the engine 116 for new/good sensors. If the start temperature of the engine 116 is relatively higher, then the time period is lower. Thus, the activation time of the lambda sensor 112 varies based on the start temperature of the engine 116.

[0017] According to the present invention, the controller 110 and method of heater diagnostics for lambda sensor 112 without measuring resistance is disclosed. The present invention enables abnormality (such as aging) diagnoses of heater element 114 of the lambda sensor 112 without the resistance measurement. The present invention uses the time period between when voltage to the heater element 114 is applied and the voltage of the lambda sensor 112 crosses the dead band. This time period increase with heater aging profile. So with the help of this time period, the heater element 114 of the lambda sensor 112 is diagnosed.

[0018] 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 (110) to diagnose a heater element (114) of a lambda sensor (112), the lambda sensor (112) positioned in an exhaust conduit (118) of an engine (116) of a vehicle (100), characterized in that, said controller (110) configured to,
supply voltage to said heater element (114) of said lambda sensor (112);
monitor activation time of said lambda sensor (112) based on output voltage of said lambda sensor (112), and
diagnose said heater element (114) to be abnormal if said activation time is beyond a pre-determined threshold time (106).

2. The controller (110) as claimed in claim 1, wherein said activation time is monitored until said output voltage of the lambda sensor (112) crosses a dead band.

3. The controller (110) as claimed in claim 1, wherein said activation time is dependent on starting temperature of said engine (116).

4. The controller (110) as claimed in claim 1 measures starting temperature of said engine (116) and correspondingly selects the pre-determined threshold time (106).

5. The controller (110) as claimed in claim 1, wherein application of said voltage to said heater element (114) is initiated once pre-conditional checks are satisfied, said pre-conditions comprising reaching dew point of said lambda sensor (112), an exhaust temperature within a temperature range, and a battery voltage is within a voltage range.

6. A method for diagnosing a heater element (114) of a lambda sensor (112), said method comprising the steps of:
supplying a voltage to said heater element (114) of said lambda sensor (112);
monitoring activation time of said lambda sensor (112) based on output voltage of said lambda sensor (112), and
diagnosing said heater element (114) to be abnormal if said activation time is beyond a pre-determined threshold time (106).

7. The method as claimed in claim 6, wherein said activation time is monitored till said output voltage of the lambda sensor (112) crosses a dead band.

8. The method as claimed in claim 6, wherein said activation time is dependent on starting temperature of an engine (116).

9. The method as claimed in claim 6 comprises measuring starting temperature of said engine (116) and correspondingly selecting said pre-determined threshold time (106).

10. The method as claimed in claim 6, wherein supplying said voltage to said heater element (114) is initiated after satisfying pre-conditional checks, said pre-conditional checks comprises reaching dew point of said lambda sensor (112), an exhaust temperature within a temperature range, and a battery voltage is within a voltage range.