Diagnosis of the condition of a particle filter
AssigneeJaguar Land Rover Limited
InventorBrian Varney
Life of this patent
Estimating the term…
Abstract
An on-board diagnostic for a particle filter of a vehicle exhaust system records repeating data about flow and pressure around the particle filter. Data is recorded in virtual data bins having successive thresholds or filters within a numerical scale. Each data point is typically recorded in several bins to permit a rapid calculation of averaged data for use in the diagnostic. Sensitivity of less frequently recorded data is preserved, while giving quickly delivery of a result from the diagnostic.
Claims23
A method of performing a periodic diagnostic check on an exhaust particle filter in the exhaust of an internal combustion engine to detect a fault with the exhaust particle filter, the method comprising:
- defining, for each of one or more variable parameters of the exhaust particle filter, a plurality of thresholds of successively increasing value, each threshold corresponding to a data bin, each data bin having a trigger limit corresponding to a maximum sum of values placed in the data bin;
- continually measuring said one or more variable parameters at a pre-determined time interval to obtain successive values of said parameters;
- placing each obtained value in every data bin having a corresponding threshold that is lower than said value;
- for each data bin, continually summing the values placed in the data bin to determine a sum of the values placed in the data bin;
- for each data bin, when the sum of the values placed in the data bin reaches the trigger limit of the data bin, calculating an average value in the data bin;
- testing said average value against a pre-determined value indicative of a fault with the exhaust particle filter to determine if the average value is indicative of the fault with the exhaust particle filter;
- outputting an alert to a vehicle driver in response to determining that the average value is indicative of the fault with the exhaust particle filter;
- and
- clearing the data bin in which the trigger limit was reached for re-accumulation of successive values.
A method of performing a periodic diagnostic check on an exhaust particle filter in the exhaust of an internal combustion engine to detect a fault with the exhaust particle filter, the method comprising:
- defining, for each of one or more variable parameters of the exhaust particle filter, a plurality of thresholds of successively increasing value, each threshold corresponding to a digital filter;
- continually measuring said one or more variable parameters at a pre-determined time interval to obtain successive values of said parameters;
- for each successive value, passing the value through one or more of the digital filters having a corresponding threshold lower than said value;
- testing an output of said digital filter against a pre-determined value indicative of a fault with the exhaust particle filter to determine if the output of said digital filter is indicative of the fault with the exhaust particle filter, and
- outputting an alert to a vehicle driver in response to determining that the output of said digital filter is indicative of the fault with the exhaust particle filter.
Dependencies are inferred from the claim text.