초록 ▼

An engine control system ( 22 ) of a diesel engine ( 20 ) that powers a motor vehicle processes data in execution of a strategy (FIG. 4 ) to provide control of both timing and duration of forced regeneration of a diesel particulate filter ( 42 ). The overall strategy is a hybrid of model-based and c

An engine control system ( 22 ) of a diesel engine ( 20 ) that powers a motor vehicle processes data in execution of a strategy (FIG. 4 ) to provide control of both timing and duration of forced regeneration of a diesel particulate filter ( 42 ). The overall strategy is a hybrid of model-based and closed-loop control strategies. Redundant elements of the strategy (FIG. 6 ) determine when forced regeneration is called for. Forced regeneration is initiated by retarding the timing of the start of main fuel injection ( 100 ). Fueling is then adjusted ( 98 ) both to enhance catalytic action and to make the process transparent to a driver of the vehicle.

대표청구항 ▼

1. A method of imposing a forced regeneration cycle on a diesel particulate filter that treats exhaust gas passing through an exhaustsystem of a turbocharged diesel engine to force regeneration of the filter, the method comprising:during engine running time, repeatedly processing data that represent

1. A method of imposing a forced regeneration cycle on a diesel particulate filter that treats exhaust gas passing through an exhaustsystem of a turbocharged diesel engine to force regeneration of the filter, the method comprising:during engine running time, repeatedly processing data that represents engine speed, data that represents engine fueling, data that represents turbocharger boost, and data that represents exhaust gas recirculation (EGR) from the exhaust system back into the engine, through an engine emissions model to yield values representing rates at which diesel particulate matter (DPM) from the engine is entering the exhaust system and values for NO x concentration in the exhaust gas;repeatedly processing the values for NO x concentration in the exhaust gas, values representing concentration of O 2 in the exhaust gas entering the filter, and values representing temperature of exhaust gas entering the filter through a DPM oxidation model to yield values of DPM oxidation rate data representing the rate at which DPM is being oxidized in the exhaust system;repeatedly processing the values of DPM oxidation rate data and the values representing a rate at which DPM from the engine is entering the exhaust system data through a DPM accumulation model to yield values of net DPM accumulation representing net accumulation of DPM in the filter at various points of time during engine running time;repeatedly processing accumulated engine running time through an ash accumulation model to yield data representing ash accumulation in the filter;repeatedly processing the values of net DPM accumulation and the data representing ash accumulation in the filter through regeneration initiating/terminating logic for commanding a forced regeneration cycle when a result of the latter processing calls for initiation of forced regeneration of the filter and for discontinuing the forced regeneration cycle when a subsequent result calls for termination of the forced regeneration cycle. 2. A method as set forth in claim 1 in which the step of repeatedly processing the values of DPM oxidation rate data and the values representing a rate at which DPM from the engine is entering the exhaust system data through a DPM accumulation model to yield values of net DPM accumulation representing net accumulation of DPM in the filter at various points of time during engine running time further comprises:also processing data representing DPM trapping efficiency of the filter and data representing effective geometric size of DPM trapping medium in the filter to yield values representing net DPM trapped in the filter per unit of geometric size of the DPM trapping medium. 3. A method as set forth in claim 2 in which the step of repeatedly processing the values of net DPM accumulation and the data representing ash accumulation in the filter through regeneration initiating/terminating logic for commanding a forced regeneration cycle when of a result of the latter processing calls for initiation of forced regeneration of the filter and for discontinuing the forced regeneration cycle when a subsequent result calls for termination of the forced regeneration cycle comprises:processing the values representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium and data distinguishing values of DPM trapped in the filter per unit of geometric size of the DPM trapping medium that call for forced regeneration of the filter from those that do not call for forced regeneration; andwhen a result of the latter processing discloses that a value of data representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium calls for regeneration of the filter, operating the engine in an elevated temperature mode of operation that elevates the exhaust gas temperature to a temperature for forcing regeneration of the filter, andwhen a subsequent result discloses that a value of data representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium does not call for regeneration of the filter, discontinuing operation of the engine in the elevated temperature mode of operation. 4. A method as set forth in claim 1 including executing a forced regeneration cycle in consequence of a command for a forced regeneration cycle, wherein the forced regeneration cycle comprises:providing engine fueling data representing engine fueling in the absence of forced regeneration of the filter;as the forced regeneration cycle progresses, repeatedly processing both baseline engine fueling data representing engine fueling at commencement of the forced regeneration cycle and engine speed data that represents engine speed according to a map that correlates values representing various timings for engine fueling during the forced regeneration cycle with both values of baseline engine fueling and values of engine speed to yield timing values for the timing of engine fueling as the forced regeneration cycle progresses;processing data representing light off temperature of catalytic material of the filter and data representing actual temperature of the catalytic material, as the forced regeneration cycle progresses, to yield adjustment values for adjusting the timing values;processing the adjustment values and the timing values to yield adjusted timing values for the timing of engine fueling during the forced regeneration cycle;processing the adjusted timing values and the engine speed data according to a map that correlates fueling modification values with both the adjusted timing values and values of engine speed to yield fueling modification values;processing the engine fueling data and the fueling modification values to yield adjusted fueling values;using the adjusted fueling values instead of the engine fueling data for fueling the engine during the forced regeneration cycle; andusing the adjusted timing values for the timing of engine fueling during the forced regeneration cycle. 5. A method as set forth in claim 1 including the further steps of:executing a forced regeneration cycle in consequence of a command for a forced regeneration cycle, wherein the forced regeneration cycle comprises elevating the exhaust gas temperature to a temperature for forcing regeneration of the filter; andduring elevation of the exhaust gas temperature, regulating boost of a turbocharger that is powered by engine exhaust gas to deliver charge air to the engine to counteract the full effect of the elevation of exhaust gas temperature on turbocharger boost. 6. A method of imposing a forced regeneration cycle on a diesel particulate filter that treats exhaust gas passing through an exhaust system of a diesel engine to force regeneration of the filter, the method comprising:providing engine fueling data representing engine fueling in the absence of forced regeneration of the filter;during engine running time, repeatedly processing data that represents parameters useful in determining a rate at which diesel particulate matter (DPM) is accumulating in the filter through a DPM accumulation model to yield values of DPM accumulation representing accumulation of DPM in the filter at various points of time during engine running time;processing the values of DPM accumulation and data that distinguishes DPM accumulation values calling for forced regeneration of the filter from those not calling for forced regeneration of the filter;when a result of the latter processing discloses that a DPM accumulation value calls for forced regeneration of the filter, initiating forced regeneration by retarding the timing of engine fueling to elevate the exhaust gas temperature to a temperature for forcing regeneration of the filter;as the forced regeneration cycle progresses, repeatedly processing baseline engine fueling data representing engine fueling at commencement of the forced regeneration cycle, engine speed data that represents engine speed, data representing light off temperature of cat alytic material of the filter, and data representing actual temperature of the catalytic material, to yield adjusted timing values for timing of engine fueling and fueling modification values;processing the engine fueling data and the fueling modification values to yield adjusted fueling values;using the adjusted fueling values instead of the engine fueling data for fueling the engine during the forced regeneration cycle; andusing the adjusted timing values for the timing of engine fueling during the forced regeneration cycle. 7. A method of imposing a forced regeneration cycle on a diesel particulate filter that treats exhaust gas passing through an exhaust system of a diesel engine to force regeneration of the filter, the method comprising:providing engine fueling data representing engine fueling in the absence of forced regeneration of the filter;during engine running time, repeatedly processing data that represents temperature of exhaust gas entering the filter, data that represents exhaust gas flow entering the filter, and data that utilizes both exhaust gas temperature and flow to distinguish a filter that has trapped an amount of diesel particulate matter (DPM) calling for forced regeneration from a filter that does not call for forced regeneration to yield result data that a) calls for forced regeneration of the filter when the data that represents temperature of exhaust gas entering the filter and the data that represents exhaust gas flow entering the filter disclose that the filter has trapped an amount of DPM calling for forced regeneration, and b) calls for no forced regeneration when the data that represents temperature of exhaust gas entering the filter and the data that represents exhaust gas flow entering the filter disclose that the filter does not call for regeneration;when the result data calls for forced regeneration of the filter, initiating forced regeneration by retarding the timing of engine fueling to elevate the exhaust gas temperature to a temperature for forcing regeneration of the filter;as the forced regeneration cycle progresses, repeatedly processing, baseline engine fueling data representing engine fueling at commencement of the forced regeneration cycle, engine speed data that represents engine speed, data representing light off temperature of catalytic material of the filter, and data representing actual temperature of the catalytic material, to yield adjusted timing values for timing of engine fueling and fueling modification values;processing the engine fueling data and the fueling modification values to yield adjusted fueling values;using the adjusted fueling values instead of the engine fueling data for fueling the engine during the forced regeneration cycle; andusing the adjusted timing values for the timing of engine fueling during the forced regeneration cycle. 8. A method of imposing a forced regeneration cycle on a diesel particulate filter that treats exhaust gas passing through an exhaust system of a diesel engine to force regeneration of the filter, the method comprising:during engine running time, repeatedly processing data that represents a rate at which diesel particulate matter (DPM) from the engine is entering the exhaust system, data that represents a rate at which DPM is being oxidized in the exhaust system, and data that represents DPM trapping efficiency of the filter, to yield values representing net rate at which DPM is being trapped in the filter at various points of times during the engine running time;processing the values representing net rate at which DPM is being trapped in the filter and data representing effective geometric size of DPM trapping medium in the filter to yield values representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium;processing the values representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium and data distinguishing values of DPM trapped in the filter per unit of geomet ric size of the DPM trapping medium that call for forced regeneration of the filter from those that do not call for forced regeneration; andwhen a result of the latter processing discloses that a value of data representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium calls for regeneration of the filter, operating the engine in an elevated temperature mode of operation that elevates the exhaust gas temperature to a temperature for forcing regeneration of the filter, andwhen a subsequent result discloses that a value of data representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium does not call for regeneration of the filter, discontinuing operation of the engine in the elevated temperature mode of operation. 9. A method as set forth in claim 8 including the further steps of:during engine running time, repeatedly processing data that represents temperature of exhaust gas entering the filter, data that represents exhaust gas flow entering the filter, and data that utilizes both exhaust gas temperature and flow to distinguish a filter that has trapped an amount of DPM calling for forced regeneration from a filter that does not call for forced regeneration to yield additional data that a) calls for forced regeneration of the filter when the data that represents temperature of exhaust gas entering the filter and the data that represents exhaust gas flow entering the filter disclose that the filter has trapped an amount of DPM calling for forced regeneration, and b) calls for no forced regeneration when the data that represents temperature of exhaust gas entering the filter and the data that represents exhaust gas flow entering the filter disclose that the filter does not call for regeneration; andwhen the additional data calls for forced regeneration of the filter in the absence of a call for forced regeneration resulting from processing the values representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium and data distinguishing values of DPM trapped in the filter per unit of geometric size of the DPM trapping medium, operating the engine in the elevated temperature mode of operation, andwhen subsequent additional data calls for no forced regeneration of the filter in the absence of a call for forced regeneration resulting from processing the values representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium and data distinguishing values of DPM trapped in the filter per unit of geometric size of the DPM trapping medium, discontinuing operating the engine in the elevated temperature mode of operation. 10. A method as set forth in claim 8 wherein:the step of processing the values representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium and data distinguishing values of DPM trapped in the filter per unit of geometric size of the DPM trapping medium that call for forced regeneration of the filter from those that do not call for forced regeneration comprises a) comparing values representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium and an upper limit of accumulation and b) comparing values representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium and a lower limit of accumulation; andwhen comparison of values representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium and the upper limit of accumulation discloses that a value of data representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium is greater than the upper limit of accumulation, operating the engine in the elevated temperature mode of operation, andwhen comparison of values representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium and the lower limit of accumulation discloses that a value of data representing DPM trapped in the fil ter per unit of geometric size of the DPM trapping medium is less than the lower limit of accumulation, discontinuing operating the engine in the elevated temperature mode of operation. 11. A method of imposing a forced regeneration cycle on a diesel particulate filter that treats exhaust gas passing through an exhaust system of a diesel engine to force regeneration of the filter, the method comprising:during engine running time, repeatedly processing data for a first set of engine operating parameters to yield values representing amounts of accumulation of diesel particulate matter (DPM) in the filter at various points of times during the engine running time;during engine running time, repeatedly processing data for a second set of engine operating parameters different from the first set of engine operating parameters to yield values representing amounts of accumulation of DPM in the filter at various points of times during the engine running time;when the processing of data for one of the first and second sets of engine operating parameters discloses a value calling for regeneration of the filter, operating the engine in a mode of operation for forcing regeneration of the filter; andwhen a value resulting from subsequent processing of data for the one set of engine operating parameters discloses an amount of accumulation of DPM in the filter does not call for regeneration of the filter, discontinuing that mode of operation. 12. A method as set forth in claim 11 wherein:the step of repeatedly processing data for a first set of engine operating parameters to yield values representing amounts of accumulation of DPM in the filter at various points of times during the engine running time comprises repeatedly processing data that includes a rate at which DPM from the engine is entering the exhaust system, a rate at which DPM is being oxidized in the exhaust system, and DPM trapping efficiency of the filter, to yield values representing net amounts of accumulation of DPM in the filter per unit of geometric size of DPM trapping medium in the filter at various points of times during the engine running time; andthe step of repeatedly processing data for a second set of engine operating parameters different from the first set of engine operating parameters to yield values representing amounts of accumulation of diesel particulate matter (DPM) in the filter at various points of times during the engine running time comprises processing data that represents temperature of exhaust gas entering the filter, data that represents exhaust gas flow entering the filter, and data that utilizes both exhaust gas temperature and flow to distinguish a filter that has trapped an amount of diesel particulate matter (DPM) calling for forced regeneration from a filter that does not call for forced regeneration. 13. A method of imposing a forced regeneration cycle on a diesel particulate filter that treats exhaust gas passing through an exhaust system of a diesel engine to force regeneration of the filter, the method comprising:providing engine fueling data representing engine fueling in the absence of forced regeneration of the filter;as the forced regeneration cycle progresses, repeatedly processing both baseline engine fueling data representing engine fueling at commencement of the forced regeneration cycle and engine speed data that represents engine speed according to a map that correlates values representing various timings for engine fueling during the forced regeneration cycle with both values of baseline engine fueling and values of engine speed to yield timing values for the timing of engine fueling as the forced regeneration cycle progresses;processing data representing light off temperature of catalytic material of the filter and data representing actual temperature of the catalytic material, as the forced regeneration cycle progresses, to yield adjustment values for adjusting the timing values;processing the adjustment values and the timing va lues to yield adjusted timing values for the timing of engine fueling during the forced regeneration cycle;processing the adjusted timing values and the engine speed data according to a map that correlates fueling modification values with both the adjusted timing values and values of engine speed to yield fueling modification values;processing the engine fueling data and the fueling modification values to yield adjusted fueling values;using the adjusted fueling values instead of the engine fueling data for fueling the engine during the forced regeneration cycle; andusing the adjusted timing values for the timing of engine fueling during the forced regeneration cycle. 14. A method as set forth in claim 13 wherein the step of processing data representing light off temperature of catalytic material of the filter and data representing actual temperature of the catalytic material, as the forced regeneration cycle progresses, to yield adjustment values for adjusting the timing values comprises:rate limiting the data representing light off temperature of catalytic material of the filter to yield a succession of values that, over a span of time, progressively approach, and finally arrive at, a value representing the light off temperature;processing the succession of values and the data representing actual temperature of the catalytic material, as the forced regeneration cycle progresses, to yield error data; andprocessing the error data through a P-I-D function that performs one of more of proportional, derivative, and integral functions on the error data to yield the adjustment values for adjusting the timing values. 15. A method as set forth in claim 14 wherein the step of processing the adjustment values and the timing values to yield adjusted timing values for the timing of engine fueling during the forced regeneration cycle comprises:algebraically summing the adjustment values and the timing values to yield a succession of sums, and then rate limiting the succession of sums to yield the adjusted timing values. 16. A method as set forth in claim 13 wherein the step of processing the adjustment values and the timing values to yield adjusted timing values for the timing of engine fueling during the forced regeneration cycle comprises:algebraically summing the adjustment values and the timing values to yield a succession of sums, and then rate limiting the succession of sums to yield the adjusted timing values. 17. A method for developing diesel particulate matter (DPM) oxidation rate data representing the rate at which DPM in diesel engine exhaust gas is being oxidized during passage through an exhaust system of a diesel engine that includes a diesel particulate filter that treats the exhaust gas, the method comprising:during engine running time, repeatedly processing data that represents parameters useful in determining the concentration of NO x in exhaust gas entering the exhaust system from the engine to yield NO x concentration data for NO x concentration in the exhaust gas; andrepeatedly processing a) the NO x concentration data, b) data representing concentration of O 2 in the exhaust gas entering the filter, c) data representing temperature of exhaust gas entering the filter, and d) data for developing DPM oxidation rate data from NO x concentration data, O 2 concentration data, and exhaust gas temperature data, to yield values of DPM oxidation rate data representing the rate at which DPM is being oxidized in the exhaust system. 18. A turbocharged diesel engine comprising:an exhaust system comprising a diesel particulate filter that treats exhaust gas from the engine; anda control system for imposing a forced regeneration cycle on the diesel particulate filter to force regeneration of the filter, wherein the control system comprises a processor thata) during engine running time, repeatedly processes data that represents engine speed, data that represents engine fueling, data that represents turbocharger boost, and data that represents exhaust gas recirculation (EGR) from the exhaust system back into the engine, through an engine emissions model to yield values representing rates at which diesel particulate matter (DPM) from the engine is entering the exhaust system and values for NO x concentration in the exhaust gas,b) repeatedly processes the values for NO x concentration in the exhaust gas, values representing concentration of O 2 in the exhaust gas entering the filter, and values representing temperature of exhaust gas entering the filter through a DPM oxidation model to yield values of DPM oxidation rate data representing the rate at which DPM is being oxidized in the exhaust system,c) repeatedly processes the values of DPM oxidation rate data and the values representing a rate at which DPM from the engine is entering the exhaust system data through a DPM accumulation model to yield values of net DPM accumulation representing net accumulation of DPM in the filter at various points of time during engine running time,d) repeatedly processes accumulated engine running time through an ash accumulation model to yield data representing ash accumulation in the filter, ande) repeatedly processes the values of net DPM accumulation and the data representing ash accumulation in the filter through regeneration initiating/terminating logic for commanding a forced regeneration cycle when a result of the latter processing calls for initiation of forced regeneration of the filter and for discontinuing the forced regeneration cycle when a subsequent result calls for termination of the forced regeneration cycle. 19. An engine as set forth in claim 18 in which the processor's processing of the values of DPM oxidation rate data and the values representing a rate at which DPM from the engine is entering the exhaust system data through a DPM accumulation model to yield values of net DPM accumulation representing net accumulation of DPM in the filter at various points of time during engine running time also comprises processing data representing DPM trapping efficiency of the filter and data representing effective geometric size of DPM trapping medium in the filter to yield values representing net DPM trapped in the filter per unit of geometric size of the DPM trapping medium. 20. An engine as set forth in claim 19 in which the processor's processing of the values of net DPM accumulation and the data representing ash accumulation in the filter through regeneration initiating/terminating logic for commanding a forced regeneration cycle when of a result of the latter processing calls for initiation of forced regeneration of the filter and for discontinuing the forced regeneration cycle when a subsequent result calls for termination of the forced regeneration cycle comprises processing the values representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium and data distinguishing values of DPM trapped in the filter per unit of geometric size of the DPM trapping medium that call for forced regeneration of the filter from those that do not call for forced regeneration, and when a result of the latter processing discloses that a value of data representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium calls for regeneration of the filter, causes the engine to operate in an elevated temperature mode of operation that elevates the exhaust gas temperature to a temperature for forcing regeneration of the filter, and when a subsequent result discloses that a value of data representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium does not call for regeneration of the filter, causes discontinuance of the operation of the engine in the elevated temperature mode of operation. 21. An engine as set forth in claim 18 in which the processor causes the engine to execute a forced regeneration cycle in consequence of a command for a forced regeneration cycle, and as the forced r egeneration cycle progresses, the processora) repeatedly processes both baseline engine fueling data representing engine fueling at commencement of the forced regeneration cycle and engine speed data that represents engine speed according to a map that correlates values representing various timings for engine fueling during the forced regeneration cycle with both values of baseline engine fueling and values of engine speed to yield timing values for the timing of engine fueling as the forced regeneration cycle progresses,b) repeatedly processes both baseline engine fueling data representing engine fueling at commencement of the forced regeneration cycle and engine speed data that represents engine speed according to a map that correlates values representing various timings for engine fueling during the forced regeneration cycle with both values of baseline engine fueling and values of engine speed to yield timing values for the timing of engine fueling as the forced regeneration cycle progresses,c) processes data representing light off temperature of catalytic material of the filter and data representing actual temperature of the catalytic material, as the forced regeneration cycle progresses, to yield adjustment values for adjusting the timing values,d) processes the adjustment values and the timing values to yield adjusted timing values for the timing of engine fueling during the forced regeneration cycle,e) processes the adjusted timing values and the engine speed data according to a map that correlates fueling modification values with both the adjusted timing values and values of engine speed to yield fueling modification values,f) processes engine fueling data representing engine fueling in the absence of forced regeneration of the filter and the fueling modification values to yield adjusted fueling values,g) causes the adjusted fueling values instead of the engine fueling data to be used for fueling the engine during the forced regeneration cycle, andh) causes the adjusted timing values to be used for the timing of engine fueling during the forced regeneration cycle. 22. An engine as set forth in claim 1 in which the processor, in consequence of a command for a forced regeneration cycle, causes the engine to execute a forced regeneration cycle that comprises elevating the exhaust gas temperature to a temperature for forcing regeneration of the filter, and during elevation of the exhaust gas temperature, regulates boost of a turbocharger that is powered by engine exhaust gas to deliver charge air to the engine to counteract the full effect of the elevation of exhaust gas temperature on turbocharger boost. 23. A turbocharged diesel engine comprising:an exhaust system comprising a diesel particulate filter that treats exhaust gas from the engine; anda control system for imposing a forced regeneration cycle on the diesel particulate filter to force regeneration of the filter, wherein the control system comprises a processor thata) during engine running time, repeatedly processes data that represents parameters useful in determining a rate at which diesel particulate matter (DPM) is accumulating in the filter through a DPM accumulation model to yield values of DPM accumulation representing accumulation of DPM in the filter at various points of time during engine running time,b) processes the values of DPM accumulation and data that distinguishes DPM accumulation values calling for forced regeneration of the filter from those not calling for forced regeneration of the filter,c) when a result of the latter processing discloses that a DPM accumulation value calls for forced regeneration of the filter, initiates forced regeneration by retarding the timing of engine fueling to elevate the exhaust gas temperature to a temperature for forcing regeneration of the filter,d) as the forced regeneration cycle progresses, repeatedly processes baseline engine fueling data representing engine fueling at commencement of the forced regenerati on cycle, engine speed data that represents engine speed, data representing light off temperature of catalytic material of the filter, and data representing actual temperature of the catalytic material, to yield adjusted timing values for timing of engine fueling and fueling modification values;processes engine fueling data that represents engine fueling in the absence of forced regeneration of the filter and the fueling modification values to yield adjusted fueling values;causes the adjusted fueling values instead of the engine fueling data to be used for fueling the engine during the forced regeneration cycle; andcauses the adjusted timing values to be used for the timing of engine fueling during the forced regeneration cycle. 24. A turbocharged diesel engine comprising:an exhaust system comprising a diesel particulate filter that treats exhaust gas from the engine; anda control system for imposing a forced regeneration cycle on the diesel particulate filter to force regeneration of the filter, wherein the control system comprises a processor thata) during engine running time, repeatedly processes data that represents temperature of exhaust gas entering the filter, data that represents exhaust gas flow entering the filter, and data that utilizes both exhaust gas temperature and flow to distinguish a filter that has trapped an amount of diesel particulate matter (DPM) calling for forced regeneration from a filter that does not call for forced regeneration to yield result data that 1) calls for forced regeneration of the filter when the data that represents temperature of exhaust gas entering the filter and the data that represents exhaust gas flow entering the filter disclose that the filter has trapped an amount of DPM calling for forced regeneration, and 2) calls for no forced regeneration when the data that represents temperature of exhaust gas entering the filter and the data that represents exhaust gas flow entering the filter disclose that the filter does not call for regeneration,b) when the result data calls for forced regeneration of the filter, initiates forced regeneration by retarding the timing of engine fueling to elevate the exhaust gas temperature to a temperature for forcing regeneration of the filter,c) as the forced regeneration cycle progresses, repeatedly processes baseline engine fueling data representing engine fueling at commencement of the forced regeneration cycle, engine speed data that represents engine speed, data representing light off temperature of catalytic material of the filter, and data representing actual temperature of the catalytic material, to yield adjusted timing values for timing of engine fueling and fueling modification values,d) processes engine fueling data representing engine fueling in the absence of forced regeneration of the filter and the fueling modification values to yield adjusted fueling values,e) causes the adjusted fueling values instead of the engine fueling data to be used for fueling the engine during the forced regeneration cycle, andf) causes the adjusted timing values to be used for the timing of engine fueling during the forced regeneration cycle. 25. A turbocharged diesel engine comprising:an exhaust system comprising a diesel particulate filter that treats exhaust gas from the engine; anda control system for imposing a forced regeneration cycle on the diesel particulate filter to force regeneration of the filter, wherein the control system comprises a processor thata) during engine running time, repeatedly processes data that represents a rate at which diesel particulate matter (DPM) from the engine is entering the exhaust system, data that represents a rate at which DPM is being oxidized in the exhaust system, and data that represents DPM trapping efficiency of the filter, to yield values representing net rate at which DPM is being trapped in the filter at various points of times during the engine running time,b) processes the values representing net rate at which DPM is being trapped in the filter and data representing effective geometric size of DPM trapping medium in the filter to yield values representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium,c) processes the values representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium and data distinguishing values of DPM trapped in the filter per unit of geometric size of the DPM trapping medium that call for forced regeneration of the filter from those that do not call for forced regeneration, andd) when a result of the latter processing discloses that a value of data representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium calls for regeneration of the filter, causes the engine to operate in an elevated temperature mode of operation that elevates the exhaust gas temperature to a temperature for forcing regeneration of the filter, ande) when a subsequent result discloses that a value of data representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium does not call for regeneration of the filter, causes discontinuance of operation of the engine in the elevated temperature mode of operation. 26. An engine as set forth in claim 25 wherein the processora) during engine running time, repeatedly processes data that represents temperature of exhaust gas entering the filter, data that represents exhaust gas flow entering the filter, and data that utilizes both exhaust gas temperature and flow to distinguish a filter that has trapped an amount of DPM calling for forced regeneration from a filter that does not call for forced regeneration to yield additional data that 1) calls for forced regeneration of the filter when the data that represents temperature of exhaust gas entering the filter and the data that represents exhaust gas flow entering the filter disclose that the filter has trapped an amount of DPM calling for forced regeneration, and 2) calls for no forced regeneration when the data that represents temperature of exhaust gas entering the filter and the data that represents exhaust gas flow entering the filter disclose that the filter does not call for regeneration; andb) when the additional data calls for forced regeneration of the filter in the absence of a call for forced regeneration resulting from processing the values representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium and data distinguishing values of DPM trapped in the filter per unit of geometric size of the DPM trapping medium, causes the engine to operate in the elevated temperature mode of operation, andc) when subsequent additional data calls for no forced regeneration of the filter in the absence of a call for forced regeneration resulting from processing the values representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium and data distinguishing values of DPM trapped in the filter per unit of geometric size of the DPM trapping medium, causes discontinuance of operation of the engine in the elevated temperature mode of operation. 27. An engine as set forth in claim 25 wherein:a) the processor's processing of the values representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium and data distinguishing values of DPM trapped in the filter per unit of geometric size of the DPM trapping medium that call for forced regeneration of the filter from those that do not call for forced regeneration comprises 1) comparing values representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium and an upper limit of accumulation and 2) comparing values representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium and a lower limit of accumulation, andb) when comparison of values representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium and the u pper limit of accumulation discloses that a value of data representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium is greater than the upper limit of accumulation, the processor causes the engine to operate in the elevated temperature mode of operation, andc) when comparison of values representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium and the lower limit of accumulation discloses that a value of data representing DPM trapped in the filter per unit of geometric size of the DPM trapping medium is less than the lower limit of accumulation, the processor causes discontinuance of operation of the engine in the elevated temperature mode of operation. 28. A turbocharged diesel engine comprising:an exhaust system comprising a diesel particulate filter that treats exhaust gas from the engine; anda control system for imposing a forced regeneration cycle on the diesel particulate filter to force regeneration of the filter, wherein the control system comprises a processor thata) during engine running time, repeatedly processes data for a first set of engine operating parameters to yield values representing amounts of accumulation of diesel particulate matter (DPM) in the filter at various points of times during the engine running time,b) during engine running time, repeatedly processes data for a second set of engine operating parameters different from the first set of engine operating parameters to yield values representing amounts of accumulation of DPM in the filter at various points of times during the engine running time,c) when the processing of data for one of the first and second sets of engine operating parameters discloses a value calling for regeneration of the filter, causes the engine to operate in a mode of operation for forcing regeneration of the filter, andd) when a value resulting from subsequent processing of data for the one set of engine operating parameters discloses an amount of accumulation of DPM in the filter does not call for regeneration of the filter, cause discontinuance of that mode of operation. 29. An engine as set forth in claim 28 whereina) the processor's repeated processing of data for a first set of engine operating parameters to yield values representing amounts of accumulation of DPM in the filter at various points of times during the engine running time comprises repeatedly processing data that includes a rate at which DPM from the engine is entering the exhaust system, a rate at which DPM is being oxidized in the exhaust system, and DPM trapping efficiency of the filter, to yield values representing net amounts of accumulation of DPM in the filter per unit of geometric size of DPM trapping medium in the filter at various points of times during the engine running time, andb) the processor's repeated processing of data for a second set of engine operating parameters different from the first set of engine operating parameters to yield values representing amounts of accumulation of diesel particulate matter (DPM) in the filter at various points of times during the engine running time comprises processing data that represents temperature of exhaust gas entering the filter, data that represents exhaust gas flow entering the filter, and data that utilizes both exhaust gas temperature and flow to distinguish a filter that has trapped an amount of diesel particulate matter (DPM) calling for forced regeneration from a filter that does not call for forced regeneration. 30. A turbocharged diesel engine comprising:an exhaust system comprising a diesel particulate filter that treats exhaust gas from the engine; anda control system for imposing a forced regeneration cycle on the diesel particulate filter to force regeneration of the filter, wherein the control system comprises a processor thata) as the forced regeneration cycle progresses, repeatedly processes both baseline engine fueling data representing engine fueling at commencemen t of the forced regeneration cycle and engine speed data that represents engine speed according to a map that correlates values representing various timings for engine fueling during the forced regeneration cycle with both values of baseline engine fueling and values of engine speed to yield timing values for the timing of engine fueling as the forced regeneration cycle progresses,b) processes data representing light off temperature of catalytic material of the filter and data representing actual temperature of the catalytic material, as the forced regeneration cycle progresses, to yield adjustment values for adjusting the timing values,c) processes the adjustment values and the timing values to yield adjusted timing values for the timing of engine fueling during the forced regeneration cycle,d) processes the adjusted timing values and the engine speed data according to a map that correlates fueling modification values with both the adjusted timing values and values of engine speed to yield fueling modification values,e) processes engine fueling data representing engine fueling in the absence of forced regeneration of the filter and the fueling modification values to yield adjusted fueling values,f) causes the adjusted fueling values instead of the engine fueling data to be used for fueling the engine during the forced regeneration cycle, andg) causes the adjusted timing values to be used for the timing of engine fueling during the forced regeneration cycle. 31. An engine as set forth in claim 30 wherein as the forced regeneration cycle progresses, the processor's processing of data representing light off temperature of catalytic material of the filter and data representing actual temperature of the catalytic material to yield adjustment values for adjusting the timing values comprisesa) rate limiting the data representing light off temperature of catalytic material of the filter to yield a succession of values that, over a span of time, progressively approach, and finally arrive at, a value representing the light off temperature,b) processing the succession of values and the data representing actual temperature of the catalytic material, as the forced regeneration cycle progresses, to yield error data; andc) processing the error data through a P-I-D function that performs one of more of proportional, derivative, and integral functions on the error data to yield the adjustment values for adjusting the timing values. 32. An engine as set forth in claim 31 wherein the processor's processing of the adjustment values and the timing values to yield adjusted timing values for the timing of engine fueling during the forced regeneration cycle comprisesa) algebraically summing the adjustment values and the timing values to yield a succession of sums, and thenb) rate limiting the succession of sums to yield the adjusted timing values. 33. An engine as set forth in claim 30 wherein the processor's processing of the adjustment values and the timing values to yield adjusted timing values for the timing of engine fueling during the forced regeneration cycle comprisesa) algebraically summing the adjustment values and the timing values to yield a succession of sums, and thenb) rate limiting the succession of sums to yield the adjusted timing values. 34. A turbocharged diesel engine comprising:an exhaust system comprising a diesel particulate filter that treats exhaust gas from the engine; anda control system for imposing a forced regeneration cycle on the diesel particulate filter to force regeneration of the filter, wherein the control system comprises a processor thata) during engine running time, repeatedly processes data that represents parameters useful in determining the concentration of NO x in exhaust gas entering the exhaust system from the engine to yield NO x concentration data for NO x concentration in the exhaust gas; andb) repeatedly processing 1) the NO x concentration data, 2) data representing concentration of O 2 in the exhaust gas entering the filter, 3) data representing temperature of exhaust gas entering the filter, and 4) data for developing DPM oxidation rate data from NO x concentration data, O 2 concentration data, and exhaust gas temperature data, to yield values of DPM oxidation rate data representing the rate at which DPM is being oxidized in the exhaust system.