Abstract: A urea injection control system (10) for a vehicle having an exhaust line (16) in fluid communication with a SCR catalyst (18) and a urea injector (14) for injecting urea into the exhaust line includes a controller (12) for controlling the flow rate of urea injection at the urea injector. The controller (12) compares an optimum urea flow rate (20) with a flexible urea flow rate (22) determined by a flexible flow rate calculator. The controller (12) selects the minimum value of the optimum urea flow rate (20) and the flexible urea flow rate (22), and controls the urea injector (14) to inject urea at the minimum value.

Abstract: An algorithm (26) in an engine control system (14) develops data indicative of pressure across a DPF (20) as a function of time and data indicative of flow rate through the DPF as a function of time, calculates derivatives (32, 30) (38, 36) with respect to time of the data, processes the derivatives (44, 42, 50, 48, 56, 54, 58) to confirm validity of a calculation of particulate loading of the DPF (load_pf) when a result of processing the derivatives discloses the absence of transient conditions in the DPF that would prevent the calculation from being valid and to not confirm validity of a calculation of particulate loading of the DPF when a result of processing the derivatives discloses the presence of transient conditions in the DPF that would prevent the calculation from being valid.

Abstract: A method for regenerating a diesel particulate filter (20) in the exhaust system (16) of an engine (12). When a request to regenerate the device is issued, a control system (14) operates the engine to begin conditioning exhaust. The conditioning process comprises a warming phase that occurs prior to initiation of regeneration and a heating phase during which regeneration can occur. During the process, data related to the warming phase and the heating phase is evaluated. The engine is operated to terminate the process prior to having reduced the amount of trapped particulate matter to a target amount when evaluation of the data discloses that the process should be terminated.

Abstract: A method for regenerating a diesel particulate filter (20) in the exhaust system (16) of an engine (12). When a request to regenerate the device is issued, a control system (14) operates the engine to begin conditioning exhaust. The conditioning process comprises a warming phase that occurs prior to initiation of regeneration and a heating phase during which regeneration can occur. During the process, data related to the warming phase and the heating phase is evaluated. The engine is operated to terminate the process prior to having reduced the amount of trapped particulate matter to a target amount when evaluation of the data discloses that the process should be terminated.

Abstract: An algorithm (26) in an engine control system (14) develops data indicative of pressure across a DPF (20) as a function of time and data indicative of flow rate through the DPF as a function of time, calculates derivatives (32, 30) (38, 36) with respect to time of the data, processes the derivatives (44, 42, 50, 48, 56, 54, 58) to confirm validity of a calculation of particulate loading of the DPF (load_pf) when a result of processing the derivatives discloses the absence of transient conditions in the DPF that would prevent the calculation from being valid and to not confirm validity of a calculation of particulate loading of the DPF when a result of processing the derivatives discloses the presence of transient conditions in the DPF that would prevent the calculation from being valid.