초록 ▼

A method of minimizing torque disturbances in an internal combustion engine for a vehicle having a lean NOx trap that is periodically purged. The method includes the steps of generating feedforward values of first engine characteristics as a function of desired engine torque and generating feedback

A method of minimizing torque disturbances in an internal combustion engine for a vehicle having a lean NOx trap that is periodically purged. The method includes the steps of generating feedforward values of first engine characteristics as a function of desired engine torque and generating feedback values of second engine characteristics as a function of intake manifold pressure. Target values are then calculated for predetermined engine variables based on the first and second engine characteristics. Engine variables are then set to the target values to compensate for torque disturbances resulting from the lean NOx trap purge cycle. According to the disclosed method, the feedforward path schedules the throttle, fuel rate and spark timing based on an engine model to produce a demanded engine torque. The feedback path then uses the values of fuel rate and spark timing to compensate for torque variations. This is accomplished by determining an error term as a function of a reference trajectory intake manifold pressure and measured intake manifold pressure.

대표청구항 ▼

[ What is claimed is:] [1.]1. A method of minimizing torque disturbances in an internal combustion engine for a vehicle having a lean NOx trap that is periodically purged, said method comprising the steps of:determining a first setpoint for predetermined engine characteristics based on a feedforward

[ What is claimed is:] [1.]1. A method of minimizing torque disturbances in an internal combustion engine for a vehicle having a lean NOx trap that is periodically purged, said method comprising the steps of:determining a first setpoint for predetermined engine characteristics based on a feedforward control scheme;determining a second setpoint for predetermined engine characteristics based on a feedback control scheme;generating target values for predetermined engine variables based on said first and second setpoints; andsetting said engine variables to said target values to compensate for torque disturbances resulting from said lean NOx trap purge cycle.