초록 ▼

A system and method is provided for controlling noxious emissions, such as NOx, from an internal combustion engine. The invention utilizes a closed loop and an open loop control algorithm to control one or more compensating levers, each compensating lever corresponding to a controllable engine opera

A system and method is provided for controlling noxious emissions, such as NOx, from an internal combustion engine. The invention utilizes a closed loop and an open loop control algorithm to control one or more compensating levers, each compensating lever corresponding to a controllable engine operating parameter that when changed yields a change in the NOx emissions. In the closed loop control approach, the mass flow rate of the NOx is compared to a predetermined threshold to obtain a delta value. This delta value is applied through a PID controller to generate a corresponding change in one or more compensating levers. In the open loop portion, predetermined relationships are generated between one or more compensating levers and changes in a measure of the noxious emissions. Current values for one or more of the levers are compared against nominal values, and the change in these values are evaluated using predetermined relationships to produce a number of NOx delta values. These NOx delta values can be combined into a composite delta value that is applied to the inverse of the predetermined relationship for one of the compensating levers to determine a change command for that lever.

대표청구항 ▼

1. A method for controlling an internal combustion engine to minimize the exhaust of NOx arising from the combustion of fuel in the engine, comprising the steps of:generating a plurality of command inputs for controlling the combustion of fuel in the engine; acquiring data from sensors indicative of

1. A method for controlling an internal combustion engine to minimize the exhaust of NOx arising from the combustion of fuel in the engine, comprising the steps of:generating a plurality of command inputs for controlling the combustion of fuel in the engine; acquiring data from sensors indicative of operating conditions of the engine; using the data to measure a mass flow rate of NOx in the exhaust; determining a delta value equal to the difference between the measure of the mass flow rate of NOx and a reference value; generating a closed loop command value to change a pre-determined one of the command inputs according to a pre-determined relationship correlating the delta value to changes in the pre-determined one of the command inputs to reduce that difference; modifying the pre-determined one of the command inputs by the closed loop command value; and providing the plurality of command inputs, including the modified one of the inputs, to a controller operable to control the combustion of fuel in the engine.