Air/fuel ratio manipulation code for optimizing dynamic emissions

A method for achieving targeted concentrations of tailpipe emissions produced by an internal combustion engine equipped with at least one catalytic converter and an ECU for controlling the operation of the engine comprising the steps of:

• a) providing i) a secondary controller for developing actuator signals for controlling a specific engine operation affecting emissions generated by the engine instead of the ECU, ii) an emission analyzer for generating control instructions inputted to the secondary controller which the secondary controller uses to develop the actuator signals, and iii) a bench gas analyzer for analyzing selected engine and tailpipe emission components which is inputted to the emission analyzer;
• b) monitoring selected vehicle sensor signals generated by the vehicle during a specified drive cycle which affect the actuator signals to generate a control map having a control parameter correlated to a number of sensed engine operating conditions with the secondary controller additionally generating actuator signals for the range of control parameters recorded in the control map to replicate the ECU actuator signals whereby the secondary controller is able to interpolate the control map and duplicate the ECU actuator signals;
• c) generating at least one emissions map by the emissions analyzer from emission data collected from the vehicle's sensors including emission sensors and the bench gas analyzer including bench emission sensors with the emissions map correlating the emissions with at least one engine operating parameter and the control parameter used in generating the control map;
• d) modifying the control parameter values for those engine operating parameter values which produced maximum emissions in the emission map to reduce emissions;
• e) changing the control parameter in the control map to the values set in the modified emission map;
• f) inputting the modified control map to the secondary controller and repeating the drive cycle under control of secondary controller;
• and
• g) repeating steps c, d, e and f until emissions generated by the engine have reached desired levels.

A system for achieving targeted tailpipe emissions produced by an internal combustion engine having a catalytic converter system and an ECU for controlling the operation of said engine, said system comprising:

• a) a secondary controller for selectively controlling at least one engine operation in place of the ECU controlling said one engine operation, said ECU continuing to control all other engine operations;
• said secondary controller including i) means for monitoring vehicular sensor input signals and actuator signals generated by the ECU when controlling said one engine operation in response to said vehicular sensor input signals, ii) means to generate a control map from data acquired from said monitoring means which at any given time during a drive cycle correlates a control parameter for controlling said one engine operation in response to at least one selected vehicle sensor indicating a sensed operating condition of said engine, iii) means to generate an actuator signal controlling said one engine operation with said control parameter and iv) means for modifying said control map in response to instructions from an outside source;
• b) a bench gas analyzer having a plurality of gas sensors for sensing specific emission compounds in the engine and tailpipe exhaust and including timing means associated with said bench gas analyzer for correlating sensed emission compounds in the exhaust gas with specific drive cycle intervals as well as total emissions sensed during the drive cycle;
• and
• c) an emissions analyzer including a CPU and associated memory receiving vehicle sensor input signals and bench gas analyzer signals and generating map modification instructions to said secondary controller, said emissions analyzer including i) means to monitor said vehicle sensor signals to generate said control map;
• ii) means to generate at least one emission map from vehicle emission sensor data and bench gas analyzer data which at any given time during a drive cycle correlates sensed vehicle emissions with said control parameter and said at least one selected operating condition sensed by said vehicle sensor;
• iii) means to modify said control parameter in said control map at selected operating conditions where emissions recorded on said emission map exceed a set limit;
• and iv) means to input said modified control parameter map as instructions to said secondary controller's means for modifying.