US 4,383,441 A · Method for generating a table of engine calibration control values

Abstract

This specification discloses a method for generating a table of engine calibration control values for an adaptive spark and EGR control strategy. The adaptive strategy adjusts spark timing and magnitude of EGR as a function of engine energy usage per distance traveled while maintaining feedgas emissions at a constant level over a wide variety of driving patterns including urban, suburban and highway. This adaptive strategy has advantageous fuel consumption characteristics which are greatest at the most constrained feedgas levels. Drivability can be enhanced because of the greater calibration flexibility inherent to the adaptive technique.

Claims12

Dependent claims

A method for generating a table of spark advance and percent EGR for use by an adaptive vehicle control system having a target emission value, said method comprising:

generating a plurality of vehicle driving cycle segments relating vehicle speed with time;
associating vehicle speed versus time coordinates of a vehicle driving cycle segment with corresponding points of a discrete engine matrix of engine load versus engine speed thus describing engine operation during a driving cycle segment;
determining for each vehicle driving cycle, at each point of the discrete engine matrix, an optimal calibration of engine control variables including percent EGR and spark advance so that fuel economy is maximized at the selected target emission value;
calculating for each vehicle driving segment one energy density representative of energy usage divided by distance traveled during the vehicle driving segment;
correlating each point on the discrete engine matrix of a driving cycle segment with the energy density of the driving cycle segment;
and
eliminating all but one when there is a plurality of the optimal calibrations of engine control variables associated with a point of a discrete engine matrix as a result of having a plurality of vehicle driving cycle segments to obtain a suggested tag group of engine control variables to be used with the associated energy density thereby defining each suggested tag group of engine control variables as a point on a three dimensional matrix having axes of energy, engine torque and engine speed.

4 more elements

Dependencies are inferred from the claim text.

Method for generating a table of engine calibration control values

Life of this patent

Method for generating a table of engine calibration control values

Life of this patent

Abstract

Claims12