Duty cycle monitoring system for an engine

Abstract

A system and method for monitoring engine performance utilizes a monitoring micro-controller that integrates with an engine/vehicle controller to receive data indicative of the current operating conditions of the engine/vehicle. A duty cycle map is defined within the micro-controller by a plurality of sectors bounded by a specific performance curve based on two or more engine operating parameters, such as engine torque and speed. Each sector corresponds to a range of values for the specific operating parameters. During iterations of the monitoring routine, current data indicative of the specific engine operating parameters is sensed and compared with the range of values for each duty cycle sector. A duty cycle parameter, such as elapsed time or fuel consumption, is maintained for each sector. When the current engine operating conditions fall within a particular target sector, its corresponding duty cycle parameter is updated. This process is continued over several iterations to define a duty cycle map over a predetermined number of engine operating hours. In one embodiment, a long term map is accumulated between engine rebuilds, for example. In another embodiment, the long term duty cycle map is augmented by sequentially accessed short term maps, each storing duty cycle information for much shorter engine hours. The duty cycle maps can be used to evaluate engine maintenance requirements or suggest modifications to engine control routines and fueling strategies.