Purge Valve Blockage Detection Using Statistical Signal Processing

The patent applies periodic action by commanding a series of opening and closing cycles of the purge valve during normal engine operation rather than requiring continuous idle running. The ECU performs multiple test cycles where the purge valve is alternately opened and closed, allowing fault detection through periodic measurement of engine parameters such as torque, engine speed, and inlet pressure variations during these cycles.

The patent utilizes parameter changes by monitoring variations in engine operating parameters (torque, engine speed, inlet pressure, mixture richness) that occur when the purge valve state changes. The system detects faults by analyzing whether these parameters vary beyond predetermined thresholds in response to purge valve actuation, enabling accurate fault detection without requiring the engine to run at idle.

The patent implements preliminary action by performing purge valve fault detection during normal engine operation before the vehicle is parked or before idle periods would naturally occur. The ECU integrates the fault detection function into the regular engine control routine, allowing validation of purge valve operation to be completed as part of normal driving cycles rather than requiring separate dedicated idle testing periods.

The patent ensures continuity of useful action by enabling purge valve detection to occur during normal engine operation across various operating conditions. The system can continuously monitor and detect purge valve faults during regular driving without interrupting the vehicle's useful operation, thereby maintaining both detection reliability and minimizing time loss.