Sensing Combustion Misfire Events in Engines by Comparing Signals Derived From Two Different Types of Oxygen Sensors

A combustion misfire sensor assembly for monitoring for a combustion misfire in an internal combustion engine with continual periodic combustion events, the assembly comprising:

• a first oxygen sensor configured to be disposed in an exhaust plenum of the engine;
• wherein the first oxygen sensor is a resistive-based oxygen sensor comprising:
• a metal oxide semiconductor layer bridging a gap between first and second electrodes;
• and
• a porous protective layer covering the metal oxide semiconductor layer;
• a second oxygen sensor configured to be disposed in the exhaust plenum in proximity to the first oxygen sensor;
• wherein the second oxygen sensor is a voltaic-based or ampometric-based oxygen sensor;
• processing circuitry operatively connected to the first and second oxygen sensors and configured to:
• monitor for a combustion misfire by comparing a first combustion signal and a second combustion signal;
• wherein the first combustion signal is derived from the first oxygen sensor and indicates an exhaust state of the engine based on a time-varying resistance of the first oxygen sensor;
• wherein the second combustion signal is derived from the second oxygen sensor and indicates the exhaust state of the engine based on a time-varying response of the second oxygen sensor;
• and
• wherein the first oxygen sensor has a first response time for detecting a change in temperature and/or oxygen content of exhaust gases in the exhaust plenum that is at least twice as fast as a second response time of the second oxygen sensor for detecting the same change in temperature and/or oxygen content of exhaust gases in the exhaust plenum.