Methods and apparatus are provided which generate an error signal if a sensor is either anticipated to fail or fails. At least two sensors provide input signals having magnitudes that approximately correspond to a sensed event. A processor calculates an actual correlation error for the two signals. A...http://www.google.com/patents/US7228249?utm_source=gb-gplus-sharePatent US7228249 - Methods and apparatus for determining the condition of a sensor and identifying the failure thereof
