Faults in a sensor (10) are detected by excess rate fault determination by taking the differentiated (58, 107), rate limited (60, 100, 111) integral (64, 112) from the raw sensor output (72, 113) and indicating a fault (15, 117) in the event that the difference exceeds a predetermined magnitude (76,...http://www.google.com.hk/patents/US4337516?utm_source=gb-gplus-share專利 US4337516 - Sensor fault detection by activity monitoring
