A Self-Validating Pressure Sensor

A new prototype of self-validating pressure sensor is described. The elastic body of the transducer is based on circular-flat diaphragm structure. Eight groups of strain gauges are distributed on the diaphragm. One group of metal strain gauge with little temperature drift is used as primary pressure sensor, the other seven groups of semiconductor strain gauges with high sensitivity are used as calibration references. Consistency checking is used to detect sensor fault. The outputs of self-validating pressure sensor including validated measurement value (VMV) of pressure, validated uncertainty (VU) of pressure and measurement value status (MVS) of pressure are calculated using the high consistency data. A new fault diagnosis method based on wavelet packet decomposition feature extraction and support vector machine multi-classification is used to identify six sensor fault status. A double DSPs system is implemented to acquire the output signal and complete self-validating methods. The experiment results show that the designed pressure sensor prototype implements the self-validating function. It can detect fault in real-time and identify sensor status with high accuracy.