Orientation independent monitoring technique for accelerometers

To maintain continuous production, adequate monitoring systems are needed on all components of equipment that are prone to failure. However, it is not economically feasible to attach a dedicated monitoring system on every piece of equipment. Therefore, the alternative is to purchase a portable system that can be moved between components. Most monitoring algorithms, however, require the sensor to be aligned in a very specific direction relative to the component. This is frequently difficult and requires a substantial amount of time. Unfortunately, if the sensor is not precisely aligned, the reliability of the scheme dramatically decreases. Thus, when the probe is removed and later reattached, unless the sensor is exactly realigned, most algorithms cannot compare the two signals to determine if anything has changed. To overcome this situation, this paper utilizes multivariate models to formulate a methodology that allows acceleration signals to be monitored independent of sensor orientation. The paper demonstrates how the accelerometer's orientation can be changed during testing without detracting from the scheme's ability to track the condition of the component, thus allowing the probe to be easily removed and reattached.