Signal detection and monitoring

A method for detecting and monitoring a signal includes: detecting an alignment point for a periodic signal segment of a periodic signal generated by an apparatus being monitored for standard functionality; activating the apparatus from a period prior to the alignment point to an end point of the periodic signal segment; locating a first point of the periodic signal segment; and locating a second point of an additional periodic signal segment. The method further comprises: determining a lowest point of the periodic segment; determining a difference feature between the first and second points; determining a minimum angle between the first and second points; analyzing the lowest point with respect to the difference feature and minimum angle; and normalizing the periodic signal in response to locating the first and second points. The signal may be a pressure of a water pump, a sound or vibration of an engine, or a distance signal of gear engagement. These may be used to judge the health or running state of the apparatus.