Power-fold actuator noise diagnostic system

This paper describes a testing system designed specifically to allow the checking of power fold actuator on a mirror assembly line. A benchmarking was carried out to obtain the envelope of auto-spectrum functions for diagnosis purposes which allow for picking up bad power fold samples from good ones. The signal processing algorithm and principle of auto-spectrum envelope analysis is illustrated. Although the measurements were conducted by use of a microphone and a tri-axial accelerometer, only one transducer measuring either noise or vibration signals is needed to serve diagnosis purpose using the envelope analysis. The diagnosis process is similar to learning process of a standard medical diagnosis. A simple device is developed using a fixture to hold and actuate power fold actuator. The diagnosis algorithm can be implemented in any of industrial PC computer based data acquisition system with conventional programmable signal processing functions including auto-spectrum analysis.