Mechanical diagnostics-past, present and future

The background and current trends of the automatic diagnostics of mechanical systems are reviewed. Particular attention is given to a breakthrough in this field involving the introduction of the Mechanical Systems Diagnostic Analyzer in the late 1970s. Further advances in this field are also discussed, with particular emphasis on a reasonably expert system. Scientific-Atlanta´s Rotor Analysis and Diagnostic system (RADS-AT), which allows a nonexpert user to quickly bring rotor-induced vibration in helicopters below the accepted level (typically 0.2 in/s.)