Phase plane displays detect incipient failure in servo system testing
F. J. Affenito, Joseph G. Wohl · NASA STI Repository (National Aeronautics and Space Administration) · 1967
Computer based data conditioning and display technique detects incipient failure in servo system testing, for use in prelaunch checkout of complex nonlinear servomechanisms. These phase plane displays enable identification of, on line, unusual or abnormal servo responses which can be displayed compactly in the time domain on a cathode ray tube.