US Patent 11314232 Frequency response diagnostics for characterizing servo controlled mechanisms

A server includes a processor to supply a torque command to an amplifier that controls a motor that drives a linkage; include, in the torque command, an alternating signal wave that is to test a frequency response of the motor and the linkage; receive, from the amplifier, an instantaneous torque value of the motor and an instantaneous mechanical parameter value of the linkage at each time step according to a sampling rate and over a period of time; store an aggregate of both these values; determine, for a first frequency of the alternating signal wave, a magnitude and phase shift between the aggregate of the instantaneous mechanical parameter values and the aggregate of the instantaneous torque values; and generate, using an aggregate of magnitude and phase shift data for multiple frequencies of the alternating signal wave, a fingerprint to be used in performing diagnostics of motor and linkage.