Diagnostics for Periodically Excited Actuators

Electromechanical actuators that operate cyclically or with periodically varying loads present unique opportunities for condition-based diagnostics. Signal processing techniques can be tailored to exploit periodic variation in the electrical and mechanical variables and waveforms associated with these machines. These analytical techniques improve signal resolution and permit detection of fine changes in system parameters. This article presents low-intrusion instrumentation tailored to periodic loads. These instruments can provide subtle diagnostic information from measurements of quantities such as vibration and electrical current. Extraction of cyclostationary signal components and development of diagnostic metrics are discussed in this article and demonstrated on an industrially relevant case, a diaphragm pump