On analytical frequency domain compensator design

An algorithm for generating discrete and continuous time forward path compensator coefficients is presented. The servo loop configuration considers a compensator, G_c, and plant, G_p, in the forward path with unity gain feedback. This structure is basic to many controller designs incorporating sensors that directly detect an error signal (i.e. optical tracker pointing error, gyro attitude error). Although limited in flexibility, since the open loop zeros are included in the closed loop servo response, the configuration is common to many applications employing off-the-shelf control processors. Forward path compensator design is typically performed via Bode or root locus techniques. The algorithm presented is derived for a general linear time-invariant plant structure and provides an analytical procedure for determining the compensator coefficients. It is applicable to the initial stages of the design process and can be readily tuned as the design progresses