Generalized feedforward tuning rules for non-realizable delay inversion

• We propose new feedforward tuning rules when perfect compensation is not realizable.
• A new generalized open-loop tuning rule for feedforward compensator is presented.
• Simple guidelines are given for aggressive, moderate, and conservative results.
• We also propose a switching feedforward compensator to avoid oscillations.

This paper describes the problem of load disturbance rejection using feedforward for the case when perfect compensation is not realizable due to processes delays inversion. First, a new generalized open-loop design tuning rule for feedforward compensators is proposed. Simple and intuitive guidelines are given for aggressive, moderate, and conservative performance results. Moreover, a switching feedforward compensator is proposed to be used when oscillations are not allowed in the process output. Simulation results show important improvements in disturbance rejection, reference tracking error and control effort.