Tuning rules for a reset PI compensator with variable reset

The PI+CI compensator is a simple reset compensator, its base system is a PI, which has been shown to be effective in a number of practical applications. One fundamental parameter to be tuned is the reset ratio; for lag dominant systems or systems with integrators it is known to give good results overcoming PI compensation. In this work, a systematic method for the tuning of a variable reset ratio (variable at the reset instants) is developed for first and second order plants.