A General Form for Reset Control Including Fractional Order Dynamics

Currently, reset control focuses on using structures which allow new resetting rules in order to avoid limit cycle to be caused and improve the performance of the system. This paper investigates the properties of some reset strategies, of integer and fractional order, which reset controller states to fixed or variable non-zero values and are able to eliminate or reduce the overshoot in first and higher order systems, respectively. Based on them, a general reset control strategy with fractional order dynamics is proposed with both fixed and variable resetting to non-zero values. A comparative study is given to show its benefits in terms of prevention of limit cycle and reduction of the overshoot. As a result, some guidelines to be considered for the design of such controllers depending on the application are offered.