Autotuners and Fractional Calculus. Applications to the Control of Nonlinear Processes
摘要
Fractional calculus has seen a growing interest in the control community during the past two decades. Most papers focus on the design and analysis of fractional order controllers, as generalization of the standard PID controller. Applications range from chemical plants, biomedical engineering, vibration control and mechanical systems, to name only a few. Most of the times, the tuning of such controllers is done based on a process model. Identifying a process model can be time consuming and difficult to determine accurately. In the case of nonlinear processes, usually very few operating points are of interest. A procedure to extract relevant process information in these operating points and use this information to tune fractional order controllers would reduce the design steps by eliminating process modeling. In this paper, an alternative approach to sine wave autotuners is considered based on a single sine test applied to the process. The methods extracts relevant process data that is further used to tune PID-type controllers. Experimental validations and comparisons to existing sine based autotuners are provided on two nonlinear processes: mass-spring-damper system and a vertical take off and landing platform.