Improved NCTF Control Method for a Two-Mass Rotary Positioning Systems

Abstract

In this study, a nominal characteristic trajectory following (NCTF) controller with extended minimal resource allocation network (EMRAN) compensator is introduced for two-mass rotary point-to-point (PTP) positioning systems. Generally, the NCTF controller consists of a nominal characteristic trajectory (NCT) and a compensator. The objective of the compensator is to make the object motion follow the NCT and end at its origin. The NCTF controller is designed based on a simple open-loop experiment of the object. The parameters and an exact model of the plant are not necessary for controller design. This paper presents a new method to improve the conventional NCTF controller in order to increase the positioning performance and robustness of the system by using EMRAN as a compensator. The NCTF-EMRAN controller is evaluated and discussed based on results of simulation. The effect of the design parameters on the robustness of the NCTF-EMRAN controller to inertia variations is evaluated and compared with conventional NCTF controller. It is shown that NCTF-EMRAN controller has a better positioning performance and much more robust than existed NCTF controller.