Nominal characteristic trajectory following (NCTF) control has been proposed to realize high-precision control systems with minimal information and expertise. NCTF control is effective at suppressing the adverse effects of friction and has demonstrated precision motion and high robustness. To improve the vibration-suppression characteristics of NCTF control systems, a method of incorporating additional compensators (which are easy to design) has been proposed and proven effective. However, the robustness of NCTF control with additional compensators has not been verified. They have also not yet been evaluated for application to a rotary mechanism with a gear reducer (commonly used in robots). This study experimentally investigated the robustness and performance improvement of NCTF control of a rotary mechanism with a gear reducer using additional compensators. To evaluate robustness, additional units were used to increase the moment of inertia and to add disturbance to the mechanism. Despite some degradation in performance owing to the added inertia and disturbance, the overall performance remained good, demonstrating the efficacy of the proposed control approach. This study demonstrated the potential of NCTF control systems augmented with additional compensators to boost servomechanism performance in automation, particularly in robots subjected to variable loads and disturbances.

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