2025 Volume 37 Issue 4 Pages 717-724
An automatic seating detection system is developed for an automatic hand nut runner that tightens self-locking nuts. Our research is of particular significance in the field of aircraft assembly, where the use of special self-locking nuts is common. This nut has a different shape from commonly used nuts and does not loosen easily. Therefore, irregular torque values are observed during tightening, making it challenging to detect seating automatically. This paper proposes a method for detecting the seating of self-locking nuts using evolutionary computation techniques. The proposed method is based on anomaly detection by Hotelling. First, sensor values are used to create an indicator, and when the indicator meets a criterion, seating is determined. The indexes used for the judgment are generated by evolutionary computation. Numerical experiments validate the proposed method and demonstrate its practical application.
