Adaptive Neural Network with Dynamically Adjusted Activation Function Based Robust Control of Robot Manipulators


YILMAZ B. M., Hindistan C.

2025 Innovations in Intelligent Systems and Applications Conference, ASYU 2025, Bursa, Türkiye, 10 - 12 Eylül 2025, (Tam Metin Bildiri) identifier

  • Yayın Türü: Bildiri / Tam Metin Bildiri
  • Doi Numarası: 10.1109/asyu67174.2025.11208277
  • Basıldığı Şehir: Bursa
  • Basıldığı Ülke: Türkiye
  • Anahtar Kelimeler: Lyapunov stability, neural network based control, robot manipulators
  • Manisa Celal Bayar Üniversitesi Adresli: Evet

Özet

This paper proposes a hybrid control strategy for the trajectory tracking of robotic manipulators operating under time-varying uncertainties and external disturbances. The control framework combines a robust controller with a neural network-based estimator to effectively manage both structured and unstructured uncertainties. The robust component attenuates bounded disturbances and a portion of the model uncertainties, while the remaining unknown dynamics are estimated by a neural network term without requiring a known regressor matrix. To enhance estimation accuracy, a novel activation function with a dynamically adjusting center is introduced. Unlike conventional fixed-form activation functions, the proposed structure generates a unique activation function for each input instance, allowing the network to better capture complex and time-varying system behaviors. This adaptive mechanism significantly improves the network's ability to track changes in system dynamics in real time. The stability of the closed-loop system is ensured through Lyapunov-based analysis, and simulation results confirm the enhanced tracking performance and robustness of the proposed method under challenging and uncertain conditions.