Lagrangian Neural Network-Based Control

Improving Robotic Trajectory Tracking via Linearized Feedback

Verfasst von

Manuel Weiss, Alexander Pawluchin, Jan Hendrik Ewering, Thomas Seel, Ivo Boblan

Abstract

This letter introduces a control framework that leverages Lagrangian neural network (LNN) for computed torque control (CTC) of robotic systems with unknown dynamics. Unlike prior LNN-based controllers that are placed outside the feedback-linearization framework (e.g., feedforward), we embed an LNN inverse-dynamics model within a CTC loop, thereby shaping the closed-loop error dynamics. This strategy, referred to as LNN-CTC, ensures a physically consistent model and improves extrapolation, requiring neither prior model knowledge nor extensive training data. The approach is experimentally validated on a robotic arm with four degrees of freedom and compared with conventional model-based CTC, physics-informed neural network (PINN)-CTC, deep neural network (DNN)-CTC, an LNN-based feedforward controller, and a PID controller. Results demonstrate that LNN-CTC significantly outperforms model-based baselines by up to 30 % in tracking accuracy, achieving high performance with minimal training data. In addition, LNN-CTC outperforms all other evaluated baselines in both tracking accuracy and data efficiency, attaining lower joint-space RMSE for the same training data. The findings highlight the potential of physics-informed neural architectures to generalize robustly across various operating conditions and contribute to narrowing the performance gap between learned and classical control strategies.

Details

Organisationseinheit(en)
Institut für Mechatronische Systeme
Externe Organisation(en)
Berliner Hochschule für Technik (BHT)
Typ
Artikel
Journal
IEEE Robotics and Automation Letters
Band
11
Seiten
2546-2553
Anzahl der Seiten
8
ISSN
2377-3766
Publikationsdatum
20.01.2026
Publikationsstatus
Veröffentlicht
Peer-reviewed
Ja
ASJC Scopus Sachgebiete
Steuerungs- und Systemtechnik, Biomedizintechnik, Mensch-Maschine-Interaktion, Maschinenbau, Maschinelles Sehen und Mustererkennung, Angewandte Informatik, Steuerung und Optimierung, Artificial intelligence
Elektronische Version(en)
https://doi.org/10.1109/LRA.2026.3653326 (Zugang: Offen )