Aleksandar Pavlov, Joong-Ku Lee, Joshua Brown, Nicola Bailey, Jee-Hwan Ryu, Ildar Farkhatdinov
IEEE Telepresence (2026) — in press
Accurate dynamic modelling is critical for stable and safe human-robot interaction with haptic robots. This paper presents an open-source MATLAB Simulink framework for the HRX-1 haptic robot dynamic model. The model consists of a continuous dynamic plant with integrated discrete-time position, torque/current cascaded control loops acting within a virtual environment. This architecture enables realistic simulation of real hardware behaviour which includes sampled sensing and control delay. Evaluation of the model is conducted through simulated haptic interaction experimentation between a virtual wall environment and external virtual user force through passivity-based Z-width analysis in the KB (stiffness-damping) plane. Two sampling times/frequencies representative of the real system were used to conduct simulations demonstrating stable and unstable interaction. Results showed the stable interaction KB region is decreased significantly for decreased sampling frequency, introducing enough delay to violate passivity, inject energy and produce unstable behaviour.