Haptic interaction is critical in physical Human-Robot Interaction (pHRI), given its wide applications in manufacturing, medical and healthcare, and various industry tasks. A stable haptic interface is always needed while the human operator interacts with the robot. Passivity-based approaches have been widely utilised in the control design as a sufficient condition for stability. However, it is a conservative approach which therefore sacrifices performance to maintain stability. This paper proposes a novel concept to characterise an ultimately passive system, which can achieve the boundedness of the energy in the steady-state. A so-called Ultimately Passive Controller (UPC) is then proposed. This algorithm switches the system between a nominal mode for keeping desired performance and a conservative mode when needed to remain stable. An experimental evaluation on two robotic systems, one admittance-based and one impedance-based, demonstrates the potential interest of the proposed framework compared to existing approaches. The results demonstrate the possibility of UPC in finding a more aggressive trade-off between haptic performance and system stability, while still providing a stability guarantee.

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ChatGPT is widely used among students, a situation that challenges educators. The current paper presents two strategies that do not push educators into a defensive role but can empower them. Firstly, we show, based on statistical analysis, that ChatGPT use can be recognized from certain keywords such as ‘delves’ and ‘crucial’. This insight allows educators to detect ChatGPT-assisted work more effectively. Secondly, we illustrate that ChatGPT can be used to assess texts written by students. The latter topic was presented in two interactive workshops provided to educators and educational specialists. The results of the workshops, where prompts were tested live, indicated that ChatGPT, provided a targeted prompt is used, is good at recognizing errors in texts but not consistent in grading. Ethical and copyright concerns were raised as well in the workshops. In conclusion, the methods presented in this paper may help fortify the teaching methods of educators. The computer scripts that we used for live prompting are available and enable educators to give similar workshops.@en