Wael Bachta, researcher at ISIR and lecturer at Sorbonne University, will defend his Habilitation to Supervise Research (HDR) on Tuesday 27 June 2023 at 10am on the Pierre et Marie Curie campus of Sorbonne University.
Title of his work: Human-robot physical interaction and assistance with station standing and mobility.
The members of the jury are as follows:
- Catherine ACHARD, Professor, Sorbonne University, (Examiner),
- Philippe FRAISSE, Professor, University of Montpellier, (Rapporteur),
- Hélène PILLET, Professor, École Nationale Supérieure des Arts et Métiers, (Examiner),
- Philippe SOUERES, Research Director, LAAS – CNRS, (Rapporteur),
- Jean-Louis VERCHER, Research Director, ISM – Université Aix-Marseille, (Rapporteur).
Summary by Wael Bachta
Haptic interfaces and assistance for standing and locomotion
My research focuses on human-robot physical interaction. I have been able to develop this theme by working on several projects, the main ones being :
- The control of haptic interfaces with intermittent contacts: I contributed to the design of a small, hollow, instrumented end-effector that can both track the operator’s finger movement in free space and restore the operator’s efforts when encountering virtual objects. I have also designed control laws that increase the realism of the immersive experience.
- Assisting a person who has to handle a relative’s motorised wheelchair: I contributed to the development of an intuitive guidance interface, which can replace those available on the market, to help carers handle a relative’s motorised wheelchair. To do this, I used a handlebar with pressure sensors to extract the information needed to guide the wheelchair and implement a suitable movement strategy.
- Modelling assisted walking, design and control of a robotic cane: Studying the role of a conventional cane experimentally and numerically enabled me to design a robotic cane that preserves the intrinsic characteristics of its conventional counterpart. I have also implemented a control law that automatically synchronises the movement of this cane with that of its users.
- The development of a posture control loop using an active device based on light touch: I modelled the relationship between the movement of a mobile platform touched lightly by the finger and postural balance. This modelling enabled the implementation of a control law that changes a person’s postural state through the movement of the platform. The change in postural state is automatic and often occurs without the participant noticing it. I also set up an experimental campaign in a clinical environment to validate the idea of using this technology for rehabilitation purposes.
From this factual summary, it can be seen that my research theme applies to personal assistance. This assistance is divided into two parts. The first is assistance to an operator or carer. The second involves assisting people with posture or locomotion problems.
The implementation of these applications was multidisciplinary. Starting from a robotics base, I have drawn on biomechanics, movement sciences and neuroscience. My approach to human-robot physical interaction is based on using the limits of human multisensory integration to manipulate the sensory feedback transmitted by the interfaces. I have often preferred to use the limits of human perception to refine and optimise my proposals. Indeed, despite its power and versatility, human perception has its limits, which we need to be aware of in order to be able to include it judiciously when developing control laws for physical human-robot interaction. As an example, I used the perceptual limits of the temporal dissonance between vision and touch to develop the control law for the haptic interface with intermittent contact and I relied on the ambiguity of finger movement attribution that the central nervous system has to deal with to maintain postural balance.
Contact: Wael Bachta, Lecturer
