Partial Assistance with Lower-Limb Exoskeletons to Enhance Gait and Balance in Daily Living Activities
This thesis addresses key challenges in developing adaptive lower-limb exoskeletons to enhance balance, mobility, and user autonomy during daily living activities. It presents a comprehensive exploration of three critical aspects: push recovery during standing, partial assistance during gait and stair navigation, and real-time locomotion transition detection.
A novel push recovery framework integrates a bio-inspired stepping strategy and online optimization of step parameters, enabling natural and effective responses to external perturbations. Experimental validation demonstrates the framework's capability to enhance stability and support synergistic human-exoskeleton interaction.
To support daily living activities such as walking and stairs navigation, 3D path and flow controllers were developed, extending 2D implementations by incorporating hip abduction/adduction control to improve mediolateral stability. These controllers maintain natural movement variability while offering targeted balance assistance. Experimental results reveal that the path controller enhances trajectory alignment with inter-joint coordination patterns, while the flow controller provides intuitive and user-preferred support.
For locomotion transition detection, a machine learning-trained threshold-based method was introduced, achieving high real-time classification accuracy across two distinct exoskeletons, eWalk and Autonomyo. Personalization techniques, including Bayesian optimization, tailored the system to individual gait patterns, enhancing robustness and adaptability.
The findings emphasize the importance of incorporating dynamic balance mechanisms, intuitive control frameworks, and user-specific adaptability to address the complex demands of daily living activities while maintaining user autonomy and comfort. Future research should aim to integrate all these aspects, balance recovery, partial assistance during daily living activities, and transition detection, into cohesive frameworks. These frameworks should explore dynamic and real-world environments while prioritizing user-centric design approaches. Involving end-users, physiotherapists, and clinicians in the development process can further enhance that exoskeleton systems align with practical needs and preferences, advancing their potential to improve mobility and quality of life for individuals with walking impairments.
Dr Ronan Boulic (président) ; Dr Mohamed Bouri, Prof. Auke Ijspeert (directeurs) ; Prof. Roger Gassert, Prof. Laura Marchal-Crespo, Prof. Herman van der Kooij (rapporteurs)
2025
Lausanne
2025-05-02
11153
189