"Hybrid Model Control of WalkON Suit for Precise and Robust Gait Assistance of Paraplegics"
- Year of publication
- K. Park, J. Choi, K. Kong
- 2021 IEEE International Conference on Robotics and Automation (ICRA)
Powered exoskeletons for people with paraplegia have been widely developed. To generate the basic but essential motions for daily human life, precise control algorithms to follow the joint reference trajectories are necessary. The dynamic characteristics of the exoskeletal joints, however, varies signifi-cantly during walking because the load side is exchanged from legs in the air to the wearer’s body. To ensure robustness and tracking performance for any case of gait even in the presence of exogenous disturbances such as human’s active movements and repeated ground contacts, customized robust control algorithms need to be developed. In this paper, therefore, hybrid model control of the powered exoskeleton, WalklON Suit, utilized with the disturbance observer is introduced. A hybrid nominal model, whose model parameters are interchanged between the gait phases, i.e., swing and stance, is developed by the parameter adatpation algorithm. By the proposed method, the disturbance observer can fully reject the exogenous disturbance during walking and achieve high-performance gait assistance to the people with complete paraplegia. In this paper, the experimental verification of the designed model and the controller with the WalkON Suit, are also introduced.