Evaluation of treadmill velocity control based on user's intention of acceleration or deceleration

Yasutaka Nakashima, Takeshi Ando, Yo Kobayashi, Masakcitsu G. Fujie

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)


We have been developing a new mobility-aid robotic vehicle, 'Tread-Walk 2 (TW-2)', which supports walking for the elderly. TW-2 is controlled by natural walking movements, particularly ground reaction force, during gait. However, in our previous work, a user of this vehicle experienced some discomfort both when he started walking and when he stopped walking. This problem was caused by inaccurate estimation of the user's anteroposterior force at the heel contact and the toe off. The estimation of the user's anteroposterior force is closely related to the inaccurate estimation of the vertical component of the ground reaction force, which is approximated by a square waveform in the stance phase. In this paper, we evaluate a novel treadmill control algorithm that allows the anteroposterior force to be estimated more accurately. To evaluate how well the treadmill control algorithm is capable of acceleration and deceleration in accordance with the intention of the operator, we measure the transformation of walking velocity and kicking power, and the trajectory of the toe position produced by the proposed controller and the previous one compared with level ground walking. The results show that the proposed control algorithm allows the actual walking velocity of the participant to track and converge to the target velocity, while the participant using the previous controller is unable to follow the target velocity and shows no convergence when the velocity is reduced from 2.0 to 1.0 km/h. Thus, when using the proposed controller, walking velocity decreases as the user reduces anteroposterior force, similarly to level ground walking.

Original languageEnglish
Title of host publicationWorld Automation Congress Proceedings
PublisherIEEE Computer Society
Number of pages6
ISBN (Electronic)9781889335490
Publication statusPublished - Oct 24 2014
Externally publishedYes
Event2014 World Automation Congress, WAC 2014 - Waikoloa, United States
Duration: Aug 3 2014Aug 7 2014

Publication series

NameWorld Automation Congress Proceedings
ISSN (Print)2154-4824
ISSN (Electronic)2154-4832


Other2014 World Automation Congress, WAC 2014
Country/TerritoryUnited States

All Science Journal Classification (ASJC) codes

  • Control and Systems Engineering


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