Parametric Design and Analysis of the Arc Motion of a User-Interactive Rollator Handlebar with Hall Sensors

  • Ji Ho Park
  • Bi Oh Park
  • Won Gu LeeEmail author
Regular Paper


Most user-interactive rollator handles fabricated so far have had errors in classifying users’ walking intentions due to the structure not considering gravity, in addition to their usage not being intuitive. Here, we introduce a smart handle based on ‘arc motion’ horizontal to the ground to classify the user’s walking intentions accurately. In designing the handle, the limit of grip angle is adopted considering the arc motion. This minimizes the deflection of the handle by gravity and can allow the handle to be optimized for the grip motion. Moreover, we applied the results of our analysis of users’ walking intentions in the arc motion to machine learning. In understanding the user’s intentions to walk, we created two support vector machine classifiers from handle data collected through four Hall sensors. This combination of the arc motion and machine learning has significantly reduced classification errors. As a result, we ensured an accuracy of 0.95, which is a widely used standard in control.


Smart handle Arc motion User-interactive Hall sensor Support vector machine 



This research was supported by the National Research Foundation of Korea (NRF- 2019R1F1A1062434).

Author Contributions

WGL conceived the idea and initiated the project. JHP, BOP and WGL wrote the main manuscript. JHP and BOP prepared Figures and Tables. BOP implemented the main algorithms for the classification via machine learning. JHP and WGL designed the prototype of the hardware. JHP conducted the experiment on the handlebar. All authors reviewed the final version of the manuscript.

Compliance with Ethical Standards

Conflict of interest

The authors declare that they have no conflict of interest.

Supplementary material

12541_2019_192_MOESM1_ESM.docx (1.1 mb)
Supplementary material 1 (DOCX 1162 kb)


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Copyright information

© Korean Society for Precision Engineering 2019

Authors and Affiliations

  1. 1.Department of Mechanical EngineeringKyung Hee UniversityYonginRepublic of Korea

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