Sensors (Jan 2020)

A Novel Sensorised Insole for Sensing Feet Pressure Distributions

  • Ines Sorrentino,
  • Francisco Javier Andrade Chavez,
  • Claudia Latella,
  • Luca Fiorio,
  • Silvio Traversaro,
  • Lorenzo Rapetti,
  • Yeshasvi Tirupachuri,
  • Nuno Guedelha,
  • Marco Maggiali,
  • Simeone Dussoni,
  • Giorgio Metta,
  • Daniele Pucci

DOI
https://doi.org/10.3390/s20030747
Journal volume & issue
Vol. 20, no. 3
p. 747

Abstract

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Wearable sensors are gaining in popularity because they enable outdoor experimental monitoring. This paper presents a cost-effective sensorised insole based on a mesh of tactile capacitive sensors. Each sensor’s spatial resolution is about 4 taxels/cm 2 in order to have an accurate reconstruction of the contact pressure distribution. As a consequence, the insole provides information such as contact forces, moments, and centre of pressure. To retrieve this information, a calibration technique that fuses measurements from a vacuum chamber and shoes equipped with force/torque sensors is proposed. The validation analysis shows that the best performance achieved a root mean square error (RMSE) of about 7   N for the contact forces and 2   N m for the contact moments when using the force/torque shoe data as ground truth. Thus, the insole may be an alternative to force/torque sensors for certain applications, with a considerably more cost-effective and less invasive hardware.

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