Insole sensor system for real-time detection of biped slip

Abstract

The study of bipedal gait is important for two primary reasons: biomimetic robotics and human gait rehabilitation. Both fields have numerous models describing bipedal locomotion that require a no-slip interaction with the ground for accuracy. This paper presents a low cost wearable sensor system capable of identifying slip in real time, which could afford rehabilitative analysts important information on the nature of patient falls, and provide robot designers a feedback ability with which to implement an active traction control system. The system can functionally provide better than 90% detection rates when calibrated to an individual.

A novel foot slip detection algorithm using unscented Kalman Filter innovation

“…q4 a y == -g cos (8) where 8 and ware tilt angle and angular velocities of the block, respectively. The axand a y are accelerations in local x-and y-directions, and g is acceleration due to gravity.…”

“…Onodera and coworkers used intelligent shoes to detect slip based on the postural instability of a human subject determined from pressure sensors and optional gyro data [7]. Lincoln and Bamberg [8] used an insole instrumented with six strategically placed force sensitive resistors and a 3-axis accelerometer. They used a slip metric determined by thresholding the acceleration and normal force measured.…”

Just enough measurement: A proposed paradigm for designing medical instrumentation

“…Since slippery surfaces are associated with 66% of fall-related hip fractures [21], understanding whether a fall is caused by a slip or other conditions is important. A companion paper demonstrates that our instrumented insole can be used to identify the onset of slip with better than 90% detection rates when calibrated to an individual [27].…”

Force Sensing Insole for a Balance Enhancement System

“…Low cost systems containing force sensitive resistors have been previously used on insole applications for measurement of forces under the foot [8,9,[35][36][37]. However, these systems are limited to a partial measurement of the vertical ground reaction force, which limits the accuracy and generalization capacities of such devices.…”

“…Similar to the previous system, other research has been conducted at the Univeristy of Utah, where the same commercial force sensitive resistors have been used to build instrumented insoles for different applications, from detection of slip by analyzing the acceleration of the foot and the normal force during foot contact with the ground [36] to evaluation of changes on force distribution on the feet during standing for balance assessment [35] Figure 2.10: Instrumented insole containing 12 force sensitive resistors for kinetic gait analysis [9].…”