Today we performed fully integrated tests on the brace prototype, the main purpose being to verify our design constraints:

  • 40ms response time
  • Brace triggers and latches at >400dps inversion speed, prevents further inversion of ankle

Below is a photo of our test setup with the 3D-printed brace prototype mounted on the test foot model mounted on a wooden test platform.

drawing
Test Setup


Test 1 - Response Time

Test Procedure

  • Mount model foot with brace on test platform, string attached to sole of foot
  • Run youtube 120fps stopwatch on laptop, place visibly by test platform
  • Set up phone to film test setup from an appropriate angle (film in slo-mo)
  • Manually pull on string to trigger an inversion event
  • Review slo-mo video, record time from when yellow trigger LED turns on to when latch engages with gear
  • Run 3 trials


Test Video


Test Results

Trial Response time (ms)
1 25
2 26
3 16

Pass criterion: response time of all 3 trials are under 40ms - TEST PASSES!


Test 2 - Weighted Pulley Test

Test Procedure

  • Mount model foot with brace on test platform, string attached to sole of foot and pulleyed over hook
  • Set up phone to film test setup from an appropriate angle
  • Connect dev board to laptop, run Python script to plot measured inversion speeds in real-time
  • Attach weight to end of string, let go, expect brace to prevent full inversion
  • Re-drop the weight after a few seconds to show that brace is able to reset automatically and is capable of re-triggering


Test Video


Pass criterion: brace triggers and prevents full inversion every time measured inversion speed surpasses 400dps - TEST PASSES!


Test 3 - Correctness of Inversion Measuring

Test Procedure:

  • Set up phone to film test setup from an appropriate angle
  • Connect dev board to laptop, run Python script to plot measured inversion speeds in real-time
  • Hold brace, move around foot part, together with lower leg, inversion motion, dorsiflexion motion


Test Video


Pass criterion: only inversion motion is measured as seen by the live plotter, dorsiflexion and other movements do not register as large spikes in measured inversion speed (qualitative test) - TEST PASSES!