New Strain Gage Calibration

• The same test and clibration were conducted on the real rise leg.

Test 1: x-axis displacement

• Displacement was made up to 0.4 inch in every 0.01 inch.
• The straigt spring has linearity pretty much.
• Test Result:
  

Test 2: y-axis displacement

• Displacement was made up to 0.5 inch in every 0.01 inch.
• Curved spring shows linearity somewhat up to a certain level of displacement (around 0.23") but shows irregular responses because of the friction of the buckles.
• Test Result:
  

Calibration

• Curve Fit using Pseudo Inverse (Data points which have greater forces than 6N in test 2 (y-axis force) were ignored for curve fit because they were considered as outliers.)
• F = C * V => C = F * pinv(V)

      |F_x,  0 | = |c11, c12| * |V_1, V_2|
      | 0 , F_y|   |c21, c22|   

• Result
  • C = [ -2.3651, 1.1732 ; -1.0474, -4.9881 ]

Calibration Result

• F vs V_s (Test 1: x-axis force):
  

• F vs V_c (Test 2: y-axis force):