Space Grant Consortium - University of Wisconsin - Green Bay

Figure 1 - A calibration equation for the LVDT
A calibration equation was produced by moving the robot in one-tenth of an inch increments and
taking individual measurements from the LVDT. Figure 1 shows that the voltage reading of the
LVDT and the linear displacement is linear, with R 2 = 1, affirming the quality of the linear fit.
A MATLAB script imported the voltage data, converted it to position data using the calibration
equation, di fferentiated t he pos ition da ta w ith r espect t o t ime, a nd ge nerated pl ots of velocity
versus time.
Results
Distance (inches)
LVDT Calibration
1.5
1
0.5
0
-8 -6 -4 -2 0 2 4
Voltage (volts)
Linear (9-Jul)
y = -0.1014x + 0.2466
R² = 1
Data w as collected f or a n ormal x -axis movement of one i nch. F igure 2 s hows t he up r amp,
stabilization, and down ramp of a robotic move in the x direction.
9-Jul
Figure 2 - Ramp from 0 to 50 IPM and back to 0, X Axis, one inch move
3