-- DanielSantos? - 13 Jul 2006

Adhesion Testing

Main page for information on adhesion testing of foot structures for climbing robot platforms.

• PulleyStageTests - Initial tests of flat and spherical urethane pads using rudimentary setup

YZ Linear Stage

Controlled linear stage to test sample feet using 6-axis force plate. Uses two Pittman motors (GM9236S015? -R1 24V 500CPR 5.7:1) to drive two leadscrews (.200 in/rev). Stage purchased from Velmex. Low-level control of motors (PWM commands and decoding of encoder lines) is done via PIC microprocessor. High-level (position/speed) control done through Labview over serial interface with PIC microporcessor.

• YZAdhesionTesting1 - Tests performed using 100Hz control loop with +/- 25um positioning precision. Stage used as-is from manufacturer.
• YZAdhesionTesting2 - Tests performed using 250Hz control loop after stage and been dismantled and set-screws adjusted
• YZAdhesionTesting3 - Tests performed using 1kHz control loop on PIC w/ trajectory files

XYZ Linear Stage

• XYZAdhesionTesting1 - 3-axis tests performed using 1kHz control loop on PIC w/ trajectory files
  • Sampling Force/Torque at 1kHz; Sampling Position at 500Hz
  • Performing Position Control w/ Gain of "10" - Units in ((1/1024)DC%)/(Encoder Tick) - ((1/1024)*16V)/(1.7um for X/Y and 0.4um for Z)

• XYZAdhesionTesting2 - 3-axis tests performed using 1kHz control loop on PIC w/ trajectory files
  • Fixed bug in processing Encoder pulses - previously had been missing "ticks" and position was "drifting"
  • Changed Gain to 5 b/c encoder ticks doubled

• XYZAdhesionTesting3 - 3-axis tests performed using 1kHz control loop on PIC w/ trajectory files
  • Increased maximum length of time of a trajectory file - previously had been limited to 65.535 seconds

• XYZAdhesionTesting4 - 3-axis tests performed using 1kHz control loop on PIC w/ trajectory files
  • Moved the sample to the force plate side and substrate to the stage side - sample fixed, substrate moves
  • Allows for better alignment, b/c can see through glass to determine alignment
  • Allows for video recording through glass if desired