Revision as of 17:49, 19 December 2009

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Dec 2009 - full range backdrive loops

time domain

• Backdrive was -31000 to +21000 (full range), robot applied either a constant +3 amps or -3 amps. This plot is versus time. JR3 data is correctly aligned with robot data. Notice that change in force reading with robot (and thus backdrive) position

http://18.85.17.197/for_wiki/png/ltf/tn/TN_fullrange_backdrive_wmp_3amps_and_jr3.JPG [1]

http://18.85.17.197/for_wiki/png/ltf/tn/TN_fullrange_backdrive_wmp_3amps_zoom.JPG [2]

force vs motor rotations

• Previous experiment with data ploted WRT to robot motor rotations - notice the periodic relationship in the forces wrt to motor.

http://18.85.17.197/for_wiki/png/ltf/tn/TN_fullrange_backdrive_vs_ak_motor_wmp_3amps_w_jr3.JPG [3]

• Zoom into edge of above to make apparent the 0.55 motor rotation shift when robot torque current changes from +3 amps to -3 amps.

http://18.85.17.197/for_wiki/png/ltf/tn/TN_fullrange_backdrive_vs_ak_motor_wmp_3amps_w_jr3_zoom.JPG [4]

Dec 2009 - dynamic tests

• 3 amp discrete discrete sine waves applied. This plot is versus time.

http://18.85.17.197/for_wiki/png/ltf/tn/TN_discrete_sine_sweep_with_jr3.JPG [5]

Dec 2009 - static test

potential function @ BD -11000, sweep -9 to 9 amps (in reverse BD experiment)

• The backdrive motor was fixed at -11000, and the robot current was stepped with the following pattern: 0.2, -0.2, 0.4, -0.4, 0.6 amps, ..., 9, -9 amps. After the current step the system was allowed to settle. The LW was collected via RS232 - appx 87 samples averaged. This plot consists of appx 12 hrs of collection the full experiment cycled the backdrive motor from 21000 to -29000 (steps of -2000). This plot contains only the instances where the backdrive motor position == -11000. The LW (charge amp was not zeroed except at the very start of the experiment and its drift is apparent.) Ltf_matlab_source#ltf_pf-2009-12-16.m

http://18.85.17.197/for_wiki/png/ltf/tn/TN_ltf_potential_plot_9amps_bd_m11000.JPG [6]

force dependence on BD position (forward BD motion)

• the BD motor was driven in the forward direction on 12-15-09 - the result was a strong dependence of force on BD position. Ltf_matlab_source#ltf_bd_dep-121509.m

http://18.85.17.197/for_wiki/png/ltf/tn/TN_force_dependence_on_bd_posion_121509.JPG [http://18.85.17.197/for_wiki/png/ltf/force_dependence_on_bd_posion_121509.png

mile encoder study

• Bench test with +-6 amps for 20 hrs

http://18.85.17.197/for_wiki/png/ltf/tn/TN_inc_mile_encoder_hist_560000.JPG [7]

early experiments

resonance observed developing belt thrash test

• Holding the BD motor fixed, driving the robot motor w/current mode square wave at specified frequency.

http://18.85.17.197/for_wiki/png/ltf/tn/TN_belt_resonance.JPG [8]

zoom in - resonance observed developing belt thrash test

• Zooming into a specific section:

http://18.85.17.197/for_wiki/png/ltf/tn/TN_belt_resonance_zoom.JPG [9]