Ltf science
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Contents
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]