Revision as of 18:28, 26 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_fullrange_backdrive_wmp_3amps_and_jr3.JPG [1]

http://18.85.17.197/for_wiki/png/ltf/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_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_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. (freq range ~10hz to 20hz)

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

• continuous time sine sweep from 1 to 200 hz. This plot is versus experiment time (but has a drive frq trace)

http://18.85.17.197/for_wiki/png/ltf/TN_continuous_sine_sweep_w_jr3.JPG [6]

• Phase response - the movie:

http://18.85.17.197/for_wiki/png/ltf/sine_drive_phase_response_8_to_30hz.avi

how to do dynamic test

Requires the use of 3 programs on the LTF, and a number of programs on a support PC

• on the PC start wifi_fast and the matlab plotter "plot_lifefix". When starting wifi_fast, specify a log file (-f) that is descriptive of the test.
• for JR3 viewing, start a 2nd matlab plotter "plot_jr3"

• start move_ecat with the desired position profile.
  • to (slowly) sweep a position : ./move_ecat -m p2p -a 1 -d 1 -p 200 -r 100 -i -28000 -f 19000
    • -p 200 -> 200 passes, -r 100 -> 100 rpm. -i and -f specify position end points
  • to hold position for ~100 seconds : ./move_ecat -m p2p -a 1 -d 1 -p 1 -r 100 -i 0 -P 99999

• start the jr3 logger (w/1000 hz sample rate) with optional UDP logger and a description logging file name.
  • python log_loadcell.py -U 192.168.192.15 -R 1000 -f jr3_<TEST_DESCRIPTION>.txt

• make sure that the charge amp is in the measure mode, be verifying that the LWactual plot is noisy.
  • may require the use of charge_amp_control.py

• edit the lifefix_test.py stimulus program to set the desired amplitude of the tests.
• run the stimulus program
  • python lifefix_test.py sweep
• often lifefix_test will run indefinitely, use the command "python lifefix_test.py stop" when enough data has been collected.

• stop all the data collectors
• load the data into matlab, and if necessary, align the JR3 data with the SWIFI data.

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_ltf_potential_plot_9amps_bd_m11000.JPG [7]

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_force_dependence_on_bd_posion_121509.JPG [8]

mile encoder study

• Bench test with +-6 amps for 20 hrs

http://18.85.17.197/for_wiki/png/ltf/TN_inc_mile_encoder_hist_560000.JPG [9]

• MR encoder dependence on motor phase angle (no load, voltage limited)

http://18.85.17.197/for_wiki/png/ltf/TN_ec30_w_mr_enc_mod1000.JPG [10]

• MILE encoder dependence on motor phase angle(RE40 negative voltage)

http://18.85.17.197/for_wiki/png/ltf/TN_re40_drive_of_ec30_mile_qV_vs_mod2048_minus2600rpm.JPG [11]

• MILE encoder dependence on motor phase angle(RE40 positive voltage)

http://18.85.17.197/for_wiki/png/ltf/TN_re40_drive_of_ec30_mile_qV_vs_mod2048_2600rpm.JPG [12]

• unloaded MILE at 7000-8000 rpm, voltage limited. Notice the very large motor amp spikes - but less on the qIq. This suggests there is a large qId term.

http://18.85.17.197/for_wiki/png/ltf/TN_ec30_w_mile_enc_mod.JPG [13]

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_belt_resonance.JPG [14]

zoom in - resonance observed developing belt thrash test

• Zooming into a specific section:

http://18.85.17.197/for_wiki/png/ltf/TN_belt_resonance_zoom.JPG [15]