Prototype MR Damper Characterization Tests Using White Noise

Perform tests at 2 amplitudes, 2 frequency ranges, and 2 voltage ranges.

Five trials are conducted to provide data intended for MR damper characterization and modeling. The two inputs to the MR Damper are the displacement and the voltage, and the output is the measured force. In each trial displacement input to the MR damper using a hydraulic actuator. The actuator command is a white noise input. The file for each trial contains displacement input and voltage input, and force output.

Channels included in unprocessed data files:
1) Main Displacement Measurement (D1)
2) Force (F)
3) Acceleration of Actuator (A)
4) Command to Actuator (U)
5) Voltage to MR Damper Circuit (Y)
6) Second Displacement measurement (D2)

Channels included in converted data files:
1) Damper Displacement (D)
2) Force (F)
3) Acceleration of Actuator (A)
4) Voltage to MR Damper Circuit (Y)
5) Calculated velocity of MR damper (V)

In these tests the DSP board was used to generate a random excitation which was sent to the actuator, and a random signal to send to the MR Damper. This is then the two input,single output system which must be modeled. The MATLAB file was generated by creating a 1000 Hz random signal(raninp) and filtering it with an 8 pole elliptic filter (ranfilt.m) to the appropriate frequency range. Then the signal was exponentiated to make it positive and scaled to fit in the appropriate range (0-1V, 0-2.25V).
For the white noise inputs, the code used in the filename has the following corresponding frequencies:

ranran_50_u - 60 sec (0-50 Hz, ffilter = 1500, fs = 3000)
ransim - 20 sec (using simulation)
ransim_u - 20 sec (using simulation, fs = 3000, Y filtered at 20000Hz)
ranran_50 - 20 sec (0-50 Hz, fs = 3000, Y filtered at 20000Hz)
ranran_20 - 40 sec (0-20 Hz, fs = 3000, Y filtered at 20000Hz)

For more detailed description, see white_noise_signal_description.csv in the Documentation.

The unit of input and output data in the unprocessed data files is Volts.
The unit of input and output data in the converted data files is N and cm.
The converted data are obtained from the unprocessed data.

These data sets were taken using a custom data acquisition system. The data acquisition system employed consisted of eight Syminex XFM82 3-decade programmable antialiasing filters having a 90 dB signal to noise ratio and simultaneous sample and hold, an Analogic LSDAS-16-AC-mod2 data acquisition board having 16 bit A/D converters, an Analogic CTRTM-05 counter-timer board, a Gateway 2000 P5-90 computer, and the HEM Data Corporation Snap-Master software. The sampling frequency is 3000 Hz and all channels are filtered at 100 Hz using the programmable anti-aliasing filters.