♥ framework of National Project „Intelligent
system for simultaneous control and
monitoring of structures", PNCDI2 II
Partnerships, Project 81 031 SIMOCA,
2007-2010
♦ hardware system (Figs. 1-3)
• 200x500x1.25 mm cantilevered aluminum plate
on which the strain gauges (SGD-5/350-LY11,
Omega Engineering) and MFC actuators
(M8557P1MFC, Smart Materials) are bonded
• signal conditioners (OM5-WBS-3-C, Omega
Engineering) are converting strain gauges bridge
signals to high level and for bridge supply
• TREK high voltage amplifiers (PA05039,
—500V÷+1500V) for the MFC actuators supply
• PC with implemented control laws in LabView:
robust LQG/LTR or robust H∞ control
• Data Acquisition Card (NI PCIe-6259) used for
applying to the MFC actuator the control signal,
amplified by the high voltage amplifiers
• the first four natural frequencies (Hz): 5, 26, 31,
157, pseudo-identification by impulse excitation
• the “chirp” type monitoring signal and disturbance
signal are generated by a functions generator
(Velleman or LabView), as input signals to the
MFCs
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FIG. 1 – DEMONSTRATOR OF INTELLIGENT STRATEGY FOR MONITORING AND ACTIVE CONTROL
|
FIG. 2 – PHILOSOPHY OF SIMULTANEOUSLY ACTIVE CONTROL AND HEALTH MONITORING Details in: Ursu, I., G. Tecuceanu, A. Toader, V. Berar (2010), Simultaneous active vibration control and health monitoring of structures. Experimental results, INCAS Bulletin, 2, 2, 114-127 |
FIG. 3 – ELECTRIC CIRCUIT FOR LOW COST MONITORING |
♥ tentative conclusions
• the control (its presence or
absence) doesn’t significantly
influence the impedance
signature, the only important
and positive effect being that
of increasing the operation
time of the structure
• illustration of active LQG
control efficiency: Piezo MFC1
is used in the triple role of
disturbance insertion, insertion
control insertion and sensor for
measuring strain, simplified via
a bridge circuit
• control efficiency:
about 8 dB attenuation
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FIG. 4 – a) ACTIVE CONTROL EFFICIENCY; b) SOME OF RESEARCH TEAM MEMBERS |