Broadband vibration compensation of a plate with piezoelectric actuators/sensors
The objective of this box is to achieve broadband reduction of the vibrations of a plate. A vibration generated by a noise source on the plate is considerably reduced by means of piezoelectric actuators and sensors. This leads to an effective reduction in the audible sound on the side opposite the noise source. The noise source can be of various types; in this case it is a loudspeaker. The area of application of vibration compensation is wherever position or weight play a role. The type of plate is of no significance for the operating principle, so it could also be an arched housing, for example.
PLATE (actively vibration-damped)
Material PMMA; area within the fixation 760 × 560 mm; thickness 10 mm; lowest natural frequencies 87 Hz, 136.5 Hz, 193 Hz
ENCLOSURE (passively damped)
Material MDF panels, wall thickness 38 mm (rear panel 57 mm), dimensions 840 x 640 x 510 mm
PIEZO ACTUATORS | SENSORS
Patch ‘DuraActTM‘, 35 x 60 mm, material PIC 255, glued (two-component adhesive), 4 sensors, 28 actuators (single-sided), electr. voltage +/-100 V (-250 to 1000 V maximum)
Real time system dSpace controller board 1103, four inputs for the sensors + 1 input for switching on the controller, four outputs for the actuator groups, modal control—the amplitudes of the first three modular forms can be determined by appropriate addition or subtraction of the sensor signals. Each mode is then controlled by its own P controller (including high pass and low pass). The correcting variables are superimposed with the correct sign at the outputs.
AREAS OF APPLICATION
Rectangular flat or arched discs or plates, window panes, machinery covers or housings, enclosures of electrical or household appliances
Reduction of the vibration speed of the plate by approx. 20 dB, reduction of the sound pressure by approx. 20 dB, broadband reduction of the sound pressure in the range of 50 Hz to 150 Hz
Please contact us for further information!