COMPARISON OF SEVERAL STRATEGIES IN THE ACTIVE STRUCTURAL ACOUSTIC CONTROL USING STRUCTURAL STRAIN MEASUREMENTS

✍ Scribed by P. MASSON; A. BERRY

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 325 KB
• Volume: 233
• Category: Article
• ISSN: 0022-460X
• DOI: 10.1006/jsvi.1999.2839

✦ Synopsis

Two optimized approaches are herein proposed to lighten the real-time computation of the radiated acoustic power from planar structures using discrete strain measurements. These approaches are compared to a reference approach involving "nite di!erences reconstruction of the displacement "eld from the strain "eld. The "rst optimized approach allows the direct calculation of the radiated acoustic power from the discrete strain "eld while the second optimized approach employs an accelerated evaluation of the radiated acoustic power based on a wavelet transform of the displacement "eld. The evaluation of the radiated acoustic power from discrete strain values is experimentally assessed using the reference "nite di!erences approach and both optimized approaches. Piezoelectric "lm (PVDF) strain sensors are used for this validation as well as a feedforward "ltered-X LMS controller. Details on the real-time implementation of the cost functions are presented, especially on the o!-line adaptation of the control "lter. Formal comparisons using acoustic and vibration measurements are presented to better illustrate the control performance and mechanism of the di!erent approaches. Experimental results serve to demonstrate the interest of using the optimized approaches as compared to the reference approach and it is shown that a signi"cant gain in computational burden can be obtained using the proposed optimized approaches without sacri"cing the control performance.