Dj. Pines et Ah. Vonflotow, SPATIALLY CONVOLVING WAVE-PROPAGATION SENSORS FOR STRUCTURAL CONTROL - PART I - ANALYTICAL DEVELOPMENT FOR ONE-DIMENSIONAL STRUCTURES, Journal of intelligent material systems and structures, 8(11), 1997, pp. 929-952
A novel method for sensing actual disturbance information which can pr
opagate along one-dimensional structural waveguides is developed. The
motivation for this work arises from the inability to realize most act
ive wave control designs using output information from physical measur
ements such as deflection, slope, curvature and internal shear force.
Often the use of actual physical measurements leads to instability and
suboptimal performance of certain active wave control loops. Thus, th
ere is a desire to develop wave-propagation filters which can extract
magnitude and direction of structural disturbances along dispersive an
d non-dispersive members. In this work a distributed wave sensing sche
me is reported which exploits the characterization of 1-dimensional st
ructural motion in terms of traveling waves. This form of the solution
is then combined with distributed sensors to convolve future and past
measurements into a single temporal signal to overcome the problem of
causality and spatial aliasing inherent in discrete sensor approaches
. Thus, by imposing specific shapes to spatially convolving sensors, i
t is possible to combine the output of these sensors with point measur
ements to observe directional propagating wave components. Because thi
s method requires some approximation of the spatial domain, there will
be errors due to spatial discretization and truncation. This work add
resses these issues and presents analytical results for one-dimensiona
l structural elements.