Gs. Aglietti et al., A MODELING TECHNIQUE FOR ACTIVE CONTROL DESIGN STUDIES WITH APPLICATION TO SPACECRAFT MICROVIBRATIONS, The Journal of the Acoustical Society of America, 102(4), 1997, pp. 2158-2166
Microvibrations, at frequencies between 1 and 1000 Hz, generated by on
board equipment, can propagate throughout a spacecraft structure and
affect the performance of sensitive payloads. To investigate strategie
s to reduce these dynamic disturbances by means of active control syst
ems, realistic yet simple structural models are necessary to represent
the dynamics of the electromechanical system. In this paper a modelin
g technique which meets this requirement is presented, and the resulti
ng mathematical model is used to develop some initial results on activ
e control strategies. Attention is focused on a mass loaded panel subj
ected to point excitation sources, the objective being to minimize the
displacement at an arbitrary output location. Piezoelectric patches a
cting as sensors and actuators are employed. The equations of motion a
re derived by using Lagrange's equation with vibration mode shapes as
the Ritz functions. The number of sensors/actuators and their location
is variable. The set of equations obtained is then transformed into s
tate variables and some initial controller design studies are undertak
en. These are based on standard linear systems optimal control theory
where the resulting controller is implemented by a state observer. It
is demonstrated that the proposed modeling technique is a feasible rea
listic basis for in-depth controller design/evaluation studies. (C) 19
97 Acoustical Society of America. [S0001-4966(97)02510-1] PACS numbers
: 43.40.Dx, 43.40.Vn [CBB].