Modal control of beam flexural vibration

An active control system was developed to control the flexural vibrations o f a beam with a modal filtering with only one secondary actuator. Segmented piezoelectric actuators and sensors were used for driving and sensing the bending beam vibrations. The primary actuator was fed by a broadband random disturbance signal in order to excite the first five modes of the structur e. However, only the second to fifth modes were controlled. The control alg orithm was implemented on a DSP board and the input and output signals were filtered using high order low pass filters. These filters, implemented on the DSP board avoid the degrading effect on the control performances of the higher order modes and which are not controlled. The modal filtering was a chieved by computing. To this end, it is based on a previous identification procedure. This latter models, in one step, the dynamics of the structure and also the transfer function of the electronic circuits of the controller . The identified filtered modes were then used to compute the gain matrix u sing a LQR technique (linear quadratic regulator). Simulations of the activ e control were carried out and practical implementation of the control algo rithms was pet-formed. Experimental and simulation results were then compar ed and discussed. (C) 2000 Acoustical Society of America. [S0001-4966(00)03 804-2].