Abstract:
Active control techniques when coupled with the smart material technology plays a vital role in mitigating the adverse e_ects of vibrations from exible structures. In the present work, analysis of vibration control problem is considered in a detailed manner on a cantilever structure platform. The beam structure utilized in present work corporates the e_ect of shear in it, which shows correction over the conventional beam model. Finite element analysis has been carried out in order to approximate the beam model. Elemental length of this passive beam structure is sandwiched between the layer of sensor and actuator which are made from the piezoelectric material. Thus, making the overall structure, an intelligent structure equipped with sensor and actuator.
In the present work, the analysis is carried out in the presence of impulse and sinusoidal disturbances. The frequency of the sinusoidal disturbance is matched with the dominant mode frequency of the structure, thereby creating resonance condition. The adverse e_ects of the disturbances are minimized by the use of two discrete time control schemes. One is Discrete time Linear Quadratic Regulator (DLQR) control which is an optimal technique. This strategy is coupled with full order observer. The other scheme used in this work is Discrete Sliding Mode Control (DSMC). This scheme incorporates an output feedback, instead of utilizing an observer. Thereby, making system cost e_ective as the necessity of the observer is eliminated.
Lastly, position control of link manipulator system which is a kind of exible structure has been carried out. To achieve position tracking two control strategies have been investigated. One is Discrete time LQR control with full order observer and the other is based on Integral Fast Output Sampling (IFOS) Control algorithm. System of Linear Matrix Inequalities (LMI's) are solved in order to obtain the gain of the IFOS control. These LMI's are solved with the help of CVX toolbox of MATLAB. Finally the conclusions are drawn for the whole work.