Common light-weight structures are often subjected to extensive vibrations contributing to mechanical damages and failures; thus, active vibration control of them is of crucial importance. In this article, a fully clamped orthotropic square plate is investigated so as to compensate transversal vibrations. The square plate is bonded at the top and bottom with four piezoelectric actuators. Rectangular piezoelectric patches are polarized along the Z-axis and a voltage across their thickness is applied to them in order to control vibrations. The first-order shear deformation plate theory is employed to model the orthotropic plate. After that, the generalized differential quadrature method is utilized to convert the continuous equations of plate motion to discrete ones. Finally, both the LQR and fuzzy logic controller are used in order to compensate plate vibrations.