An　active　control　methodology　is　presented　for　suppressing　the　vibratory　response　of　flexible　redundant　manipulators　with　bonded　piezoceramic　actuators　and　strain　gage　sensors.　Firstly,　the　dynamic　equation　of　the　manipulator　is　decoupled　by　means　of　the　complex　mode　theory　and　the　state-space　expression　of　the　controlled　system　is　developed.　Secondly,　a　continuous　linear　quadratic　regulator　(LQR)　state　feedback　controller　is　designed　based　on　the　minimum　principle.　Thirdly,　a　full-order　Luenberger　state　observer　featuring　an　assigned　degree　of　stability　is　determined　via　the　duality　between　control　and　estimation.　Finally,a　numerical　simulation　is　carried　out　on　a　planar　3R　flexible　redundant　manipulator.　The　simulation　results　reveal　that　the　dynamic　performance　of　the　system　is　improved　rapidly　and　significantly.