Dynamic modeling and vibration control of a single-link flexible manipulator using a combined linear and angular velocity feedback controller.

The use of lightweight, thin flexible structures creates a dilemma in the aerospace and robotic industries. While increased operating efficiency and mobility can be achieved by employing such structures, these benefits are compromised by significant structural vibrations due to the increased flexibility. To address this problem, extensive research in the area of vibration control of flexible structures has been performed over the last two decades. The majority of the research has been based on the use of discrete piezoceramic actuators (PZTs) as active dampers, as they are commercial availability and have high force and bandwidth capabilities. Many different active vibration control strategies have previously been proposed, in order to effectively suppress vibrations. The synthesized vibration controllers will be less effective or even make the system to become unstable if the actuator locations and control gains are not chosen properly. However, there is currently no quantitative procedure that deals with these procedures simultaneously. This thesis presents a theoretical and numerical study of vibration control of a singlelink flexible manipulator attached to a rotating hub, with PZTs bonded to the surface of the link. A commercially available fibre optic sensor called ShapeTape is introduced as a new feedback sensing technique, which is complemented by a quantitative and definitive model based procedure for selecting the individual PZT locations and gains. Based on Euler-Bernoulli beam theory, discrete finite element equations are obtained using Lagrange’s equations for a PZT-mounted beam element. Slewing of the flexible link by a rotating hub induces vibrations in the link that persist long after the hub stops rotating. These vibrations are suppressed through a combined scheme of PD-based hub motion control and proposed PZT actuator control, which is a composite linear (L-type)