Modeling and vibration control of aerial vehicles [robotic live-line maintenance]

Many robotized manipulator systems for live-line maintenance work are used to avoid the risk of electrical shock, the danger of falling from a high place, the requirement of heavy labor and so on. However,the efficiency of the system is not so high compared with the direct hot-line work using rubber-insulated gloves because the manipulator itself vibrates together with the bucket and boom due to the disturbance forces such as the inertial force caused by the position change, the wind force, and the reaction force of the manipulator. Therefore, it is necessary to suppress the vibration of the bucket by using an appropriate actuator. The paper presents a scheme to actively control the vertical vibration of these aerial vehicles due to the disturbances such as the sudden change of derricking angle and the external forces by using a small plunger attached to the derricking cylinder. Simulations show that the 1st mode vibration is suppressed efficiently by the proposed method without exciting the higher modes' vibration. A detailed mathematical model of the aerial vehicle, its vibration characteristics, detection method of the 1st mode vibration and the controller design based on the lag-element and the disturbance observer are described.