Vibration control for two dimensional wire driven positioning robot

The vibration reduction control of a two dimensional wire driven positioning control robot is presented. Generally, a robotic arm has a cantilever structure in order to obtain a wide working space. Unfortunately, the cantilever structure requires a large drive mechanism and a lot of power. However, when the wrist of the robotic arm is suspended, the cantilever structure can be avoided, and therefore only a compact and small power mechanism is required. However, an unexpected problem of vibration occurs since the robot hand is suspended by wires. On the other hand, the controlled object can be modeled as a two mass dynamical system. Hence, we propose control schemes to avoid the vibration. When the displacement between the two mass dynamical systems is detected, and the displacement signal is included in the closed control loop of the first mass system, then better control response would be expected. It had been confirmed that the vibration was reduced effectively by using the proposed scheme.