Design and motion analysis of load-carrying and transmit robot (LCT-Robot) for small openings

This paper proposes a Load-carrying and transmit robot (LCT-Robot), which is based on a novel modular joint, for the purpose of telemaintenance of the Tokamak First wall (FW). The LCT-Robot, which is installed on a Multipurpose transport cask (MTC) and plays the role of transmitting and load-carrying, has the adaptability to several of maintenance tasks by carrying different types of micro-robots. The transmission mechanism of LCT-Robot modular joint and structural “lightweight” design is comprehensively considered through establishing the geometric parameter constraint equations related to Tokamak FW. It can steadily provide the ability of long-distance transmitting and performs maintenance tasks when the weight of the micro-robot is changed. Without any gravity compensation, the LCT-robot equipped with ordinary drive motor can bear a wide range of load. It not only satisfies the higher load, but also enhances the efficiency of the drive motor. For avoiding frequent acceleration and deceleration of the LCT-robot, the entire process through small openings from the placement state (0-state) to the flattened state (3-state) is analyzed and the effective translational distance of MTC is confirmed. As a result, experiment verifies the effectiveness of the LCT-robot, which has a length of 2.95 meters and can smoothly pass through small openings (Width: 200 mm, Height: 250 mm).