A Large-scale Suction-based Climbing Parallel Robot for Wall Painting Application

This paper presents a large-scale climbing robot that employs a parallel mechanism with three translational degrees of freedom as its locomotion method. Using a robot frame having a triangular pyramid shape, the robot provides a good stability during the locomotion and task execution. Three suction cups, called the perimeter cups, are attached to the vertices of the robot's pyramid base, whereas three other suction cups called the middle cups, are attached to the end-effector of the parallel mechanism. The climbing motion is made by attaching and releasing the perimeter and middle cups one after another. The synchronization between the parallel mechanism's motion and the suction cups during locomotion, as well as the improved gait trajectory, was established to ensure successful climbing. The control scheme of the robot integrates the servo control, the suction control, and the application control in a modular fashion. The successful climbing of the robot proves the scalability of the proposed climbing robot using active suction cups with an optimized design. Finally, a painting application was presented to demonstrate the robot's capability to perform a wall painting task.