A Novel Autonomous Climbing Robot for Cleaning an Elliptic Half-Shell

Abstract

In this chapter, based on analyzing the characteristics of the working target, a new kind of autoclimbing robot is proposed, which is used for cleaning the spherical surface of the National Grand Theatre in China. The robot's mechanism and its unique aspects are presented in detail. A distributed controller based on a CAN bus is designed to meet the requirements of controlling the robot. The control system is divided into six parts, five CAN bus control nodes and a remote controller, which are designed and established based mainly on the microprocessor P80C592. Then the motion functions are described in detail. From the safety point of view, the process of climbing from one strip to another is very dangerous because the robot has to adapt to the outer shape of the building. Additionally, this robot has to be quite big in order to realize all necessary functions. Therefore, in designing this mechanism and its controls, an equilibrium between safety and size has to be reached. This is why the kinematics model of the climbing process is introduced. For system design and control purposes, the dynamics of the robot are calculated by applying the Lagrange equation. The force distribution of the front and rear supporting mechanisms is computed in a way that ensures the safety of the climbing process. After that, a new approach to path planning for wall-cleaning robots is presented considering movement security, cleaning efficiency and the percentage of cleaning coverage. The successful on-site test confirms the principles described above and the robot's ability to work on a spherical surface.