Autonomous Climbing Robot for Tank Inspection

Abstract

A detailed design of mechanisms is presented, along with the required electromagnetic system to attach the robot to the tank's wall. This is a novel mechanical design in which the robotic wheels rotate changing the instantaneous center of rotation. The robot mechanics is designed and simulated using Solidworks. The proposed electromagnetic system has to provide the necessary currents to control magnetic forces to be strong enough to attach the robot to the wall. However, because of the electromagnetic forces the control positioning method has to consider the strong Coulomb friction that appears against wheels movement. The sensor and acquisition system for navigation and control are also detailed. An inspection system has been proposed based on client/server architecture. Autonomous tracking and a mapping system powered by IMU sensor fusion is proposed. This design is suitable to be used along with the robot motion positioning strategy and, especially, the system must be robust to the disturbances and noise. The robot runs a server application and a remote PC is the client. The robot configuration has been developed with the capability of climbing up steel walls and navigating welding lines. The remote inspection system has been illustrated. A sensorial system and data fusion strategy to estimate the absolute robot position have been proposed. In order to track the desired trajectories, the robot's kinematics is described. Some simulations of the position control of the wheels and the complete control for the tracking performance were simulated using Matlab/Simulink. This robotic system has demonstrated the capability to track an accurate trajectory given by the defined kinematic equations.