Obstacle-Overcoming and Stabilization Mechanism of a Rope-Riding Mobile Robot on a Façade

Abstract

A two-rope driven mobile robot (TRDMR) that moves on the façade of a building by suspending it on a fiber rope is being developed. When the TRDMR is suspended from the rope on the façade, a function is needed to overcome the obstacle, and the additional moment generated in the working environment tilts the pitch angle and destabilizes the robot system. In this study,a new mechanism for overcoming obstacles and stabilizing posture for TRDMR is proposed. The pitch angle of the TRDMR can be controlled using the rope tension slider (RTS), which controls the point at which the tension of the rope acts on the robot. Therefore, it is possible to overcome obstacles of various heights and maintain a stabilized posture by completely adhering to the façade with only one actuator having a simple structure. Static and kinematic analysis were performed to know the position of the tension point to overcome the 300 mm obstacle, and the maximum additional moment that can maintain a stabilized posture when using the RTS was calculated through static analysis. It was verified that TRDMR with RTS can overcome a 300 mm obstacle on a 5.6 m high test bench. When an additional moment of approximately −75 Nm was applied, in the case of TRDMR without RTS, the pitch angle was inclined by −9.56 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^\circ$</tex-math></inline-formula> . In contrast, in the case of TRDMR with RTS, TRDMR was stabilized by keeping it horizontal.