Test Driven Design of a System for Removing Graffiti from Retroreflective Signs

Abstract

The remediation of graffiti from highway signs is a labor intensive and potentially hazardous task. Accordingly, this paper presents the initial design stages of tools that could be used to clean graffiti from signs. Two design concepts are presented – one for pedestrian accessible signs and one for overhead signs – and the concepts share a common end-effector design. The paper is primarily aimed at developing an understanding of the interactions between the end-effector's scrubbers and the sign's resultant retroreflectivity. This is accomplished through a factorial experiment to test the effects of load, speed, brush type, and sign surface material on the retroreflectivity. This work shows the feasibility of such a tool for cleaning graffiti from signs along the roadways.