Slip Suppression Control to Improve the Performance of a Mobile Cleaning Robot Under Different Road Surface Conditions

When iron ore and coal cargo are unloaded onto a ship, some of that cargo falls, and can eventually pollute the sea. As a countermeasure, workers clean the cargo hold doors, but this dangerous activity has caused fatal accidents due to falls. The use of robots in cleaning work has a problem. That is the occurrence of slippage when a compact and lightweight robot attempts to clear a heavy obstacle. In this research, we aim to suppress slippage by controlling the driving force of the cleaning robot according to changes in the suiface conditions. We proposed a slip suppression control system that achieves slip suppression by controlling the driving force according to the estimated variation of the friction coefficient. In order to verify the effectiveness of the proposed method, we produced a test course with essential features of a work site, and then we carried out a heavy load transport test of the cleaning robot. We demonstrated an effective slip suppression system for the lightweight robot that can respond to variable friction on a suiface that changes as it is cleaned.