A robust estimator for wall following

An early goal in autonomous navigation research is to build a research vehicle which can travel through office areas and factory floors, A simple strategy for directing the robot's movement in a hallway is to maintain a fixed distance from the wall. The problem is complicated by the fact that there are many factors in the environment, such as opened doors, pillars or other temporary objects, that can introduce 'noise' into the distance measure. To maintain a proper path with minimum interruption, the robot should have the ability to make decisions, based on measurements, and adjust its course only when it is deemed necessary. This report describes a new algorithm which enables the robot to move along and maintain a fixed distance from a reference object. The method, based on a robust estimator of the location, combines information from earlier measurements with current observations from range sensors to effectively produce an estimate of the distance between the robot and the object. A simulation study, showing the trajectories generated using this algorithm with different parameters for different environments, is presented.