<title>Control of mobile robots in unstructured environments using discrete event modeling</title>

Abstract

Unstructured environments pose significant challenges to the operation and control of mobile robots. Thorough task planning is often not possible due to the unpredictable nature of the workspace environment. For example, in underground mining environments, the operator generally does not have accurate global knowledge of the environment, making it difficult or impossible to provide the mobile robot with sufficient information to navigate successfully to a desired destination. The unpredictability of the environment makes realtime sensing and decision making an essential component of the mobile robot. The formalism of discrete event systems is well suited for modeling the internal and external asynchronous events associated with the navigation of a mobile robot. This work proposes the use of a hierarchical Petri net-based discrete event technique to model the sensing and control systems of mobile robots in unstructured environments. The discrete event model can be monitored to provide the operator with realtime progress information. The paper describes a simulated mobile robot in a 3D graphics environment which is controlled by a discrete event model in order to demonstrating the modeling of navigation in unstructured environments.