A Control Architecture for Robotic Excavation in Construction

This article presents a hybrid control architecture developed for robotic excavation. The lower-level controllers are designed using a combination of sliding mode control and fuzzy logic control. Control strategies at the higher level involve task decomposition in association with statecharts, and task execution and verification. Typical machine tasks are decomposed into subtasks and/or states. Graphical notation is introduced to facilitate software implementation of the control flow within statecharts. For each subtask, a statechart via its states at different priority levels selects to activate a number of corresponding lower-level controllers as a result from resolution of the machine resources and the control and data flows. The control architecture is designed with a view to managing hierarchical complexity, and facilitating the application of formal verification methods, software reuse, and lower-level control results. Field test results through the task of digging a trench are provided to demonstrate the feasibility of robotic excavation in moving toward construction automation. ∗To whom correspondence should be addressed. E-mail: quangha@ eng.uts.edu.au.