Parameterized scripts for motion planning

Presents an approach for real time planning and execution of the motions of complicated robotic systems. The approach is motivated by the observation that a robot´s task can be described as a series of simple steps, or a script. The script is a general template which encodes knowledge for a class of tasks and is fitted to a specific instance of a task. The script receives information about its environment in the form of parameters, which it uses to bind variables in the template and allows it to deal with the current task conditions. Changes or variations in the robot´s environment can be easily handled with this parameterized script approach. New tasks for the robot to perform can be added in the form of subscripts, which could handle exceptional cases. We apply this approach to the task of autonomous excavation, and demonstrate its validity on an actual hydraulic excavator. We obtain good results, with the autonomous system approaching the performance of an expert human operator