On-line robot motion planning in dynamic environments

Abstract

In a constantly changing and partially unpredictable environment, robot motion planning must be on-line. The planner then receives a continuous flow of information about occurring events and generates motoin plans. While planned motions are being executed, new plans are generated in response to incoming events. This thesis describes an on-line planner for two cooperating arms whose task is to grab parts of various types on a conveyor belt and transfer them to their respective goals while avoiding collision with obstacles. Parts arrive on the belt in random order, at any time. Both goals and obstacles may be dynamically changed. This scenario is typical of manufacturing cells serving machine-tools, assembling products, or packaging objects. The proposed approach breaks the overall planning problem into subproblems, eachinvolving a low-dimension configuration or configuration-time space, and orchestrates very fast primitives solving these subproblems. This thesis describes this approach and...