A computer program for scheduling the activities of multiple agents that share limited resources has been incorporated into the Automated Scheduling and Planning Environment (ASPEN) software system, aspects of which have been reported in several previous NASA Tech Briefs articles. In the original intended application, the agents would be multiple spacecraft and/or robotic vehicles engaged in scientific exploration of distant planets. The program could also be used on Earth in such diverse settings as production lines and military maneuvers. This program includes a planning/scheduling subprogram of the iterative repair type that reasons about the activities of multiple agents at abstract levels in order to greatly improve the scheduling of their use of shared resources. The program summarizes the information about the constraints on, and resource requirements of, abstract activities on the basis of the constraints and requirements that pertain to their potential refinements (decomposition into less-abstract and ultimately to primitive activities). The advantage of reasoning about summary information is that time needed to find consistent schedules is exponentially smaller than the time that would be needed for reasoning about the same tasks at the primitive level.
This program was written by Bradley Clement, Anthony Barrett, Gregg Rabideau, and Russell Knight for Caltech for NASA's Jet Propulsion Laboratory.
This software is available for commercial licensing. Please contact Don Hart of the California Institute of Technology at (818) 393- 3425. Refer to NPO-30340.
This Brief includes a Technical Support Package (TSP).
Abstract-Reasoning Software for Coordinating Multiple Agents.
(reference NPO-30340) is currently available for download from the TSP library.
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Overview
The document presents a technical support package from NASA's Jet Propulsion Laboratory (JPL) detailing a software program designed for the scheduling and coordination of multiple agents, such as spacecraft and robotic vehicles, particularly in the context of scientific exploration. This software is integrated into the Automated Scheduling and Planning Environment (ASPEN) and employs an iterative repair planner/scheduler that operates at abstract levels to enhance the efficiency of resource allocation among agents.
Key features of the software include its ability to summarize state and resource information for activities at various levels of abstraction. By reasoning about this summarized information, the software can centrally plan and schedule activities for multiple rovers, effectively coordinating their interactions over shared resources. This approach allows for the identification and resolution of potential conflicts, such as path collisions and bandwidth over-subscription, before they occur.
The software generates models and initial schedules for rovers using the ASPEN Modeling Language, facilitating the exploration of science targets along designated paths. It utilizes Multiple Traveling Salesmen scheduling routines to optimize the scheduling process. Additionally, the software translates rover models into new ASPEN models by calculating and incorporating resource and state requirements for abstract activities. This translation is crucial for the Generalized Timeline Software (GTL), which interprets the abstract characterizations to identify and repair conflicts in the overall schedule.
The document emphasizes the advantages of reasoning at an abstract level, which significantly reduces the time required to find consistent schedules compared to reasoning at the primitive level. The software's heuristic routines efficiently choose and decompose abstract activities into more detailed ones, determining appropriate methods for conflict resolution among both abstract and detailed activities.
The program was developed by a team of researchers from Caltech for NASA and is available for commercial licensing. The document also includes references to related works and highlights the potential applications of the software beyond space exploration, such as in production lines and military maneuvers.
Overall, this software represents a significant advancement in the field of autonomous multi-agent coordination, promising to enhance the effectiveness of missions involving multiple spacecraft and robotic systems.
