The Temporal Logic of the Tower Chief System

The purpose is to describe the logic used in the reasoning scheme employed in the Tower Chief system, a runway configuration management system. First, a review of classical logic is given. Defensible logics, truth maintenance, default logic, temporally dependent propositions, and resource allocation and planning are discussed

An expert system for temporal planning with an application to runway configuration management

January 24, 1991Also issued as a Ph. D. thesis, Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1991Includes bibliographical references (p. 100-105)This thesis describes an expert system to aid in the management of operations in complex qualitative domains characterized by multiple parallel activities with time-critical relationships. An extension to "standard" temporal logic required for reasoning about inferred allocation of resources and a detailed representation of temporally dependent facts, including persistence, is presented. The non-linear planning paradigm commonly used in planning programs is extended into the temporal domain to facilitate scheduling as well as ordering of plan steps. This enhancement requires new structures and analytical methods for the detection and resolution of serendipitous interactions and conflicts between proposed schedules. A computer implementation of these concepts is discussed in detail. The expert system is organized into three modules: the time map manager or temporal database manager which stores, organizes, and retrieves time dependent knowledge; the temporal system analyzer which uses this knowledge to forecast and analyze domain dynamics; and the planner/scheduler which formulates and schedules activities in order to satisfy goals generated by the temporal system analyzer. Finally, Tower Chief, an application of the system to scheduling runway configuration changes and maintenance at large airports, is described.Research supported by the National Aeronautics and Space Administratio

PI in the sky: The astronaut science advisor on SLS-2

The Astronaut Science Advisor (ASA, also known as Principal-Investigator-in-a-Box) is an advanced engineering effort to apply expert systems technology to experiment monitoring and control. Its goal is to increase the scientific value of information returned from experiments on manned space missions. The first in-space test of the system will be in conjunction with Professor Larry Young's (MIT) vestibulo-ocular 'Rotating Dome' experiment on the Spacelab Life Sciences 2 mission (STS-58) in the Fall of 1993. In a cost-saving effort, off-the-shelf equipment was employed wherever possible. Several modifications were necessary in order to make the system flight-worthy. The software consists of three interlocking modules. A real-time data acquisition system digitizes and stores all experiment data and then characterizes the signals in symbolic form; a rule-based expert system uses the symbolic signal characteristics to make decisions concerning the experiment; and a highly graphic user interface requiring a minimum of user intervention presents information to the astronaut operator. Much has been learned about the design of software and user interfaces for interactive computing in space. In addition, we gained a great deal of knowledge about building relatively inexpensive hardware and software for use in space. New technologies are being assessed to make the system a much more powerful ally in future scientific research in space and on the ground

Presentations from the MIT/Industry Cooperative Research Program Annual Meeting, 1991

Cover titleMay 1991Includes bibliographical reference