Concepts,methods, and languages for building timely intelligent systems

We describe the ABE/RT toolkit—a set of design, development, and experimentation tools for building time-stressed intelligent systems-and its use for the Lockheed Pilot's Associate application. We use the termtimely systems to refer to systems with hard real-time requirements for interacting with a human operator or other agents with similar time-scales. The ABE/RT methodology is based on a philosophy of rigorous engineering design in which the application developer works to guarantee the system's timeliness by identifying the various events which require timely responses, determining the worst-case frequencies of these events and the deadlines and durations of the tasks that respond to the events, and then verifying that the run-time system has enough processing resources to complete all mandatory taks by their deadlines. We believe this is the only way in the near-term to build complex real-time intelligent systems that will be reliable enough for critical applications with demanding users. The ABE/RT Toolkit contains a set of languages for specifying the structure and behavior of timely systems, together with tools to simulate those models, log and analyze data collected during simulation runs, predict an application's performance on a specified target hardware architecture, and deploy the application on the target architecture.This research was partially funded by the Defense Advanced Research Projects Agency, 1400 Wilson Blvd., Arlington, VA 22209, under contracts F30602-85-C-0135 and F33615-85-C-3804, administered by the Air Force Systems Command, Rome Air Development Center and the Air Force Cockpit Technology Directorate, Wright Research and Development Center, respectively. Use of this material, including copying, by the U.S. government is permitted in accordance with the terms of those contracts.