The objective of this research is to develop abstractions by which the controlled process and computation state in a cyber-physical system can both be expressed in a form that is useful for decision-making across real-time task scheduling and control actuation domains. The approach is to quantify the control degradation in terms of response time, thereby tying computer responsiveness to the controlled process performance and use such cost functions to effectively manage computational resources. Similarly, control strategies can be adjusted so as to be responsive to computational state. Unmanned aircraft will be used as vehicles to demonstrate our approach. The intellectual merit of this research is that it takes disparate fields, control and computation, and builds formal abstractions in both the computation-to-control and control-to-computation directions. These abstractions are grounded in terms of physical reality (e.g., time, fuel, energy) and encapsulate in a form comprehensible and meaningful to each domain, the relevant attributes of the other domain. This research is important because cyber-physical systems are playing an increasing role in all walks of life. It will allow design approaches to be systematic and efficient rather than ad hoc. It is based on a large body of our prior work that has begun to successfully bridge the representational and algorithmic gap that separates the control and computer science & engineering communities. Dissemination of results will be by means of courses in our universities, instructional materials, research and tutorial publications and industry collaboration (e.g., General Motors R&D). The plan is to hire minority/female students.
Cyber-physical systems are playing an ever-increasing role in all walks of modern life but they have traditionally been designed in an ad hoc way. Their increasing complexity, however, makes such a design approach impractical and highly inefficient. This project has laid the foundations for a more systematic and efficient design methodology, which will be key to the development of cheaper, better, and more environment-friendly products and systems. Specifically, this project has taken computation and control, and built formal abstractions in both the computation-to-control and control-to-computation directions. These abstractions are grounded in terms of physical reality (e.g., time, fuel, energy, etc.) and encapsulate in a form comprehensible and meaningful to each domain the relevant attributes of the other domain. They can be used to improve overall computational and physical actuation resource efficiency across computational and controlled-plant domains. The formal approach developed in this project allows the relevant aspects of each domain to become available, in a readily accessible form, to workers in the other domain. This project has been pursued with a close collaboration with members of the GM R&D Center who have participated in formulation of research ideas and postential application of our design approach to automotive systems, such as automotive cruise control. In addition, the research results have been migrated to the classroom, in the training of both control and computer engineers and scientists.
