Experimenting with Hybrid Control

Abstract

There is a growing realization among educators andemployers that students of automatic control should be encouraged tothink of the subject in broader terms. The systems approach shouldembrace communication requirements, signal processing, data logging,etc. all the way up to and including the level of complexity suggestedby the phrase "enterprise control." Designing a controlexperiment that is illustrative and instructional in this broadersense presents a number of challenges beyond those discussedabove. The systems under consideration must be very flexible. Ofcourse the hardware must continue to be reliable and relatively easyto understand at an intuitive level. They should also reflect thecomplexity of purpose and the possibility of multi-modal operationthat one expects to find in complex systems. With these qualities inmind, we have assembled and extensively exercised an experimentalhybrid control system for use in an instructional/research laboratoryat Harvard. Our goal with this paper is to describe for others thestructure of the system and to present a sample of the experimentsthat were facilitated by it.An important feature of the facility we describe is that it uses severaltypes of sensing modalities including position sensing, tactile sensingand more conventional vision sensing. It can interact with objectsof different complexity and is subject to communication constraints arising in a completelynatural and generic way. In constructing it we have used off-the-shelfcomponents wherever possible and made choices with an eye towardflexibility and reliability.The research and scientific content in this material has been submitted to the IEEE Control Systems Magazine.