Supervising Passenger Land-Transport Systems

Abstract

In this paper, we propose a supervisory control approach, based on controlled automata concepts, for the planning for online service-operations control of a new class of passenger land-transport systems ( PLanTSs). A PLanTS belongs to a class of dynamic demand-responsive transportation systems. Rapid advances in information and communication technologies are providing a new infrastructural and communications basis upon which higher levels of automation, flexibility, and integration in the development of such transportation systems can be achieved, but to achieve these necessitates the use of more formal approaches for system planning and design. The supervisory control theory of Ramadge and Wonham offers one such methodology, which presents the design for service-operations control as a formal synthesis of a modular supervisory controller. Importantly, the design solution is guaranteed to satisfy the given behavioral specifications in some optimal fashion, without blocking the completion of certain defined mandatory tasks. The supervisory design methodology is presented and illustrated in detail via what, in our opinion, is a simplified but realistic PLanTS model. A structural property of the PLanTS model is used to analytically establish the nonblocking property of the modular supervisory controller designed. All automaton models for the PLanTS and the behavioral specifications considered are provided, together with the automata design of the corresponding modular supervisor.