Hierarchical Hybrid Control: a Case Study

A case study of the difficulties associated with the design of hybrid control systems is presented. We use the Intelligent Vehicle Highway System (IVHS) architecture of [1, 2], a system that involves both continuous state and discrete event controllers as our example of a hierarchical hybrid system. We point out that even though conventional analysis tools suggest that the proposed design should fulfill certain performance requirements simulation results show that it does not. We consider this as an indication that the conventional tools currently in use for the design and verification of control systems may be inadequate for the design of hierarchical control of hybrid systems. 1 Introduction The term hybrid system is used to describe a large and varied class of systems. A large class of hybrid systems can be described by the architecture of Figure 1. A typical hybrid system is arranged in two (or more) layers [3, 4]. Different levels of abstractions of the plant model are used at ea..