Hierarchical Hybrid Control: A Case Study

A case study of the difficulties encountered in the design of hierarchical, hybrid control systems is presented. As our example we use the Intelligent Vehicle Highway System (IVHS) architecture proposed for vehicle platooning, a system that involves both continuous state and discrete event controllers. 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 controllers for hybrid systems. The analysis also indicates certain shortcomings of the current IVHS design. We propose solutions to fix these problems.