A mixed approach to rigorous development of control designs

The control law of a typical industrial system has a modulating (continuous) component and a sequential/modal component. Control engineers are traditionally good at specifying the modulating part of the control laws unambiguously, correctly and completely. Software engineers have similar skills on the sequential component. In this paper, we discuss a mixed approach in which software and control engineers collaborate to develop control designs. The proposed approach is based upon a novel modeling notation called RRM diagrams. A formal refinement method based on RRM diagrams is developed which enables the development of sequential components as well as control designs. We illustrate our method by considering the case study of a simplified Adaptive Cruise Controller (ACC).