Automatic control systems typically incorporate legacy code and components that were originally designed to operate independently. Furthermore, they operate under stringent safety and timing constraints. Current design strategies deal with these requirements and characteristics with ad hoc approaches. In particular, when designing control laws, implementation constraints are often ignored or cursorily estimated. Indeed, costly redesigns are needed after a prototype of the control system is built because of missed timing constraints and subtle transient errors. In this paper, we use the concepts of platform-based design to develop a methodology for the design of automatic control systems that builds in modularity and correct-by-construction procedures. We illustrate our strategy by describing the (successful) application of the methodology to the design of a time-based control system for a helicopter-based uninhabited aerial vehicle.

Abstract An O ( n log n ) heuristic for the Euclidean Steiner Minimal Tree (ESMT) problem is presented. The algorithm is based on a decomposition approach which first partitions the vertex set into triangles via the Delaunay triangulation, then “recomposes” the suboptimal Steiner Minimal Tree (SMT) according to the Voronoi diagram and Minimum Spanning Tree (MST) of the point set. The ESMT algorithm was implemented in FORTRAN‐IV and tested on a number of randomly generated point sets in the plane drawn from a uniform distribution. Comparison of the O ( n log n ) algorithm with an O ( n 4 ) algorithm clearly indicates that the O ( n log n ) algorithm is as good as the previous O ( n 4 ) algorithm in achieving reductions in the ratio SMT/MST of the given vertex set. This is somewhat surprising since the O ( n 4 ) algorithm considers more potential Steiner points and alternative tree configurations.