From Control Systems to Control Software

This article describes an approach to documenting control programs, whereby the control program code is annotated with logical expressions describing the set of reachable program states. This approach constitutes the application of the Floyd-Hoare paradigm to control programs. It is shown that domain knowledge gathered by control theory about control-system specifications is applicable to developing stability and performance proofs of the corresponding control programs. The analyses discussed in this article can be used in various contexts. In particular, the analyses can be used in an autocoding environment, whereby diagram-based specifications in Simulink or other languages can be turned into formally annotated target codes with extensive proofs of stability and performance. These proofs are tightly woven in the codes, which can then be verified independently by a proof checker.