VeriPhy: Verified Controller Executables from Verified Cyber-Physical System Models

Paper in proceeding, 2018

We present VeriPhy, a verified pipeline which automatically transforms verified high-level models of safety-critical cyberphysical systems (CPSs) in differential dynamic logic (dL) to verified controller executables. VeriPhy proves that all safety results are preserved end-to-end as it bridges abstraction gaps, including: i) the gap between mathematical reals in physical models and machine arithmetic in the implementation ii) the gap between real physics and its differentialequation models iii) and the gap between nondeterministic controller models and machine code. VeriPhy reduces CPS safety to the faithfulness of the physical environment, which is checked at runtime by synthesized, verified monitors. We use three provers in this effort: KeYmaera X, HOL4, and Isabelle/HOL. To minimize the trusted base, we cross-verify KeYmaera X in Isabelle/HOL. We evaluate the resulting controller and monitors on commodity robotics hardware.