  The verification of cyber-physical systems operating in a safety-critical
environment requires formal system models. The validity of the verification
hinges on the precision of the model: possible behavior not captured in the
model can result in formally verified, but unsafe systems. Yet, manual
construction is delicate and error-prone while automatic construction does not
scale for large and complex systems. As a remedy, this paper devises an
automatic construction algorithm that utilizes information contained in
artifacts of the development process: a runtime monitoring specification and
recorded test traces. These artifacts incur no additional cost and provide
sufficient information so that the construction process scales well for large
systems. The algorithm uses a hybrid approach between a top-down and a
bottom-up construction which allows for proving the result conservative, while
limiting the level of over-approximation.

Formal Languages and Automata Theory