  Software engineering of modular robotic systems is a challenging task,
however, verifying that the developed components all behave as they should
individually and as a whole presents its own unique set of challenges. In
particular, distinct components in a modular robotic system often require
different verification techniques to ensure that they behave as expected.
Ensuring whole system consistency when individual components are verified using
a variety of techniques and formalisms is difficult. This paper discusses how
to use compositional verification to integrate the various verification
techniques that are applied to modular robotic software, using a First-Order
Logic (FOL) contract that captures each component's assumptions and guarantees.
These contracts can then be used to guide the verification of the individual
components, be it by testing or the use of a formal method. We provide an
illustrative example of an autonomous robot used in remote inspection. We also
discuss a way of defining confidence for the verification associated with each
component.
