  This paper presents a control design method that achieves safety for systems
with unmodeled dynamics at the plant input. The proposed method combines
control barrier functions (CBFs) and integral quadratic constraints (IQCs).
Simplified, low-order models are often used in the design of the controller.
Parasitic, unmodeled dynamics (e.g. actuator dynamics, time delays, etc) can
lead to safety violations. The proposed method bounds the input-output behavior
of these unmodeled dynamics in the time-domain using an alpha-IQC. The
alpha-IQC is then incorporated into the CBF constraint to ensure safety. The
approach is demonstrated with a simple example.
