  In this paper, we illustrate a new correct-by-construction switching
controller for a power converter with event-triggered measurements. The
event-triggered measurement scheme is beneficial for high frequency power
converters because it requires relatively low-speed sampling hardware and is
immune to unmodeled switching transients. While providing guarantees on the
closed-loop system behavior is crucial in this application, off-the-shelf
abstraction-based techniques cannot be directly employed to synthesize a
controller in this setting because controller cannot always get instantaneous
access to the current state. As a result, the switching action has to be based
on slightly out-of-date measurements. To tackle this challenge, we introduce
the out-of-date measurement as an extra state variable and project out the
inaccessible real state to construct a belief space abstraction. The properties
preserved by this belief space abstraction are analyzed. Finally, an
abstraction-based synthesis method is applied to this abstraction. We
demonstrate the controller on a constant on-time buck voltage regulator plant
with an event-triggered sampler. The simulation verifies the effectiveness of
our controller.
