  Flying animals, such as bats, fly through their fluidic environment as they
create air jets and form wake structures downstream of their flight path. Bats,
in particular, dynamically morph their highly flexible and dexterous armwing to
manipulate their fluidic environment which is key to their agility and flight
efficiency. This paper presents the theoretical and numerical analysis of the
wake-structure-based gait design inspired by bat flight for flapping robots
using the notion of reduced-order models and unsteady aerodynamic model
incorporating Wagner function. The objective of this paper is to introduce the
notion of gait design for flapping robots by systematically searching the
design space in the context of optimization. The solution found using our gait
design framework was used to design and test a flapping robot.
