Body torque modulation for a microrobotic fly

The Harvard Microrobotics Lab has previously demonstrated the world´s first at-scale robotic insect capable of vertical takeoff with external power. Both of the robot´s wings were driven by a single power actuator and 1-DOF mechanical transmission-making independent control of both wings, and therefore asymmetric flapping and the generation of a net body torque, impossible. This paper presents a method to modulate body torques by altering the kinematics of each wing transmission independently, via the introduction of two additional control actuators. Theoretical kinematic and dynamic predictions based on a pseudo-rigid body model are compared to the observed wing trajectories. Controllable body torques are necessary for the development of control algorithms for eventual stable hovering and free flight.