Computed Torque Control for an Aerial Robot Equipped with Two Coaxial Rotors Having a 2-DOF Tilt Mechanism

Since all of the rotors' configuration in conventional drone are fixed to the fuselage, the attitude of the drone needs to be tilted during revel flight motion in the application of human transportation, delivery of goods, etc. It is also difficult for such drones to maintain a stable flight in the proximity inspections of bridges, buildings, etc. Therefore, we have already proposed an aerial robot that has two tilted coaxial rotors so as to realize multifunctional locomotion modes, where some excrements have been conducted to verify the omnidirectional locomotion modes for the robot to traveling on the ground. In this research, we present a computed torque control strategy for the robot, because a model of the robot can be simplified to a fully actuated model, which has six actuator inputs and six generalized coordinate outputs. Thus, a control allocation problem of the system is solvable, where a coordinate transformation is used to simply the allocation problem. Some simulations are demonstrated to verify the effectiveness of the computed torque control strategy for the robot.