Structural Design, Control and Experimental Validation of a Novel Hexacopter with Synchronized-Tilting Rotors
Hui Zhou, Zhangyin Feng, Lei Ma, Yongkui Sun, Duo Zhao · 2023
A novel hexacopter with tiltable rotors is presented to tackle challenges of fully-actuated vehicles such as low ef-ficiency and excessive actuators. The tilting motion of all rotors is coupled together by bevel gears, which requires only one additional servo motor to synchronize the tilting of all rotors and change the rotor configurations of the vehicle. When these rotors are coplanar, the vehicle becomes a conventional hexacopter with high flight efficiency. Meanwhile, the non-coplanar rotor configurations that make the vehicle a fully-actuated system, allow the vehicle to decouple its translational and rotational dynamics. Its fully-actuated property can be changed by adjusting the servo motor rotation angle. Subsequently, based on the reachable set, we propose a 6-D trajectoryrR3and SO(3)) tracking control algorithm applicable to the vehicle with different rotor configurations, which prioritizes position tacking over attitude tracking, takes a reference 6-D trajectory as an input and adjusts the desired attitude of the vehicle in real time. The algorithm is suitable for seamless switching between under-actuated and fully-actuated configurations. Finally, A series of experiments are designed to verify the feasibility of the vehicle design and the practicability of the introduced control algorithm.