5-DOF aircraft and control method

Quadrotor Aircraft Implementing 5 Degrees of Freedom via Single Servo Motor Mechanical Tilting

This technology is a quadrotor-based tilt-rotor aircraft. It features a mechanical mechanism that connects rotor shafts at the front and rear of the body to a single servo motor using a belt-pulley or gear transmission structure, allowing for synchronized tilting of all rotors, along with a 5-degree-of-freedom control method utilizing this mechanism.

Conventional multi-rotors are limited to 4 degrees of freedom because their thrust direction is fixed relative to the airframe. This makes translational movement impossible without tilting the entire aircraft and restricts stable hovering while in a tilted state.

This technology uses a mechanical tilting system with a single servo motor to tilt the rotation axes of all rotors simultaneously, enabling thrust direction control independent of the airframe's attitude. It proposes a controller that calculates optimal control inputs based on a dynamic model decomposed into underactuated and fully actuated subsystems, allowing for 5-degree-of-freedom flight with minimal actuators. It is highly applicable to missions where tilting the airframe is not feasible, such as precision photography, facility inspection, and close-proximity flight in confined spaces, meeting the demand for high-performance aircraft with minimal hardware.

‍

‍

Key Features:

• A first drive unit including a first rotor shaft installed horizontally at the front of the body and a pair of rotors installed vertically at both ends.
• A second drive unit including a second rotor shaft installed horizontally at the rear of the body and a pair of rotors installed vertically at both ends.
• A rotor tilting unit that transmits the driving force of a servo motor installed in the middle of the body to rotate both rotor shafts in the same direction by the same amount.
• A controller that outputs tilting control signals to the rotor tilting unit to manage the fully actuated and underactuated subsystems.

‍

This invention was developed with support from the Ministry of Science and ICT's development of image-based detection and avoidance technology, and the Ministry of Education's development of tilt-rotor control techniques based on coupling/uncoupling mechanisms for autonomous cooperative transport.