5-Degree-of-Freedom Aircraft and Control Method

This technology is a quadrotor-based tilt-rotor aircraft. It features a kinematic mechanism that synchronizes and tilts the angle of all rotors by connecting the rotor shafts at the front and rear of the body to a single servo motor via a belt-pulley or gear transmission structure, along with a 5-degree-of-freedom control method utilizing this mechanism.

Conventional multirotors are limited to 4-degree-of-freedom control because the 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 utilizes a mechanical tilting system driven by a single servo motor to tilt the rotation axes of all rotors simultaneously, enabling thrust direction control independent of the airframe's attitude. By proposing a controller that calculates optimal control inputs based on a dynamic model decomposed into underactuated and fully actuated subsystems, it achieves 5-degree-of-freedom flight with fewer 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 actuators.

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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 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 the first and second rotor shafts simultaneously in the same direction and by the same amount.
• Achieves 5-degree-of-freedom flight by tilting the rotation axes so that all four rotors maintain the same tilt angle relative to the body.