Design and operational accuracy analysis of a decoupled morphing mechanism for hypersonic vehicle nose cone

The variable working conditions faced by different flight stages in the whole process of hypersonic flight put forward different requirements for the aerodynamic shape of the aircraft. This paper presents a decoupled multi-stage extension and arbitrarily directional bending deformable nose cone design method for hypersonic vehicles. Combined with the flight conditions, the loads and required driving forces during the morphing of the nose cone were calculated under different flight attitudes. By establishing the coupled dynamic model of extension, bending and rotation of the mechanism, the driving torque, law of motion and positioning accuracy with clearance of the nose cone were systematically analyzed. Research shows that the maximum extension driving torque of the nose cone is approximately 81.81 N·m, the rotational driving torque of the curved section is approximately 43.65 N·m, and the bending driving torque of the curved section is approximately 52.97 N·m. The axial extension morphing of the nose cone is 1300 mm, and the maximum bending Angle is 32.09°. Under clearance conditions, the translation displacement error of the deformable nose cone mechanism is within 1.5 mm, and the angular displacement error is approximately 0.4°. The analysis results show that the structure designed in this paper has the advantages of large morphing range, and high actuation accuracy for hypersonic vehicle morphing.