无人机舵面柔性铰链片的偏舵原理及结构分析

Analysis and Structure Design of a Flexible Lamellate Hinge for UAV (Unmanned Aerial Vehicle) Control Surface

针对小型无人机的特点,研究发展了一种提高无人机舵面效率的设计概念,即采用柔韧特性良好的复合材料片状结构——舵面柔性铰链片来执行舵面铰链功能,通过铰链片的柱状弯曲来实现舵面的偏转。模型风洞吹风实验结果显示,采用柔性铰链片比定轴铰链其舵面的气动效率提高约40%。文中介绍了舵面柔性铰链片的设计思想,并对其偏舵原理和结构进行了较为详细的分析,建立了一套柔性铰链片结构的工程计算方法。舵面柔性铰链片的设计概念在某型无人机中已经被成功地应用。

A new concept of a flexible lamellate hinge for UAV (Unmanned Aerial Vehicle) control surfaces is presented. The flexible lamellate hinge is a strip of lamellate jointing stabilizer and control surface, it can increase the aerodynamics efficiency of the control surface by preventing airflow turbulence through gap between stabilizer and control surface. The results of the model test in the wind tunnel show that the aerodynamics efficiency of the control surface using flexible lamellate hinge increases about 40 percent than that of the traditional ones. The design objectives of a flexible lamellate hinge include: (i) to meet the demand of control surface movement and (ii) to support control surface and its aerodynamics load. The lamellar hinge is designed as thin GFRP (glass-fiber reinforced polymer) laminates. The principle of control surface movement is analyzed. Different from traditional control surface, it is not rotary movement on fixed axis. When control surface is moving, the lamellar hinge is bent into column shape, and column radius and center of curvature vary with the movement of control surface. Column radius ρ is in direct proportion to the lamellar hinge width W and is in inverse proportion to deflection angle of control surfaces φ and we also give the motion equation of point in control surface for control mechanism design. The key point in designing flexible lamellate hinge structure is bending rigidity and/or flexural rigidity, it is achieved by composite laminates design. The flexibility of control surface can be calculated in term of cantilever theory. We designed a lamellar hinge for a certain type of UAV, the bound of deflection angle of its control surface is -35°~25°, and its flexibility undergoing aerodynamics load is less than 2 mm.