面向狭小空间的起落架收放轨迹智能设计方法

扁平化气动外形是高超声速飞行器获得较高升阻比的优先布局，但该外形严重约束了起落架的收藏空间，常规机构很难满足要求，只能采用复杂机构的三维运动实现起落架的窄空间收放。然而，当前主流的计算机辅助设计迭代试凑法在解决空间机构设计问题方面非常依赖工程经验，耗时耗力且很难得到最优结果。为解决这一问题，创新性地提出基于智能优化算法的起落架复杂机构自主设计方法。首先，分析并建立起落架收放机构的运动学理论模型；然后，建立起落架结构间距离描述及碰撞检测模型，并运用深度神经网络自主设计起落架收放机构的最优运动轨迹；最后，以某狭窄舱段的起落架收放策略设计为例，应用该设计方法进行设计。结果表明:所提设计方法可以快速得到最优的起落架收放机构设计方案，可用于指导高超声速飞行器起落架收放机构的设计。 

Intelligent design method of landing gear retraction and extension trajectory for narrow space

The flattened aerodynamic shape is the preferred layout for hypersonic vehicles to obtain high lift drag ratio, but this shape seriously restricts the collection space of the landing gear, and the conventional mechanism is difficult to meet the requirements. Engineers can only use the three-dimensional motion of the complex mechanism to realize the narrow space retraction and retraction of the landing gear. However, the current mainstream iterative trial and error method of computer-aided design relies heavily on engineering experience in solving the design problems of spatial mechanisms, which is time-consuming and labor-consuming, and it is difficult to obtain the optimal results. To address this problem, an intelligent optimization algorithm based method for autonomous design of complex landing gear mechanisms is proposed in this paper. First, theoretical kinematics model of retraction mechanism is built after analysis. Then, the model of inter-structure distances between landing gears and fuselage is established for detecting collisions, and the optimal motion trajectory of landing gear mechanisms is designed autonomously by using the deep neural network based learning optimization algorithm. Finally, the proposed method is applied to a landing gear mechanism design of certain hypersonic aircraft with a narrow cabin. The results show that the optimal design scheme for retractable mechanism can be obtained quickly by the proposed method, which can be used to guide the design of landing gear retractable mechanism for hypersonic aircraft.