可动态重构的旋翼飞行器设计与运动特性分析

Design and Motion Characteristics Analysis on a Dynamically Reconfigurable Rotorcraft

针对旋翼飞行器因机体结构受运动路径中空间变窄限制而无法连续穿越的问题,研究设计了一种可动态重构的旋翼飞行器,通过改变机体构形实现对空间变化的运动应对,提高飞行器在复杂环境下连续运动作业的能力。该系统采用链式模块化结构,通过旋转关节实现构形的2维变化。根据机体结构特点和运动控制方式,基于D-H(Denavit-Hartenberg)规则推导了空间变换矩阵,求解了变化重心,建立了机体运动学模型。基于几何、动力和控制响应约束,提出了构形变换的求解方法,并针对该模型给出了边界条件。最后进行了飞行器稳定性、操纵性及临界构形实验。结果表明,构形变换过程中,飞行器姿态稳定,无明显突变,各轴向最大变化量在4°以内;濒近临界构形时飞行器操控顺畅,跟踪控制响应能够在0.1 s内完成。实验验证了姿态可控的临界构形角度集为{180°, 180°, 113°},通过几何运算,采用固定航向方式,飞行器的通过半径可缩小21.89%,结合航向控制的方式,最大通过半径可缩小67%。飞行器具备稳健完成动态重构和通过窄间隙的能力。

A dynamically reconfigurable rotorcraft is proposed to solve the problem that the rotorcraft can’t pass continuously a narrow space along its path due to its body structure limits. The motion response to the space change is achieved by changing the body structure, and the continuous mobile operation performance of the rotorcraft in a complex environment is improved. The system with a chained modular structure can change its 2D configuration by rotating joints. The kinematic model of the airframe is established according to the structural characteristics and motion control mode, the spatial transformation matrix is derived based on the D-H(Denavit-Hartenberg) rule, and the changed center of gravity is also obtained. A solution method of configuration transformation based on geometric, dynamic and control response constraints is proposed,and the corresponding boundary conditions are derived. The experiments demonstrating flight stability, maneuverability and critical configuration are conducted. The results show that the attitude of the rotorcraft is stable without obvious mutation,and the maximum variations of different axes are all within 4°during the whole configuration transformation. The flight control remains smooth and the tracking control response can be completed in 0.1 s when approaching the critical configuration.The angle set of the critical configuration with controllable attitudes is {180°, 180°, 113°} in the experiments. Geometric evaluations show that the passing radius can be reduced by 21.89% in the fixed heading mode, and the maximum passing radius can be reduced by 67% when combining with heading control. The rotorcraft can complete dynamic reconfiguration when passing through a narrow gap.