一种用于接触作业的全驱动旋翼飞行机械臂设计与实现
Design and Implementation of a Fully Actuated Rotor Aerial Manipulator for Contact Operations
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摘要: 传统欠驱动旋翼无人机的动力单元推力方向平行, 无法在不改变姿态的情况下产生横向推力, 限制了飞行机械臂的交互能力与应用场景。针对此问题, 本文设计了一种全驱动旋翼飞行机械臂, 通过倾斜动力单元的安装角度改变推力的方向, 根据该结构设计了控制分配矩阵进而验证其全驱动特性, 并从控制结构上实现了位置与姿态的独立控制; 提出了用于接触作业的飞行机械臂的接触力控制方法, 将接触检测任务分为接近阶段与移动接触阶段, 采用力/运动混合控制器完成接触面法线方向上的力控制。户外实验结果表明, 所设计的全驱动旋翼飞行机械臂实现了稳定飞行和移动接触作业, 与欠驱动平台相比, 飞行过程中的位置移动不依赖于姿态改变, 姿态角稳定在±1.5° 以内, 且在移动接触过程中实现了接触面法线方向上的接触力控制。Abstract: The power unit thrust directions of the conventional under-actuated rotor UAV (unmanned aerial vehicle) are parallel, so that it can't generate lateral thrust without changing the attitude, which limits the interaction capability and application scenarios of the aerial manipulator (AM). To solve this problem, a fully actuated rotor AM is designed to change the thrust direction by tilting the installation angle of the power unit. The control distribution matrix based on this structure is designed to verify the full actuation characteristics, and then the independent control of position and attitude is realized by the control structure. A contact force control method of the AM for contact operations is proposed, which divides the contact detection task into the approach state and the moving contact state. A hybrid force/motion controller is used to achieve force control in the normal direction of the contact surface. The outdoor experiment results indicate that the fully actuated rotor AM achieves stable flight and moving contact operation. Compared with the under-actuated platform, the position change during flight doesn't depend on attitude change, and the attitude angle is kept within ±1.5°; the contact force in the normal direction of the contact surface can be controlled during moving contact.