接触作业型飞行机械臂系统的力/位置混合控制

针对飞行机械臂系统移动接触作业问题,使用了一个力/位置混合控制框架,用以控制飞行器系统持续可靠地接触外部环境同时保持一定大小的接触力,并实现在接触过程中的期望轨迹跟踪.首先将作业空间分成2个子空间--约束空间和自由空间,并分别进行力控制和位置控制.对于力控制问题,证明闭环无人机系统是一个类弹簧-质量-阻尼系统,然后在约束子空间中设计逆动力学控制器来实现接触力控制.自由飞行空间中的运动控制依靠轨迹规划和位置控制器来实现.最后,开发了基于六旋翼飞行机器人的单自由度飞行机械臂系统,在飞行状态下进行接触墙面并跟踪倾斜直线轨迹的实验.结果显示本文所使用方法能够保证在平稳移动的同时控制期望的接触力.

Hybrid Force/Position Control of Aerial Manipulators in Contact Operation

For the contact operation problem of the aerial manipulator system during moving, a hybrid force and position control framework is applied to controlling the system to contact with the external environment continuously and reliably with a constant force, and implement the desired trajectory tracking during the contact process. Firstly, the workspace is divided into two sub-spaces, i.e. the constrained space and the free-flight space, where the contact force control and position control are adopted respectively. For the force control problem, the closed-loop UAV (unmanned aerial vehicle) system is proven to behave as a spring-mass-damper-like system, and an inverse-dynamics-based controller is designed to implement the contact force control in the constrained sub-space. The motion control in free-flight space depends on trajectory planning and position controllers. Finally, a 1-DOF (degree-of-freedom) aerial manipulator system based on a hex-rotor UAV is developed, and the system is commanded to track a oblique line trajectory in flight mode while contacting with wall surface. The results indicate that the proposed method contributes to maintaining steady motion, and controlling the desired contact force.