空间柔性机械臂抓捕非合作目标的接触碰撞动力学研究

空间柔性机械臂抓捕非合作目标是在轨服务的一项重要技术。抓捕时非合作目标与抓捕手爪发生接触碰撞，冲击力导致柔性臂杆产生大变形。因此，建立精确高效的抓捕动力学模型是制定抓捕控制方案和提高抓捕成功率的基础。目前，普遍基于浮动坐标法采用模态坐标描述机械臂变形，同时，基于弹簧阻尼器模型建立接触碰撞模型。但是，该方法无法描述机械臂大变形，并且在处理多点接触碰撞时效率不高。本项目针对机械臂抓捕非合作目标任务，开展大变形柔性机械臂的接触碰撞动力学研究，拟解决以下关键问题：(1) 在建模阶段对弹性力虚功率进行改造，实现高频截断，解决大变形柔性多体系统建模方法无法利用模态技术进行模型降阶的难题；(2) 基于互补方法建立目标和手爪的多点接触碰撞模型，采用短时间内的平均缝隙代替瞬时缝隙，实现统一的数学模型描述接触碰撞全过程；(3) 开展线下仿真计算，为机械臂抓捕非合作目标的可行性评估和制定抓捕控制方案提供参考。

It is an important technology of on-orbit servicing to capture the non-cooperative target with the space flexible manipulator. Because of the impact between the non-cooperative target and the end-effector, the collision force causes the large deformation of the flexible link. Therefore, an accurate and efficient dynamic model is the basis of the capture control scheme and the improvement of the success rate. At present, based on the floating coordinate frame method, modal coordinates are widely used to describe the deformation of the flexible manipulator, and the contact impact model is established based on the spring damper model. However, this method cannot describe the large deformation of the manipulator, and it’s not efficient to deal with multi-point contact impact problem. The project will carry out a research on contact impact dynamics of large deformation flexible manipulator for the task of capturing a non-cooperative target. The key issues to be resolved of the project include the following aspects. (1) In the modeling phase, the modification of the virtual power of elastic forces will be presented to truncate the high-frequency components. This operation can solve the problem that the modeling method for the large deformation flexible multibody system cannot use the modal analysis technology to achieve the model order reduction. (2) The complementary model is established for the multi-point contact impact between the non-cooperative target and the end-effector. Using the short time average gap instead of the instantaneous gap, the unified mathematical model is given to describe the whole contact impact process. (3) The offline simulation calculation is carried out, which provides references for the feasibility assessment of capturing the non-cooperative target and the design of the capture control plan.