Dynamics and control of small aerial vehicles in contact with environment and of space webs for debris removal.

该提案在两个应用的背景下处理动力学和控制方面的基本问题：小型无人驾驶飞行器的自主操作和空间碎片清除。这项研究最终将使开发社区以及制造和营销无人机的公司受益。它还将有助于推进主动清除空间碎片的技术，这对于继续和可持续地利用近地轨道用于卫星运行和空间科学是必要的。这笔赠款的资金将导致通过研究生学习和直接参与拟议的研究专题来培训五名高素质人员。**随着小型无人机系统的应用迅速扩展到民用领域，这些系统已经成为世界各地许多机器人组织的研究重点。无人机在传统的移动机器人领域提出了许多挑战，特别是在系统设计、控制律开发、状态估计、定位和地图绘制、路径规划、避障和多无人机的协调操作方面。在本提案中，我们离开这些常规主题，首次研究小型旋转飞行器，如四旋翼飞行器，在与环境相撞的条件下的动力学和控制问题。我们的动机是这样一个事实，即无人机的操作带有与周围物体碰撞的巨大风险，特别是在室内和未知的非结构化环境中。因此，为了使小型无人机系统更安全，扩大它们的自主性，并最终实现它们在社会上的普遍接受，我们这笔赠款的目标是研究飞行器在撞击条件下的动力学建模和响应，并开发控制方法，使旋转式无人机能够从与环境的碰撞中恢复过来。**我们的第二个定向申请源于申请人在空间机器人领域的前沿研究，特别是与自主捕获故障卫星和空间碎片相关的问题。在这一点上，在轨服务和空间碎片补救的理由是明确的，关于这些飞行任务的作用和必要性几乎没有争论。到目前为止，我们的研究已经产生了创新的解决方案，用于使用安装在维修(“追逐者”)卫星上的机械臂来捕获未知翻滚目标的运动规划和控制问题。我们计划通过调查利用系绳空间网捕获碎片、随后使其稳定和脱离轨道，进一步努力确定积极清除大型空间碎片的可行解决办法。到目前为止，只有少数研究人员对空间网(也称为系留网)的概念进行了研究。据我们所知，没有综合的建模工具可以用来对整个碎片清除情景进行足够准确的、但在计算上实用的模拟。这将需要对飞行任务的所有阶段进行分析和建模，从部署系绳网开始，到网与目标之间的撞击和随后的接触，最后是将碎片运送到墓地或更低的轨道。在上述阶段中，网与目标之间的撞击以及随后对目标的包围和稳定是空间网捕获碎片的动力学建模和控制方面最具挑战性和研究最少的问题。这将是我们在本赠款范围内对空间碎片清除进行调查的主要领域。将考虑的两个主题都建立在申请者在接触力学和动力学建模方面的先前研究和专业知识的基础上。

This proposal addresses fundamental problems in dynamics and control in the context of two applications: autonomous operation of small unmanned aerial vehicles (UAVs) and space debris removal. The research will ultimately benefit the development community and companies building and marketing UAVs. It will also serve to advance technologies for active space debris removal, which is necessary for a continued and sustainable utilization of near-earth orbits for satellite operation and space science. The funding of this grant will lead to training of five highly qualified personnel through their graduate studies and direct participation in the proposed research topics. **Small unmanned aerial vehicles have become a research focus of many robotics groups around the world as applications of these systems have been rapidly expanding into civilian domains. UAVs present numerous challenges in the traditional areas of mobile robotics, in particular, systems design, control law development, state estimation, localization and mapping, path planning, obstacle avoidance and coordinated operation of multiple UAVs. In the present proposal, we depart from these conventional topics and investigate, for the first time, the problems of dynamics and control of small rotary vehicles, such as quadrotors, under the conditions of impact with the environment. We are motivated by the fact that operation of UAVs carries with it a significant risk of collision with surrounding objects, particularly indoors and in unknown, unstructured environments. Therefore, to make small UAV systems safer, to expand their autonomy and ultimately achieve their acceptance in the society at large, our goal for this grant is to investigate dynamics modeling and response of an aerial vehicle under impact conditions, and to develop control methodologies to enable a rotary UAV to recover from a collision with its environment. **Our second targeted application stems from the applicant's leading-edge research in the area of space robotics, and specifically, problems associated with autonomous capture of malfunctioning satellites and space debris. The case for on-orbit servicing and space debris remediation is unequivocal at this point and there is little debate on the role and necessity for these missions. Our research to date has lead to innovative solutions to problems of motion planning and control for capture of unknown tumbling targets using a robotic arm mounted on the servicing ("chaser") satellite. We plan to expand our efforts towards identifying a feasible solution for active removal of large space debris, by investigating the employment of tethered space webs for capture, subsequent stabilization and de-orbiting of the debris. The space webs (also called tethered nets) concept has been investigated by only a few researchers to date. To our knowledge, there are no comprehensive modeling tools which can be used for a sufficiently accurate, yet computationally practical simulation of the complete debris removal scenario. This would require analysis and modeling of all phases of the mission, starting from tether-net deployment, through impact and ensuing contact between the net and the target, and ending with transporting the debris to a graveyard or lower orbit. Among the aforementioned phases, the impact between the net and the target and subsequent enclosure and stabilization of the target represent the most challenging and least researched problems in dynamics modeling and control of debris capture with a space web. This will be the main area of our investigation on space debris removal in the context of the present grant. Both topics to be considered build on the applicant's prior research and expertise in contact mechanics and dynamics modelling.