Autonomous Spacecraft Proximity Operations with Uncooperative Resident Space Objects

最近的一项研究确定，今后10年将发射1，200多颗卫星，这些卫星的制造和实施收入预计将达到1，940亿美元。虽然大多数卫星的运行不会出现重大问题，但统计数据预测，少数但相当数量的卫星将出现各种严重程度的在轨异常或故障，给政府和私人组织造成数十亿美元的损失。如许多研究所表明的那样，对这类驻留空间物体进行近距离操作（目视检查、接近、会合和对接以及捕获、维护/修理）可以节省大量费用。为了使这些近距离操作可行，必须在传统任务的基础上提高机载能力，这意味着显著提高自主性，以及高度精确的相对轨迹制导和控制。这些挑战在实际情况中更加复杂，因为由于机械或电气故障或燃料耗尽，目标RSO可能不合作，在某种意义上，它可能以未知的角速率旋转，没有通信能力，形状不确定，或具有未知的物理参数（质量和质量惯性矩）。此外，干扰航天器相对运动的未建模轨道摄动可能影响安全执行精确机动的能力。 本研究计划的主要目标是开发非线性制导和自适应控制系统，使自主航天器与非合作RSO接近操作。具体而言，非线性制导和自适应控制系统，分别负责计算和跟踪所需的相对轨迹相对于一个不合作的RSO，将开发。这些系统将在卡尔顿航天器近距离操作试验台进行实验验证，该试验台由能够在实验室环境中执行自主制导和控制机动的气浮自由浮动嵌入式航天器平台组成。由于新的指导和控制方法，拟议的研究将导致更高的运动跟踪精度和增强的鲁棒性，从而促进机器人航天器和其不确定的环境，这是由于需要执行接近操作与不合作的RSO之间的无缝交互。鉴于加拿大对这种复杂的空间活动的兴趣日益增加，这项研究将使加拿大的民用和军用空间组织（如加拿大国防研究与发展部、加拿大武装部队和加拿大航天局）在全球空间市场的这一利基市场中处于这些技术的最前沿。作为一个额外的好处，开发的技术可以促进在未知或具有挑战性的环境中操作的其他智能航空航天代理（如自主无人机和无人驾驶飞行器）的类似算法的开发。

A recent study determined that more than 1,200 satellites will be launched over the next 10 years, and revenues from the manufacture and implementation of these satellites is expected to reach $194 billion. While most will perform without major problems, statistics predict that a small but significant number will experience on-orbit anomalies or failures of various severity, resulting in losses of billions of dollars for governments and private organizations. As demonstrated by numerous studies, performing proximity operations (visual inspection, approach, rendezvous and docking, and capture, service/repair) with such Resident Space Objects (RSO) could achieve substantial savings. To make those proximity operations feasible, the on-board capabilities must be improved over traditional missions, which means significantly increased autonomy, and highly accurate relative trajectory guidance and control. These challenges are further complicated in practical situations because, due to mechanical or electrical failures, or fuel depletion, the target RSO will likely be uncooperative, in the sense that it could be rotating at an unknown angular rate, have no communication capabilities, be of an uncertain shape, or have unknown physical parameters (mass and mass moments of inertia). Moreover, un-modeled orbital perturbations disturbing the relative motion of the spacecraft may impact the capability to perform accurate maneuvers safely. The main objective of this research program is to develop nonlinear guidance and adaptive control systems enabling autonomous spacecraft proximity operations with uncooperative RSO. Specifically, nonlinear guidance and adaptive control systems, respectively responsible to calculate and track the desired relative trajectory with respect to an uncooperative RSO, will be developed. These systems will be experimentally validated at Carleton's Spacecraft Proximity Operations Testbed, which consists of air-bearing free-floating embedded spacecraft platforms capable of performing autonomous guidance and control maneuvers in a laboratory environment. Thanks to the new guidance and control methods, the proposed research will lead to higher motion tracking accuracy and enhanced robustness; thereby facilitating seamless interactions between a robotic spacecraft and its uncertain environment, which arises from the need to execute proximity operations with uncooperative RSO. Given the increasing interests in such complex space operations in Canada, this research will place civil and military Canadian space organizations (such as Defence Research and Development Canada, Canadian Armed Forces, and Canadian Space Agency) at the forefront of these technologies, in this niche of the global space market. As an added benefit, the techniques developed may foster the development of similar algorithms for other intelligent aerospace agents operating in unknown or challenging environment, such as autonomous drones and unmanned aerial vehicles.