Space robots have been proposed to perform several tasks in orbit, such as repairing, refueling, and assembly. All those activities require the robot to interact with external objects in a safe and compliant form to avoid high impact forces that may damage the robot's components or the object to manipulate. Impedance controllers have demonstrated to be a suitable approach to perform similar tasks in ground. Therefore, implementing and analyzing impedance-based techniques in space is also worthy of study. Not only that, but also, methods that can reduce the number of components, weight and complexity should be considered. This article proposes the use of the disturbance observer for the design of an impedance controller to perform a safe capture of a target satellite by a space robot. First, the observer aids in the determination of the contact force between the servicer and the target. Later, once the almost perfect match between the actual and estimated contact force is demonstrated, the estimated force is used as input for an impedance controller with trajectory tracking. The advantages of estimating the contact force instead of measuring it are also discussed in the document. The design of the impedance control is performed such that the capturing process is compliant and safe, and, thus, it can help to advance toward an autonomous capture of space objects. A simulation experiment was set up to evaluate the performance of the proposed method. The results demonstrate that the contact force is bounded and behaves smoothly in a spring–mass–damper-like manner, imposing a stable contact between the robot's end effector and the servicer's capturing spot.

中文翻译：

---

在轨道上对物体进行顺应力传感器的较少捕获

已经提出了太空机器人在轨道上执行若干任务，例如维修，加油和组装。所有这些活动都要求机器人以安全且合规的形式与外部对象进行交互，以避免可能会损坏机器人组件或要操纵的对象的高冲击力。阻抗控制器已被证明是在地面执行类似任务的合适方法。因此，在空间中实施和分析基于阻抗的技术也值得研究。不仅如此，还应考虑减少组件数量，重量和复杂性的方法。本文提出使用干扰观测器来设计阻抗控制器，以通过太空机器人对目标卫星进行安全捕获。第一的，观察者有助于确定服务者与目标之间的接触力。之后，一旦证明了实际接触力和估算接触力之间的几乎完美匹配，估算力就用作具有轨迹跟踪的阻抗控制器的输入。在文档中还讨论了估计接触力而不是测量接触力的优点。执行阻抗控制的设计，使得捕获过程顺应且安全，因此，它可以帮助推进对空间物体的自主捕获。建立了一个仿真实验，以评估该方法的性能。结果表明，接触力是有限的，并且以弹簧-质量-阻尼器的方式平稳运行，从而在机器人与机器人之间形成了稳定的接触。