In this paper, the contact force detection, isolation and estimation problems for an orbital robot are addressed. First, an observer based on a base-joints dynamics is reviewed and analyzed considering the issues related to a space robotic application. Then, a new scheme is derived reformulating the dynamics in terms of the motion of the centroid of the whole robot and the joints. In both observers, three momentum-based residuals are defined, which can be used to reconstruct the external contact wrench. The reconstruction through the proposed observer turns out to provide superior performance with respect to the base-joints one thanks to the decoupling of the angular and joint momentum residuals from the spacecraft linear velocity, which is an inaccurate measurement in real space scenarios. The advantages of the proposed observer are shown through both simulative and hardware validation featuring a 7 degrees of freedom (DoF) arm mounted on a 6 DoF moving base.

在本文中，解决了轨道机器人的接触力检测，隔离和估计问题。首先，考虑到与空间机器人应用相关的问题，对基于基本关节动力学的观察者进行了审查和分析。然后，推导了一种新方案，该方案根据整个机器人和关节的质心运动来重新定义动力学。在两个观察者中，定义了三个基于动量的残差，这些残差可用于重建外部接触扳手。由于角和关节动量残差与航天器线速度的解耦，通过提议的观察者进行的重构证明相对于基关节具有更好的性能，这在实际空间场景中是不准确的测量。