Analysis of Sensor Errors of a Suspension Systems for Space Robots

Orbital and planetary space robotic arms play a critical role in future space exploration. They are mounted on satellites, landers, and rovers. On satellites, orbital robotic arms can extend the operational life of target satellites, facilitate the inspection of orbital assets, and assist in the deorbiting process. However, ensuring a reliable performance of the robotic arm requires thorough on-ground verification and validation. Although designed for zero- or low-gravity conditions, space robotic arms face a challenge when tested in Earth’s gravity. The limited torque provided by the robot’s joints hinders its ability to perform effective movements on ground. To address this challenge, the Institute of Robotics and Mechatronics at the German Aerospace Center (DLR) and the University of Duisburg-Essen have developed the Motion Suspension System (MSS), a cable-driven parallel robot that mechanically supports robotic arms and enables them to operate on ground in a full three-dimensional workspace. For its use as a qualification device for orbital robotic arms, a sensitivity analysis of the sensor errors is crucial. This study focuses on the impact of angle and force sensor errors on the overall performance of the MSS. Hereby, the study uses analytical computation validated by experimental results.