Aerial-ground testbed for simulating compliant bimanual on-orbit operations: From aerial to space robotic manipulation

This paper presents the design and development of an aerial-ground robotics testbed for simulating bimanual manipulation operations on orbit relying on aerial robotics platforms, considering as representative use case the capture and maintenance of a non-cooperative free-floating satellite. The proposed testbed design is intended to facilitate the realization of simulations involving physical interaction, taking benefit of the technologies derived from aerial robotic manipulation, to be used as a complementary or alternative solution to existing ground testbed facilities. The system consists of a fully actuated multi-rotor (FAMR) that emulates the free flying/free floating dynamics of a target satellite, and a lightweight and compliant anthropomorphic dual arm system (LiCAS) to conduct the manipulation task, implementing the dynamics simulation in Simscape Multibody. The human-size and human-like kinematics of the LiCAS allow to replicate the manipulation skills of human operators, whereas its very low weight (2.5 kg) makes it possible to mount it on lightweight industrial robotic arms used to reproduce the spacecraft motion. Two types of compliant interactions are considered. On the one hand, impedance control for the post-contact phase is implemented in the simulation layer, using the right arm to hold the target and maintain the relative pose with the base while the left arm conducts the manipulation task. On the other hand, collision detection and passive accommodation is evaluated in the physical testing system relying on the mechanical joint compliance of the LiCAS dual arm. Collision reflexes between the free-floating FAMR and the compliant arm will be also experimentally evaluated by applying the principle of momentum conservation on the multi-rotor. The proposed approach takes benefit of the similarities between space and aerial robotic manipulation in terms of dynamic modeling, presenting simulation and experimental results in an indoor testbed to validate the developed framework.