Momentum Transfer by Impact: SDRE and Space Debris

The codes present simulations of the momentum transfer by impact using SDRE to reduce the momentum of non-cooperative space debris.

The codes are related to the paper:

Nekoo, S. R., I. Sharf, B. C. Arrue, A. Ollero, “Momentum Transfer by Impact: A Step Towards Grasping of Non-Cooperative Space Debris,” Aerospace Science and Technology, 2025, 111084. DOI: https://doi.org/10.1016/j.ast.2025.111084.

Download the paper (Open Access): https://doi.org/10.1016/j.ast.2025.111084

The simulations are time-consuming due to the complexity of the dynamics; hence, the *.mat files were added to be loaded easily. The results can be generated fast in this way. The whole package should be downloaded to have the *.mat files as well.

The impact between a free-floating or -flying space manipulator (SM) and an uncooperative target object is studied, for the purpose of transferring momentum from the object to the SM. The impact model employed to simulate contact between the robot end-effector and the object is discrete and impulsive, and it accounts for energy dissipation during impact by using the well-known Newton’s hypothesis and energetic’s definition of the coefficient of restitution (CoR). The resulting CoR is implemented to calculate the impact force, post-impact velocity of the object, and generalized rates of the SM after the collision. The motion of the SM is controlled before and after the collision via a nonlinear optimal approach, the so-called state-dependent Riccati equation (SDRE). The SDRE is a state-feedback controller design; however, a recent modification presented a design to apply the SDRE to the output feedback control. The output- and state-dependent Riccati equation (OSDRE) uses a transformation between the output variables and the states to bypass the kinematics of a system and control the outputs directly. This led to point-to-point motion control of SMs in free-floating mode using the base to push the end-effector towards the desired position. A combination of the OSDRE and the aforementioned impact modeling is introduced in this work to transfer the energy and momentum of a non-cooperative object in space to an SM, thus achieving a nearly stationary condition of the object, amenable to subsequent capture. The specific application directs attention to the collection of uncooperative space debris, which is a prominent topic in space robotics. A planar system case study is presented to discuss and demonstrate the application in various scenarios.

See video of the simulations: https://ars.els-cdn.com/content/image/1-s2.0-S1270963825011472-mmc2.mp4