Adaptive Control Scheme for Space Debris Capture in the Presence of Mass and Inertia Uncertainty

Abstract

This paper proposes an adaptive control scheme for capturing uncooperative space debris having uncertain inertial parameters. Debris parameters may be unknown or uncertain due to limited data or changes in orbit due to collisions. To address this challenge, the proposed scheme integrates an inertial parameter identification law with the impedance control strategy of FlexeS (Flexible Capture System). During the pre-capture phase, motion data is utilized to identify the debris' center of mass (CM), leading to the optimal capture point that minimizes impact moments. During contact, the impedance-controlled actuator(s) is(are) activated while the scheme concurrently provides accurate estimates of the debris mass and inertia, enabling the updating of controller gains and thus ensuring sufficient contact time for successful capture. Hence, the proposed adaptive scheme allows FlexeS to handle the debris parameter uncertainties. The simulation study demonstrates the scheme's effectiveness and necessity. The performance of the proposed adaptive scheme is compared with a non-adaptive scheme. The results affirm the superiority of the adaptive scheme in achieving successful soft capture of uncooperative debris in the presence of mass and inertia uncertainties and highlight its potential for future space debris mitigation missions.