Distortion Analysis and Compensation for a Space Contact HIL Simulator with Force Delay and Dead Zone

A space contact hardware-in-the-loop (HIL) simulator is a key facility for ground testing of space contact processes. It must faithfully reproduce the dynamics in space. Force delay is known to induce instability. To suppress velocity drift from noisy force signals, a dead zone is often introduced. In this study, we show that a dead zone is able to not only induce divergence, but also induce convergence. To address this issue, we propose an integrated compensator that combines a hybrid Smith predictor with a dead zone disturbance observer. It jointly addresses delay and dead zone distortions. The proposed method is effective for both divergent and convergent distortions. Verifications and applications validate the approach.