Divergence compensation for hardware-in-the-loop simulation of stiffness-varying discrete contact in space

• Hardware-in-the-loop simulator can simulate the contact process in space.
• A divergence compensation approach is proposed for stiffness-varying discrete contact.
• Force measurement delay is compensated by phase lead based force compensation.
• Dynamic response delay of motion simulator is compensated by response error based force compensation.
• Simulations and experiments verify that the proposed compensation approach is effective.

The hardware-in-the-loop (HIL) contact simulation for flying objects in space is challenging due to the divergence caused by the time delay. In this study, a divergence compensation approach is proposed for the stiffness-varying discrete contact. The dynamic response delay of the motion simulator and the force measurement delay are considered. For the force measurement delay, a phase lead based force compensation approach is used. For the dynamic response delay of the motion simulator, a response error based force compensation approach is used, where the compensation force is obtained from the real-time identified contact stiffness and real-time measured position response error. The dynamic response model of the motion simulator is not required. The simulations and experiments show that the simulation divergence can be compensated effectively and satisfactorily by using the proposed approach.