Contact stiffness and damping identification for hardware-in-the-loop contact simulator with measurement delay compensation

• Hardware-in-the-loop simulator can simulate the contact process in space.
• A contact stiffness and damping identification approach is proposed.
• Force measurement delay needs to be compensated in the identification.
• Phase lead compensation can reconstruct the actual force from the delayed force.
• Simulations and experiments verify that the proposed approach is effective.

The hardware-in-the-loop (HIL) contact simulator is to simulate the contact process of two flying objects in space. The contact stiffness and damping are important parameters used for the process monitoring, compliant contact control and force compensation control. In this study, a contact stiffness and damping identification approach is proposed for the HIL contact simulation with the force measurement delay. The actual relative position of two flying objects can be accurately measured. However, the force measurement delay needs to be compensated because it will lead to incorrect stiffness and damping identification. Here, the phase lead compensation is used to reconstruct the actual contact force from the delayed force measurement. From the force and position data, the contact stiffness and damping are identified in real time using the recursive least squares (RLS) method. The simulations and experiments are used to verify that the proposed stiffness and damping identification approach is effective.