Research on the Dynamics of the Active Heave Compensation System for Shipborne Tethered Balloons

Abstract Waves and gusts have a significant impact on the offshore operations of shipborne tethered aerostats. The radar, electronic reconnaissance equipment, and other systems carried by tethered aerostats experience vertical oscillations due to balloon motion, which reduces the operational accuracy of electronic devices. This paper establishes a virtual prototype dynamics model of an active heave compensation system for shipborne tethered aerostats and analyzes its dynamic characteristics. First, the measured irregular waves under sea state 3 conditions were fitted to obtain irregular wave data as external excitation. Second, aerodynamic simulations of a tethered aerostat were conducted to determine the lift coefficient under gust conditions, which was then converted into lift force using relevant formulas. Finally, a bushing force model was employed to simulate the flexible tethered cable, accurately reflecting the mechanical properties of real cables while integrating the entire mechanical system. Simulation analysis of the constructed virtual prototype demonstrates that, compared to systems without active heave compensation, the operational deployment of this system reduces both the vertical displacement fluctuation range of the aerostat and the tension between the aerostat and cable. This enhancement not only improves the operational precision of onboard electronic equipment but also effectively mitigates the risk of cable breakage caused by excessive tension. However, as lift force increases, fluctuations in the aerostat’s displacement, velocity, and acceleration intensify, thereby diminishing the compensation effectiveness of the active heave compensation system.