Dynamic Balance Control of CT Gantry Systems Based on Multi-Body Dynamics and Modal Coupling Analysis

This study presents a dynamic balance control method for CT gantry systems using a high-fidelity multi-body dynamics model with modal coupling effects. The gantry structure was modeled with 14 rigid bodies and 22 flexible modes identified from modal testing data. Unbalance disturbances equivalent to 50–300 g·mm were introduced to evaluate system response. Simulation results show that unbalance-induced vibration amplitudes increased by up to 62% near critical speeds. By integrating modal feedback into the balance control algorithm, the proposed method reduced radial vibration by 38.5% and rotational torque fluctuation by 41.3% across operating speeds from 0.5 to 2.5 r/s, improving mechanical stability and imaging reliability.