This study proposed a method for simultaneously reducing mass imbalance and vibration in gimbal systems utilizing a tuned mass damper (TMD) as a balancing weight. Finite element analysis (FEA) and experiments were used for testing the method. Mass imbalance in gimbal systems generally causes external disturbance torque. To reduce this, a balancing weight can be used. However, weight increase due to balancing weight causes resonance in the gimbal system, which generates bias error in the gyroscope sensor. This study demonstrated that both mass imbalance reduction and vibration reduction effects could be achieved by utilizing a TMD as a balancing weight. FEA results showed that the mass imbalance reduction effect of the gimbal was not affected by TMD. The magnitude of vibration response at the resonance point was reduced by about 98% with TMD. When a TMD was applied, the magnitude of the vibration response at the resonance point was reduced by 98% to the same level as that of the gimbal. Bias error of the gyroscope sensor was reduced by about 95% or more. These results show that a TMD is useful for effectively reducing mass imbalance and vibration in gimbal systems while improving gyroscope sensor performance.

In this study, the disturbance torque that maintains the gimbal at a specific angle during the centrifugal acceleration test was analyzed. Newton"s Second Law for Rotation was applied, to calculate the disturbance torque. A Theoretic solution for calculating the disturbance torque was derived, by separating the horizontal/vertical components of the moment of inertia. The Theoretic solution was verified, by numerical analysis (RecurDyn) of the simplified Gimbal model. To include the effect of acceleration, the distance between the central axis of the gimbal and the accelerated test equipment was applied as 0 and L (non-Zero). As a result of the analysis, it was found that the main disturbance torque is not related to acceleration, but to self-centrifugal force caused by rotation. A centrifugal acceleration test was conducted, to verify the operational performance of gimbal. The disturbance torque was calculated, by measuring the torque used to operate the gimbal"s motor. The result was compared with the disturbance torque, calculated by the Theoretic solution of the gimbal. The error between the result of test and Theoretic solution of torque was less than 4.5%.