Figure 2.

FEA shows the operation modes and pseudo modes of CSQMG, comparing to the resonant mode of the HRGs. In the operating modes of CSQMG, also known as anti-phase modes, the four lumped masses vibrate along the radial of the symmetry center in the drive mode, and vibrate along the tangential orientation under the sense mode. Moreover, the two adjacent lumped masses oscillate in anti-phase motion. Corresponding to the operation modes, the two in-phase modes are regarded as the pseudo modes.