If the geometric parameters are designed to make sure
0 < kh < 1, the compound pendulum will amplify mechanically
ultra-low frequency tilt vibration according to Eq.
(9). The closer kh is to zero, the more sensitive the compound
pendulum response to ultra-low frequency tilt
vibration.
Considering ultra-high frequency tilt vibration, namely
x1, Eq. (6) can be expressed as