| 摘要 |
A vibration sensor for measuring the flow of vibrational energy through a structure comprises four accelerometers (24-27) placed in cruciform arrangement on the surface of the structure. The signals from the accelerometers are processed in pairs using sum/difference amplifiers (36-40) to give two rotational (41, 42) and one translational (43) acceleration signal. The acceleration signals are frequency modulated (46-48) by a local oscillator (53) of preselected frequency, low-pass filtered (62-64) and the rotational acceleration signals (68, 70) then multiplied (72, 73) in phase quadrature (54) with the translational acceleration signal (69). The DC components of the resulting signals (76) are proportional to the time-average vibrational power flow. Knowledge of the flow paths facilitates the design of the structure to minimize effects of unwanted vibrations. |
