A Low-Frequency Micro Accelerometer Based on Three-Lobed Leaf Spring and a Focus Probe

A new micro accelerometer is proposed to measure and reduce low-frequency vibrations actively. It is mainly composed of a seismic mass, a leaf spring, and a focus probe modified from a digital versatile disc (DVD) pickup head. When a vibration occurs, the leaf spring will exhibit an elastic deformation; the seismic mass will move up and down due to the effect of inertia, whose displacement can be detected by the focus probe. Therefore, the measured acceleration can be obtained. The accelerometer was designed, and its proper parameters were obtained. The accelerometer was calibrated and tested using a high-precision vibration generator. The experimental results demonstrate that the proposed accelerometer has a sensitivity of 10.8 V/g, a resolution of 3.0 × 10-4 g, and a working frequency range of 1-10 Hz. Also, the uncertainty of the accelerometer was analyzed in detail and an evaluation result of 7.0 × 10-4 g (K = 2) was obtained. It can be used to detect the low-frequency microvibrations in high-precision measurement and machining fields.