Resonant accelerometer with self-test

• Published in: Sensors and actuators. A, Physical Physical, 2001-08, Vol.92 (1), p.161-167
• Main Authors: Aikele, M., Bauer, K., Ficker, W., Neubauer, F., Prechtel, U., Schalk, J., Seidel, H.
• Format: Article
• Language: English
• Subjects: Accelerometer; Applied sciences; Duffing oscillator; Exact sciences and technology; General equipment and techniques; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Measurements common to several branches of physics and astronomy; Mechanical engineering. Machine design; Mechanical oscillator; Metrology, measurements and laboratory procedures; Physics; Precision engineering, watch making; Resonant; Self-test; Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing; Thermal excitation; Velocity, acceleration and rotation
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/S0924-4247(01)00558-1

A new resonant accelerometer is presented consisting of a doubly clamped beam coupled to a seismic mass. The beam is thermally excited by an implanted resistor and its vibration is sensed piezoresistively. An acceleration which deflects the seismic mass leads to characteristic strains inside the resonator, shifting its resonance frequency. We studied the oscillation characteristics of the resonant beam. The non-linearity at high excitation amplitudes is treated theoretically and experimentally. Further, it is shown that the electrical and thermal cross-talk can be eliminated. The resonant sensing principle ensures a quasi-digital output signal, high sensitivity and a mechanical integrity test. Advanced automotive safety systems and x-by wire applications require a high reliability of the employed sensors. The sensor presented here allows an on-going self-test without any constructive changes of the sensor element. The self-test concept, we developed also finds applications in other sensors with resonant structures.